Regional quality groups in the Society for Vascular Surgery® Vascular Quality Initiative

Preoperative risk score for mortality within 3 years of visceral segment fenestrated endovascular aortic repair

OBJECTIVE

The purpose of this study was to create a risk score for the event of mortality within 3 years of complex fenestrated visceral segment endovascular aortic repair utilizing variables existing at the time of preoperative presentation.

METHODS

After exclusions, 1916 patients were identified in the Vascular Quality Initiative who were included in the analysis. The first step in development of the risk score was univariable analysis for the primary outcome of mortality within 3 years of surgery. χ2 analysis was performed for categorical variables, and comparison of means with independent Student t-test was performed for ordinal variables. Variables that achieved a univariable P value less than 0.1 were then placed into Cox regression multivariable time dependent analysis for the development of mortality within 3 years. Variables that achieved a multivariable significance of less than 0.1 were utilized for the risk score, with point weighting based on the beta-coefficient. Variables with a beta coefficient of 0.25 to 0.49 were assigned 1 point, 0.5 to 0.74 2 points, 0.75 to 0.99 3 points, and 1.0 to 1.25 4 points. A cumulative score for each patient was then summed, the percentage of patients at each score experiencing mortality within 3 weeks was then calculated, and a comparison of score outcomes was conducted with binary logistic regression. Area under the curve analysis was performed.

RESULTS

The primary outcome of mortality within 3 years of surgery occurred in 12.8% of patients (245/1916). The mean age for the study population was 73.35 years (standard deviation [SD], 8.26 years). The mean maximal abdominal aortic aneurysm (AAA) diameter was 60.43 mm (SD, 10.52 mm). The mean number of visceral vessels stented was 3.3 (SD, 0.76). Variables present at the time of surgery that were included in the risk score were: hemodialysis (3 points); age >87, chronic obstructive pulmonary disease, hypertension, AAA diameter >77 mm (all 2 points); and body mass index <20 kg/m2, female sex, congestive heart failure, active smoking, chronic renal insufficiency, age 80 to 87 years, and AAA diameter 67 to 77 mm (all 1 point). BMI >30 kg/m2 (mean, 34.46 kg/m2) and age <67 years were protective (-1 point). Testing the model resulted in an area under the curve of 0.706. Hosmer and Lemeshow goodness of fit test for logistic regression utilizing the 15 different risk score total groups revealed a model predictive accuracy of 87.3%. Significant escalations in 3-year mortality were noted to occur at scores of 6 and greater. Mean AAA diameter was significantly larger for patients who had higher risk scores (P < .001).

CONCLUSIONS

A novel risk score for mortality within 3 years of fenestrated visceral segment aortic endograft has been developed that has excellent accuracy in predicting which patients will survive and derive the strongest benefit from intervention. This facilitates risk-benefit analysis and counseling of patients and families with realistic long-term expectations. This potentially enhances patient-centered decision-making.

Endovascular therapy versus bypass for chronic limb-threatening ischemia in a real-world practice

OBJECTIVE

The recent Best Endovascular vs Best Surgical Therapy in Patients with Critical Limb Ischemia (BEST-CLI) study showed that bypass was superior to endovascular therapy (ET) in patients with chronic limb-threatening ischemia (CLTI) deemed suitable for either approach who had an available single-segment great saphenous vein (GSV). However, the superiority of bypass among those lacking GSV was not established. We aimed to examine comparative treatment outcomes from a real-world CLTI population using the Vascular Quality Initiative-Medicare-linked database.

METHODS

We queried the Vascular Quality Initiative-Medicare-linked database for patients with CLTI who underwent first-time lower extremity revascularization (2010-2019). We performed two one-to-one propensity score matchings (PSMs): ET vs bypass with GSV (BWGSV) and ET vs bypass with a prosthetic graft (BWPG). The primary outcome was amputation-free survival. Secondary outcomes were freedom from amputation and overall survival (OS).

RESULTS

Three cohorts were queried: BWGSV (N = 5279, 14.7%), BWPG (N = 2778, 7.7%), and ET (N = 27,977, 77.6%). PSM produced two sets of well-matched cohorts: 4705 pairs of ET vs BWGSV and 2583 pairs of ET vs BWPG. In the matched cohorts of ET vs BWGSV, ET was associated with greater hazards of death (hazard ratio [HR] = 1.34, 95% confidence interval [CI], 1.25-1.43; P < .001), amputation (HR = 1.30, 95% CI, 1.17-1.44; P < .001), and amputation/death (HR = 1.32, 95% CI, 1.24-1.40; P < .001) up to 4 years. In the matched cohorts of ET vs BWPG, ET was associated with greater hazards of death up to 2 years (HR = 1.11, 95% CI, 1.00-1.22; P = .042) but not amputation or amputation/death.

CONCLUSIONS

In this real-world multi-institutional Medicare-linked PSM analysis, we found that BWGSV is superior to ET in terms of OS, freedom from amputation, and amputation-free survival up to 4 years. Moreover, BWPG was superior to ET in terms of OS up to 2 years. Our study confirms the superiority of BWGSV to ET as observed in the BEST-CLI trial.

A dedicated risk prediction model of 1-year mortality following endovascular aortic aneurysm repair involving the renal-mesenteric arteries

OBJECTIVE

Treatment goals of prophylactic endovascular aortic repair of complex aneurysms involving the renal-mesenteric arteries (complex endovascular aortic repair [cEVAR]) include achieving both technical success and long-term survival benefit. Mortality within the first year after cEVAR likely indicates treatment failure owing to associated costs and procedural complexity. Notably, no validated clinical decision aid tools exist that reliably predict mortality after cEVAR. The purpose of this study was to derive and validate a preoperative prediction model of 1-year mortality after elective cEVAR.

METHODS

All elective cEVARs including fenestrated, branched, and/or chimney procedures for aortic disease extent confined proximally to Ishimaru landing zones 6 to 9 in the Society for Vascular Surgery Vascular Quality Initiative were identified (January 2012 to August 2023). Patients (n = 4053) were randomly divided into training (n = 3039) and validation (n = 1014) datasets. A logistic regression model for 1-year mortality was created and internally validated by bootstrapping the AUC and calibration intercept and slope, and by using the model to predict 1-year mortality in the validation dataset. Independent predictors were assigned an integer score, based on model beta-coefficients, to generate a simplified scoring system to categorize patient risk.

RESULTS

The overall crude 1-year mortality rate after elective cEVAR was 11.3% (n = 456/4053). Independent preoperative predictors of 1-year mortality included chronic obstructive pulmonary disease, chronic renal insufficiency (creatinine >1.8 mg/dL or dialysis dependence), hemoglobin <12 g/dL, decreasing body mass index, congestive heart failure, increasing age, American Society of Anesthesiologists class ≥IV, current tobacco use, history of peripheral vascular intervention, and increasing extent of aortic disease. The 1-year mortality rate varied from 4% among the 23% of patients classified as low risk to 23% for the 24% classified as high risk. Performance of the model in validation was comparable with performance in the training data. The internally validated scoring system classified patients roughly into quartiles of risk (low, low/medium, medium/high and high), with 52% of patients categorized as medium/high to high risk, which had corresponding 1-year mortality rates of 11% and 23%, respectively. Aneurysm diameter was below Society for Vascular Surgery recommended treatment thresholds (<5.0 cm in females, <5.5 cm in males) in 17% of patients (n = 679/3961), 41% of whom were categorized as medium/high or high risk. This subgroup had significantly increased in-hospital complication rates (18% vs 12%; P = .02) and 1-year mortality (13% vs 5%; P < .0001) compared with patients in the low- or low/medium-risk groups with guideline-compliant aneurysm diameters (≥5.0 cm in females, ≥5.5 cm in males).

CONCLUSIONS

This validated preoperative prediction model for 1-year mortality after cEVAR incorporates physiological, functional, and anatomical variables. This novel and simplified scoring system can effectively discriminate mortality risk and, when applied prospectively, may facilitate improved preoperative decision-making, complex aneurysm care delivery, and resource allocation.

Outcomes following carotid revascularization for stroke stratified by Modified Rankin Scale and time of intervention

OBJECTIVES

The relationship between baseline Modified Rankin Scale (mRS) in patients with prior stroke and optimal timing of carotid revascularization is unclear. Therefore, we evaluated the timing of transfemoral carotid artery stenting (tfCAS), transcarotid artery revascularization (TCAR), and carotid endarterectomy (CEA) after prior stroke, stratified by preoperative mRS.

METHODS

We identified patients with recent stroke who underwent tfCAS, TCAR, or CEA between 2012 and 2021. Patients were stratified by preoperative mRS (0-1, 2, 3-4, or 5) and days from symptom onset to intervention (time to intervention; ≤2 days, 3-14 days, 15-90 days, and 91-180 days). First, we performed univariate analyses comparing in-hospital outcomes between separate mRS or time-to-intervention cohorts for all carotid intervention methods. Afterward, multivariable logistic regression was used to adjust for demographics and comorbidities across groups, and outcomes between the various intervention methods were compared. Primary outcome was the in-hospital stroke/death rate.

RESULTS

We identified 4260 patients who underwent tfCAS, 3130 patients who underwent TCAR, and 20,012 patients who underwent CEA. Patients were most likely to have minimal disability (mRS, 0-1 [61%]) and least likely to have severe disability (mRS, 5 [1.5%]). Patients most often underwent revascularization in 3 to 14 days (45%). Across all intervention methods, increasing preoperative mRS was associated with higher procedural in-hospital stroke/death (all P < .03), whereas increasing time to intervention was associated with lower stroke/death rates (all P < .01). After adjustment for demographics and comorbidities, undergoing tfCAS was associated with higher stroke/death compared with undergoing CEA (adjusted odds ratio, 1.6; 95% confidence interval, 1.3-1.9; P < .01) or undergoing TCAR (adjusted odds ratio, 1.3; 95% confidence interval, 1.0-1.8; P = .03).

CONCLUSIONS

In patients with preoperative stroke, optimal timing for carotid revascularization varies with stroke severity. Increasing preoperative mRS was associated with higher procedural in-hospital stroke/death rates, whereas increasing time to-intervention was associated with lower stroke/death rates. Overall, patients undergoing CEA were associated with lower in-hospital stroke/deaths. To determine benefit for delayed intervention, these results should be weighed against the risk of recurrent stroke during the interval before intervention.

Outcomes of Aortobifemoral Bypass Based on Configuration of the Proximal Anastomosis

BACKGROUND

Aortobifemoral bypass (ABF) remains an important treatment modality in the revascularization of aortoiliac occlusive disease. Despite ABF being performed for decades, questions remain regarding the preferred technique for the proximal anastomosis, specifically whether an end-to-end (EE) or an end-to-side (ES) configuration is superior. The goal of this study was to compare the outcomes of ABF based on proximal configuration.

METHODS

We queried the Vascular Quality Initiative registry for ABF procedures performed between 2009 and 2020. Univariate and multivariate logistic regression analyses were used to compare perioperative and 1-year outcomes between EE and ES configurations.

RESULTS

Of the 6,782 patients (median [interquartile range] age, 60.0 [54-66 years]) who underwent ABF, 3,524 (52%) had an EE proximal anastomosis and 3,258 (48%) had an ES proximal anastomosis. Postoperatively, the ES cohort had a higher frequency of extubation in the operating room (80.3% vs. 77.4%; P < 0.01), lower change in renal function (8.8% vs. 11.5%; P < 0.01), and lower use of vasopressors (15.6% vs. 19.1%; P < 0.01), but higher rates of unanticipated return to the operating room (10.2% vs. 8.7%; P = 0.037) compared with the EE configuration. At 1-year follow-up, the ES cohort had a significantly lower primary graft patency rate (87.5% vs. 90.2%; P < 0.01) and higher rates of graft revision (4.8% vs. 3.1%; P < 0.01) and claudication symptoms (11.6% vs. 9.9%; P < 0.01). The ES configuration was significantly associated with a higher rate of 1-year major limb amputations in univariate (1.6% vs. 0.9%; P < 0.01) and multivariate (odds ratio, 1.95, confidence interval, 1.18-3.23, P=<0.01) analyses.

