A pilot study for long-term outcome assessment after aortic aneurysm repair using Vascular Quality Initiative data matched to Medicare claims

Factors associated with 90-day reintervention following lower extremity revascularization

OBJECTIVE

Peripheral artery disease (PAD) represents a high-volume, high-cost burden on the health care system. The Centers for Medicare and Medicaid Services has developed the Bundled Payments for Care Improvement-Advanced program, in which a single payment is provided for all services administered in a postsurgical 90-day episode of care. Factors associated with 30- and 90-day reinterventions after PAD interventions would represent useful data for both payors and stake holders.

METHODS

We conducted a national cohort study of adults 65 years and older in the Vascular Quality Initiative and Centers for Medicare and Medicaid Services-linked dataset who underwent an open, endovascular, or hybrid revascularization procedure for PAD between January 1, 2010, and December 31, 2018. Procedures for acute limb ischemia and aneurysms were excluded. The primary outcome was 90-day reintervention. Reintervention at 30 days was a secondary outcome. Covariates of interest included demographics, comorbidities, and patient- and facility-level characteristics. Multivariable Cox regression was used to determine the association between patient- and facility-level characteristics and the risk of 30- and 90-day reinterventions.

RESULTS

Among 42,429 patients (71.3% endovascular, 23.3% open, and 5.4% hybrid), median age was 74 years (interquartile range, 69-80 years), 57.9% were male, and 84.3% were White. Chronic limb-threatening ischemia was the operative indication in 40.4% of the procedures. Overall, 42.8% were completed in the outpatient setting (40.3% outpatient, 2.5% office-based lab). Over 70% of procedures for chronic limb-threatening ischemia were completed as inpatient, whereas 60% of the claudication interventions were done as outpatient. The 90-day reintervention rate was 14.5%, and the 30-day reintervention rate was 5.5%. Compared with inpatient procedures, PAD interventions completed in the outpatient or office-based lab setting had significantly higher 90- and 30-day reintervention rates (reference, inpatient; outpatient 90-day reintervention: hazard ratio [HR], 1.41; 95% confidence interval [CI] 1.25-1.60; outpatient 30-day reintervention: HR, 1.90; 95% CI, 1.62-2.24; office-based lab 90-day reintervention: HR, 2.09; 95% CI, 1.82-2.41; office-based lab 30-day reintervention: HR, 3.54; 95% CI, 3.17-3.94). Open and hybrid approaches demonstrated lower risk of reintervention compared with endovascular procedures at 30 and 90 days and, compared with aortoiliac disease, all other anatomic segments of disease were associated with higher 90-day reintervention, but no difference was noted at 30 days.

CONCLUSIONS

Although outpatient PAD interventions may be convenient for patients and providers, the outpatient setting is associated with a significant risk of subsequent reintervention. Additional work is needed to understand how to improve the longevity of outpatient PAD interventions.

Using Administrative Data to Better Treat Chronic Limb Threatening Ischemia

Chronic limb threatening ischemia (CLTI) is the most severe manifestation of peripheral arterial disease and represents a particularly high-risk subgroup of patients. As such, efforts to better understand this complex patient population through well-designed clinical research studies are critical to improving CLTI care. Prospective randomized clinical trials (RCTs) remain the gold standard in clinical research, but these trials are resource-intensive and have highly selective patient populations, which limit their feasibility and generalizability. Alternatively, retrospective studies are less expensive than RCTs, have a larger sample size, and are more generalizable owing to a broader patient population. Health care administrative data provide rich sources of information that may be used for research purposes and are increasingly being used for the study of vascular surgery conditions, including CLTI. Although administrative data are collected for billing purposes, they may be leveraged to study a broad range of topics in vascular surgery including those related to health care delivery, epidemiology, health disparities, and outcomes. This review provides an overview of administrative data available for CLTI research, the strengths and limitations of these data sources, current areas of investigation, and future opportunities for further study with the goal of improving outcomes in this high-risk population.

Long-term outcomes of carotid endarterectomy vs transfemoral carotid stenting in a Medicare-matched database

BACKGROUND

Carotid endarterectomy (CEA) is associated with lower risk of perioperative stroke compared with transfemoral carotid artery stenting (TFCAS) in the treatment of carotid artery stenosis. However, there is discrepancy in data regarding long-term outcomes. We aimed to compare long-term outcomes of CEA vs TFCAS using the Medicare-matched Vascular Quality Initiative Vascular Implant Surveillance and Interventional Outcomes Network database.

METHODS

We assessed patients undergoing first-time CEA or TFCAS in Vascular Quality Initiative Vascular-Vascular Implant Surveillance and Interventional Outcomes Network from January 2003 to December 2018. Patients with prior history of carotid revascularization, nontransfemoral stenting, stenting performed without distal embolic protection, multiple or nonatherosclerotic lesions, or concomitant procedures were excluded. The primary outcome of interest was all-cause mortality, any stroke, and a combined end point of death or stroke. We additionally performed propensity score matching and stratification based on symptomatic status.

RESULTS

A total of 80,146 carotid revascularizations were performed, of which 72,615 were CEA and 7531 were TFCAS. CEA was associated with significantly lower risk of death (57.8% vs 70.4%, adjusted hazard ratio [aHR], 0.46; 95% confidence interval [CI], 0.41-0.52; P < .001), stroke (21.3% vs 26.6%; aHR, 0.63; 95% CI, 0.57-0.69; P < .001) and combined end point of death and stroke (65.3% vs 76.5%; HR, 0.49; 95% CI, 0.44-0.55; P < .001) at 10 years. These findings were reflected in the propensity-matched cohort (combined end point: 34.6% vs 46.8%; HR, 0.53; 95% CI, 0.46-0.62) at 4 years, as well as stratified analyses of combined end point by symptomatic status (asymptomatic: 63.2% vs 74.9%; HR, 0.49; 95% CI, 0.43-0.58; P < .001; symptomatic: 69.9% vs 78.3%; HR, 0.51; 95% CI, 0.45-0.59; P < .001) at 10 years.

CONCLUSIONS

In this analysis of North American real-world data, CEA was associated with greater long-term survival and fewer strokes compared with TFCAS. These findings support the continued use of CEA as the first-line revascularization procedure.

One-year aneurysm-sac dynamics are associated with reinterventions and rupture following infrarenal endovascular aneurysm repair

OBJECTIVE

One-year aneurysm sac changes have previously been found to be associated with mortality and may have the potential to guide personalized follow-up following endovascular aneurysm repair (EVAR). In this study, we examined the association of these early sac changes with long-term reintervention and rupture.

METHODS

We identified all patients undergoing first-time EVAR for intact abdominal aortic aneurysm between 2003 and 2018 in the Vascular Quality Initiative with linkage to Medicare claims for long-term outcomes. We included patients with an imaging study at 1 year postoperatively. Aneurysm sac behavior was defined as per the Society for Vascular Surgery guidelines: stable sac (<5 mm change), sac regression (≥5 mm), and sac expansion (≥5 mm). Outcomes included mortality, reintervention, and rupture within 8 years, which were assessed with Kaplan-Meier methods and multivariable Cox regression analysis. Secondarily, we utilized polynomial spline interpolation to demonstrate the continuous relationship of diameter change to 8-year hazard of reintervention, rupture, or mortality as a composite outcome.

RESULTS

Of 31,185 EVAR patients, 16,102 (52%) had an imaging study at 1 year and were included in this study. At 1 year, 44% of sacs remained stable, 49% regressed, and 6.2% displayed expansion. Following risk adjustment, compared with a stable sac at 1 year, sac regression was associated with lower 8-year mortality (49% vs 53%; hazard ratio [HR], 0.92; 95% confidence interval [CI], 0.85-0.99; P = .036), reintervention rate (8.9% vs 15%; HR, 0.58; 95% CI, 0.50-0.68; P < .001), and rupture rate (2.0% vs 4.0%; HR, 0.45; 95%CI, 0.29-0.69; P < .001). Conversely, compared with a stable sac, sac expansion was associated with higher 8-year mortality (64% vs 53%; HR, 1.31; 95% CI, 1.14-1.51; P < .001) and reintervention rate (27% vs 15%; HR, 1.98; 95% CI, 1.57-2.51; P < .001), but similar risk of rupture (7.2% vs 4.0%; HR, 1.61; 95% CI, 0.88-2.96; P = .12). Polynomial spline interpolation demonstrated that, compared with no diameter change at 1 year, increased sac regression was associated with an incrementally lower risk of late outcomes, whereas increased sac expansion was associated with an incrementally higher risk of late outcomes.

CONCLUSIONS

Following EVAR, compared with a stable sac at 1-year imaging, sac regression and expansion are associated with a lower and higher risk respectively of long-term mortality, reinterventions, and ruptures. Moreover, the amount of regression or expansion seems to be incrementally associated with these late outcomes, too. Future studies are needed to determine how to improve 1-year sac regression, and whether it is safe to extend follow-up intervals for patients with regressing sacs.

Association between readmission care fragmentation and outcomes after interventions for peripheral arterial disease

OBJECTIVE

Lower extremity revascularization (LER) for peripheral artery disease is complicated by the frequent need for readmission. However, it is unclear if readmission to a nonindex LER facility (ie, a facility different from the one where the LER was performed) compared with the index LER facility is associated with worse outcomes.

METHODS

This was a national cohort study of older adults who underwent open, endovascular, or hybrid LER for peripheral artery disease (January 1, 2010, to December 31, 2018) in the Vascular Quality Initiative who were readmitted within 90 days of their vascular procedure. This dataset was linked to Medicare claims and the American Hospital Association Annual Survey. The primary outcome was 90-day mortality and the secondary outcome was major amputation at 90 days after LER. The primary exposure was the location of the first readmission after LER (categorized as occurring at the index LER facility vs a nonindex LER facility). Generalized estimating equations logistic regression models were used to assess the association between readmission location and 90-day mortality and amputation.

RESULTS

Among 42,429 patients who underwent LER, 33.0% were readmitted within 90 days. Of those who were readmitted, 27.3% were readmitted to a nonindex LER facility, and 42.2% of all readmissions were associated with procedure-related complications. Compared with patients readmitted to the index LER facility, those readmitted to a nonindex facility had a lower proportion of procedure-related reasons for readmission (21.5% vs 50.1%; P < .001). Most of the patients readmitted to a nonindex LER facility lived further than 31 miles from the index LER facility (39.2% vs 19.6%; P < .001) and were readmitted to a facility with a total bed size of <250 (60.1% vs 11.9%; P < .001). Readmission to a nonindex LER facility was not associated with 90-day mortality or 90-day amputation. However, readmission for a procedure-related complication was associated with major amputation (90-day amputation: adjusted odds ratio, 3.33; 95% confidence interval, 2.89-3.82).

CONCLUSIONS

Readmission after LER for a procedure-related complication is associated with subsequent amputation. This finding suggests that quality improvement efforts should focus on understanding various types of procedure-related failure after LER and its role in limb salvage.

Sex differences in outcomes among adults undergoing abdominal aortic aneurysm repair

OBJECTIVE

Although the differences in short-term outcomes between male and female patients in abdominal aortic aneurysm (AAA) repair have been well studied, it remains unclear if these sex disparities extend to other long-term adverse outcomes after AAA repair, such as reintervention and late rupture.

METHODS

We performed a retrospective cohort study of 13,007 patients who underwent either endovascular (EVAR) or open AAA repair (OAR) between 2003 and 2015 using data from the Vascular Quality Initiative registries. Eligible patients were linked to fee-for-service Medicare claims to identify late outcomes of rupture and aneurysm-specific reintervention.

