Lower extremity angioplasty for claudication: A population-level analysis of 30-day outcomes

Quality of Surgical Care Within the Criminal Justice Health Care System

Importance

Individuals who are incarcerated represent a vulnerable group due to concerns about their ability to provide voluntary and informed consent, and there are considerable legal protections regarding their participation in medical research. Little is known about the quality of surgical care received by this population.

Objective

To evaluate perioperative surgical care provided to patients who are incarcerated within the Texas Department of Criminal Justice (TDCJ) and compare their outcomes with that of the general nonincarcerated population.

Design, Setting, and Participants

This cohort study analyzed data from patients who were incarcerated within the TDCJ and underwent general or vascular surgery at the University of Texas Medical Branch (UTMB) from 2012 to 2021. Case-specific outcomes for a subset of these patients and for patients in the general academic medical center population were obtained from the American College of Surgeons National Quality Improvement Program (ACS-NSQIP) and compared. Additional quality metrics (mortality index, length of stay index, and excess hospital days) from the Vizient Clinical Data Base were analyzed for patients in the incarcerated and nonincarcerated groups who underwent surgery at UTMB in 2020 and 2021 to provide additional recent data. Patient-specific demographics, including age, sex, and comorbidities were not available for analysis within this data set.

Main Outcome and Measures

Perioperative outcomes (30-day morbidity, mortality, and readmission rates) were compared between the incarcerated and nonincarcerated groups using the Fisher exact test.

Results

The sample included data from 6675 patients who were incarcerated and underwent general or vascular surgery at UTMB from 2012 to 2021. The ACS-NSQIP included data (2012-2021) for 2304 patients who were incarcerated and 602 patients who were not and showed that outcomes were comparable between the TDCJ population and that of the general population treated at the academic medical center with regard to 30-day readmission (6.60% vs 5.65%) and mortality (0.91% vs 1.16%). However, 30-day morbidity was significantly higher in the TDCJ population (8.25% vs 5.48%, P = .01). The 2020 and 2021 data from the Vizient Clinical Data Base included 629 patients who were incarcerated and 2614 who were not and showed that the incarcerated and nonincarcerated populations did not differ with regard to 30-day readmission (12.52% vs 11.30%) or morbidity (1.91% vs 2.60%). Although the unadjusted mortality rate was significantly lower in the TDCJ population (1.27% vs 2.68%, P = .04), mortality indexes, which account for case mix index, were similar between the 2 populations (1.17 vs 1.12).

Conclusions and Relevance

Findings of this cohort study suggest that patients who are incarcerated have equivalent rates of mortality and readmission compared with a general academic medical center population. Future studies that focus on elucidating the potential factors associated with perioperative morbidity and exploring long-term surgical outcomes in the incarcerated population are warranted.

Socioeconomic status is not associated with unfavorable outcomes in patients with acute limb ischemia

OBJECTIVE

Whether socioeconomic status (SES) is associated with health outcomes in patients with acute limb ischemia (ALI) is largely unknown. We aimed to determine whether SES is associated with worse presentations and outcomes for patients with ALI.

METHODS

We performed a retrospective medical record review of patients who presented with ALI between April 2016 and October 2020 at a single tertiary care center. SES was quantified using individual variables (median household income, level of education, and employment) and a composite endpoint, the neighborhood deprivation index (NDI). The NDI is a standardized and reproducible index that uses census tract data (higher number indicates lower SES status). The NDI summarizes 8 domains of socioeconomic deprivation. ALI severity was categorized using the Rutherford classification. The association between SES and the severity of ALI at presentation and between SES and other health outcomes were analyzed using bivariate analysis of variance, independent t test, and multivariate logistic regression.