CONCLUSIONS

While the ES cohort seemed to have less physiologic insult immediately postoperatively, the EE configuration appeared to have improved 1-year outcomes. To our knowledge, this study is one of the largest population-based studies comparing the outcomes of the proximal anastomotic configurations. Longer-term follow-up is needed to determine which configuration is optimal.

In-hospital outcomes after carotid endarterectomy for stroke stratified by modified Rankin scale score and time of intervention

OBJECTIVE

Although the benefits of carotid endarterectomy (CEA) for treating symptomatic carotid stenosis are well known, the optimal timing of intervention after acute stroke and whether the optimal timing will vary with preoperative stroke severity has remained unclear. Therefore, we assessed the effect of stroke severity and timing of the intervention on the postoperative outcomes for patients who had undergone CEA for stroke.

METHODS

We identified all patients in the Vascular Quality Initiative who had undergone CEA from 2012 to 2020 for prior stroke. The patients were stratified using the preoperative modified Rankin scale score (mRS score, 0-5) and time to CEA after stroke onset (≤2 days, 3-14 days, 15-90 days, 91-180 days). After univariate comparisons, the patients were stratified into the following mRS cohorts for further analysis: 0 to 1, 2, 3 to 4, and 5. The primary outcome was in-hospital stroke/death.

RESULTS

We identified 15,601 patients, of whom 30% had had an mRS score of 0, 34% an mRS score of 1, 17% an mRS score of 2, 11% an mRS score of 3, 8% an mRS score of 4, and 1% an mRS score of 5. Overall, 9.3% of the patients had undergone CEA within ≤2 days, 46% within 3 to 14 days, 36% in 15 to 90 days, and 8.4% within 90 to 180 days. A decreasing mRS score and an increasing time to CEA were associated with lower rates of perioperative stroke/death (P_trend < .01). After risk adjustment, with CEA at 3 to 14 days as the comparator group, the mRS score 0 to 1 group had had a higher incidence of stroke/death after CEA within ≤2 days (3.6% vs 2.0%; odds ratio [OR], 1.8; 95% confidence interval [CI], 1.2-2.7). The mRS score 2 group had had a similar incidence of stroke/death after CEA within ≤2 days (4.4% vs 3.9%; OR, 1.2; 95% CI, 0.6-2.3) but a lower incidence after CEA at 15 to 90 days (2.1% vs 3.9%; OR 0.5; 95% CI, 0.3-0.96). The mRS score 3 to 4 group had had a higher incidence of stroke/death after CEA within ≤2 days (8.0% vs 3.8%; OR, 2.4; 95% CI, 1.5-3.9) but a similar incidence of stroke/death after CEA at 15 to 90 days (3.0% vs 3.8%; OR, 0.8; 95% CI, 0.5-1.3). For the mRS score 5 group, the stroke/death rates were ≥6.5% across all the time to CEA groups. However, the low sample size limited meaningful comparisons.

CONCLUSIONS

Patients with minimal disability after stroke (mRS score, 0-1) seemed to benefit from CEA within 3 to 14 days. However, those with severe disability (mRS score 5) have a very high risk from CEA at any time point given the poor outcomes. In contrast to the current guidelines, patients with mild disability (mRS score 2) could benefit from delaying CEA to 15 to 90 days, and those with moderate disability (mRS score 3-4) might benefit from CEA within 3 to 90 days given the acceptable in-hospital outcomes. These data should be considered within the context of the clinical situation in the weeks after index event to determine the net benefit of delayed CEA.

Outcomes after transcarotid artery revascularization stratified by preprocedural symptom status

OBJECTIVE

Previous studies on carotid endarterectomy and transfemoral carotid artery stenting demonstrated that perioperative outcomes differed according to preoperative neurologic injury severity, but this has not been assessed in transcarotid artery revascularization (TCAR). In this study, we examined contemporary perioperative outcomes in patients who underwent TCAR stratified by specific preprocedural symptom status.

METHODS

Patients who underwent TCAR between 2016 and 2021 in the Vascular Quality Initiative were included. We stratified patients into the following groups based on preprocedural symptoms: asymptomatic, recent (symptoms occurring <180 days before TCAR) ocular transient ischemic attack (TIA), recent hemispheric TIA, recent stroke, or formerly symptomatic (symptoms occurring >180 days before TCAR). First, we used trend tests to assess outcomes in asymptomatic patients versus those with an increasing severity of recent neurologic injury (recent ocular TIA vs recent hemispheric TIA vs recent stroke). Then, we compared outcomes between asymptomatic and formerly symptomatic patients. Our primary outcome was in-hospital stroke/death rates. Multivariable logistic regression was used to adjust for demographics and comorbidities across groups.

RESULTS

We identified 18,477 patients undergoing TCAR, of whom 62.0% were asymptomatic, 3.2% had a recent ocular TIA, 7.6a % had recent hemispheric TIA, 18.0% had a recent stroke, and 9.2% were formerly symptomatic. In patients with recent symptoms, we observed higher rates of stroke/death with increasing neurologic injury severity: asymptomatic 1.1% versus recent ocular TIA 0.8% versus recent hemispheric TIA 2.1% versus recent stroke 3.1% (Ptrend < .01). In formerly symptomatic patients, the rate of stroke/death was higher compared with asymptomatic patients, but this difference was not statistically significant (1.7% vs 1.1%; P = .06). After risk adjustment, compared with asymptomatic patients, there was a higher odds of stroke/death in patients with a recent stroke (odds ratio [OR], 2.8; 95% confidence interval [CI], 2.1-3.7; P < .01), a recent hemispheric TIA (OR, 2.0; 95% CI, 1.3-3.0; P < .01), and former symptoms (OR, 1.6; 95% CI, 1.1-2.5; P = .02), but there was no difference in stroke/death rates in patients with a recent ocular TIA (OR, 0.9; 95% CI, 0.4-2.2; P = .78).

CONCLUSIONS

After TCAR, compared with asymptomatic status, a recent stroke and a recent hemispheric TIA were associated with higher stroke/death rates, whereas a recent ocular TIA was associated with similar stroke/death rates. In addition, a formerly symptomatic status was associated with higher stroke/death rates compared with an asymptomatic status. Overall, our findings suggest that classifying patients undergoing TCAR as symptomatic versus asymptomatic may be an oversimplification and that patients' specific preoperative neurologic symptoms should instead be used in risk assessment and outcome reporting for TCAR.

One year clinical outcomes of Rutherford 6 chronic limb threatening ischemia patients undergoing lower limb endovascular revascularisation from Singapore

BACKGROUND

Percutaneous transluminal angioplasty (PTA) is widely used as a first-line revascularisation option in patients with chronic limb threatening ischemia (CLTI). This study aimed to evaluate the short-term endovascular revascularisation treatment outcomes of a cohort of Rutherford 6 (R6) CLTI patients, from a multi-ethnic Asian population in Singapore. Patients with R6 CLTI who underwent endovascular revascularisation from June 2019 to February 2020 at Singapore General Hospital, a tertiary vascular centre in Singapore, were included and followed up for one year. Primary outcome measures included number and type of reinterventions required, 3-, 6- and 12-month mortality, 6- and 12-month amputation free survival (AFS), wound healing success and changes in Rutherford staging after 3, 6 and 12 months.

RESULTS

Two hundred fifty-five procedures were performed on 86 patients, of whom 78 (90.7%) were diabetics, 54 (62.8%) had coronary artery disease (CAD) and 54 (62.8%) had chronic kidney disease (CKD). 42 patients (48.8%) required reintervention within 6 months. Multivariate analysis revealed that the presence of CAD was a significant independent predictor for reintervention. Mortality was 15.1%, 20.9% and 33.7% at 3, 6 and 12 months respectively. AFS was 64.0% and 49.4% at 6 and 12 months. Inability to ambulate, congestive heart failure (CHF), dysrhythmia and CKD were significant independent predictors of lower 12-month AFS.

CONCLUSIONS

PTA for R6 CLTI patients was associated with relatively high mortality and reintervention rates at one year. CAD was an independent predictor of reintervention. More research is required to help risk stratify which CLTI patients would benefit from an endovascular-first approach versus conservative treatment or an immediate major lower extremity amputation policy.

Outcomes of Axillofemoral Bypass for Intermittent Claudication

OBJECTIVE

While endovascular therapy is often first-line treatment for medically refractory intermittent claudication (IC) caused by aorto-femoral disease, suprainguinal bypass is commonly performed. Although this is often aorto-femoral bypass (AoFB), axillo-femoral bypass (AxFB) is still sometimes performed despite limited data evaluating its utility in the management of IC. Our goal was to assess the safety and durability of AxFB performed for IC.

METHODS

The Vascular Quality Initiative (2009-2019) was queried for suprainguinal bypass performed for IC. Univariable and multivariable analyses were used to compare perioperative and one-year outcomes between AxFB and a comparison cohort of AoFB.

RESULTS

We identified 3,261 suprainguinal bypasses performed for IC: 436 AxFB and 2,825 AoFB. Overall, mean age was 61.4 ± 9.1 years, 58.8% of patients were male sex, and 59.7% currently smoked. Patients undergoing AxFB, compared with AoFB, were more often older, male, never-smokers, and ambulated with assistance (all P<.001). They more often had hypertension, diabetes, coronary artery disease, congestive heart failure, chronic obstructive pulmonary disease, end-stage renal disease, previous outflow peripheral endovascular interventions, and previous inflow or outflow bypass. AxFB, compared with AoFB, were more often uni-femoral (all P<.05). Patients undergoing AxFB, compared with AoFB, had shorter postoperative length of stay (median 4 vs. 6 days) and fewer perioperative pulmonary (3% vs. 7.9%) and renal complications (5.5% vs. 9.9%), but more perioperative ipsilateral major amputations (.9% vs. 0.04%) (all P<.05). There were no significant differences in perioperative myocardial infarction (2.8% vs. 2.7%), stroke (.7% vs. 1.1%), and death (1.8% vs. 1.7%) rates, respectively. At one year, Kaplan-Meier analysis demonstrated that the AxFB, compared with AoFB cohort, exhibited higher rates of death (7.3% vs. 3.6%, P=.002); graft occlusion or death (14.3% vs. 7.2%, P=.001); ipsilateral major amputation or death (12.5% vs. 5.6%, P<.001); and reintervention, amputation, or death (19% vs. 8.6%, P<.001). On multivariable analysis, AxFB was independently associated with increased risk of one-year reintervention, amputation, or death (HR 1.6, 95% CI 1.03-2.4, P=.04).

CONCLUSIONS

This retrospective analysis suggests that long-term complications were more frequent in patients who underwent AxFB as compared to AoFB, although patients treated with AxFB were at higher risk with more comorbidities. Since AxFB is associated with significant perioperative morbidity, mortality, and long-term complications, serious consideration should be given prior to its use for IC.

The U.S. Preventive Services Task Force Abdominal Aortic Aneurysm Screening Guidelines Negligibly Impacted Repair Rates in Male Never-Smokers and Female Smokers

OBJECTIVE

In 2014, in addition to male smokers aged 65-75, the U.S. Preventive Services Task Force (USPSTF) recommended abdominal aortic aneurysm (AAA) screening for male never-smokers aged 65-75 with cardiovascular risk factors (Grade C). The USPSTF evolved from a negative to neutral position on screening for female smokers aged 65-75 (Grade I). We sought to determine whether 2014 guidelines resulted in more AAA repairs in these populations.