RESULTS

The mean age of our cohort was 76 ± 6.7 years, 22% were female, 94% were White, and 77% underwent EVAR. The 10-year rupture incidence was slightly higher for women at 4.8 per 1000 person-years, vs 3.9 for men, but this difference was not statistically significant after risk adjustment (hazard ratio [HR] = 1.13, 95% confidence interval [CI]: 0.74-1.73). Likewise, we found no sex difference in reintervention rates (5.1 vs 4.8 in women per 1000 person-years) even after risk adjustment (HR = 0.95, 95% CI: 0.83-1.09). Regression models suggest effect modification by repair type for reintervention, where women who underwent index EVAR had a higher risk of reintervention than men (HR = 1.08, 95% CI: 0.93-1.26), whereas women who underwent OAR were at a lower risk of reintervention than men (HR = 0.79, 95% CI: 0.58-1.08); however, neither effect reached statistical significance within each subgroup. In addition, we found that the risk of reintervention for women vs men varied by clinical presentation, where women were less likely to undergo reintervention after an elective or symptomatic AAA repair but were more likely to undergo reintervention after a repair for AAA rupture (HR = 1.70, 95% CI: 1.05-2.75).

CONCLUSIONS

Male and female patients who underwent AAA repair had similar rates of reintervention and late aneurysm rupture in the 10 years after their procedure. However, our findings suggest that repair type and clinical presentation may affect the role of sex in clinical outcomes and warrant further exploration in these subgroups.

Propensity-Score Matched Analysis of Three Years Survival of Trans Carotid Artery Revascularization Versus Carotid Endarterectomy in the Vascular Quality Initiative Medicare-Linked Database

OBJECTIVE

Carotid endarterectomy (CEA) remains the gold standard procedure for carotid revascularization. Transfemoral carotid artery stenting (TFCAS) was introduced as a minimally invasive alternative procedure in patients who are at high risk for surgery. However, TFCAS was associated with an increased risk of stroke and death compared to CEA.

BACKGROUND

Transcarotid artery revascularization (TCAR) has outperformed TFCAS in several prior studies and has shown similar perioperative and 1-year outcomes compared with CEA. We aimed to compare the 1-year and 3-year outcomes of TCAR versus CEA in the Vascular Quality Initiative (VQI)-Medicare-Linked [Vascular Implant Surveillance and Interventional Outcomes Network (VISION)] database.

METHODS

The VISION database was queried for all patients undergoing CEA and TCAR between September 2016 to December 2019. The primary outcome was 1-year and 3-year survival. One-to-one propensity-score matching (PSM) without replacement was used to produce 2 well-matched cohorts. Kaplan-Meier estimates, and Cox regression was used for analyses. Exploratory analyses compared stroke rates using claims-based algorithms for comparison.

RESULTS

A total of 43,714 patients underwent CEA and 8089 patients underwent TCAR during the study period. Patients in the TCAR cohort were older and were more likely to have severe comorbidities. PSM produced two well-matched cohorts of 7351 pairs of TCAR and CEA. In the matched cohorts, there were no differences in 1-year death [hazard ratio (HR)=1.13; 95% CI, 0.99-1.30; P =0.065]. At 3-years, TCAR was associated with slight increased risk of death (HR=1.16; 95% CI, 1.04-1.30; P =0.008). When stratifying by initial symptomatic presentation, the increased 3-year death associated with TCAR persisted only in symptomatic patients (HR=1.33; 95% CI, 1.08-1.63; P =0.008). Exploratory analyses of postoperative stroke rates using administrative sources suggested that validated measures of claims-based stroke ascertainment are necessary.

CONCLUSIONS

In this large multi-institutional PSM analysis with robust Medicare-linked follow-up for survival analysis, the rate of death at 1 year was similar in TCAR and CEA regardless of symptomatic status. The slight increase in the risk of 3-year death in symptomatic patients undergoing TCAR is likely confounded by more severe comorbidities despite matching. A randomized controlled trial comparing TCAR to CEA is necessary to further determine the role of TCAR in standard-risk patients requiring carotid revascularization.

Renin-Angiotensin-Aldosterone System Inhibitors Are Associated With Favorable Outcomes Compared to Beta Blockers in Reducing Mortality Following Abdominal Aneurysm Repair

Background The best medical therapy to control hypertension following abdominal aortic aneurysm repair is yet to be determined. We therefore examined whether treatment with renin-angiotensin-aldosterone system inhibitors (RAASIs) versus beta blockers influenced postoperative and 1-year clinical end points following abdominal aortic aneurysm repair in a Medicare-linked database. Methods and Results All patients with hypertension undergoing endovascular aneurysm repair and open aneurysm repair in the Vascular Quality Initiative Vascular Implant Surveillance and Interventional Outcomes Network database between 2003 and 2018 were included. Patients were divided into 2 groups based on their preoperative and discharge medications, either RAASIs or beta blockers. Our cohort included 8789 patients, of whom 3523 (40.1%) were on RAASIs, and 5266 (59.9%) were on beta blockers. After propensity score matching, there were 3053 matched pairs of patients in each group. After matching, RAASI use was associated with lower risk of postoperative mortality (odds ratio [OR], 0.3 [95% CI, 0.1-0.6]), myocardial infarction (OR, 0.1 [95% CI, 0.03-0.6]), and nonhome discharge (OR, 0.6 [95% CI, 0.5-0.7]). Before propensity score matching, RAASI use was associated with lower 1-year mortality (hazard ratio [HR], 0.4 [95% CI, 0.4-0.5]) and lower risk of aneurysmal rupture (HR, 0.7 [95% CI, 0.5-0.9]). These results persisted after propensity score matching for mortality (HR, 0.4 [95% CI, 0.4-0.5]) and aneurysmal rupture (HR, 0.7 [95% CI, 0.5-0.9]). Conclusions In this large contemporary retrospective cohort study, RAASI use was associated with favorable postoperative outcomes compared with beta blockers. It was also associated with lower mortality and aneurysmal rupture at 1 year of follow-up.

Outcomes of Complex Endovascular Treatment of Post-Dissection Aneurysms

OBJECTIVE

Reports of endovascular treatment of chronic post-dissection aneurysms are limited to high volumes centres, posing questions about generalisability.

METHODS

All endovascular repairs of intact pararenal and thoraco-abdominal aneurysms in the Vascular Quality Initiative from 2014 to 2021 were studied, and peri-operative and long term outcomes were compared between repairs of degenerative and post-dissection aneurysms. Peri-operative outcomes were compared using mixed effects logistic regression, and long term outcomes using Medicare linkage.

RESULTS

There were 123 patients who completed treatment for post-dissection aneurysms and 3 635 for degenerative aneurysms, with 36% of post-dissection repairs and 6.7% of degenerative repairs performed in a staged fashion (p < .001). The majority (84%) of post-dissection aneurysms were extensive thoraco-abdominal aneurysms (TAAAs: Crawford Type 1, 2, 3, 5), compared with 22% of degenerative aneurysms (p < .001). Physician modified endografts were the primary repair type for post-dissection (73%), while commercially available fenestrated grafts were the dominant repair for degenerative (48%). The first stage of staged procedures was associated with a 2.8% peri-operative mortality rate, 5.1% spinal cord ischaemia, and 8.9% thoraco-abdominal life altering events (the composite of peri-operative death, stroke, permanent spinal cord ischaemia, and dialysis). Th final stage procedure and fluoroscopy times were similar, but technical success was lower in post-dissection repairs (75% vs. 83%, p = .018), both due to issues with the main endograft or bridging vessels (11% vs. 6.6%, p = .055), and types 1and 3 endoleak at completion (17% vs. 10%, p = .035). In addition, high volume surgeons had two fold higher odds of technical success than their low volume counterparts. Adjusted peri-operative outcomes were similar between pathology types, including when comparisons were restricted to extensive TAAAs. Crude and adjusted three year survival were similar, but three year re-interventions were significantly higher following post-dissection repairs (p < .001).

CONCLUSION

Complex endovascular repair of chronic post-dissection aneurysms is feasible but is associated with high rates of re-interventions and non-trivial rates of lack of technical success. More data are needed to evaluate the long term durability of these procedures, and the utility of centralising these complex procedures.

The impact of completion and follow-up endoleaks on survival, reintervention, and rupture

OBJECTIVE

Endoleaks may be seen at case completion of endovascular abdominal aortic aneurysm repair (EVAR), and the presence of an endoleak may impact outcomes. However, the clinical implications of various endoleaks seen during follow-up is not well-described. Therefore, we studied the impact of endoleaks at completion and at follow-up on mid-term outcomes.

METHODS

We reviewed patients who underwent EVAR from 2003 to 2016 within the Vascular Quality Initiative-Medicare database and identified patients with endoleak at procedure completion and during follow-up, excluding those presenting with rupture. We stratified cohorts by presence of completion and follow-up endoleak subtypes. The primary outcome was 5-year survival, and secondary outcomes included 5-year freedom from reintervention and freedom from rupture. We used Kaplan-Meier estimates and log-rank tests to analyze differences in time-to-event endpoints.

RESULTS

Of 21,745 patients with completion endoleak data, 5085 (23%) had an endoleak. Compared with those without endoleak, those with type I endoleaks had lower 5-year survival (69% vs 75%; P < .001), type II endoleaks had higher survival (79%; P < .001), and types III, IV, and indeterminate were not statistically different (73%, 73%, and 75%, respectively). Freedom from reintervention for types I and III endoleaks were significantly lower than no endoleak cohort (I: 76%; P < .001; III: 72%; P < .001 vs 83%), but freedom from rupture was higher for those with type II and III endoleak (95% and 97% vs 94%; P < .001). Of 14,479 patients with detailed follow-up endoleak data, 2290 (16%) had an endoleak. Compared with those without endoleak, types I and III had significantly lower 5-year survival (I: 80%; P = .002; III: 66%; P < .001 vs 84%), but there were no differences for types II (82%) and indeterminate (77%). Those with any type of follow-up endoleak had lower 5-year freedom from reintervention (I: 70%; P < .001; II: 76%; P = .006; III: 36%; P < .001; indeterminate: 60%; P = .007 vs 84%), and lower freedom from rupture (I: 92%; P < .001; II: 91%; P = .16; III: 88%; P = .01; indeterminate: 90%; P = .11 vs 94%).

CONCLUSIONS

Compared with patients with no endoleak, those with type I completion endoleaks have lower 5-year survival and freedom from reintervention. Patients with types I and III follow-up endoleaks also have lower survival, and any endoleak at follow-up is associated with lower freedom from reintervention and freedom from rupture. These data highlight the importance of careful patient selection and close postoperative follow-up after EVAR, as the presence of endoleaks, specifically type I and III, over time portends worse outcomes.

Association between sex and long-term outcomes of endovascular treatment for peripheral artery disease

BACKGROUND

Endovascular peripheral vascular intervention (PVI) has become the primary revascularization technique used for peripheral artery disease (PAD). Yet, there is limited understanding of long-term outcomes of PVI among women versus men. In this study, our objective was to investigate sex differences in the long-term outcomes of patients undergoing PVI.

METHODS

We performed a cohort study of patients undergoing PVI for PAD from January 1, 2010 to September 30, 2015 using data in the Vascular Quality Initiative (VQI) registry. Patients were linked to fee-for-service Medicare claims to identify late outcomes including major amputation, reintervention, major adverse limb event (major amputation or reintervention [MALE]), and mortality. Sex differences in outcomes were evaluated using cumulative incidence curves, Gray's test, and mixed effects Cox proportional hazards regression accounting for patient and lesion characteristics using inverse probability weighted estimates.