RESULTS

During the study period, 278 patients were treated for ALI, of whom 211 had complete SES data available. The mean age was 64 years, 55% were men, and 57% were White. The Rutherford classification of disease severity was grade 1, 2a, 2b, and 3 for 6%, 54%, 32%, and 8% of patients, respectively. Patients with a low SES status per the NDI were more likely to have a history of peripheral arterial disease and chronic kidney disease at presentation. The ALI etiology (thrombotic vs embolic) was not associated with SES. No significant differences were seen between SES and the severity of ALI at presentation (p = 0.96) or the treatment modality (p = 0.80). No associations between SES and 30-day or 1-year mortality were observed (mean NDI, 0.15 vs 0.26, p = 0.58, and 0.20 vs 0.26, p = 0.71, respectively) or between SES and 30-day or 1-year limb loss (mean NDI, 0.06 vs 0.30, p = 0.18, and 0.1 vs 0.32, p = 0.17, respectively). Lower SES (higher NDI) was associated with increased 30-day readmission (mean NDI, 0.49 vs 0.15, p = 0.021). However, this association was not significant on multivariate analysis (odds ratio 1.4, 95% CI 0.9-2.1, p = 0.06).

CONCLUSIONS

SES was not associated with the severity of ALI at patient presentation. Although SES was associated with the presence of peripheral arterial disease and chronic kidney disease at presentation, SES was not a predictor of short-term or 1-year limb loss and mortality. Overall, ALI presentation and treatment outcomes were independent of SES.

Reinterventions in Patients with Claudication and Chronic Limb Threatening Ischemia

BACKGROUND

Patients with peripheral artery disease (PAD) present with claudication or chronic limb threatening ischemia (CLTI). CLTI patients have a more advanced stage of atherosclerosis and increased comorbidities compared to claudicants, and are at an elevated risk of major amputation and mortality after lower extremity revascularization (LER). However, the frequency of reinterventions for claudication and CLTI have not been compared. Our hypothesis is that patients with CLTI undergo more frequent reinterventions to prevent major amputation.

METHODS

A single-center retrospective chart review of consecutive patients undergoing lower extremity revascularization (LER) for PAD in 2013-2015 was performed. Patients were stratified based on indication for revascularization into claudication or CLTI. Patient characteristics, outcomes, and reinterventions were compared between the 2 groups.

RESULTS

There were 826 patients undergoing LER and 44% (N = 361) had CLTI. Patients treated for CLTI were more likely to be smokers (P < 0.001), to have diabetes (P< 0.001), chronic renal insufficiency (P< 0.001), end stage renal disease (P< 0.001), and cardiac disease (P< 0.001). CLTI patients were less likely to be on optimal medical management as reflected by decreased rate of aspirin (P< 0.001), ADP receptor/P2Y12 inhibitors (P< 0.001), and statins (P< 0.001) compared to patients with claudication. Patients with CLTI had significantly higher major amputation (3.7% vs. 0.2%, P< 0.001) and mortality (1.4% vs. 0.2%, P = 0.092) at 30 days. At long-term follow up, patients with CLTI had higher rates of major amputation (15.5% vs. 1.3%, P < 0.001) and mortality (37.1% vs. 18.1%, P < 0.001) compared to patients with claudication. There was a significant difference in mean follow-up time between the 2 cohorts (claudication: 3.7 ± 1.5 years versus CLTI: 2.6 ± 1.8 years, P < 0.001). There was no significant difference in the ipsilateral reintervention rate between the 2 groups (claudication: 39.6% vs. CLTI: 42.7%, P = 0.37) or the mean number of ipsilateral reinterventions (claudication: 2.0 ± 1.6 vs. CLTI: 2.0 ± 1.7). However, after adjusting for follow-up time, the mean number of reinterventions per year was significantly higher for CLTI patients compared to patients with claudication (1.4 ± 2.2 vs. .6 ± 0.7 intervention per year, P < 0.001).

CONCLUSIONS

Patients undergoing LER for CLTI undergo more frequent reinterventions over time compared to patients treated for claudication. Research on reinterventions after LER should include reporting of the frequency of reintervention adjusted for the follow up period in addition to the reintervention rate defined as the percentage of patients undergoing reintervention.

Major adverse limb events and major adverse cardiac events after contemporary lower extremity bypass and infrainguinal endovascular intervention in patients with claudication

OBJECTIVE

Major adverse limb events (MALEs) and major adverse cardiovascular events (MACEs) at 30 days provide standardized metrics for comparison and have been adopted by the Society for Vascular Surgery's objective performance goals for critical limb ischemia. However, MALEs and MACEs have not been widely adopted within the claudication population, and the comparative outcomes after lower extremity bypass (LEB) and infrainguinal endovascular intervention (IEI) remain unclear. The purpose of this study was to compare MALEs and MACEs after LEB and IEI in a contemporary national cohort and to determine predictors of MALEs and MACEs after revascularization for claudication.