METHODS

We queried the Vascular Quality Initiative national database (2013-2018) for elective endovascular aortic repairs and open aortic repairs. We implemented difference-in-differences (DID) analysis, a causal inference technique that adjusts for secular time trends, to isolate changes in repair numbers due to the 2014 USPSTF guidelines. Our DID models compared changes in repair numbers in patient groups targeted by the USPSTF updates (intervention group) to those in unaffected, older patient groups (control), before and after 2014. The first model compared changes in repair numbers between male never-smokers aged 65-75 (intervention group) and 76-85 (control). The second model compared repair numbers between female smokers aged 65-75 (intervention group) and 76-85 (control).

RESULTS

There was no significant change in male never-smokers (n=1,295) aged 65-75 (42%) vs. 76-85 (58%) undergoing AAA repairs after guideline updates, averaged over 4.5 years (+2.4 percentage points; 95% Confidence Interval [CI] -.56-5.26). However, when their primary insurer was Medicare, male never-smokers aged 65-75 compared with 76-85 underwent significantly more repairs over 4.5 years (+3.69 percentage points; 95% CI.16-7.22; representing a 10.4% relative increase from baseline in the proportion of male never-smokers on Medicare undergoing AAA repair). Comparing female smokers (n=2,312) aged 65-75 (54%) vs. 76-85 (46%), there was no significant change in repairs over 4.5 years (-.66 percentage points; 95% CI -4.57-3.26).

CONCLUSIONS

The USPSTF 2014 AAA guidelines were associated with modestly increased repairs in male never-smokers aged 65-75 only on Medicare. There was no impact among female smokers. Higher-grade recommendations and improved guideline adherence may be requisites for change.

Outcomes after transfemoral carotid artery stenting stratified by preprocedural symptom status

OBJECTIVE

The available data on outcomes after transfemoral carotid artery stenting (TFCAS) originate from the early experience with TFCAS. Although most previous studies stratified outcomes according to a symptomatic or asymptomatic presentation, they often did not specify the degree of presenting neurologic injury. We previously reported that the outcomes after carotid endarterectomy differed according to neurologic injury severity, the contemporary perioperative outcomes of TFCAS stratified by the specific presenting symptom status are unknown.

METHODS

Patients with data in the Vascular Quality Initiative database who had undergone TFCAS from 2016 to 2020 were included. We stratified patients according to their preprocedural symptom status as asymptomatic, formerly symptomatic (last symptoms >180 days before the procedure), or recently symptomatic (symptoms <180 days before the procedure). The symptoms included stroke, hemispheric transient ischemic attack (TIA), and ocular TIA. We compared the occurrence of in-hospital stroke or death (stroke/death) among the asymptomatic, formerly symptomatic, and specific subtypes of recently symptomatic patients. Multivariable logistic regression models were constructed to adjust for the baseline differences among the groups.

RESULTS

Of the 9807 included patients, 2650 (27%) had had recent stroke, 842 (9%), recent hemispheric TIA, and 360 (4%), recent ocular TIA. In addition, 795 patients (8%) were formerly symptomatic and 5160 (53%) were asymptomatic. The patients with recent stroke had a perioperative stroke/death rate of 5.5%, higher than that of patients with recent hemispheric TIA (2.4%; P < .001) or recent ocular TIA (2.8%; P = .03) and asymptomatic patients (1.4%; P < .001). The stroke/death rate was greater for patients with recent ocular TIA than for asymptomatic patients (2.8% vs 1.4%; P = .04). Formerly symptomatic patients had higher stroke/death rates compared with asymptomatic patients (3.5% vs 1.4%; P < .001). On multivariable-adjusted analysis, recent stroke was associated with higher stroke/death compared with recent hemispheric TIA (odds ratio [OR], 2.6; 95% confidence interval [CI], 1.6-4.3; P < .001) and asymptomatic status (OR, 4.1; 95% CI, 3.0-5.6; P < .001) and demonstrated a trend toward higher stroke/death compared with recent ocular TIA (OR, 2.0; 95% CI, 1.0-3.9; P = .06). Furthermore, asymptomatic status was associated with lower stroke/death compared with formerly symptomatic status (OR, 0.4; 95% CI, 0.2-0.6; P < .001).

CONCLUSIONS

For patients undergoing TFCAS, recent stroke was associated with greater odds of in-hospital stroke/death after TFCAS compared with recent hemispheric TIA. Also, formerly symptomatic status was associated with greater odds of stroke/death compared with asymptomatic status. These findings support further symptom stratification by the degree of the presenting neurologic injury in the preoperative risk assessment.

Interplay of Diabetes Mellitus and End-Stage Renal Disease in Open Revascularization for Chronic Limb-Threatening Ischemia

BACKGROUND

Chronic limb-threatening ischemia (CLTI) in patients with end-stage renal disease (ESRD) confers a significant survival disadvantage and is associated with a high major amputation rate. Moreover, diabetes mellitus (DM) is an independent risk factor for developing CLTI. However, the interplay between end-stage renal disease (ESRD) and DM on outcomes after peripheral revascularization for CLTI is not well established. Our goal was to assess the effect of DM on outcomes after an infrainguinal bypass for CLTI in patients with ESRD.

METHODS

Using the Vascular Quality Initiative dataset from January 2003 to March 2020, records for all primary infrainguinal bypasses for CLTI in patients with ESRD were included for analysis. One-year and perioperative outcomes of all-cause mortality, reintervention, amputation-free survival (AFS), and major adverse limb event (MALE) were compared for patients with DM versus those without DM.

RESULTS

Of a total of 1,058 patients (66% male) with ESRD, 726 (69%) patients had DM, and 332 patients did not have DM. The DM group was younger (median age, 65 years vs. 68 years; P = 0.002), with higher proportions of obesity (body-mass index>30 kg/m2; 34% vs. 19%; P < 0.001) and current smokers (26% vs. 19%; P = 0.013). The DM group presented more frequently with tissue loss (76% vs. 66%; P < 0.001). A distal bypass anastomosis to tibial vessels was more frequently performed in the DM group compared to the non-DM group (57% vs. 45%; P < 0.001). DM was independently associated with higher perioperative MALE (OR 1.34; 95% CI, 1.06-1.68; P = 0.013), without increased risks of loss of primary patency and composite outcomes of amputation or death. On the mean follow-up of 11.4 ± 5.5 months, DM patients had a significantly higher rate of one-year MALEs (43% vs. 32%; P = 0.001). However, the one-year primary patency and AFS did not differ significantly. After adjusting for confounders, the risk-adjusted hazards for MALE (HR 1.34; 95% CI, 1.06-1.68; P = 0.013) were significantly increased in patients with DM. However, DM was not associated with increased risk of AFS (HR 1.16; 95% CI, 0.91-1.47; P = 0.238), or loss of primary patency (HR 1.04; 95% CI, 0.79-1.37; P = 0.767).

CONCLUSIONS

DM and ESRD each independently predict early and late major adverse limb events after an infrainguinal bypass in patients presenting with CLTI. However, in the presence of ESRD, DM may increase perioperative adverse events but does not influence primary patency and AFS at one year. The risk profile associated with ESRD appears to supersede that of DM, with no additive effect.

Association of state tobacco control policies with active smoking at the time of intervention for intermittent claudication

OBJECTIVE

Active smoking among patients undergoing interventions for intermittent claudication (IC) is associated with poor outcomes. Notwithstanding, current levels of active smoking in these patients are high. State-level tobacco control policies have been shown to reduce smoking in the general US population. We evaluated whether state cigarette taxes and 100% smoke-free workplace legislation are associated with active smoking among patients undergoing interventions for IC.

METHODS

We queried the Vascular Quality Initiative database for peripheral endovascular interventions, infrainguinal bypasses, and suprainguinal bypasses for IC. Active smoking at the time of intervention was defined as smoking within one month of intervention. We implemented difference-in-differences analysis to isolate changes in active smoking owing to cigarette taxes (adjusted for inflation) and implementation of smoke-free workplace legislation. The difference-in-differences models estimated the causal effects of tobacco policies by adjusting for concurrent temporal trends in active smoking unrelated to cigarette taxes or smoke-free workplace legislation. The models controlled for age, sex, race/ethnicity, insurance type, diabetes, chronic obstructive pulmonary disease, state, and year. We tested interactions of taxes with age and insurance.

RESULTS

Data were available for 59,847 patients undergoing interventions for IC in 25 states from 2011 to 2019. Across the study period, active smoking at the time of intervention decreased from 48% to 40%. Every $1.00 cigarette tax increase was associated with a 6-percentage point decrease in active smoking (95% confidence interval, -10 to -1 percentage points; P = .02), representing an 11% decrease relative to the baseline proportion of patients actively smoking. The effect of cigarettes taxes was greater in older patients and those on Medicare. Among patients aged 60 to 69 and 70 to 79 years, every $1.00 tax increase resulted in 14% and 21% reductions in active smoking relative to baseline subgroup prevalences of 53% and 29%, respectively (P < .05 for both); however, younger age groups were not affected by tax increases. Among insurance groups, only patients on Medicare exhibited a significant change in active smoking with every $1.00 tax increase (an 18% decrease relative to a 33% baseline prevalence; P = .01). The number of states implementing smoke-free workplace legislation increased from 9 to 14 by 2019; however, this policy was not significantly associated with active smoking prevalence. At follow-up (median, 12.9 months), $1.00 tax increases were still associated with decreased smoking prevalence (a 25% decrease relative to a 33% baseline prevalence; P < .001).

CONCLUSIONS

Cigarette tax increases seem to be an effective strategy to decrease active smoking among patients undergoing interventions for IC. Older patients and Medicare recipients are the most responsive to tax increases.

Registry Assessment of Peripheral Interventional Devices objective performance goals for superficial femoral and popliteal artery peripheral vascular interventions

BACKGROUND

The Superficial Femoral Artery-Popliteal EvidencE Development Study Group developed contemporary objective performance goals (OPGs) for peripheral vascular interventions (PVI) for superficial femoral artery (SFA)-popliteal artery disease using the Registry Assessment of Peripheral Interventional Devices.

METHODS

The Society for Vascular Surgery Vascular Quality Initiative PVI registry from January 2010 to October 2016 was used to develop OPGs based on SFA-popliteal procedures (n = 21,377) for intermittent claudication and critical limb ischemia (CLI). OPGs included 1-year rates for target lesion revascularization (TLR), major amputation, and 1 and 4-year survival rates. OPGs were calculated for the SFA and popliteal arteries and stratified by four treatments: angioplasty alone (percutaneous transluminal angioplasty [PTA]), self-expanding stenting, atherectomy, and any treatment type. Outcomes were illustrated by unadjusted Kaplan-Meier analyses.

RESULTS

Cohorts included PTA (n = 7505), stenting (n = 9217), atherectomy (n = 2510) and any treatment (n = 21,377). The mean age was 69 years, 58% were male, 79% were White, and 52% had CLI. The freedom from TLR OPGs at 1 year in the SFA were 80.3% (PTA), 83.2% (stenting), 83.9% (atherectomy), and 81.9% (any treatments). The freedom from TLR OPGs at 1 year in the popliteal were 81.3% (PTA), 81.3% (stenting), 80.2% (atherectomy), and 81.1% (any treatments). The freedom from major amputation OPGs at 1 year after SFA PVI were 93.4% (PTA), 95.7% (stenting), 95.1% (atherectomy), and 94.8% (any treatments). The freedom from major amputation OPG at 1 year after popliteal PVI were 90.5% (PTA), 93.7% (stenting), 91.8% (atherectomy), and 91.8%, (any treatments). The 4-year survival OPGs after SFA PVI were 76% (PTA), 80% (stenting), 82% (atherectomy), and 79% (any treatments), and for the popliteal artery were 72% (PTA), 77% (stenting), 82% (atherectomy), and 75% (any treatment). On a multivariable analysis, which included patient-level, leg-level, and lesion-level covariates, CLI was the single independent factor associated with increased TLR, amputation, and mortality.