RESULTS

In this cohort of 15,437 patients, 44% (n = 6731) were women. Women were less likely to present with claudication than men (45% vs. 49%, p < 0.001, absolute standardized difference, d = 0.08) or be able to ambulate independently (ambulatory: 70% vs. 76%, p < 0.001, d = 0.14). There were no major sex differences in lesion characteristics, except for an increased frequency of tibial artery treatment in men (23% vs. 18% in women, p < 0.001, d = 0.12). Among patients with claudication, women had a higher risk-adjusted rate of major amputation (hazard ratio [HR] = 1.72, 95% confidence interval [CI]: 1.18-2.49), but a lower risk of mortality (HR = 0.86, 95% CI: 0.75-0.99). There were no sex differences in reintervention or MALE for patients with claudication. However, among patients with chronic limb-threatening ischemia, women had a lower risk-adjusted hazard of major amputation (HR = 0.79, 95% CI: 0.67-0.93), MALE (HR = 0.86, 95% CI: 0.78-0.96), and mortality (HR = 0.86, 95% CI: 0.79-0.94).

CONCLUSION

There is significant heterogeneity in PVI outcomes among men and women, especially after stratifying by symptom severity. A lower overall mortality in women with claudication was accompanied by a higher risk of major amputation. Men with chronic limb-threatening ischemia had a higher risk of major amputation, MALE, and mortality. Developing sex-specific approaches to PVI that prioritizes limb outcomes in women can improve the quality of vascular care for men and women.

Using the Evaluating Devices Using Claims and RegisTry Data (EDUCATe) Plan within the Vascular Implant Surveillance and Interventional Outcomes Network (VISION) to Analyze the Long-Term Outcomes following Endovascular Aortic Aneurysm Repair

BACKGROUND

Implanted devices undergo clinical trials to assess their safety and effectiveness. However, pivotal device trials are limited in their follow-up while postmarket surveillance may incompletely capture late failure. Linking clinical trials to Medicare claims can address these limitations. This study matched patients from investigational device exemption (IDE) clinical trials for endovascular aortic aneurysm repair (EVAR) to Medicare claims-based registry data to compare long-term device outcomes between the 2 sources.

METHODS

Patient-level data from 2 industry-sponsored IDE trials of EVAR devices was provided by a single industry partner. Trial data were matched at the patient level to data from the Vascular Implant Surveillance and Interventional Outcomes Network (VISION), a registry that is a part of the Society for Vascular Surgery Patient Safety Organization. The primary outcomes analyzed were survival and freedom from aneurysm-related reintervention.

RESULTS

Of 159 clinical trial patients, 134 were eligible for claims-based matching and 115 (85.5%) were successfully matched to VISION registry data. For the matched cohort, the Kaplan-Meier estimated survival was 94.8% at 1 year, 82.6% at 3 years, and 68.1% at 5 years. Estimates for freedom from reintervention were 90% at 1 year, 82.4% at 3 years, and 78.1% at 5 years. The estimates for survival were nearly identical between the clinical trial data and that found in the VISION data (log-rank P = 0.89). Freedom from reintervention was similar between the groups, with IDE trial reported freedom from reintervention of 87.3% and 73.3%, compared to VISION of 92.6% and 83% at 1 and 5 years, respectively (log-rank P = 0.13).

CONCLUSIONS

Clinical trial patients who undergo EVAR can be successfully matched to claims-based registry data to improve long-term device surveillance and outcomes reporting. Claims-based results agreed well with IDE trial results for patients through 5 years, supporting the accuracy of claims-based data for longer-term surveillance. Linking clinical trial and claims-based registry data can lead to robust device monitoring.

Loss of follow-up after carotid revascularization is associated with worse long-term stroke and death

OBJECTIVES

Society for Vascular Surgery practice guidelines recommend surveillance with duplex ultrasound scanning at baseline (within 3 months from discharge), every 6 months for 2 years, and annually afterward following carotid endarterectomy or carotid artery stenting. There is a growing concern regarding the significance of postoperative follow-up after several vascular procedures. We sought to determine whether 1-year loss to follow-up (LTF) after carotid revascularization was associated with worse outcomes in the Vascular Quality Initiative (VQI) linked to Vascular Implant Surveillance and Interventional Outcomes Network (VISION) database.

METHODS

All patients who underwent carotid revascularization in the VQI VISION database between 2003 and 2016 were included. LTF was defined as failure to complete 1-year follow-up in the VQI long-term follow-up dataset. Data about stroke and mortality were captured in the VISION dataset using a list of Current Procedural Terminology, International Classification of Diseases (Ninth Revision), and International Classification of Diseases (Tenth Revision) codes linked to index procedures in VQI. Kaplan-Meier life-table methods and Cox proportional hazard modeling were used to compare 5- and 10-year outcomes between patients with no LTF and those who were LTF.

RESULTS

A total of 58,840 patients were available for analysis. The 1-year LTF rate was 43.8%. Patients who were LTF were older and more frequently symptomatic, with chronic obstructive pulmonary diseases, chronic kidney diseases, and congestive heart failure. Also, patients who underwent carotid artery stenting were more likely to be LTF compared with carotid endarterectomy patients (54.5% vs 42.3%; P < .001). The incidence of postoperative (30 days) stroke was higher in the LTF group (2.9% vs 1.7%; P < .001). Cox regression analysis revealed that LTF was associated with an increased risk of long-term stroke at 5 years (hazard ratio [HR]: 1.4, 95% confidence interval [CI]: 1.2-1.6; P < .001) and 10 years (HR: 1.3, 95% CI: 1.2-1.5; P < .001). It was also associated with significantly higher mortality at 5 years (HR: 2.5, 95% CI: 2.3-2.8; P < .001) and 10 years (HR: 2.2, 95% CI: 1.9-2.5; P < .001). Stroke or death was significantly worse in the LTF group at 5 years (HR: 2.3, 95% CI: 2.1-2.5; P < .001) and up to 10 years (HR: 2.02, 95% CI: 1.8-2.3; P < .001).

CONCLUSIONS

One-year follow-up after carotid revascularization procedures was found to be associated with better stroke- and mortality-free survival. Surgeons should emphasize the importance of follow-up to all patients who undergo carotid revascularization, especially those with multiple comorbidities and postoperative neurological complications.

Editor's Choice - Real World Study of Mortality After the Use of Paclitaxel Coated Devices in Peripheral Vascular Intervention

OBJECTIVE

This observational cohort study examined outcomes after peripheral vascular intervention (PVI) with paclitaxel coated devices (PCD) and non-PCD, and evaluated heterogeneity of treatment effect in populations of interest.

METHODS

The study included patients undergoing percutaneous transluminal angioplasty and or stent placement between 1 October 2015 and 31 December 2018 in the Vascular Quality Initiative Registry linked to Medicare claims. It determined differences in patient mortality and ipsilateral major amputation after PVI with PCD and non-PCD using Kaplan-Meier analyses and Cox regressions with inverse probability weighting in three cohorts: (A) patients treated for femoropopliteal or infrapopliteal occlusive disease with or without any other concurrent treatment (n = 11 452); (B) those treated for isolated superficial femoral or popliteal artery disease (n = 5 519); and (C) patients with inclusion criteria designed to approximate RCT populations (n = 2 278).

RESULTS

The mean age of patients was 72.3 (SD = 10.9) years, and 40.6% were female. In cohort A, patients receiving PCD had a lower mortality rate (HR 0.88, 95% CI 0.79 - 0.98) than those receiving non-PCD. There was no significant difference in mortality between groups in cohort B (HR 0.91, 95% CI 0.80 - 1.04) and cohort C (HR 1.10, 95% CI 0.84 - 1.43). Patients receiving PCD did not have a significantly elevated risk of major amputation compared with those receiving non-PCD (cohort A: HR 0.84, 95% CI 0.70 - 1.00; cohort B: HR 0.84, 95% CI 0.67 - 1.06; and cohort C: HR 1.05, 95% CI 0.51 - 2.14).

CONCLUSION

No increased patient mortality or major amputation was found at three years after PVI with PCD vs. non-PCD in this large, linked registry claims study, after accounting for heterogeneity of treatment effect by population. The analysis and results from three cohorts intended to mirror the cohorts of previous studies provide robust and niche real world evidence on PCD safety and help to understand and reconcile previously discrepant findings.

Perioperative and long-term outcomes after open conversion of endovascular aneurysm repair versus primary open aortic repair

BACKGROUND

The use of endovascular abdominal aortic aneurysm repair (EVAR) has superseded that of open aneurysm repair (OAR) as the procedure of choice for abdominal aortic aneurysm repair. However, significant rates of late reintervention and aneurysm rupture have been reported after EVAR, resulting in the need for conversion to OAR (C-OAR). To assess the relative effects of C-OAR on patients, we compared the outcomes of these patients to those of patients who had undergone P-OAR.

METHODS

The data from all patients who had undergone C-OAR and P-OAR in the Vascular Quality Initiative Vascular Implant Surveillance and Interventional Outcomes Network database from 2003 to 2018 were queried. Multivariable logistic regression and Kaplan-Meier survival and Cox proportional hazard regression analyses were used to assess the perioperative long-term outcomes.

RESULTS

A total of 4763 patients were included (91.4%, P-OAR; 8.6%, C-OAR). C-OAR was associated with a significant increase in the odds of perioperative mortality (odds ratio, 1.7; 95% confidence interval [CI], 1.1-2.7; P = .027) and renal complications (odds ratio, 1.5; 95% CI, 1.1-2; P = .004) vs P-OAR. At 5 years, conversion was associated with a higher risk of mortality (hazard ratio [HR], 1.5; 95% CI, 1.3-1.9; P < .001), aneurysmal rupture (HR, 1.9; 95% CI, 1.2-3.1; P = .007), and reintervention (HR, 1.4; 95% CI, 1.05-1.97; P = .022) compared with P-OAR. These results also persisted at 10 years, with conversion associated with a higher risk of mortality (HR, 1.5; 95% CI, 1.2-1.8; P < .001), rupture (HR, 1.8; 95% CI, 1.1-2.8; P = .018), and reintervention (HR, 1.5; 95% CI, 1.1-2.1; P = .010).

CONCLUSIONS

The results from the present study have demonstrated that C-OAR is associated with a significantly higher risk of perioperative morbidity and mortality compared with P-OAR. We found a significant increase in mortality, aneurysm rupture, and reintervention at 5 and 10 years of follow-up.

Disparities in 5-year outcomes and imaging surveillance following elective endovascular repair of abdominal aortic aneurysm by sex, race, and ethnicity

OBJECTIVES

Sex, racial, and ethnic disparities in postoperative outcomes following abdominal aortic aneurysm repair have been described, but differences in long-term outcomes are poorly understood. Our aim was to identify differences in 5-year outcomes and imaging surveillance after elective endovascular aortic aneurysm repair (EVAR) by sex, race, and ethnicity and to explore potential mechanisms underlying these differences.

METHODS

We identified patients undergoing elective EVAR in the Vascular Quality Initiative from 2003 to 2017 with linkage to Medicare claims through 2018 for long-term outcomes. Our primary outcome was 5-year aneurysm rupture. Secondary outcomes were 5-year reintervention and mortality and 2-year loss-to-imaging follow-up (defined as no aortic imaging from 6 to 24 months after EVAR). We used Kaplan-Meier and Cox regression analyses to evaluate these outcomes by sex/race/ethnicity and constructed multivariable models to explore potential contributing factors.