METHODS

A national data set of LEB and IEI performed for claudication was obtained using National Surgical Quality Improvement Program vascular targeted Participant Use Data Files from 2011 to 2014. Patients were stratified by LEB vs IEI and compared by appropriate univariate analysis. The primary outcomes were MALE (defined as untreated loss of patency, reintervention on the index arterial segment, or amputation of the index limb) and MACE (defined as stroke, myocardial infarction, or death). Multivariable logistic regression was used to identify predictors of MALEs and MACEs.

RESULTS

A total of 3925 infrainguinal revascularization procedures (2155 LEB and 1770 IEI) were performed for claudication. There was no difference in 30-day MALEs between LEB and IEI (4.0% vs 3.2%; P = .17). On multivariable logistic regression, predictors of 30-day MALEs included tibial revascularization (odds ratio [OR], 2.2; P < .0001) and prior LEB on the same arterial segment (OR, 1.8; P = .004). LEB had significantly higher 30-day MACEs (2.0% vs 1.0%; P = .01) but similar mortality (0.5% vs 0.4%; P = .6). Predictors of MACEs included LEB vs IEI (OR, 2.1; P = .01), chronic obstructive pulmonary disease (OR, 2.2; P = .01), dialysis dependence (OR, 4.4; P = .003), and diabetes (OR, 1.9; P = .02).

CONCLUSIONS

In this large national cohort, LEB and IEI for claudication are associated with similar 30-day MALEs. Tibial revascularization and revascularization after prior failed bypass predict MALEs in claudicants and should therefore be undertaken with caution. LEB was associated with more 30-day MACEs but comparable 30-day mortality compared with IEI. Patients with end-stage renal disease, chronic obstructive pulmonary disease, and diabetes are at high risk for MACEs. The risk of 30-day MACEs after LEB should be weighed against the longer term outcomes of LEB vs IEI and conservative management, particularly in these higher risk patients. This analysis helps define contemporary 30-day outcomes after infrainguinal revascularization performed for claudication and serves as a baseline with which the short-term outcomes of future treatments can be compared.

Endovascular Versus Open Revascularization for Peripheral Arterial Disease

OBJECTIVE

The aim of this study was to determine whether endovascular or open revascularization provides an advantageous approach to symptomatic peripheral arterial disease (PAD) over the longer term.

SUMMARY OF BACKGROUND DATA

The optimal revascularization strategy for symptomatic lower extremity PAD is not established.

METHODS

We evaluated amputation-free survival, overall survival, and relative rate of subsequent vascular intervention after endovascular or open lower extremity revascularization for propensity-score matched cohorts of Medicare beneficiaries with PAD from 2006 through 2009.

RESULTS

Among 14,685 eligible patients, 5928 endovascular and 5928 open revascularization patients were included in matched analysis. Patients undergoing endovascular repair had improved amputation-free survival compared with open repair at 30 days (7.4 vs 8.9%, P = 0.002). This benefit persisted over the long term: At 4 years, 49% of endovascular patients had died or received major amputation compared with 54% of open patients (P < 0.001). An endovascular procedure was associated with a risk-adjusted 16% decreased risk of amputation or death compared with open over the study period (hazard ratio: 0.84; 95% confidence interval, 0.79-0.89; P < 0.001). The amputation-free survival benefit associated with an endovascular revascularization was more pronounced in patients with congestive heart failure or ischemic heart disease than in those without (P = 0.021 for interaction term). The rate of subsequent intervention at 30 days was 7.4% greater for the endovascular vs the open revascularization cohort. At 4 years, this difference remained stable at 8.6%.

CONCLUSIONS

Using population-based data, we demonstrate that an endovascular approach is associated with improved amputation-free survival over the long term with only a modest relative increased risk of subsequent intervention.