CONCLUSIONS

The Superficial Femoral Artery-Popliteal EvidencE Development OPGs define a new, contemporary benchmark for SFA-popliteal interventions using a large subset of real-world evidence to inform more efficient peripheral device clinical trial designs to support regulatory and clinical decision-making. It is appropriate to discuss proposals intended for regulatory approval with the US Food and Drug Administration to refine the OPG to match the specific trial population. The OPGs may be updated using coordinated registry networks to assess long-term real-world device performance.

Contemporary outcomes of endovascular abdominal aortic aneurysm repair in patients deemed unfit for open surgical repair

OBJECTIVE

Endovascular abdominal aortic aneurysm repair (EVAR) has been preferred to open surgical repair (OSR) for the treatment of abdominal aortic aneurysms (AAAs) in high-risk patients. We compared the perioperative and long-term outcomes of EVAR for patients designated as unfit for OSR using a large national dataset.

METHODS

The Vascular Quality Initiative database was queried for patients who had undergone elective EVAR for AAAs >5 cm from 2013 to 2019. The patients were stratified into two cohorts according to their suitability for OSR (fit vs unfit). The primary outcomes included perioperative (in-hospital) major adverse events, perioperative mortality, and mortality at 1 and 5 years. Patient demographics and postoperative outcomes were analyzed to identify the predictors of perioperative and long-term mortality.

RESULTS

Of 16,183 EVARs, 1782 patients had been deemed unfit for OSR. The unfit cohort was more likely to be older and female, with a greater proportion of hypertension, coronary artery disease, congestive heart failure, chronic obstructive pulmonary disease, and larger aneurysm diameters. Postoperatively, the unfit cohort was more likely to have experienced cardiopulmonary complications (6.5% vs 3%; P < .001), with greater perioperative mortality (1.7% vs 0.6%; P < .001) and 1- and 5-year mortality (13% and 29% for the unfit vs 5% and 14% for the fit cohorts, respectively; P < .001). A subgroup analysis of the unfit cohort revealed that those deemed unfit because of a hostile abdomen had significantly lower 1- and 5-year mortality (6% and 20%, respectively) compared with those considered unfit because of cardiopulmonary compromise and frailty (14% and 30%, respectively; P = .451). Reintervention-free survival at 1 and 5 years was significantly greater in the fit cohort (93% and 82%, respectively) compared with that for the unfit cohort (85% and 68%, respectively; P < .001). The designation as unfit for OSR was an independent predictor of both perioperative (odds ratio, 1.59; 95% confidence interval [CI], 1.03-2.46; P = .038) and long-term mortality (hazard ratio [HR], 1.92; 95% CI, 1.69-2.17; P < .001). Advanced age (odds ratio, 2.91; 95% CI, 1.28-6.66; P = .011) was the strongest determinant of perioperative mortality, and end-stage renal disease (HR, 2.51; 95% CI, 1.78-3.55; P < .001) was the strongest predictor of long-term mortality. Statin use (HR, 0.77; 95% CI, 0.69-0.87; P < .001) and angiotensin-converting enzyme inhibitor use (HR, 0.83; 95% CI, 0.75-0.93; P < .001) were protective of long-term mortality.

CONCLUSIONS

Despite low perioperative mortality, the long-term mortality of those designated by operating surgeons as unfit for OSR was rather high for patients undergoing elective EVAR, likely owing to the competing risk of death from medical frailty. An unfit designation because of a hostile abdomen did not confer any additional risks after EVAR. Judicious estimation of the patient's life expectancy is essential when considering the treatment options for this subset of patients deemed unfit for OSR.

Investigating uncommon vascular diseases using the Vascular Low Frequency Disease Consortium

BACKGROUND

Standardized databases such as the Vascular Quality Initiative and National Surgical Quality Improvement Project assess the quality of care related to common vascular surgery procedures, but are not designed for uncommon vascular diseases. We describe a method of assessing uncommon vascular diseases using a multi-institutional collaboration, the Vascular Low Frequency Disease Consortium (VLFDC).

METHODS

Uncommon vascular diseases are identified through a systematic literature review. A disease-specific database is developed and tested at a single institution, then refined and circulated to participating VLFDC investigators. Detailed inclusion and exclusion criteria and data point definitions are provided, allowing for standardized data collection across institutions. Each participating institution identifies all patients over a specific time period and enters the data into a VLFDC-provided database. The data are then de-identified and transmitted to our centralized data center for analysis.

RESULTS

Since 2003, the VLFDC has conducted and published nine studies and enrolled 4532 patients, involving 232 institutions and 271 investigators. The studies include renal artery aneurysms, isolated femoral artery aneurysms, spontaneous mesenteric dissection, adventitial cystic disease, carotid body tumors, and vascular Ehlers-Danlos syndrome. Each published study reported on a minimum of 10 times the number of patients collected in previously published studies over the same time period, allowing stronger conclusions to be drawn from the larger sample size. Each study both confirmed previous management principles, which were based on small single-institution experiences, and challenged conventional management paradigms.

CONCLUSIONS

When only small clinical series exist to provide guidance in managing uncommon vascular diseases, and/or where conflicting recommendations are made on the treatment of uncommon vascular diseases, a multi-institutional consortium can provide high-volume standardized data that either confirm or changes prior management principles.

Tibial bypass in patients with intermittent claudication is associated with poor outcomes

OBJECTIVE

Given that intermittent claudication (IC) rarely progresses to chronic limb-threatening ischemia and limb loss, safety and durability of elective interventions for IC are essential. Whether patients with IC benefit from tibial intervention is controversial, and data supporting its utility are limited. Despite endovascular therapy expansion, surgical bypass is still commonly performed. We sought to assess outcomes of bypass to tibial arteries for IC.

METHODS

The Vascular Quality Initiative (2003-2018) was queried for infrainguinal bypasses performed for IC. Perioperative and 1-year outcomes were compared between bypasses constructed to tibial and popliteal arteries.

RESULTS

Of 5347 infrainguinal bypasses, 1173 (22%) and 4184 (78%) were tibial and popliteal bypasses, respectively. Overall, mean age was 65 ± 10 years, and patients were often men (72%) and current smokers (42%). Tibial bypasses commonly targeted posterior tibial (40%), tibioperoneal trunk (23%), and anterior tibial (19%) arteries. Great saphenous vein was more often used for tibial bypass than for popliteal bypass (78% vs 54%; P < .001). Patients undergoing tibial compared with popliteal bypass more often had impaired ambulation and prior ipsilateral bypasses and were less often taking antiplatelets and statins (all P < .05). In the perioperative period, tibial bypass patients had longer postoperative length of stay (4.5 ± 3.5 vs 3.5 ± 2.8 days), more pulmonary complications (1.3% vs 0.6%), and higher return to the operating room (7% vs 4%; all P < .05). Perioperative myocardial infarction (1.2% vs 0.8%; P = .19), stroke (0.4% vs 0.4%; P = .91), and mortality (0.3 vs 0.3%; P = .86) rates were similar between the cohorts. At 1 year, tibial compared with popliteal bypasses exhibited lower freedom from occlusion/death (81% vs 89%; P < .001), ipsilateral major amputation/death (90% vs 94%; P < .001), and reintervention/amputation/death (73% vs 80%; P < .001), but patient survival was similar (96% vs 97%; P = .07). On multivariable analysis, tibial compared with popliteal bypass was independently associated with increased occlusion/death (hazard ratio [HR], 1.65; 95% confidence interval [CI], 1.28-2.11; P < .001), major ipsilateral amputation/death (HR, 1.6; 95% CI, 1.12-2.19; P = .003), and ipsilateral reintervention/amputation/death (HR, 1.51; 95% CI, 1.28-1.79; P < .001), with similar patient survival.

CONCLUSIONS

In patients with IC, tibial bypass was associated with poor outcomes, including major amputation. Surgeons should exhaust nonoperative therapies and present realistic outcome expectations to their patients before offering such intervention.

Extended screening guidelines for the diagnosis of abdominal aortic aneurysm

BACKGROUND

The U.S. Preventive Services Task Force (USPSTF) guidelines are the most widely used criteria for screening for abdominal aortic aneurysms (AAA). However, when the USPSTF criteria are applied retrospectively to a group of patients who have undergone treatment for AAA, there are many patients who satisfy none of the AAA screening criteria. The more sensitive Society for Vascular Surgery (SVS) guidelines have expanded the criteria for screening for AAA with the hope of capturing a greater fraction of those individuals who can undergo treatment for their AAA before presenting with AAA rupture. We sought to identify the number of patients who would have been identified as having criteria for screening for AAA by both the USPSTF and SVS criteria, in a cohort of patients who have undergone treatment for AAA.

METHODS

We assessed demographic, comorbidity, and perioperative complication data for all patients undergoing endovascular and open AAA repair in the Vascular Quality Initiative. Patients meeting each of the screening criteria were identified. Clinical factors and demographic variables were collected.

RESULTS

We identified 55,197 patients undergoing AAA repair in the Vascular Quality Initiative, including 44,602 patients who underwent endovascular aneurysm repair (EVAR) and 10,595 patients undergoing open repair. Of these, the USPTF guidelines would have identified fewer than one-third of patients (32% EVAR and 33% open repair). Applying the SVS guidelines increased the number meeting criteria for screening by 6% and 12% for the EVAR and open repair cohorts, respectively. Finally, adoption of the expanded SVS guidelines (including the "weak recommendations") would have identified an additional 34% of EVAR patients and 21% of open AAA repair patients. Use of the expanded criteria would have resulted in 27% of patients undergoing EVAR and 33% of patients undergoing open AAA repair who would not have met any screening criteria. In EVAR patients not meeting the criteria, 52% were younger than 65 years had a history of heavy smoking. Of all those who did not meet screening criteria, ruptured AAA was twice as prevalent as those who met screening criteria (8.5% vs 4.4%; P ≤ .0001).

CONCLUSIONS

Expanding established USPSTF screening guidelines to include the expanded SVS criteria may potentially double the number of patients identified with AAA. Smokers under the age of 65, and elderly patients 70 and older with no smoking history, represent two groups with AAA and potentially twice the risk of presenting with rupture.

Shunt intention during carotid endarterectomy in the early symptomatic period and perioperative stroke risk

OBJECTIVE

Whether recent stroke mandates planned shunting during carotid endarterectomy (CEA) is controversial. Our goal was to determine associations of various shunting practices with postoperative outcomes of CEAs performed after acute stroke.

METHODS

The Vascular Quality Initiative database (2010-2018) was queried for CEAs performed within 14 days of an ipsilateral stroke. Surgeons who prospectively planned to shunt either shunted routinely per their usual practice or shunted selectively for preoperative indications. Surgeons who prospectively planned not to shunt either shunted selectively for intraoperative indications or did not shunt. Univariable and multivariable analyses compared shunting approaches.