RESULTS

Among 16,040 patients, 11,764 (73%) were White males, 2891 (18%) were White females, 417 (2.6%) were Black males, 175 (1.1%) were Black females, 141 (0.9%) were Asian males, 34 (0.2%) were Asian females, 277 (1.7%) were Hispanic males, and 60 (0.4%) were Hispanic females. At 5 years, rupture rates were highest in Black females at 6.4% and lowest in white males at 2.3%. Compared with White males, rupture rates were higher in White females (hazard ratio [HR], 1.5; 95% confidence interval [CI], 1.1-2.0), Black females (HR, 2.5; 95% CI, 1.0-6.0), and Asian females (HR, 5.2; 95% CI, 1.3-21). White females also had higher mortality (HR, 1.2; 95% CI, 1.2-1.3) and loss-to-imaging-follow-up (HR, 1.2; 95% CI, 1.1-1.3), whereas Black females had higher mortality (HR, 1.4; 95% CI, 1.1-1.8) and reintervention (HR, 2.0; 95% CI, 1.4-2.8). Among other groups, Black males had higher reintervention (HR, 1.4; 95% CI, 1.0-1.8), and both Black and Hispanic males had higher loss-to-imaging-follow-up (Black: HR, 1.4; 95% CI, 1.1-1.7; Hispanic: HR, 1.3; 95% CI, 1.0-1.8). In adjusted analyses, White, Black, and Asian females remained at significantly higher risk for 5-year rupture after accounting for procedure year, clinical and anatomic characteristics, surgeon and hospital volume, and loss-to-imaging follow-up.

CONCLUSIONS

Compared with White male patients, Black females had higher 5-year aneurysm rupture, reintervention, and mortality after elective EVAR, whereas White females had higher rupture, mortality and loss-to-imaging-follow-up. Asian females also had higher rupture, and Black males had higher reintervention and loss-to-imaging-follow-up. These populations may benefit from improved preoperative counseling and clinical outreach after EVAR. A larger-scale investigation of current practice patterns and their impact on sex, racial, and ethnic disparities in late outcomes after EVAR is needed to identify tangible targets for improvement.

Use of linked registry claims data for long term surveillance of devices after endovascular abdominal aortic aneurysm repair: observational surveillance study

OBJECTIVE

To evaluate long term outcomes (reintervention and late rupture of abdominal aortic aneurysm) of aortic endografts in real world practice using linked registry claims data.

DESIGN

Observational surveillance study.

SETTING

282 centers in the Vascular Quality Initiative Registry linked to United States Medicare claims (2003-18).

PARTICIPANTS

20 489 patients treated with four device types used for endovascular abdominal aortic aneurysm repair (EVAR): 40.6% (n=8310) received the Excluder (Gore), 32.2% (n=6606) the Endurant (Medtronic), 16.0% (n=3281) the Zenith (Cook Medical), and 11.2% (n=2292) the AFX (Endologix). Given modifications to AFX in late 2014, patients who received the AFX device were categorized into two groups: the early AFX group (n=942) and late AFX group (n=1350) and compared with patients who received the other devices, using propensity matched Cox models.

MAIN OUTCOME MEASURES

Reintervention and rupture of abdominal aortic aneurysm post-EVAR; all patients (100%) had complete follow-up via the registry or claims based outcome assessment, or both.

RESULTS

Median age was 76 years (interquartile range (IQR) 70-82 years), 80.0% (16 386/20 489) of patients were men, and median follow-up was 2.3 years (IQR 0.9-4.1 years). Crude five year reintervention rates were significantly higher for patients who received the early AFX device compared with the other devices: 14.9% (95% confidence interval 13.7% to 16.2%) for Excluder, 19.5% (18.1% to 21.1%) for Endurant, 16.7% (15.0% to 18.6%) for Zenith, and early 27.0% (23.7% to 30.6%) for the early AFX. The risk of reintervention for patients who received the early AFX device was higher compared with the other devices in propensity matched Cox models (hazard ratio 1.61, 95% confidence interval 1.29 to 2.02) and analyses using a surgeon level instrumental variable of >33% AFX grafts used in their practice (1.75, 1.19 to 2.59). The linked registry claims surveillance data identified the increased risk of reintervention with the early AFX device as early as mid-2013, well before the first regulatory warnings were issued in the US in 2017.

CONCLUSIONS

The linked registry claims surveillance data identified a device specific risk in long term reintervention after EVAR of abdominal aortic aneurysm. Device manufacturers and regulators can leverage linked data sources to actively monitor long term outcomes in real world practice after cardiovascular interventions.

Contemporary incidence, outcomes, and survival associated with endovascular aortic aneurysm repair conversion to open repair among Medicare beneficiaries

OBJECTIVE

The widespread application of endovascular abdominal aortic aneurysm repair (EVAR) has ushered in an era of requisite postoperative surveillance and the potential need for reintervention. The national prevalence and results of EVAR conversion to open repair, however, remain poorly defined. The purpose of this analysis was to define the incidence of open conversion and its associated outcomes.

METHODS

The SVS Vascular Quality Initiative EVAR registry linked to Medicare claims via Vascular Implants Surveillance and Interventional Outcomes Network was queried for open conversions after initial EVAR procedures from 2003 to 2016. Cumulative conversion incidence within up to 5 years after EVAR and outcomes after open intervention were determined. Multivariable logistic regressions were used to identify independent predictors of conversion and mortality.

RESULTS

Among 15,937 EVAR patients, 309 (1.9%) underwent an open conversion: 43% (n = 132) early (<30 days) and 57% (n = 177) late (>30 days). The longitudinally observed rate of conversion was constant over time, as well as by geographic region. Independent predictors of conversion included female sex (hazard ratio [HR], 1.49; P < .001), aneurysm diameter or more than 6.0 cm at the time of index EVAR (HR, 1.74; P < .001), nonelective repair (compared with elective presentation: HR, 1.72; P < .001), and aortouni-iliac repairs (HR, 2.19; P < .001). In contrast, adjunctive operative procedures such as endo-anchors or cuff extensions (HR, 0.62; P = .06) were protective against long-term conversion. Both early (HR, 1.6; P < .001) and late (HR, 1.26; P = .07) open conversions were associated with significant 30-day (total cohort, 15%) and 1-year mortality (total cohort, 25%). Patients undergoing open conversion experienced high rates of 30-day readmission (42%) and cardiac (45%), renal (32%), and pulmonary (30%) complications.

CONCLUSIONS

This large, registry-based analysis is among the first to document the incidence and outcomes for open conversion after EVAR in a national cohort with long-term follow-up. Importantly, women, patients with large aneurysms, and complex anatomy, as well as urgent or emergent EVARs are at an increased risk for open conversion. It seems that more conversions are performed in the early postoperative period, despite perceptions that conversion is a delayed phenomenon. In all instances, conversion is associated with significant morbidity and mortality and highlights the importance of appropriate patient selection at the time of index EVAR.

Role of Renin-Angiotensin-Aldosterone System Inhibition in Patients Undergoing Carotid Revascularization

Background

Previous data suggest that using renin‐angiotensin‐aldosterone system inhibitors (RAASIs) improves survival in patients with cardiovascular diseases. We sought to investigate the association of different patterns of use of RAASIs on perioperative and 1‐year outcomes following carotid revascularization.

Methods and Results

We investigated patients undergoing carotid revascularization, either with carotid endarterectomy or transfemoral carotid artery stenting, in the VQI (Vascular Quality Initiative) VISION (Vascular Implant Surveillance and Interventional Outcomes Network) data set between 2003 and 2018. We divided our cohort into 3 groups: (1) no history of RAASI intake, (2) preoperative intake only, and (3) continuous pre‐ and postoperative intake. The final cohort included 73 174 patients; 44.4% had no intake, 50% had continuous intake, and 5.6% had only preoperative intake. Compared with continuous intake, preoperative and no intake were associated with higher odds of postoperative stroke (odds ratio [OR], 1.7 [95% CI, 1.5–1.9]; P<0.001; OR, 1.1 [95% CI, 1.03–1.2]; P=0.010); death (OR, 4.8 [95% CI, 3.8–6.1]; P<0.001; OR, 1.9 [95% CI, 1.6–2.2]; P<0.001); and stroke/death (OR, 2.05 [95% CI, 1.8–2.3]; P<0.001; OR, 1.2 [95% CI, 1.1–1.3]; P<0.001), respectively. At 1 year, preoperative and no intake were associated with higher odds of stroke (hazard ratio [HR], 1.4 [95% CI, 1.3–1.6]; P<0.001; HR, 1.15, [95% CI, 1.08–1.2]; P<0.001); death (HR, 1.7 [95% CI, 1.5–1.9]; P<0.001; HR, 1.3 [95% CI, 1.2–1.4]; P<0.001); and stroke/death (HR, 1.5 [95% CI, 1.4–1.7]; P<0.001; HR, 1.2 [95% CI, 1.17–1.3]; P<0.001), respectively.

Conclusions

Compared with subjects discontinuing or never starting RAASIs, use of RAASIs before and after carotid revascularization was associated with a short‐term stroke and mortality benefit. Future clinical trials examining prescribing patterns of RAASIs should aim to clarify the timing and potential to maximize the protective effects of RAASIs in high‐risk vascular patients.

Mortality Trends in Contemporary Abdominal Aortic Aneurysm Repairs Among Veterans

INTRODUCTION

Clinical trials at the advent of endovascular aortic aneurysm repairs (EVARs) demonstrated improved early survival with EVAR compared to open repairs; however, characterizations of routine contemporary care have been limited. This study compares postoperative survival among Veterans in clinical care following abdominal aortic aneurysm (AAA) repair with EVAR versus open repairs since the widespread adoption of EVAR.

MATERIALS AND METHODS

This retrospective cohort analysis of Veterans with AAA repairs from 2007 to 2020 at Veterans Affairs (VA) facilities evaluated survival by a repair method. Administrative International Classification of Diseases 9/10 codes and sociodemographic characteristics from structured charting were used for characterization and adjusted analyses. Demographics were compared via Chi-squared and Wilcoxon rank-sum testing and mortality evaluated using Kaplan-Meier and Cox proportional hazard analyses.

RESULTS

Among 15,480 AAA repairs (3566 open, and 11,914 EVAR), patients receiving open repairs were younger with lower Charlson scores compared to EVARs. EVAR was associated with better survival until 2.4 y post-procedure. Mean long-term survival, however, was higher for open surgery (6.3 ± 3.8 versus 5.8 ± 3.1 y in EVAR). After adjustment for gender, race, and ethnicity, EVAR was associated with worse survival (mortality hazard ratio [HR] 1.17; 95% confidence interval [CI], 1.11-1.24) as was each increment in Charlson score (HR 1.11; CI 1.10-1.12), whereas service-connected care (HR 0.73; CI, 0.70-0.77) and age (HR 0.99; CI, 0.98-0.99) were associated with better survival.

CONCLUSIONS

In contemporary Veteran aneurysm repairs, although a higher early survival rate was observed in EVAR repairs, long-term survival was higher for open repairs. Service-connected care was independently associated with greater survival after aneurysm repair.

Endovascular versus open repair in patients with abdominal aortic aneurysm: a claims-based data analysis in Japan

Objectives

Endovascular aortic repair (EVAR) evolved through competition with open aortic repair (OAR) as a safe and effective treatment option for appropriately selected patients with abdominal aortic aneurysm (AAA). Although endoleaks are the most common reason for post-EVAR reintervention, compliance with lifelong regular follow-up imaging remains a challenge.

Design

Retrospective data analysis.

Setting

The Japan Medical Data Center (JMDC), a claims database with anonymous data linkage across hospitals, consists of corporate employees and their families of ≤75 years of age.

Participants

The analysis included participants in the JMDC who underwent EVAR or OAR for intact (iAAA) or ruptured (rAAA) AAA. Patients with less than 6 months of records before the aortic repair were excluded.

Main outcome measures

Overall survival and reintervention rates.