Influence of Repeat Intervention on the Risk of Major Amputation After Infrapopliteal Angioplasty for Critical Limb Ischemia

PURPOSE

To assess the influence of repeat intervention on the risk of major amputation after infrapopliteal angioplasty for patients with critical limb ischemia (CLI).

METHODS

A multicenter database of Japanese CLI patients was interrogated to identify patients who underwent balloon angioplasty for isolated infrapopliteal lesions from April 2004 to December 2012. In that time frame, 1298 limbs of 1065 patients (mean age 72±10 years; 739 men) were eligible for this analysis. The prevalence of tissue loss was 76%, with 33% accompanied by infection. The association between repeat intervention and future risk for major amputation was evaluated using a mixed effects logistic regression model. A stratification analysis was also performed with baseline variables. A supplementary analysis compared baseline characteristics between the cases with and without repeat intervention. Hazard ratios (HR) and their 95% confidence intervals (CI) are reported.

RESULTS

Median follow-up was 1.2 years (interquartile range 0.4-2.5), during which time 143 (11.0%) limbs had major amputations and 499 (38.4%) underwent repeat intervention. The mixed effects modeling revealed that repeat intervention was significantly associated with future risk for major amputation (unadjusted HR 3.01, 95% CI 2.05 to 4.41, p=0.001). From the stratification analysis, repeat intervention significantly increased future risk of major amputation in cases with regular dialysis (HR 3.35, 95% CI 2.14 to 5.26, p<0.001), whereas it did not in those without dialysis. The supplemental analysis showed that patients with repeat intervention within 1 year had a higher prevalence of nonambulatory status, regular dialysis, tissue loss, and infection at baseline compared to those without repeat intervention for 1 year.

CONCLUSION

In the patients with CLI due to infrapopliteal lesions, the need for repeat intervention increased the risk of future major amputation. However, this correlation was not applicable to nondialysis patients.

One year health status benefits following treatment for new onset or exacerbation of peripheral arterial disease symptoms: the importance of patients' baseline health status

OBJECTIVE/BACKGROUND

Limited information is available on expected health status gains following invasive treatment in peripheral arterial disease (PAD). One year health status outcomes following invasive treatment for PAD were compared, and whether pre-procedural health status was indicative of 1 year health status gains was evaluated.

METHODS

Pre-procedural and 1 year health status (Short Form-12, Physical Component Score [PCS]) was prospectively assessed in a cohort of 474 patients, enrolled from 2 Dutch vascular clinics (March 2006-August 2011), with new or exacerbation of PAD symptoms. One year treatment strategy (invasive vs. non-invasive) and clinical information was abstracted. Quartiles of baseline health status scores and mean 1 year health status change scores were compared by invasive treatment for PAD. The numbers needed to treat (NNT) to obtain clinically relevant changes in 1 year health status were calculated. A propensity weight adjusted linear regression analysis was constructed to predict 1 year PCS scores.

RESULTS

Invasive treatment was performed in 39% of patients. Patients with baseline health status scores in the lowest quartile undergoing invasive treatment had the greatest improvement (mean invasive 11.3 ± 10.3 vs. mean non-invasive 5.3 ± 8.5 [p = .001, NNT = 3]), whereas those in the highest quartile improved less (.8 ± 6.3 vs. -3.0 ± 8.2 [p = .025, NNT = 90]). Undergoing invasive treatment (p < .0001) and lower baseline health status scores (p < .0001) were independently associated with greater 1 year health status gains.

CONCLUSION

Substantial improvements were found in patients presenting with lower pre-procedural health status scores, whereas patients with higher starting health status levels had less to gain by an invasive strategy.

Illness beliefs and walking behavior after revascularization for intermittent claudication: a qualitative study

PURPOSE

Patients with peripheral artery disease (PAD) are recommended to increase physical activity to reduce cardiovascular risk. Vascular intervention (surgery or angioplasty) treats the symptom (intermittent claudication), but not the underlying cardiovascular disease. This study aims to explore the beliefs and physical activity behavior of patients with PAD who have received vascular intervention.

METHODS

Twenty participants who had received a vascular intervention for intermittent claudication between 6 months and 2 years previously participated in semistructured interviews. The interviews explored illness and treatment beliefs and walking behavior. Data were transcribed verbatim and analyzed thematically.