RESULTS

There were 5683 CEAs performed after acute ipsilateral stroke. Surgeons planned to shunt in 56.1% of cases. Patients whose surgeons planned to shunt vs planned not to shunt were more likely to have severe contralateral stenosis (8.8% vs 6.9%; P = .008), to receive general anesthesia (97.5% vs 89.1%; P < .001), and to undergo conventional CEA (94% vs 81.8%; P < .001). Unadjusted outcomes were similar between the cohorts for operative duration (124.3 ± 48.1 minutes vs 123.6 ± 47 minutes; P = .572) and 30-day stroke (3.4% vs 3%; P = .457), myocardial infarction (1.1% vs 0.8%; P = .16), and mortality (1.6% vs 1.3%; P = .28). On multivariable analysis, planning to shunt vs planning not to shunt was associated with similar risk of 30-day stroke (odds ratio [OR], 1.17; 95% confidence interval [CI], 0.82-1.67; P = .402). On subgroup analysis, in 38.4% patients, no shunt was placed, whereas the remainder received routine shunts (44.4%), preoperatively indicated shunts (11.6%), and intraoperatively indicated shunts (5.5%). Compared with no shunting, shunting by surgeons who routinely shunt was associated with a similar stroke risk (OR, 1.39; 95% CI, 0.91-2.13; P = .129), but shunting by surgeons who selectively shunt on the basis of preoperative indications (OR, 2.11; 95% CI, 1.22-3.63; P = .007) or intraoperative indications (OR, 3.34; 95% CI, 1.86-6.01; P < .001) was associated with increased stroke risk. Prior coronary revascularization independently predicted increased intraoperatively indicated shunting (OR, 1.37; 95% CI, 1.05-1.8; P = .022).

CONCLUSIONS

In CEAs performed after acute ipsilateral stroke, there is no difference in postoperative stroke risk when surgeons prospectively plan to shunt or not to shunt. Shunting is often not necessary; however, when shunting is performed, routine shunters achieve better outcomes.

Axillary-bifemoral and axillary-unifemoral artery grafts have similar perioperative outcomes and patency

OBJECTIVE

It has been suggested that more bypass outflow targets for bypass grafts improve patency and outcomes. Our objective was to examine this in a multicenter contemporary series of axillary to femoral artery grafts.

METHODS

The Vascular Quality Initiative database was queried for all axillary-unifemoral (AxUF) and axillary-bifemoral (AxBF) bypass grafts performed between 2010 and 2017 for claudication, rest pain, and tissue loss. Patients with acute limb ischemia were excluded. Patients' demographics and comorbidities as well as operative details and outcomes were recorded. Univariable, multivariable, and Kaplan-Meier analyses were used to assess long-term outcomes.

RESULTS

There were 412 (32.9%) AxUF grafts and 839 (67.1%) AxBF grafts identified. Overall, the mean age of the patients was 68.3 years, 51.1% were male, and 84.7% were white. Compared with AxBF grafts, AxUF grafts were more often performed for urgent cases; in patients who were younger, male, nonambulatory, and diabetic; and in those with preoperative anticoagulation, critical limb ischemia, prior bypass, aneurysm repair, peripheral vascular intervention, and major amputation (P < .05 for all). There were no significant differences between AxUF and AxBF grafts in perioperative wound complications (4.2% vs 2.9%; P = .23), cardiac complications (7.3% vs 10.4%; P = .08), pulmonary complications (4.1% vs 6%, P = .18), early stenosis/occlusion (0.2% vs 0.8%; P = .22), perioperative mortality (2.9% vs 3.2%; P = .77), and length of stay (6.4 ± 5.6 days vs 6.7 ± 8 days; P = .29). The mean estimated blood loss (268.1 mL vs 348.6 mL; P < .001) and mean operative time (201 minutes vs 224.1 minutes; P < .001) were significantly lower for AxUF grafts. Kaplan-Meier analysis showed that AxUF and AxBF grafts had similar freedom from graft occlusion (62.6% vs 71.8%; P = .074), major adverse limb event-free survival (57.1% vs 66.6%; P = .052), and survival (86% vs 86%; P = .897) at 1 year. Major amputation-free survival was lower for AxUF grafts (63.7% vs 73%; P = .028). Multivariable analysis also showed that the type of graft configuration did not independently predict occlusion/death (hazard ratio [HR], 1.06; 95% confidence interval [CI], 0.77-1.46; P = .72), amputation/death (HR, 1.12; 95% CI, 0.83-1.51; P = .45), major adverse limb event/death (HR, 0.97; 95% CI, 0.73-1.3; P = .85), or mortality (HR, 0.91; 95% CI, 0.65-1.26; P = .55). Three-year survival after placement of AxUF and AxBF grafts was similar (75.1% vs 78.2%; P = .414).

CONCLUSIONS

AxUF and AxBF grafts have similar perioperative and 1-year outcomes. Graft patency was not significantly different between an AxBF graft and an AxUF graft at 1 year. Overall, patients treated with these reconstructions have many comorbidities and low long-term survival.

Risk assessment of significant upper extremity arteriovenous graft infection in the Vascular Quality Initiative

OBJECTIVE

Infectious complications of arteriovenous grafts (AVGs) are a major source of morbidity. Our aim was to characterize contemporary risk factors for upper extremity AVG infection.

METHODS

The Vascular Quality Initiative (2011-2018) was queried for all patients undergoing upper extremity AVG creation. AVG infection was classified as an infection treated with antibiotics, incision and drainage, or graft removal. Multivariable analyses were used to evaluate risk factors for short- and long-term AVG infection.

RESULTS

Of 1758 upper extremity AVGs, 49 (2.8%) developed significant infection within 3 months, resulting in incision and drainage in 24% and graft removal in 76% of cases. None were managed with antibiotics alone in the study sample. Patients with significant AVG infection were more likely to be white, to be insured, to have a history of coronary artery bypass graft and intravenous (IV) drug use, to be undergoing a concomitant vascular procedure, and to be discharged on an anticoagulant. In multivariable analysis, significant AVG infection within 3 months was associated with IV drug use history (odds ratio [OR], 5; 95% confidence interval [CI], 1.75-14.3; P = .003), discharge to a health care facility (OR, 2.66; 95% CI, 1.07-6.63; P = .035), discharge on an anticoagulant (OR, 2.31; 95% CI, 1.13-4.72; P = .021), white race (OR, 2.3; 95% CI, 1.21-4.34; P = .011), and female sex (OR, 2.02; 95% CI, 1.06-3.85; P = .033). Kaplan-Meier analysis showed that freedom from graft site infection at 1 year was 96.4%. Longer term graft infection at 1 year was independently associated with IV drug use history (hazard ratio [HR], 1.98; 95% CI, 1.06-3.68; P = .032), initial discharge to a health care facility (HR, 1.88; 95% CI, 1.19-2.97; P = .007), and white race (HR, 1.64; 95% CI, 1.23-2.19; P = .001).

CONCLUSIONS

Although significant AVG infection was uncommon in the Vascular Quality Initiative, the majority were treated with graft removal. In select high-risk patients, extra care should be taken and alternative forms of arteriovenous access may be considered.

Variation in Hospital Door-to-Intervention Time for Ruptured AAAs and Its Association with Outcomes

BACKGROUND

A ruptured abdominal aortic aneurysm (rAAA) is a life-threatening condition that carries a high mortality rate. Recent guidelines have recommended a goal "door-to-intervention" time of ≤90 minutes despite a paucity of evidence to support this goal. The aim of this study was to analyze recent trends in door-to-intervention time for rAAAs and determine the effect of the 90-minute door-to-intervention benchmark on postoperative complications.

METHODS

A retrospective analysis of all patients who underwent open aortic repair (OAR) or endovascular aneurysm repair (EVAR) of a rAAA in the Vascular Quality Initiative database (2003-2018) was performed. Variation in door-to-intervention time was analyzed at the patient and hospital level. Patients were dichotomized into ≤90 or >90 minute door-to-intervention time cohorts. Hierarchical modeling controlling for the hospital random effect and multivariate logistic models was used to analyze the association on 30-day mortality and major in-hospital complications.

RESULTS

A total of 3,630 operative cases for rAAA were identified (1696 OAR and 1934 EVAR). For the OAR cohort, 1035 patients (61%) had a door-to-intervention time of ≤90 minutes. However, at the hospital level, a minority of hospitals (49%) reliably achieved the OAR goal door-to-intervention time. For OARs, there was no difference in 30-day risk-adjusted major complications or mortality between the ≤90- and > 90-minute cohorts. For EVAR, 1014 patients (53.8%) had a door-to-intervention time of ≤90 minutes and a minority of hospitals (40%) upheld the recommended ≤90 minute door-to-intervention threshold. In the EVAR group, patients with a ≤90 minute door-to-intervention time had higher rates of postoperative myocardial infarction (12.0% vs. 8.5%; P < 0.05) but no difference in 30-day risk-adjusted mortality.

CONCLUSIONS

A low percentage of rAAAs are being treated within the recommended door-to-intervention time. Despite this deficiency, the ≤90-minute benchmark has minimal impact on postoperative morbidity and mortality. Based on these findings, alternative quality metrics should be identified to improve the clinical care of patients with rAAA.

Larger Sheath Size for Infrainguinal Endovascular Intervention Is Associated With Minor but Not Major Morbidity or Mortality

BACKGROUND

Infrainguinal peripheral vascular interventions (PVIs) can be performed with a variety of sheath sizes. Our aim was to investigate the effect of sheath size on postprocedural complications after infrainguinal PVIs.

METHODS

The Vascular Quality Initiative (2010-2017) was queried for patients undergoing infrainguinal PVIs via retrograde common femoral artery access. Univariable and multivariable methods were performed to compare the effects of sheath size on access site complications, length of stay (LOS), and 30-day mortality.

RESULTS

Of the 36,901 infrainguinal PVI procedures in the data set, the mean age was 69 years, and 59.1% of patients were male. Indications for intervention were claudication (41.6%), rest pain (13.2%), and tissue loss (45.2%). The femoropopliteal and tibial arteries were treated in 84.7% and 35.4% of cases, respectively. Interventions included stenting (39.2%) and atherectomy (21.3%). Sheath sizes of 7F, 6F, 5F, and 4F were used in 5225 (14.1%), 24,541 (66.5%), 6221 (16.9%), and 914 (2.5%) cases, respectively. Differences among sheath sizes were observed based on the ambulatory status; presence of diabetes, end-stage renal disease, previously stented ipsilateral extremities, anemia, preprocedural anticoagulation; and procedural details including indications, location of intervention, and intervention type (P < 0.001 for all). On univariable analysis, sheath size (7F vs 6F vs 5F vs 4F) was associated with differences in access site hematoma (3.5% vs 2.7% vs 2.5% vs 1.2%, P < 0.001), postprocedural LOS > 1 day (18.1% vs 25.3% vs 31.1% vs 27.9%, P < 0.001), and 30-day mortality (0.9% vs 1.4% vs 1.5% vs 1.5%, P = 0.007). There was no difference in hematoma requiring intervention or access site stenosis/occlusion based on sheath size. Multivariable analysis revealed that a larger sheath size was independently associated with access site hematoma (7F: odds ratio [OR] = 4.24, 95% confidence interval [CI] = 2.28-7.89, P < 0.001; 6F: OR = 3.11, 95% CI = 1.69-5.7, P < 0.001; 5F: OR = 2.72, 95% CI = 1.46-5.05, P = 0.002) and postprocedural LOS > 1 day (7F: OR = 1.69, 95% CI = 1.39-2.05, P < 0.001; 6F: OR = 1.5, 95% CI = 1.26-1.78, P < 0.001; 5F: OR = 1.51, 95% CI = 1.26-1.8, P < 0.001). Access site hematoma requiring intervention and 30-day mortality were not independently associated with sheath size.

CONCLUSIONS

In infrainguinal PVIs, larger sheaths increased the risk of minor access site hematomas, but not major morbidity or mortality. Larger sheaths were associated with longer postprocedural LOS, possibly because of conservative management of hematomas.