Results

We identified 986 cases (837 iAAA and 149 rAAA) from JMDC with first aortic repairs between January 2015 and December 2020. The number of patients, median age (years (IQR)), follow-up (months) and post-procedure CT scan (times per year) were as follows: iAAA (OAR: n=593, 62.0 (57.0–67.0), 26.0, 1.6, EVAR: n=244, 65.0 (31.0–69.0), 17.0, 2.2), rAAA (OAR: n=110, 59.0 (53.0–59.0), 16.0, 2.1, EVAR: n=39, 62.0 (31.0–67.0), 18.0, 2.4). Reintervention rate was significantly higher among EVAR than OAR in rAAA (15.4% vs 8.2%, p=0.04). In iAAA, there were no group difference after 5 years (7.8% vs 11.0%, p=0.28), even though EVAR had initial advantage. There were no differences in mortality rate between EVAR and OAR for either rAAA or iAAA.

Conclusions

Claims-based analysis in Japan showed no statistically significant difference in 5-year survival rates of the OAR and EVAR groups. However, the reintervention rate of EVAR in rAAA was significantly higher, suggesting the need for regular post-EVAR follow-up with imaging. Therefore, international collaborations for long-term outcome studies with real-world data are warranted.

Decreasing Trends in Reintervention and Readmission After Endovascular Aneurysm Repair in a Multiregional Implant Registry

OBJECTIVES

As endovascular aortic aneurysm repair (EVAR) matures into its third decade, measures such as long-term reintervention and readmission have become a focus of quality improvement efforts. Within a large United States integrated healthcare system, we describe time trends in the rates of long-term reinterventions utilization measures.

METHODS

Data from a US multiregional EVAR registry was used to perform a descriptive study of 3,891 adults who underwent conventional infrarenal EVAR for infrarenal abdominal aortic aneurysm between 2010 to 2019. Three-year follow-up was 96.7%. Outcomes included 1-, 3-, and 5-year graft revision (defined as a procedure involving placement of a new endograft component), secondary interventions (defined as a procedure necessary for maintenance of EVAR integrity, e.g., coil embolization and balloon angioplasty/stenting), conversion to open, interventions for type II endoleaks alone, and 90-day readmission. Crude cause-specific reintervention probabilities were calculated by operative year using the Aalen-Johansen estimator, with death as a competing risk and December 31, 2020 as the study end date.

RESULTS

Excluding interventions for type II endoleak alone, 1-year secondary intervention incidence decreased from 5.9% for EVARs in 2010 to 2.0% in 2019 (p<0.001) and 3-year incidence decreased from 7.2% to 3.6% from 2010 to 2017 (p=0.03). The 3-year incidences of graft revision (mean incidence 3.4%) and conversion to open remained fairly stable (mean incidence 0.6%) over time. The 3-year incidence of interventions for type II endoleak alone also decreased from 3.4% in 2010 to 0.7% in 2017 (p=0.01). 90-day readmission rates decreased from 19.3% for index EVAR in 2010 to 9.2% in 2019 (p=0.03).

CONCLUSIONS

Comprehensive data from a multiregional healthcare system demonstrates decreasing long-term secondary intervention and readmission rates over time in patients undergoing EVAR. These trends are not explained by evolving management of type II endoleaks and suggest improving graft durability, patient selection or surgical technique. Further study is needed to define implant and anatomic predictors of different types of long-term reintervention.

Long-term Outcomes Associated With Open vs Endovascular Abdominal Aortic Aneurysm Repair in a Medicare-Matched Database

IMPORTANCE

Endovascular aneurysm repair is associated with a significant reduction in perioperative mortality and morbidity compared with open aneurysm repair in the treatment of abdominal aortic aneurysm. However, this benefit decreases over time owing to increased reinterventions and late aneurysm rupture after endovascular repair.

OBJECTIVE

To compare long-term outcomes of endovascular vs open repair of abdominal aortic aneurysm.

DESIGN, SETTING, AND PARTICIPANTS

This multicenter retrospective cohort study used deidentified data with 6-year follow-up from the Medicare-matched Vascular Quality Initiative Vascular Implant Surveillance and Interventional Outcomes Network database. Patients undergoing first-time elective endovascular or open abdominal aortic aneurysm repair from 2003 to 2018 were propensity score matched. Patients with ruptured abdominal aortic aneurysm, concomitant procedures, or prior history of abdominal aortic aneurysm repair, were excluded. Data were analyzed from January 1, 2003, to December 31, 2018.

EXPOSURES

First-time elective endovascular or open repair for abdominal aortic aneurysm.

MAIN OUTCOMES AND MEASURES

The primary long-term outcome of interest was 6-year all-cause mortality, rupture, and reintervention. Secondary outcomes included 30-day mortality and perioperative complications.

RESULTS

Among a total of 32 760 patients (median [IQR] age, 75 [70-80] years; 25 706 [78.5%] men) who underwent surgical abdominal aortic aneurysm repair, 28 281 patients underwent endovascular repair and 4479 patients underwent open repair. After propensity score matching, there were 2852 patients in each group. Open repair was associated with significantly lower 6-year mortality compared with endovascular repair (548 deaths [35.6%] vs 608 deaths [41.2%]; hazard ratio [HR], 0.83; 95% CI, 0.74-0.94; P = .002), with increases in mortality starting from 1 to 2 years (84 deaths [4.3%] vs 126 deaths [6.7%]; HR, 0.63; 95% CI, 0.48-0.83; P = .001) and 2 to 6 years (211 deaths [25.8%] vs 241 deaths [30.6%]; HR, 0.73; 95% CI, 0.61-0.88; P = .001). Open repair, compared with endovascular repair, also was associated with significantly lower rates of 6-year rupture (117 participants [5.8%] vs 149 participants [8.3%]; HR, 0.76; 95% CI, 0.60-0.97; P < .001) and reintervention (190 participants [11.6%] vs 267 participants [16.0%]; HR, 0.67; 95% CI, 0.55-0.80; P < .001). Open repair was associated with significantly higher odds of 30-day mortality (OR, 3.56; 95% CI, 2.41-5.26; P < .001) and complications.

CONCLUSIONS AND RELEVANCE

These findings suggest that overall mortality after elective abdominal aortic aneurysm repair was higher with endovascular repair than open repair despite reduced 30-day mortality and perioperative morbidity after endovascular repair. Endovascular repair additionally was associated with significantly higher rates of long-term rupture and reintervention. These findings emphasize the importance of careful patient selection and long-term follow-up surveillance for patients who undergo endovascular repair.

Data Resources for Evaluating the Economic and Financial Consequences of Surgical Care in the United States

LEVEL OF EVIDENCE

V.

Validation of an indirect linkage algorithm to combine registry data with Medicare claims

INTRODUCTION

Linkage of registries to Medicare claims data can help extend follow-up for patients receiving medical devices. This study sought to test and validate an algorithm that does not require patient identifiers to link a national vascular registry and Medicare claims data.

METHODS

We used data from the Vascular Quality Initiative (VQI), a registry capturing data from more than 600 centers on several different vascular procedures and Medicare claims from 2003 to 2018. We restricted to patients aged 65 years and older who had fee-for-service entitlement at the time of the procedure for this study. We performed an indirect linkage to combine VQI with Medicare at the patient level using a sequential algorithm based on patient's date of birth, sex, zip code, procedure date, and procedure facility. We compared this against a gold standard of a cohort directly linked using social security numbers (SSNs). We calculated the matching rate and accuracy overall, and before and after October 2015 when the ICD-10 system was adopted in the US.

RESULTS

A total of 144,045 VQI-Medicare linked patients were in the gold standard cohort. Using the indirect linking algorithm, we matched 133,966 of the 144,045 VQI patients to their Medicare claims (matching rate: 93.0%). Among these, 133,104 patients were correctly matched (matching accuracy: 99.4%). The matching rate was higher when the indirect linkage was implemented in ICD-10 coded data than in ICD-9 coded data (94.0% vs. 92.2%). Accuracy of the indirect linkage remained high for all procedure modules post-ICD-10 coding change (overall 99.4%, range 99.0-99.7%).

CONCLUSION

In this study, we successfully used indirect identifiers to link the VQI to Medicare claims with more than 90% success and more than 99% accuracy. When direct linkage of registry-claims data using SSNs is not possible because of availability, confidentiality, or both, this method for indirect linkage provides a suitable alternative. The matching rate and accuracy help ensure the accuracy of long-term follow-up and the completeness and representativeness of linked databases for relevant research and quality improvement initiatives.

Effect of postoperative antithrombotic therapy on lower extremity outcomes after infrapopliteal bypass for chronic limb-threatening ischemia

OBJECTIVE

Although the current guidelines have recommended single antiplatelet therapy (SAPT) for patients undergoing revascularization for chronic limb-threatening ischemia (CLTI), antithrombotic management has varied by patient and provider. Our aim was to examine the effects of different postoperative antithrombotic regimens on 3-year clinical outcomes after infrapopliteal bypass for CLTI.

METHODS

We identified patients who had undergone infrapopliteal bypass for CLTI in the Vascular Quality Initiative (VQI) registry from 2003 to 2017 with linkage to Medicare claims for long-term outcomes. We divided the patients into three cohorts according to the discharge antithrombotic regimen: SAPT (aspirin or clopidogrel), dual antiplatelet therapy (DAPT; aspirin and clopidogrel), or anticoagulation (AC) plus any antiplatelet (AP) agent. To reduce selection bias, we restricted the analysis cohorts to patients treated by providers who discharged >50% of patients with each antithrombotic regimen. Our primary outcome was 3-year major adverse limb events (MALE; major amputation or reintervention). The secondary outcomes included 3-year major amputation, reintervention, and mortality. We used Kaplan-Meier and Cox regression analyses to assess these outcomes stratified by antithrombotic regimen and adjusted for demographic, comorbid, clinical, and operative differences between the treatment groups with clustering at the center level.

RESULTS

Among 1812 patients (median follow-up, >2 years), 693 (38%) were discharged with SAPT, 544 (30%) with DAPT, and 575 (32%) with AC+AP. At 3 years, the MALE rates were 75% with DAPT, 74% with AC+AP, and 68% with SAPT. In adjusted analyses with SAPT as the reference group, no differences were found in 3-year MALE with DAPT (adjusted hazard ratio [aHR], 1.0; 95% confidence interval [CI], 0.85-1.3; P = .71) or AC+AP (aHR, 1.1; 95% CI, 0.96-1.3; P = .14). Across the treatment groups, we also found no differences in the individual end points of 3-year major amputation (DAPT: aHR, 0.98; 95% CI, 0.72-1.3; AC+AP: aHR, 1.3; 95% CI, 0.96-1.7), reintervention (DAPT: aHR, 1.0; 95% CI, 0.84-1.3; AC+AP: aHR, 1.1; 95% CI, 0.96-1.3), or mortality (DAPT: aHR, 1.1; 95% CI, 0.88-1.4; AC+AP: aHR, 0.95; 95% CI, 0.74-1.2). In a sensitivity analysis evaluating patients treated by providers who discharged >60%, >70%, or >80% of patients with these regimens, the association between antithrombotic regimen and MALE was unchanged.

CONCLUSIONS

Compared with SAPT, DAPT and anticoagulation therapy were not associated with improved outcomes among Medicare beneficiaries who had undergone infrapopliteal bypass for CLTI at VQI participating centers. These findings support current guidelines recommending SAPT after lower extremity bypass and suggest that the routine use of DAPT or anticoagulation therapy might not provide clinical benefit in this high-risk, elderly population. However, further evaluation of the risks and benefits of various antithrombotic regimens in relevant subgroups is warranted.

Guideline-Directed Medical Therapy in Patients with Chronic Kidney Disease Undergoing Peripheral Vascular Intervention

INTRODUCTION

Guideline-directed medical therapy (GDMT) is imperative to improve cardiovascular and limb outcomes for patients with critical limb ischemia (CLI), especially amongst those at highest risk for poor outcomes, including those with comorbid chronic kidney disease (CKD). Our objective was to examine GDMT prescription rates and their variation across individual sites for patients with CLI undergoing peripheral vascular interventions (PVIs), by their comorbid CKD status.

METHODS

Patients with CLI who underwent PVI (October 2016-April 2019) were included from the Vascular Quality Initiative (VQI) database. CKD was defined as GFR <60 mL/min/1.73 m2. GDMT included the composite use of antiplatelet therapy and a statin, as well as an angiotensin-converting enzyme inhibitor or angiotensin receptor blocker if hypertension was present. The use of GDMT before and after the index procedure was summarized in those with and without CKD. Adjusted median odds ratios (MORs) for site variability were calculated.

RESULTS

The study included 28,652 patients, with a mean age of 69.4 ± 11.7 years, and 40.8% were females. A total of 47.5% had CKD. Patients with CKD versus those without CKD had lower prescription rates both before (31.7% vs. 38.9%) and after (36.5% vs. 48.8%) PVI (p < 0.0001). Significant site variability was observed in the delivery of GDMT in both the non-CKD and CKD groups before and after PVI (adjusted MORs: 1.31-1.41).

DISCUSSION/CONCLUSION

In patients with CLI undergoing PVI, patients with comorbid CKD were less likely to receive GDMT. Significant variability of GDMT was observed across sites. These findings indicate that significant improvements must be made in the medical management of patients with CLI, particularly in patients at high risk for poor clinical outcomes.

Long-term implications of elective evar that is non-compliant with clinical practice guideline diameter thresholds

OBJECTIVE

Compliance with Society for Vascular Surgery (SVS) abdominal aortic aneurysm (AAA) clinical practice guideline (CPG)-diameter thresholds is variable for endovascular aneurysm repair (EVAR). To evaluate the implications and appropriateness of repairs that are noncompliant with current guidelines, we investigated the long-term outcomes, adherence to imaging follow-up, and associated health care costs in patients undergoing EVAR for AAA who do or do not meet recommended diameter thresholds.

METHODS

All patients receiving elective EVAR from 2003 to 2016 in the SVS Vascular Quality Initiative with linked Medicare claims were reviewed. Weekend procedures and isolated iliac aneurysms, as well as symptomatic and ruptured presentations, were excluded. Diameter thresholds for noncompliant repairs were defined as: men <55 mm; women <50 mm who did not have an iliac diameter ≥30 mm. We evaluated adherence to postoperative imaging surveillance, reimbursement amounts, reintervention, rupture, and all-cause mortality. We defined an EVAR quality metric as performance of the index procedure with freedom from conversion to open repair, 5-year rupture-free survival, and adherence to minimum imaging surveillance (at least one computed tomography scan documented between 6 and 24 months postoperatively).

RESULTS

Among 19,018 elective EVARs, 35% did not meet CPG diameter thresholds (26% within 5 mm of threshold). The rate of noncompliant repairs increased over time (24% in 2003 vs 36% in 2016; P < .001). Patients undergoing noncompliant repairs were younger, less likely to have multiple comorbidities, and more likely to receive EVAR with adherence to instructions for use criteria (89% vs 79%; P < .001). Patients undergoing noncompliant repairs had greater 5-year freedom from reintervention (86% vs 81%; P < .001), rupture-free survival (94% vs 92%; P = .01), and overall survival rates (71% vs 61%; P < .001) compared with repairs that complied with CPG diameter thresholds. Although noncompliant repairs had higher rates of 1-year imaging surveillance, overall differences were modest (68% vs 65%; P = .003). Importantly, for the entire cohort, follow-up imaging surveillance decreased over time (93% in 2003 vs 63% in 2014; P < .001). Notably, although noncompliant repairs had higher rates of achieving the composite quality metric compared with compliant repairs (43% vs 38%; P < .001), failure occurred with a significant majority of all repairs.

CONCLUSIONS

Compliance with SVS-endorsed CPG diameter thresholds for elective EVAR is poor, and rates of noncompliance are increasing. Noncompliant repairs appear to be offered more commonly to patients with fewer comorbidities and favorable anatomy, and these repairs are associated with improved rates of reintervention, rupture, and survival compared with procedures meeting CPG diameter thresholds. Importantly, noncompliant repairs fail to meet minimum quality standards in a majority of cases, which underscores the need for further policies to improve the overall quality and appropriateness of AAA care delivery nationally.

Long-term Reintervention After Endovascular Abdominal Aortic Aneurysm Repair

OBJECTIVE

To describe the long-term reintervention rate after endovascular abdominal aortic aneurysm repair (EVR), and identify factors predicting reintervention.

SUMMARY OF BACKGROUND DATA

EVR is the most common method of aneurysm repair in America, and reintervention after EVR is common. Clinical factors predicting reintervention have not been described in large datasets with long-term follow-up.

METHODS

We studied patients who underwent EVR using the Vascular Quality Initiative registry linked to Medicare claims. Our primary outcome was reintervention, defined as any procedure related to the EVR after discharge from the index hospitalization. We used classification and regression tree modeling to inform a multivariable Cox-regression model predicting reintervention after EVR.

RESULTS

We studied 12,911 patients treated from 2003 to 2015. Mean age was 75.5 ± 7.3 years, 79.9% were male, and 89.1% of operations were elective. The 3-year reintervention rate was 15%, and the 10-year rate was 33%. Five factors predicted reintervention: operative time ≥3.0 hours, aneurysm diameter ≥6.0 cm, an iliac artery aneurysm ≥2.0 cm, emergency surgery, and a history of prior aortic surgery. Patients with no risk factors had a 3-year reintervention rate of 12%, and 10-year rate of 26% (n = 7310). Patients with multiple risk factors, such as prior aortic surgery and emergent surgery, had a 3-year reintervention rate 72%, (n = 32). Modifiable factors including EVR graft manufacturer or supra-renal fixation were not associated with reintervention (P = 0.76 and 0.79 respectively).

CONCLUSIONS

All patients retain a high likelihood of reintervention after EVR, but clinical factors at the time of repair can predict those at highest risk.

Late outcomes after endovascular and open repair of large abdominal aortic aneurysms

OBJECTIVE

The risk of aortic abdominal aneurysm (AAA) rupture increases with an increasing aneurysm diameter. However, the effect of the AAA diameter on late outcomes after aneurysm repair is unclear. Therefore, we assessed the association of a large AAA diameter with late outcomes for patients undergoing open and endovascular AAA repair.

METHODS

We identified all patients who had undergone elective open or endovascular infrarenal aneurysm repair from 2003 to 2016 in the Vascular Quality Initiative linked to Medicare claims for long-term outcomes. A large AAA diameter was defined as a diameter >65 mm. We assessed the 5-year reintervention, rupture, mortality, and follow-up rates. We constructed propensity scores and used inverse probability-weighted Kaplan-Meier estimations and Cox proportional hazard models to identify independent associations between large AAA repair and our outcomes.

RESULTS

Of the 21,119 aneurysm repairs identified, 15.2% were for large AAAs. Of the 21,119 repairs, 19,017 were endovascular and 2102 were open. The large AAA cohort was less likely to have undergone endovascular aneurysm repair (EVAR; 84.9% vs 91%; P < .001), more likely to be older (median age, 76 vs 75 years; P < .001), and were less likely to be women (16.2% vs 21.7%; P < .001). After EVAR, patients with large AAAs had had lower adjusted 5-year freedom from reintervention (73.9% vs 84.6%; P < .001), freedom from rupture (88.5% vs 93.6%; P < .001), survival (58.0% vs 66.4%; P < .001), and freedom from loss to follow-up (77.7% vs 83.3%; P < .001) compared with patients with smaller AAAs. However, after open repair, the adjusted 5-year freedom from reintervention (95.8% vs 93.3%; P = .11), freedom from rupture (97.4% vs 97.8%; P = .32), survival (70.4% vs 74.0%; P = .13), and loss to follow-up (60.5% vs 62.8%; P = .86) were similar to the results for patients with smaller AAAs. For patients with large AAAs, the adjusted 5-year survival was lower after EVAR than that after open repair (55.3% vs 63.7%) but not after smaller AAA repair (67.3% vs 70.6%).

CONCLUSION

The 5-year adjusted reintervention, ruptures, mortality, and loss to follow-up rates for patients who had undergone large AAA EVAR were higher than those for patients who had undergone small AAA EVAR and large AAA open repair. Therefore, for patients with large AAAs who are medically fit, open repair should be strongly considered. Furthermore, these findings highlight the necessity for rigorous long-term follow-up after EVAR.

Medicare costs for endovascular abdominal aortic aneurysm treatment in the Vascular Quality Initiative

BACKGROUND

Reintervention after endovascular repair (EVR) of abdominal aortic aneurysms is common. However, the cumulative financial impact of reintervention after EVR on a national scale is poorly defined. Our objective was to describe the cost to Medicare for aneurysm treatment (EVR plus reinterventions) among a cohort of patients with known follow-up for 5 years after repair.

METHODS

We identified patients who underwent EVR within the Vascular Quality Initiative who were linked to their respective Medicare claims file (n = 13,995). We excluded patients who underwent EVR after September 30, 2010, and those who had incomplete Medicare coverage (n = 12,788). The remaining cohort (n = 1207) had complete follow-up until death or 5 years (Medicare data available through September 30, 2015). We then obtained and compiled the corresponding Medicare reimbursement data for the index EVR hospitalization and all subsequent reinterventions.

RESULTS

We studied 1207 Medicare patients who underwent EVR and had known follow-up for reinterventions for 5 years. The mean age was 76.2 years (±7.1 years), 21.6% of patients were female, and 91.1% of procedures were elective. The Kaplan-Meier reintervention rate at 5 years was 18%. Among patients who underwent reintervention, 154 (73.7%) had a single reintervention, 40 (19.1%) had two reinterventions, and 15 (7.2%) had three or more reinterventions. The median cost to Medicare for the index EVR hospitalization was $25,745 (interquartile range, $21,131-$28,774). The median cost for subsequent reinterventions was $22,165 (interquartile range, $17,152-$29,605). The cumulative cost to Medicare of aneurysm treatment (EVR plus reinterventions) increased in a stepwise fashion among patients who underwent multiple reinterventions, with each reintervention being similar in cost to the index EVR.

CONCLUSIONS

The overall cost incurred by Medicare to reimburse for each reintervention after EVR is roughly the same as for the initial procedure itself, meaning that Medicare cost projections would be greater than $100,000 for any individual who undergoes an EVR with three reinterventions. The long-term financial impact of EVR must be considered by surgeons, patients, and healthcare systems alike as these cumulative costs may hinder the fiscal viability of an EVR-first therapeutic approach and highlight the need for judicious patient selection paradigms.

Longitudinal Spending on Endovascular and Open Abdominal Aortic Aneurysm Repair

BACKGROUND

Endovascular repair (EVR) has replaced open surgery as the procedure of choice for patients requiring elective abdominal aortic aneurysm (AAA) repair. Long-term outcomes of the 2 approaches are similar, making the relative cost of caring for these patients over time an important consideration.