Validation of a preoperative prediction model for mortality within 1 year after endovascular aortic aneurysm repair of intact aneurysms

OBJECTIVE

Most would agree that at least 1-year survival is necessary after intact abdominal aortic aneurysm (AAA) repair to appropriately justify the cost and risk of the procedure. No validated clinical decision instruments exist to predict survival after endovascular aneurysm repair (EVAR) beyond the perioperative period. The purpose of this analysis was to create a preoperative prediction model for 1-year mortality after EVAR for intact AAA in the Society for Vascular Surgery Vascular Quality Initiative.

METHODS

All intact EVARs in the Society for Vascular Surgery Vascular Quality Initiative from 2011 to 2015 were randomly divided into training (n = 17,836) and validation (n = 2500) data sets, and 31 preoperative candidate predictors were identified. A logistic regression model for 1-year mortality was created, and bootstrapped stepwise variable elimination was used to reduce this model to a best subset of predictors. Penalized maximum likelihood estimation was used to correct for potential overfitting. The final model was internally validated by bootstrapping the area under the curve (AUC) and the calibration slope and intercept, and its performance when applied to the training and validation data sets was compared.

RESULTS

After elective and nonelective (symptomatic, intact) EVAR, 1-year mortality was 5.5% (n = 900/16,411) and 11.4% (n = 162/1425), respectively. The mean probability of 1-year mortality was 6.0% (n = 1062) in the training set and 5.7% (n = 143) in the validation cohort (P = .12). Significant preoperative predictors of 1-year mortality included chronic obstructive pulmonary disease, age, preoperative renal insufficiency (creatinine concentration ≥1.8 mg/dL or on hemodialysis), ejection fraction <50%, transfer status, body mass index <24 kg/m², preoperative beta-blocker exposure, larger AAA diameter, and lower admission hemoglobin level. Preoperative statin use was found to be protective. The bias-corrected AUC was 0.759 (Hosmer-Lemeshow goodness-of-fit P value of 0.36; calibration intercept, -0.003; slope, 0.999). When applied to the validation data set, the model had AUC of 0.724 (95% confidence interval, 0.676-0.768; calibration intercept, 0.0009; slope, 0.970), which was in excellent agreement with the original data set bias-corrected AUC. Notably, ∼27.5% (n = 4902) had four or more risk factors with a predicted 1-year post-EVAR mortality risk of 10% to 22% despite that 33.2% of these patients had AAA diameters below recommended treatment guideline minimum thresholds.

CONCLUSIONS

This validated preoperative prediction model for 1-year mortality identifies patients less likely to benefit from EVAR. Appropriateness of intact AAA EVAR care delivery can be improved by use of this clinical decision aid to determine which high-risk patients have lower probability of mortality within the first postoperative year relative to their predicted annualized rupture risk.

Assessment of failure to rescue after abdominal aortic aneurysm repair using the National Surgical Quality Improvement Program procedure-targeted data set

OBJECTIVE

Open aortic repair (OAR) is associated with higher risk of mortality compared with endovascular aneurysm repair (EVAR). The aim of this study was to compare failure to rescue (FTR) after major predischarge complications in patients undergoing OAR and EVAR.

METHODS

Patients who underwent OAR or EVAR in the American College of Surgeons National Surgical Quality Improvement Program between 2011 and 2015 were selected. Patients with ruptured aneurysm and those with type IV thoracoabdominal aneurysms were excluded. The primary outcome was FTR, defined as 30-day mortality in patients who developed at least one complication during their hospital stay. Univariable and multivariable statistics were used.

RESULTS

A total of 9097 patients underwent abdominal aortic aneurysm repair. Of those, 3291 (36.2%) had at least one major predischarge complication, 82.5% after OAR (95% confidence interval [CI], 80.9%-84.1%) vs 21.3% after EVAR (95% CI, 20.4%-22.3%; P < .001). Increased FTR was seen after aneurysm rupture, cardiac arrest, septic shock, and acute kidney injury. On multivariable analysis, FTR was not significantly different between OAR and EVAR (adjusted odds ratio, 0.87; 95% CI, 0.61-1.24; P = .44). Propensity score matching and coarsened exact matching showed similar results.

CONCLUSIONS

Although EVAR has fewer complications and lower in-hospital mortality than OAR, FTR after major predischarge complications does not depend on the type of surgical approach. When an in-hospital major complication occurs after EVAR, surgeons should be alert that FTR risk resulting in mortality is similar to that of OAR. Therefore, there is no safety net with EVAR.

Underutilization of antiplatelet and statin therapy after postoperative myocardial infarction following vascular surgery

OBJECTIVE

The objective of this study was to investigate adherence to practice guidelines for antiplatelet and statin use after postoperative myocardial infarction (POMI) and its effect on late mortality following vascular surgery in a multicenter registry.

METHODS

Antiplatelet and statin use was examined in 1749 vascular surgery procedures with POMI within the Vascular Quality Initiative (VQI) from 2005 to 2015. Our primary aim was to assess cardiac medication (CM) use at discharge, defined as (1) single antiplatelet therapy (SAPT; aspirin or P2Y₁₂ inhibitor) or dual antiplatelet therapy (DAPT; aspirin and P2Y₁₂ inhibitor) and (2) statin therapy. Long-term mortality in patients with POMI was analyzed on the basis of discharge CM. A proportional hazards model was developed to control for factors associated with mortality. Regional differences in CM use at discharge after POMI were compared.

RESULTS

Overall discharge CM use after POMI included aspirin (81%), P2Y₁₂ inhibitor (38%), statin therapy (76%), and combined antiplatelet and statin (74%). At discharge, 26% of patients were not receiving combined antiplatelet and statin therapy. SAPT (50%) was more common than DAPT (35%; P < .001). Patients with POMI undergoing carotid endarterectomy were more likely to be discharged on CM (80%) compared with patients undergoing infrainguinal bypass (78%), suprainguinal bypass (72%), endovascular aneurysm repair (71%), and open abdominal aortic aneurysm repair (59%; P < .001). Patients receiving SAPT or DAPT plus statin therapy had improved survival (79%) compared with those receiving noncombination or no therapy (69%) with mean follow-up of 5.5 years and 4.9 years, respectively (log-rank, P = .001). After adjustment for covariates including preoperative medications, treatment with SAPT or DAPT plus statin at discharge was associated with lower late mortality compared with noncombination or no therapy (hazard ratio, 0.72; 95% confidence interval, 0.56-0.93; P = .01). Regional variation in CM at discharge following POMI was also observed with a range of 33% to 100% (P = .05).

CONCLUSIONS

Within the VQI, regional and procedure-specific variation exists in CM regimen after POMI following vascular surgery. Absence of combined antiplatelet and statin therapy at discharge after POMI was associated with higher late mortality and represents an area for quality improvement in the care of these patients.

Open and endovascular aneurysm repair in the Society for Vascular Surgery Vascular Quality Initiative

The Society for Vascular Surgery Vascular Quality Initiative is a patient safety organization and a collection of procedure-based registries that can be utilized for quality improvement initiatives and clinical outcomes research. The Vascular Quality Initiative consists of voluntary participation by centers to collect data prospectively on all consecutive cases within specific registries which physicians and centers elect to participate. The data capture extends from preoperative demographics and risk factors (including indications for operation), through the perioperative period, to outcomes data at up to 1-year of follow-up. Additionally, longer-term follow-up can be achieved by matching with Medicare claims data, providing long-term longitudinal follow-up for a majority of patients within the Vascular Quality Initiative registries. We present the unique characteristics of the Vascular Quality Initiative registries and highlight important insights gained specific to open and endovascular abdominal aortic aneurysm repair.

Perioperative clopidogrel is associated with increased bleeding and blood transfusion at the time of lower extremity bypass

OBJECTIVE

Controversy persists surrounding the perceived bleeding risk associated with perioperative clopidogrel use in patients undergoing lower extremity bypass (LEB). The purpose of this study was to examine the LEB bleeding risk and clinical sequelae associated with clopidogrel.

METHODS

All LEBs in the Vascular Quality Initiative (VQI) from 2008 to 2014 were studied. The exposure was perioperative clopidogrel. Primary outcomes were blood transfusion, estimated blood loss ≥500 mL, and reoperation for bleeding. Secondary outcomes included mean operative time, major cardiac events, respiratory complications, infectious complications, and in-hospital mortality. Univariate and multivariable analyses were used to analyze patients on the basis of clopidogrel use and its association with outcomes. Nonparametric test for trend and Mantel-Haenszel methods were used to analyze association of clopidogrel use with blood transfusion and secondary outcomes.

RESULTS

Among the LEB cohort (N = 9179), 28% (n = 2544) were taking clopidogrel and 72% (n = 6635) were not. Patients taking clopidogrel were more likely to have coronary disease, prior coronary intervention, abnormal findings on stress test, and aspirin use (P < .001 for all). Patients taking clopidogrel were more likely to receive blood transfusion (38% vs 24%; P < .001) and to have estimated blood loss ≥500 mL (21% vs 12%; P < .001). Reoperation for bleeding rates were similar (0.9% vs 1.1%; P = .9). Clopidogrel use was also associated with increased mean operative times (244 minutes vs 232 minutes; P < .001) as well as with cardiac complications (8.8% vs 6.5%; P = .001), respiratory complications (2.5% vs 1.6%; P = .007), and in-hospital mortality (1.3% vs 0.8%; P = .03). Multivariable analysis demonstrated that clopidogrel was associated with increased risk of 1- or 2-unit blood transfusion (odds ratio [OR], 1.8; 95% confidence interval [CI], 1.5-2.1; P < .001) and >2-unit blood transfusion (OR, 2.0; 95% CI, 1.7-2.5; P < .001). Major cardiac events (OR, 1.2; 95% CI, 1.0-1.5; P = .05) and respiratory complications (OR, 1.4; 95% CI, 1.0-2.0; P = .03) were also independently associated with clopidogrel use. Weighted Mantel-Haenszel ORs controlling for blood transfusion amount revealed no remaining effect of clopidogrel on major cardiac events (OR, 1.1; P = .4) or respiratory complications (OR, 1.0; P = .8).

CONCLUSIONS

Perioperative clopidogrel use in LEB surgery is associated with increased blood loss and blood transfusion. Associated clinical sequelae include increased cardiac and pulmonary complications. Accordingly, surgeons should consider discontinuation of perioperative clopidogrel when it is clinically appropriate unless it is strongly indicated at the time of LEB.

Quality and Safety in Health Care, Part XXI: PSOs and the Vascular Quality Initiative

Congress provided for the formation of patient safety organizations (PSOs) so that physicians and other providers would come forward to improve the safety and quality of health care. Important legal safeguards for the providers and patients were put in place for PSOs. The Society for Vascular Surgery (SVS) PSO operates the Vascular Quality Initiative. The latter gathers information from certain commonly done vascular procedures. First, information is collected so a risk adjustment determination of each individual patient can be done. Then the details of every procedure are recorded for later analysis of the processes of the patient's care. In addition, outcome analysis from all procedures is carried out. This registry is an important source of data for research improving health care safety and quality.

Regional Variation in Postoperative Myocardial Infarction in Patients Undergoing Vascular Surgery in the United States

BACKGROUND

The aim of this study is to assess for regional variation in the incidence of postoperative myocardial infarction (POMI) following nonemergent vascular surgery across the United States to identify potential areas for quality improvement initiatives.

METHODS

We evaluated POMI rates across 17 regional Vascular Quality Initiative (VQI) groups that comprised 243 centers with 1,343 surgeons who performed 75,057 vascular operations from 2010 to 2014. Four procedures were included in the analysis: carotid endarterectomy (CEA, n = 39,118), endovascular abdominal aortic aneurysm (AAA) repair (EVAR, n = 15,106), infrainguinal bypass (INFRA, n = 17,176), and open infrarenal AAA repair (OAAA, n = 3,657). POMI was categorized by the method of diagnosis as troponin-only or clinical/ECG and rates were investigated in regions with ≥100 consecutive cases. Regions with significantly different POMI rates were defined as those >1.5 interquartile lengths beyond the 75th percentile of the distribution. Risk-adjusted rates of POMI were assessed using the VQI Cardiac Risk Index all-procedures prediction model to compare the observed versus expected rates for each region.