METHODS AND RESULTS

We linked Medicare claims to Vascular Quality Initiative registry data for patients undergoing elective EVR or open AAA repair from 2004 to 2015. The primary outcome was Medicare's cumulative disease-related spending, adjusted to 2015 dollars. Disease-related spending included the index operation and associated hospitalization, surveillance imaging, reinterventions (AAA-related and abdominal wall procedures), and all-cause admissions within 90 days. We compared the incidence of disease-related events and cumulative spending at 90 days and annually through 7 years of follow-up. The analytic cohort comprised 6804 EVR patients (median follow-up: 1.85 years; interquartile range: 0.82-3.22 years) and 1889 open repair patients (median follow-up: 2.62 years; interquartile range: 1.13-4.80 years). Spending on index surgery was significantly lower for EVR (median [interquartile range]: $25 924 [$22 280-$32 556] EVR versus $31 442 [$24 669-$40 419] open; P<0.001), driven by a lower rate of in-hospital complications (6.6% EVR versus 38.0% open; P<0.001). EVR patients underwent more surveillance imaging (1.8 studies per person-year EVR versus 0.7 studies per person-year open; P<0.001) and AAA-related reinterventions (4.0 per 100 person-years EVR versus 2.1 per 100 person-years open; P=0.041). Open repair patients had higher rates of 90-day readmission (12.9% EVR versus 17.8% open; P<0.001) and abdominal wall procedures (0.6 per 100 person-years EVR versus 1.5 per 100 person-years open; P<0.001). Overall, EVR patients incurred more disease-related spending in follow-up ($7355 EVR versus $2706 open through 5 years). There was no cumulative difference in disease-related spending between surgical groups by 5 years of follow-up (-$33 EVR [95% CI: -$1543 to $1476]).

CONCLUSIONS

We observed no cumulative difference in disease-related spending on EVR and open repair patients 5 years after surgery. Generalized recommendations about which approach to offer elective AAA patients should not be based on relative cost.

Association of Sex With Repair Type and Long-term Mortality in Adults With Abdominal Aortic Aneurysm

IMPORTANCE

Sex-based differences exist in the prevalence and clinical presentation of abdominal aortic aneurysm (AAA). However, it is unclear if sex is associated with AAA repair type and long-term mortality.

OBJECTIVE

To investigate whether a sex-related difference exists in mortality risk after AAA repair owing to differences in repair type.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study uses data from the Vascular Quality Initiative, a national clinical registry, and Medicare claims to investigate endovascular and surgical repair procedures performed between January 1, 2003, and September 30, 2015, in patients aged 65 years or older with AAA. The data were analyzed from October 1, 2018, to November 19, 2019.

EXPOSURE

Sex of the patient.

MAIN OUTCOMES AND MEASURES

Endovascular (EVR) or open surgical AAA repair type and subsequent long-term, all-cause mortality.

RESULTS

In this cohort study of 16 386 patients, 12 757 (77.9%) were men and 3629 (22.1%) were women. Women were more likely than men to be older (mean [SD] age, 77 [6.5] years vs 75 [6.6] years; P < .001), active smokers (33% vs 28%; P < .001), and to have smaller aneurysms (mean [SD] diameter, 57 [11.7] mm vs 59 [17.7] mm; P < .001). Surgical AAA repair was performed in 27% (983 of 3629) of women compared with 18% (2328 of 12 757) of men (P < .001). After inverse probability weighting for risk adjustment, women were more likely to receive open surgical repair than EVR repair (risk ratio, 1.65; 95% CI, 1.51-1.80). The 10-year unadjusted survival rate after EVR repair was 14% lower in women than in men (23% vs 37%; log-rank P < .001), but the rates were comparable after open surgical repair (36% in men vs 32% in women; log-rank P = .22). Risk-adjusted analysis showed that women were associated with higher mortality rates after EVR repair (hazard ratio, 1.13; 95% CI, 1.03-1.24), whereas both men and women had a similar risk of death after open surgical repair (hazard ratio, 0.94; 95% CI, 0.84-1.06). After further stratification by symptom severity, higher risk of mortality among women was limited to elective EVR and open surgical repair for ruptured AAA.

CONCLUSIONS AND RELEVANCE

In this study, women were 65% more likely than men to undergo open surgical repair. After EVR repair, women were 13% more likely to die than men, although no sex-based difference in mortality was found after open surgical repair. The differential treatment benefit of EVR repair in women is concerning given the shift toward an EVR-first approach to AAA repair.

Validating Publicly Available Crosswalks for Translating ICD-9 to ICD-10 Diagnosis Codes for Cardiovascular Outcomes Research

Background On October 1, 2015, the Center for Medicare and Medicaid Services transitioned from the International Classification of Diseases, Ninth Revision ( ICD-9) to the ICD, Tenth Revision ( ICD-10) compendium of codes for diagnosis and billing in health care, but translation between the two is often inexact. Here we describe a validated crosswalk to translate ICD-9 codes into ICD-10 codes, with a focus on complications after carotid revascularization and endovascular aortic aneurysm repair. Methods and Results We devised an 8-step process to derive and validate ICD-10 codes from existing ICD-9 codes. We used publicly available sources, including the General Equivalence Mapping database, to translate ICD-9 codes used in prior work to ICD-10 codes. We defined ICD-10 codes as validated if they were concordant with the initial ICD-9 codes after manual comparison by two physicians. Our primary validation measure was the percent of valid ICD-10 codes out of the total ICD-10 codes obtained during translation. We began with 126 ICD-9 diagnosis codes used for complication identification after carotid revascularization procedures, and 97 ICD-9 codes for complications after endovascular aortic aneurysm procedures. Translation generated 143 ICD-10 codes for carotid revascularization, a 14% increase from the initial 126 codes. Manual comparison demonstrated 98% concordance, with 99% agreement between the reviewers. Similarly, we identified 108 ICD-10 codes for endovascular aortic aneurysm repair, an 11% increase from the initial 97 ICD-9 codes. We again noted excellent concordance and agreement (98% and 100%, respectively). Manual review identified 4 ICD-10 codes incorrectly translated from ICD-9 codes for carotid revascularization, and 3 codes incorrectly translated for endovascular aortic aneurysm repair. Conclusions Algorithms to crosswalk lists of ICD-9 codes to ICD-10 codes can leverage electronic resources to minimize the burden of code translation. However, manual review for code validation may be necessary, with collaboration across institutions for researchers to share their efforts.

Characterizing Reimbursements for Medicare Patients Receiving Endovascular Abdominal Aortic Aneurysm Repair at Vascular Quality Initiative Centers

BACKGROUND

Endovascular aortic aneurysm repair (EVR) has a major financial impact on health care systems. We characterized reimbursement for index EVR hospitalizations among Medicare beneficiaries having surgery at Vascular Quality Initiative (VQI) centers.

METHODS

We linked Medicare claims to VQI clinical registry data for patients undergoing EVR from 2003 to 2015. Analysis was limited to patients fully covered by fee-for-service Medicare parts A and B in the year of their operation and assigned a corresponding diagnosis-related group for EVR. The primary outcome was Medicare's reimbursement for inpatient hospital and professional services, adjusted to 2015 dollars. We performed descriptive analysis of reimbursement over time and univariate analysis to evaluate patient demographics, clinical characteristics, procedural variables, and postoperative events associated with reimbursement. This informed a multilevel regression model used to identify factors independently associated with EVR reimbursement and quantify VQI center-level variation in reimbursement.

RESULTS

We studied 9,403 Medicare patients who underwent EVR at VQI centers during the study period. Reimbursements declined from $37,450 ± $9,350 (mean ± standard deviation) in 2003 to $27,723 ± $10,613 in 2015 (test for trend, P < 0.001). For patients experiencing a complication (n = 773; 8.2%), mean reimbursement for EVR was $44,858 ± $23,825 versus $28,857 ± $9,258 for those without complications (P < 0.001). Intestinal ischemia, new dialysis requirement, and respiratory compromise each doubled Medicare's average reimbursement for EVR. After adjusting for diagnosis-related group, several patient-level factors were independently associated with higher Medicare reimbursement; these included ruptured abdominal aortic aneurysm (+$2,372), additional day in length of stay (+$1,275), and being unfit for open repair (+$501). Controlling for patient-level factors, 4-fold variation in average reimbursement was seen across VQI centers.

CONCLUSIONS

Reimbursement for EVR declined between 2003 and 2015. We identified preoperative clinical factors independently associated with reimbursement and quantified the impact of different postoperative complications on reimbursement. More work is needed to better understand the substantial variation observed in reimbursement at the center level.

Five-year reintervention after endovascular abdominal aortic aneurysm repair in the Vascular Quality Initiative

OBJECTIVE

Patients who undergo endovascular abdominal aortic aneurysm repair (EVR) remain at risk for reintervention and rupture. We sought to define the 5-year rate of reintervention and rupture after EVR in the Vascular Quality Initiative (VQI).

METHODS

We identified all patients in the VQI who underwent EVR from 2003 to 2015. We linked patients in the VQI to Medicare claims for long-term outcomes. We stratified patients on baseline clinical and procedural characteristics to identify those at risk for reintervention. Our primary outcomes were 5-year rates of reintervention and late aneurysm rupture after EVR. We assessed these with Kaplan-Meier survival estimation.

RESULTS

We studied 12,911 patients who underwent EVR. The mean age was 75.5 years, 79.9% were male, 3.9% were black, and 89.1% of operations were performed electively. The 5-year rate of reintervention for the entire cohort was 21%, and the 5-year rate of late aneurysm rupture was 3%. Reintervention rates varied across categories of EVR urgency. Patients who underwent EVR electively had the lowest 5-year rate of reintervention at 20%. Those who underwent surgery for symptomatic aneurysms had higher rates of reintervention at 25%. Patients undergoing EVR emergently for rupture had the highest rate of reintervention, 27% at 4 years (log-rank across the three groups, P < .001). Black race and aneurysm size of 6.0 cm or greater were associated with significantly elevated reintervention rates (black, 31% vs white, 20% [log-rank, P < .001]; aneurysm size 6.0 cm or greater, 27% vs all others, <20% [log-rank, P < .001]). There were no significant associations between age or gender and the 5-year rate of reintervention.

CONCLUSIONS

More than one in five Medicare patients undergo reintervention within 5 years after EVR in the VQI; late rupture remains low at 3%. Black patients, those with large aneurysms, and those who undergo EVR urgently and emergently have a higher likelihood of adverse outcomes and should be the focus of diligent long-term surveillance.

Transabdominal open abdominal aortic aneurysm repair is associated with higher rates of late reintervention and readmission compared with the retroperitoneal approach

OBJECTIVE

Limited data exist comparing the transabdominal and retroperitoneal approaches to open abdominal aortic aneurysm (AAA) repair, especially late mortality and laparotomy-related reinterventions and readmissions. Therefore, we compared long-term rates of mortality, reintervention, and readmission after open AAA repair through a transabdominal compared with a retroperitoneal approach.

METHODS

We identified all patients in the Vascular Quality Initiative (VQI) undergoing open AAA repair from 2003 to 2015. Patients with rupture or supraceliac clamp were excluded. We used the VQI linkage to Medicare to ascertain rates of long-term outcomes, including rates of AAA-related and laparotomy-related (ie, hernia, bowel obstruction) reinterventions and readmissions. We used multivariable Cox regression to account for differences in comorbidities, aneurysm details, and operative characteristics.

RESULTS

We identified 1282 patients in the VQI with linkage to Medicare data, 914 (71%) who underwent a transperitoneal approach and 368 (29%) who underwent a retroperitoneal approach. Patients who underwent a retroperitoneal approach were slightly more likely to have preoperative renal insufficiency but were otherwise similar in terms of demographics and comorbidities. They more often had a clamp above at least one renal artery (61% vs 36%; P < .001) and underwent concomitant renal revascularization (9.5% vs 4.3%; P < .001). Patients who underwent a transabdominal approach more often presented with symptoms (14% vs 9.0%; P < .01) and had a femoral distal anastomosis (15% vs 7.1%; P < .001). There was no difference in 5-year survival (62% vs 61%; log-rank, P = .51). However, patients who underwent a transabdominal approach experienced higher rates of repair-related reinterventions and readmissions (5-year: 42% vs 34%; log-rank, P < .01), even after adjustment for demographic and operative differences (hazard ratio, 1.5; 95% confidence interval, 1.1-1.9; P < .01).

CONCLUSIONS

A transabdominal exposure for AAA repair is associated with higher rates of late reintervention and readmission than with the retroperitoneal approach, which should be considered when possible in operative decision-making.

Adverse Events After Atherectomy: Analyzing Long-Term Outcomes of Endovascular Lower Extremity Revascularization Techniques

Background The long-term effectiveness of atherectomy treatment for peripheral arterial disease is unknown. We studied 5-year clinical outcomes by endovascular treatment type among patients with peripheral arterial disease. Methods and Results We queried the Medicare-linked VQI (Vascular Quality Initiative) registry for endovascular interventions from 2010 to 2015. The exposure was treatment type: atherectomy (with or without percutaneous transluminal angioplasty [ PTA] ), stent (with or without PTA ), or PTA alone. The outcomes were major amputation, any amputation, and major adverse limb event (major amputation or any reintervention). We used the center-specific proportions of atherectomy procedures performed in the 12 months before a patient's procedure as the instruments to perform an instrumental-variable Cox model analysis. Among 16 838 eligible patients (median follow-up: 1.3-1.5 years), 11% underwent atherectomy, 40% received PTA alone, and 49% underwent stenting. Patients receiving atherectomy commonly underwent femoropopliteal artery treatment (atherectomy: 65%; PTA : 49%; stenting: 43%; P<0.001) and had worse disease severity (Trans-Atlantic Inter-Society Consensus score [TASC] B and greater; atherectomy: 77%; PTA : 68%; stenting: 67%; P<0.001). The 5-year rate of major adverse limb events was 38% in patients receiving atherectomy versus 33% for PTA and 32% for stenting (log rank P<0.001). Controlling for unmeasured confounding using instrumental-variable analysis, patients treated with atherectomy experienced outcomes similar to those of patients treated with PTA , except for a higher risk of any amputation (hazard ratio: 1.51; 95% CI , 1.08-2.13). However, compared with stenting, atherectomy patients had a higher risk of major amputation (hazard ratio: 3.66; 95% CI , 1.72-7.81), any amputation (hazard ratio: 2.73; 95% CI , 1.60-4.76), and major adverse limb event (hazard ratio: 1.61; 95% CI , 1.10-2.38). Conclusions Atherectomy is used to treat severe femoropopliteal and tibial peripheral arterial disease even though long-term adverse outcomes occur more frequently after this treatment modality.

Creation and Validation of Linkage Between Orthopedic Registry and Administrative Data Using Indirect Identifiers

BACKGROUND

Registries and administrative databases have unique and complementary strengths in device epidemiologic studies. We sought to develop, validate, and assess a sequential algorithm using indirect identifiers to link registry and administrative data.

METHODS

Hip and knee arthroplasty procedures performed at 6 New York State hospitals enrolled in American Joint Replacement Registry in 2014 were included. After conducting a direct linkage using patient identifiers including name and social security numbers, we validated the methodology of indirect linkage using facility ID, patients' year and month of birth, sex, and zip code, and procedure date and site (hip/knee). We further evaluated the influence of absent indirect identifier(s) and compromised data quality on linkage success.

RESULTS

Using our sequential algorithm, 3739 of the 4063 directly linked records (92.03%) were matched with indirect identifiers, with an accuracy of >99.9%. Main reasons for nonmatching included discrepancies in procedure codes and dates. When one of the indirect identifiers was not available, the linkage algorithm still achieved over 90% sensitivity and 99.8% accuracy. Analyses showed that the algorithm was robust when quality of data was moderately compromised.

CONCLUSION

This study demonstrated high sensitivity and accuracy of an algorithm to create linkages between a registry and an administrative database using indirect identifiers. The methodology will enable long-term surveillance and outcome assessment of a wide variety of devices and procedures. Variations in the coding of procedures, availability of indirect identifiers, and their quality have limited impact on this algorithm.

Claims-based surveillance for reintervention after endovascular aneurysm repair among non-Medicare patients

OBJECTIVE

Many patients who undergo endovascular aortic aneurysm repair (EVR) also undergo repeat procedures, or reinterventions, to address suboptimal device performance and prevent aneurysm rupture. Quality improvement initiatives measuring reintervention after EVR has focused on fee-for-service Medicare patients. However, because patients aged less than 65 years and those with Medicare Advantage represent an important growing subgroup, we used a novel approach leveraging a state data source that captures patients of all ages and with all types of insurance.

METHODS

We identified patients who underwent EVR (2011-2015) within the Vascular Quality Initiative registry and were also listed in the Statewide Planning and Research Cooperative System all-payer claims database of New York. We linked patients in the Vascular Quality Initiative to their Statewide Planning and Research Cooperative System claims file at the patient level with a 96% match rate. We compared outcomes between fee-for-service Medicare eligible, defined as age 65 or older or on dialysis, versus ineligible patients, defined as those younger than 65 and not on dialysis. Our primary outcome was reintervention. We used Cox proportional hazards regression and propensity score matching for risk adjustment.

RESULTS

We studied 1285 patients with a median follow-up of 16 months (range, 1-57 months). The mean age was 74 years, 79% were male, and 84% of procedures were elective. Nearly one in six patients were not Medicare eligible (14%), and the remainder (86%) were Medicare eligible. Medicare-eligible patients were less likely to be male (77% vs 91%; P < .001), have a history of smoking (79% vs 93%; P < .001), and have a nonelective procedure (15% vs 23%; P = .013). The 3-year Kaplan-Meier rate of reintervention was 21%. We found similar rates of reintervention between Medicare-eligible patients and those who were not (19% vs 20%, log-rank P = .199; unadjusted hazard ratio [HR], 0.75; 95% confidence interval [CI], 0.49-1.16). This finding persisted in both the adjusted and propensity-matched analyses (adjusted HR, 0.82; 95% CI, 0.50-1.34; propensity-matched HR, 0.70; 95% CI, 0.36-1.37).

CONCLUSIONS

Reintervention can be monitored using administrative claims from both Medicare and non-Medicare payers, and serve as an important outcome metric after EVR in patients of all ages. The rate of reintervention seems to be similar between older, Medicare-eligible individuals, and those who are not yet eligible.

Comparing Long-term Mortality After Carotid Endarterectomy vs Carotid Stenting Using a Novel Instrumental Variable Method for Risk Adjustment in Observational Time-to-Event Data

IMPORTANCE

Choosing between competing treatment options is difficult for patients and clinicians when results from randomized and observational studies are discordant. Observational real-world studies yield more generalizable evidence for decision making than randomized clinical trials, but unmeasured confounding, especially in time-to-event analyses, can limit validity.

OBJECTIVES

To compare long-term survival after carotid endarterectomy (CEA) and carotid artery stenting (CAS) in real-world practice using a novel instrumental variable method designed for time-to-event outcomes, and to compare the results with traditional risk-adjustment models used in observational research for survival analyses.

DESIGN, SETTING, AND PARTICIPANTS

A multicenter cohort study was performed. The Vascular Quality Initiative, an observational quality improvement registry, was used to compare long-term mortality after CEA vs CAS. The study included 86 017 patients who underwent CEA (n = 73 312) or CAS (n = 12 705) between January 1, 2003, and December 31, 2016. Patients were followed up for long-term mortality assessment by linking the registry data to Medicare claims. Medicare claims data were available through September 31, 2015.

EXPOSURE

Procedure type (CEA vs CAS).

MAIN OUTCOMES AND MEASURES

The hazard ratios (HRs) of all-cause mortality using unadjusted, adjusted, propensity-matched, and instrumental variable methods were examined. The instrumental variable was the proportion of CEA among the total carotid procedures (endarterectomy and stenting) performed at each hospital in the 12 months before each patient's index operation and therefore varies over the study period.

RESULTS

Participants who underwent CEA had a mean (SD) age of 70.3 (9.4) years compared with 69.1 (10.4) years for CAS, and most were men (44 191 [60.4%] for CEA and 8117 [63.9%] for CAS). The observed 5-year mortality was 12.8% (95% CI, 12.5%-13.2%) for CEA and 17.0% (95% CI, 16.0%-18.1%) for CAS. The unadjusted HR of mortality for CEA vs CAS was 0.67 (95% CI, 0.64-0.71), and Cox-adjusted and propensity-matched HRs were similar (0.69; 95% CI, 0.65-0.74 and 0.71; 95% CI, 0.65-0.77, respectively). These findings are comparable with published observational studies of CEA vs CAS. However, the association between CEA and mortality was more modest when estimated by instrumental variable analysis (HR, 0.83; 95% CI, 0.70-0.98), a finding similar to data reported in randomized clinical trials.

CONCLUSIONS AND RELEVANCE

The study found a survival advantage associated with CEA over CAS in unadjusted and Cox-adjusted analyses. However, this finding was more modest when using an instrumental variable method designed for time-to-event outcomes for risk adjustment. The instrumental variable-based results were more similar to findings from randomized clinical trials, suggesting this method may provide less biased estimates of time-dependent outcomes in observational analyses.

A comparison of reintervention rates after endovascular aneurysm repair between the Vascular Quality Initiative registry, Medicare claims, and chart review

OBJECTIVE

The accurate measurement of reintervention after endovascular aneurysm repair (EVAR) is critical during postoperative surveillance. The purpose of this study was to compare reintervention rates after EVAR from three different data sources: the Vascular Quality Initiative (VQI) alone, VQI linked to Medicare claims (VQI-Medicare), and a "gold standard" of clinical chart review supplemented with telephone interviews.

METHODS

We reviewed the medical records of 729 patients who underwent EVAR at our institution between 2003 and 2013. We excluded patients without follow-up reported to the VQI (n = 68 [9%]) or without Medicare claims information (n = 114 [16%]). All patients in the final analytic cohort (n = 547) had follow-up information available from all three data sources (VQI alone, VQI linked to Medicare, and chart review). We then compared reintervention rates between the three data sources. Our primary end points were the agreement between the three data sources and the Kaplan-Meier estimated rate of reintervention at 1 year, 2 years, and 3 years after EVAR. For gold standard assessment, we supplemented chart review with telephone interview as necessary to assess reintervention.

RESULTS

VQI data alone identified 12 reintervention events in the first year after EVAR. Chart review confirmed all 12 events and identified 18 additional events not captured by the VQI. VQI-Medicare data successfully identified all 30 of these events within the first year. VQI-Medicare also documented four reinterventions in this time period that did not occur on the basis of patient interview (4/547 [0.7%]). The agreement between chart review and VQI-Medicare data at 1 year was excellent (κ = 0.93). At 3 years, there were 81 (18%) reinterventions detected by VQI-Medicare and 70 (16%) detected by chart review for a sensitivity of 92%, specificity of 96%, and κ of 0.80. Kaplan-Meier survival analysis demonstrated similar reintervention rates after 3 years between VQI-Medicare and chart review (log-rank, P = .59).

CONCLUSIONS

Chart review after EVAR demonstrated a 6% 1-year and 16% 3-year reintervention rate, and almost all (92%) of these events were accurately captured using VQI-Medicare data. Linking VQI data with Medicare claims allows an accurate assessment of reintervention rates after EVAR without labor-intensive physician chart review.