RESULTS

Overall rates of POMI varied by procedure type: CEA 0.8%, EVAR 1.1%, INFRA 2.7%, and OAAA 4.2% (P < 0.001). Significant variation in POMI rates was observed between regions, resulting in differing ranges of POMI rates for each procedure: CEA 0.5-2.0% (P = 0.001), EVAR 0.3-3.1% (P < 0.001), INFRA 1.1-4.8% (P < 0.001), and OAAA 2.2-10.0% (P < 0.001). A single region in 3 of the 4 procedure-specific datasets was identified as a statistical outlier with a significantly higher POMI rate after CEA, EVAR, and OAAA; this region was identical for the EVAR and OAAA datasets but was a different region for the CEA dataset. No significant variation in POMI was noted between regions after INFRA. Procedure-specific clinical POMI rates (mean; range) were significantly different between regions for EVAR (0.4%; 0-1.1%, P = 0.01) and INFRA (1.4%; 0.5-2.9%, P = 0.01), but not for CEA (0.4%; 0-0.8%, P = 0.53) or OAAA (1.6%; 0-3.8%, P = 0.23). Procedure-specific troponin-only POMI rates (mean; range) were significantly different between regions for all procedures: CEA (0.4%; 0.1-1.2%, P < 0.001), EVAR (0.7%; 0-2.1%, P < 0.001), INFRA (1.3%; 0.4-2.5%, P = 0.001), and OAAA (2.5%; 0-8.5%, P < 0.001). After risk adjustment, regional variation was again noted with 3 regions having higher and 4 regions having lower than expected rates of POMI.

CONCLUSIONS

Significant variation in POMI rates following major vascular surgery exists across VQI regions even after risk adjustment. These findings may present an opportunity for focused regional quality improvement efforts.

Regional variation in patient selection and treatment for lower extremity vascular disease in the Vascular Quality Initiative

OBJECTIVE

Prior studies on the cause and effect of surgical variation have been limited by utilization of administrative data. The Vascular Quality Initiative (VQI), a robust national clinical registry, provides anatomic and perioperative details allowing a more robust analysis of variation in surgical practice.

METHODS

The VQI was used to identify all patients undergoing infrainguinal open bypass or endovascular intervention from 2009 to 2014. Asymptomatic patients were excluded. The 16 regional groups of the VQI were used to compare variation in patient selection, operative indication, technical approach, and process measures. χ² analysis was used to assess for differences across regions where appropriate.

RESULTS

A total of 52,373 interventions were included (31%). Of the 16,145 bypasses, 5% were performed for asymptomatic disease, 26% for claudication, 56% for chronic limb-threatening ischemia (CLI) (61% of these for tissue loss), and 13% for acute limb-threatening ischemia. Of the 35,338 endovascular procedures, 4% were for asymptomatic disease, 40% for claudication, 46% for CLI (73% tissue loss), and 12% for acute limb-threatening ischemia. Potentially unwarranted variation included proportion of prosthetic conduit for infrapopliteal bypass in claudication (13%-41%, median, 29%; P < .001), isolated tibial endovascular intervention for claudication (0.0%-5.0%, median, 3.0%; P < .001), discharge on antiplatelet and statin (bypass: 62%-84%; P < .001; endovascular: 63%-89%; P < .001), and ultrasound guidance for percutaneous access (claudication: range, 7%-60%; P < .001; CLI: 5%-65%; P < .001). Notable areas needing further research with significant variation include proportion of CLI vs claudication treated by bypass (38%-71%; P < .001) and endovascular intervention (28%-63%; P < .001), and use of closure devices in percutaneous access (claudication; 26%-76%; P < .001; CLI: 30%-78%; P < .001).

CONCLUSIONS

Significant variation exists both in areas where evidence exists for best practice and, therefore, potentially unwarranted variation, and in areas of clinical ambiguity. Quality improvement efforts should be focused on reducing unwarranted variation. Further research should be directed at identifying best practice where no established guidelines and high variation exists.

Patient selection and perioperative outcomes are similar between targeted and nontargeted hospitals (in the National Surgical Quality Improvement Program) for abdominal aortic aneurysm repair

OBJECTIVE

The targeted vascular module in the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) consists of self-selected hospitals that choose to collect extra clinical details for better risk adjustment and improved procedure-specific outcomes. The purpose of this study was to compare patient selection and outcomes between targeted and nontargeted hospitals in the NSQIP regarding the operative management of abdominal aortic aneurysm (AAA).

METHODS

We identified all patients who underwent endovascular aneurysm repair (EVAR) or open AAA repair from 2011 to 2013 and compared cases by whether the operation took place in a targeted or nontargeted hospital. EVAR and open repair as well as intact and ruptured aneurysms were evaluated separately. Only variables contained in both modules were used to evaluate rupture status and operation type. All thoracoabdominal aneurysms were excluded. Univariate analysis was performed for intact and ruptured EVAR and open repair grouped by complexity, defined as visceral involvement in open repair and a compilation of concomitant procedures for EVAR. Multivariable models were developed to identify effect of hospital type on mortality.

RESULTS

There were 17,651 AAA repairs identified. After exclusion of aneurysms involving the thoracic aorta (n = 352), there were 1600 open AAA repairs at targeted hospitals (21% ruptured) and 2725 at nontargeted hospitals (19% ruptured) and 4986 EVARs performed at targeted hospitals (6.7% ruptured) and 7988 at nontargeted hospitals (5.2% ruptured). There was no significant difference in 30-day mortality rates between targeted and nontargeted hospitals for intact aneurysms (EVAR noncomplex, 1.8% vs 1.4% [P = .07]; open repair noncomplex, 4.2% vs 4.5% [P = .7]; EVAR complex, 5.0% vs 3.2% [P = .3]; open repair complex, 8.0% vs 6.0% [P = .2]). For ruptured aneurysms, again there was no difference in mortality between the targeted and nontargeted hospitals (EVAR noncomplex, 23% vs 25% [P = .4]; open repair noncomplex, 38% vs 34% [P = .2]; EVAR complex, 29% vs 33% [P = 1.0]; open repair complex, 27% vs 41% [P = .09]). Multivariable analysis further demonstrated that having an operation at a targeted vs nontargeted hospital had no impact on mortality for both intact and ruptured aneurysms (odds ratio, 1.1 [0.9-1.4] and 1.0 [0.8-1.3], respectively).

CONCLUSIONS

This analysis highlights the similarities between targeted and nontargeted hospitals within the NSQIP for AAA operative management and suggests that data from the targeted NSQIP, in terms of AAA management, are generalizable to all NSQIP hospitals.

Indication for Lower Extremity Revascularization and Hospital Profiling of Readmissions

BACKGROUND

Surgical readmissions are common, costly, and the focus of national quality improvement efforts. Given the relatively high readmission rates among vascular patients, pay-for-performance initiatives such as Medicare's Hospital Readmissions Reduction Program (HRRP) have targeted vascular surgery for increased scrutiny in the near future. Yet, the extent to which institutional case mix influences hospital profiling remains unexplored. We sought to evaluate whether higher readmission rates in vascular surgery are a reflection of worse performance or of treating sicker patients.

METHODS

This retrospective observational cohort study of the national Medicare population includes 479,047 beneficiaries undergoing lower extremity revascularization (LER) in 1,701 hospitals from 2005 to 2009. We employed hierarchical logistic regression to mimic Center for Medicare and Medicaid Services methodology accounting for age, gender, preexisting comorbidities, and differences in hospital operative volume. We estimated 30-day risk-standardized readmission rates (RSRR) for each hospital when including (1) all LER patients; (2) claudicants; or (3) high-risk patients (rest pain, ulceration, or tissue loss). We stratified hospitals into quintiles based on overall RSRR for all LERs and examined differences in RSRR for claudicants and high-risk patients between and within quintiles. Next, we evaluated differences in case mix (the proportion of claudicants and high-risk patients treated) across quintiles. Finally, we simulated differences in the receipt of penalties before and after adjusting for hospital case mix.

RESULTS

Readmission rates varied widely by indication: 7.3% (claudicants) vs. 19.5% (high risk). Even after adjusting for patient demographics, length of stay, and discharge destination, high-risk patients were significantly more likely to be readmitted (odds ratio 1.76, 95% confidence interval 1.71-1.81). The Best hospitals (top quintile) under the HRRP treated a much lower proportion of high-risk patients compared with the Worst hospitals (bottom quintile) (20% vs. 56%, P < 0.001). In the absence of case-mix adjustment, we observed a stepwise increase in the proportion of hospitals penalized as the proportion of high-risk patients treated increased (35-60%, P < 0.001). However, after case-mix adjustment, there were no differences between quintiles in the proportion of hospitalized penalized (50-46%, P = 0.30).

CONCLUSION

Our findings suggest that the differences in readmission rates following LER are largely driven by hospital case mix rather than true differences in quality.

Outcomes after endovascular aneurysm repair conversion and primary aortic repair for urgent and emergency indications in the Society for Vascular Surgery Vascular Quality Initiative

OBJECTIVE

Open conversion after endovascular aortic aneurysm repair (EVAR-c) is performed nonelectively in up to 60% of cases. EVAR-c has been reported to have significantly greater risk of postoperative morbidity and mortality than primary aortic repair, but few data exist on outcomes for symptomatic or ruptured presentations. This study determined outcomes and identified predictors of postoperative major adverse cardiac events (MACEs) and mortality for patients undergoing nonelective EVAR-c compared with nonelective primary aortic repair (PAR) in the Vascular Quality Initiative (VQI).

METHODS

All VQI patients undergoing urgent/emergency EVAR-c or urgent/emergency PAR from 2002 to 2014 were reviewed. Urgent presentation was defined by repair ≤24 hours of a nonelective admission, and emergency operations had clinical or radiographic evidence, or both, of rupture. End points included in-hospital MACE (myocardial infarction, dysrhythmia, congestive heart failure) and 30-day mortality. Possible covariates identified on univariate analysis (P < .2) were entered into a multivariable model, and stepwise elimination identified the best subset of predictors. Generalized estimating equations logistic regression analysis was used to determine the relative effect of EVAR-c compared with PAR on outcomes.

RESULTS

During the study interval, we identified 277 EVAR-c, and 118 (43%) underwent urgent/emergency repair. nonelective PAR was performed in 1388 of 6152 total (23%). EVAR-c patients were older (75 ± 9 vs 71 ± 10 years; P < .0001), more likely to be male (84% vs 74%; P = .02), and had a higher prevalence of hypertension (88% vs 79%; P = .02) and coronary artery disease (38% vs 27%; P = .01). No differences in MACE (EVAR-c, 31% [n = 34] vs PAR, 30% [n = 398]) or any major postoperative complication (EVAR-c, 57% [n = 63] vs PAR, 55% [n = 740]; P = .8) were found; however, 30-day mortality was significantly greater in EVAR-c (37% [n = 41]) than in (PAR, 24% [n = 291]; P = .003), with an odds ratio (OR) of 2.2 (95% confidence interval [CI], 1.04-4.77; P = .04) for EVAR-c. Predictors of any MACE included age (OR, × 1.03 for each additional year; 95% CI, 1.01-1.03; P = .0002), male gender (OR, 1.3; 95% CI, 1.03-1.67; P = .03), body mass index ≤20 kg/m² (OR, 1.8; 95% CI, 1.13-2.87; P = .01), chronic obstructive pulmonary disease (OR, 1.2; 95% CI, 0.86-1.80; P = .25), congestive heart failure (OR, 1.5; 95% CI, 0.98-2.34; P = .06), preoperative chronic β-blocker use (OR, 1.3; 95% CI, 0.97-1.63; P = .09), and emergency presentation (OR, 2.3; 95% CI, 1.8-3.01; area under the curve, 0.70; P < .0001). Significant predictors for 30-day mortality were age (OR × 1.07 for each additional year; 95% CI, 1.05-1.09; P < .0001), female gender (OR, 1.6; 95% CI, 1.01-2.46; P = .04), preoperative creatinine >1.8 mg/dL (OR, 1.6; 95% CI, 1.04-2.35; P = .03), an emergency presentation (OR, 4.8; 95% CI, 2.93-7.93; P < .0001), and renal/visceral ischemia (OR, × 1.1 for each unit increase log (time-minutes); 95% CI, 1.02-1.22; area under the curve, 0.84; P = .01).

CONCLUSIONS

Nonelective EVAR-c patients are older and have higher prevalence of cardiovascular risk factors than PAR patients. Similar rates of postoperative complications occur; however, urgent/emergency EVAR-c has a significantly higher risk of 30-day mortality than nonelective PAR. Several variables are identified that predict outcomes after these repairs and may help risk stratify patients to further inform clinical decision making when patients present nonelectively with EVAR failure.

Defining risk and identifying predictors of mortality for open conversion after endovascular aortic aneurysm repair

OBJECTIVE

Risk of open conversion after endovascular aortic aneurysm repair (EVAR-c) is poorly defined. The purpose of this analysis was to determine outcomes of elective EVAR-c compared with elective primary open abdominal aortic aneurysm repair (PAR) in the Vascular Quality Initiative.

METHODS

Vascular Quality Initiative patients who underwent elective EVAR-c and PAR (2002-2014) were reviewed. Candidate predictors of major adverse cardiac event (MACE) and/or 30-day mortality were entered into a multivariable model, and stepwise elimination was used to reduce the number of covariates to a best subset of predictors. To estimate the additive risk of EVAR-c for MACE or 30-day mortality over PAR, this variable was added along with the best subset of predictors into generalized estimating equations logistic regression models.

RESULTS

We identified 159 EVAR-c and 3741 PAR patients. EVAR-c patients were older (73.5 ± 8.1 vs 69.5 ± 8.4 years; P < .0001), more likely to have diabetes (21% vs 15%; P = .03), and history of lower extremity bypass (9% vs 4%; P = .0006). EVAR-c was associated with a higher incidence of retroperitoneal aortic exposure (41%; n = 64 vs PAR, 26%, n = 976; P < .0001), use of a bifurcated graft (65%; n = 101 vs PAR, 52%; n = 1923; P = .001), greater blood loss (median [interquartile range], 2000 mL [1010-3500] vs PAR, 1200 mL [750-2000]; P < .0001) and longer procedure times (EVAR-c, 275 ± 122 minutes vs PAR, 232 ± 9 minutes; P < .0001). However, PAR more frequently was completed with a suprarenal and/or mesenteric cross-clamp (74%, n = 2749 vs EVAR-c, 53%, n = 83; P < .0001) and had a higher incidence of concomitant procedures (26%; n = 972 vs EVAR-c, 18%; n = 28; P = .03). Nonadjusted 30-day mortality was greater after EVAR-c: EVAR-c, 8% (n = 10) vs PAR, 3% (n = 105); P = .009. There was no difference in complication rates: EVAR-c, 33% (n = 52) vs PAR, 28% (n = 1056); P =.3. Preoperative 30-day mortality predictors included age (odds ratio [OR], 1.06/y, 95% confidence interval [CI], 1.04-1.1; P < .0001), chronic obstructive pulmonary disease (OR, 2.4; 95% CI, 1.6-3.5; P < .0001), history of leg bypass (OR, 2.3, 1.2-4.4;P =.01), suprarenal cross-clamp (OR 2.2, 1.2-4.1;P =.01), prior carotid revascularization (OR 2.2; 95% CI, 1.3-3.8; P = .0004), congestive heart failure (OR, 1.8; 95% CI, 0.9-3.5; P = .08), and female sex (OR, 1.6; 95% CI, 1.1-2.3; P = .02; area under the curve, 0.75). When controlling for covariates, EVAR-c was not significantly associated with MACE (OR, 1.2; 95% CI, 0.7-2.0; P = .4) or 30-day mortality (OR, 2.0; 0.9-4.2; P = .08).

CONCLUSIONS

EVAR-c patients are typically older, have more comorbidities, and experience greater blood loss and longer procedure times compared with PAR patients. However, postoperative morbidity and mortality are primarily driven by patient covariates and intraoperative factors, rather than the need for endograft explantation. Several preoperative variables were identified as predictors of 30-day mortality after elective EVAR-c and should be considered during the decision-making process for remedial treatment of failed endovascular PAR.

Preoperative β-blockers do not improve cardiac outcomes after major elective vascular surgery and may be harmful

OBJECTIVE

Routine initiation β-blocker medications before vascular surgery is controversial due to conflicting data. The purpose of this analysis was to determine whether prophylactic use of β-blockers before major elective vascular surgery decreased postoperative cardiac events or mortality.

METHODS

The Society for Vascular Surgery Vascular Quality Initiative (SVS-VQI) data set was used to perform a retrospective cohort analysis of infrainguinal lower extremity bypass (LEB), aortofemoral bypass (AFB), and open abdominal aortic aneurysm (AAA) repair patients. Chronic (>30 days preoperatively) β-blocker patients were excluded, and comparisons were made between preoperative (0-30 day) and no β-blocker groups. Patients were risk stratified using a novel prediction tool derived specifically from the SVS-VQI data set. Propensity-matched pairs and interprocedural specific risk stratification comparisons were performed. End points included in-hospital major adverse cardiac events (MACEs), including myocardial infarction (MI; defined as new ST or T wave electrocardiographic changes, troponin elevation, or documentation by echocardiogram or other imaging modality), dysrhythmia, and congestive heart failure, and 30-day mortality.

RESULTS

The study analyzed 13,291 patients (LEB, 68% [n = 9047]; AFB, 11% [n = 1474]; and open AAA, 21% [n = 2770]); of these, 67.7% (n = 8999) were receiving β-blockers at time of their index procedure. Specifically, 13.2% (n = 1753) were identified to have been started on a preoperative β-blocker, 54.5% (n = 7426) were on chronic β-blockers, and 32.3% (n = 4286) were on no preoperative β-blockers. Among the three procedures, patients had significant demographic and comorbidity differences and thus were not combined. A 1:1 propensity-matched pairs analysis (1459 pairs) revealed higher rates of postoperative MI with preoperative β-blockers (preoperative β-blocker relative risk, 1.65; 95% confidence interval, 1.02-2.68; P = .05 vs no β-blocker), with no difference in dysrhythmia, congestive heart failure, or 30-day mortality. When stratified into low-risk, medium-risk, and high-risk groups within each procedure, all groups of preoperative β-blocker patients had no difference or higher rates of MACEs and 30-day mortality, with the exception of high-risk open AAA patients, who had a lower rate of MI (odds ratio, 0.35; 95% confidence interval, 011-0.87; P = .04).

CONCLUSIONS

Exclusive of high-risk open AAA patients, preoperative β-blockers did not decrease rates of MACEs or mortality after LEB, AFB, or open AAA. Importantly, exposure to prophylactic preoperative β-blockers increased the rates of some adverse events in several subgroups. Given these data, the SVS-VQI cannot support routine initiation of preoperative β-blockers before major elective vascular surgery in most patients.

Heart rate variables in the Vascular Quality Initiative are not reliable predictors of adverse cardiac outcomes or mortality after major elective vascular surgery

OBJECTIVE

Heart rate (HR) parameters are known indicators of cardiovascular complications after cardiac surgery, but there is little evidence of their role in predicting outcome after major vascular surgery. The purpose of this study was to determine whether arrival HR (AHR) and highest intraoperative HR are associated with mortality or major adverse cardiac events (MACEs) after elective vascular surgery in the Vascular Quality Initiative (VQI).

METHODS

Patients undergoing elective lower extremity bypass (LEB), aortofemoral bypass (AFB), and open abdominal aortic aneurysm (AAA) repair in the VQI were analyzed. MACE was defined as any postoperative myocardial infarction, dysrhythmia, or congestive heart failure. Controlled HR was defined as AHR <75 beats/min on operating room arrival. Delta HR (DHR) was defined as highest intraoperative HR - AHR. Procedure-specific MACE models were derived for risk stratification, and generalized estimating equations were used to account for clustering of center effects. HR, beta-blocker exposure, cardiac risk, and their interactions were explored to determine association with MACE or 30-day mortality. A Bonferroni correction with P < .004 was used to declare significance.

RESULTS

There were 13,291 patients reviewed (LEB, n = 8155 [62%]; AFB, n = 2629 [18%]; open AAA, n = 2629 [20%]). Rates of any preoperative beta-blocker exposure were as follows: LEB, 66.5% (n = 5412); AFB, 57% (n = 1342); and open AAA, 74.2% (n = 1949). AHR and DHR outcome association was variable across patients and procedures. AHR <75 beats/min was associated with increased postoperative myocardial infarction risk for LEB patients across all risk strata (odds ratio [OR], 1.4; 95% confidence interval [CI], 1.03-1.9; P = .03), whereas AHR <75 beats/min was associated with decreased dysrhythmia risk (OR, 0.42; 95% CI, 0.28-0.63; P = .0001) and 30-day death (OR, 0.50; 95% CI, 0.33-0.77; P = .001) in patients at moderate and high cardiac risk. These HR associations disappeared in controlling for beta-blocker status. For AFB and open AAA repair patients, there was no significant association between AHR and MACE or 30-day mortality, irrespective or cardiac risk or beta-blocker status. DHR and extremes of highest intraoperative HR (>90 or 100 beats/min) were analyzed among all three operations, and no consistent associations with MACE or 30-day mortality were detected.

CONCLUSIONS

The VQI AHR and highest intraoperative HR variables are highly confounded by patient presentation, operative variables, and beta-blocker therapy. The discordance between cardiac risk and HR as well as the lack of consistent correlation to outcome makes them unreliable predictors. The VQI has elected to discontinue collecting AHR and highest intraoperative HR data, given insufficient evidence to suggest their importance as an outcome measure.

Clinical registries and quality measurement in surgery: a systematic review

BACKGROUND

Surgical clinical registries provide clinical information with the intent of measuring and improving quality. This study aimed to describe how surgical clinical registries have been used to measure surgical quality, the reported findings, and the limitations of registry measurements.

METHODS

Medline, CINAHL, and Cochrane were queried for English articles with the terms: "registry AND surgery AND quality." Eligibility criteria were studies explicitly assessing quality measurement with registries as the primary data source. Studies were abstracted to identify registries, define registry structure, uses for quality measurement, and limitations of the measurements used.

RESULTS

A total of 111 studies of 18 registries were identified for data abstraction. Two registries were financed privately, and 5 registries were financed by a governmental organization. Across registries, the most common uses of process measures were for monitoring providers and as platforms for quality improvement initiatives. The most common uses of outcome measures were to improve quality modeling and to identify preoperative risk factors for poor outcomes. Eight studies noted improvements in risk-adjusted mortality with registry participation; one found no change. A major limitation is bias from context and means of data collection threatening internal validity of registry quality measurement. Conversely, the other major limitation is the cost of participation, which threatens the external validity of registry quality measurement.

CONCLUSION

Clinical registries have advanced surgical quality definition, measurement, and modeling as well as having served as platforms for local initiatives for quality improvement. The implication of this finding is that subsidizing registry participation may improve data validity as well as engage providers in quality improvement.