RESULTS

Participants described a high level of ongoing symptoms (particularly pain) in their legs, despite having received vascular intervention. They viewed their illness as acute and treatable, and believed that pain was an indication of walking causing damage. They controlled their symptoms by avoiding walking and slowing their pace. Participants were generally unaware of the causes of the disease and were unaware of their increased risk of future cardiovascular health problems. There was a low level of congruence between participant beliefs about their illness and the recommendation to increase physical activity that may affect physical activity behavior.

CONCLUSIONS

Our findings suggest that patients with PAD do not change physical activity behavior after diagnosis and treatment, because they hold dysfunctional and incongruous beliefs about PAD, treatment, and physical activity.

Predictors and outcomes of restenosis following tibial artery endovascular interventions for critical limb ischemia

OBJECTIVE

Restenosis following tibial artery endovascular interventions (TAEIs) is thought to be benign but is not well characterized. This study examines the consequences and predictors of recurrent stenosis of TAEIs for critical limb ischemia.

METHODS

All TAEIs for critical limb ischemia performed between 2004 and 2010 were retrospectively reviewed. Restenosis was detected by noninvasive imaging and angiography when indicated. Restenoses were identified and the limb outcomes recorded. Tibial reinterventions were performed only for persistent, worsening, or recurrent tissue loss or rest pain with evidence of recurrence on duplex ultrasound or hemodynamic imaging. The χ test and logistic regression were applied as indicated. One-year patency rates were calculated using the Kaplan-Meier method.

RESULTS

A total of 235 limbs in 210 patients were treated for critical limb ischemia (70% tissue loss, 30% rest pain). Tissue loss included gangrene (49%) and ulcers (51%), and involved the forefoot (80%), the heel (14%), or both (6%). Seventy-eight percent of limbs had Trans-Atlantic InterSociety Consensus C/D lesions, with mean preoperative runoff score of 12. Interventions were isolated tibial (45%) or multilevel (55%) (including tibial). Mean postoperative runoff score improved to 6.6, but restenosis occurred in 96 limbs (41%) at a mean of 4 months. The 1-year primary patency was 59% with a mean follow-up of 9 months. Restenosis presented with a persistent wound (32%), worsened wound (42%), rest pain (16%), or no symptoms (10%). A repeat TAEI was performed in 42 (44%), major amputation in 26 (27%), open bypass in 20 (21%), and observation in eight (8%). The overall amputation rate was 13%, but limb loss was significantly higher in patients with restenosis (n = 26 [27%]) than in patients with no restenosis (n = 5 [4%]; P < .001). Patients with restenosis and tissue loss were more likely to have presented with gangrene (63% vs 38%; P = .0003) but had comparable wound distribution (P = NS). There was a trend toward a higher restenosis rate in patients with renal insufficiency (odds ratio, 5.57; P = .08), but this was unaffected by diabetes, statin therapy, or smoking (P = NS). The rate of repeat intervention after the first reintervention was 36%, with an 87% overall limb salvage rate.

CONCLUSIONS

TAEIs can be used successfully to treat patients with critical limb ischemia with acceptable limb salvage rates. Special attention should be given to patients with extensive tissue loss or gangrene because they are at risk for early restenosis and subsequent limb loss. Strict wound and hemodynamic surveillance, wound care, and timely reinterventions are crucial to achieve successful outcomes in this patient population. Amputation or alternative revascularization options, when feasible, should be considered in patients with restenosis and tissue loss given the high rate of limb loss with tibial reinterventions.

Utilization of lower extremity arterial disease diagnostic and revascularization procedures in Medicare beneficiaries 2000-2007

OBJECTIVE

The recent escalation in lower extremity revascularization procedures suggests a concomitant increase in peripheral arterial disease (PAD) screening. We hypothesized that self-referring physicians would show the greatest growth in noninvasive physiologic testing for PAD and similar trends for revascularization procedures. We compared utilization rates for self-referring specialties (vascular surgery, interventional radiology, and cardiology) with the utilization rate for a referral-based specialty (diagnostic radiology), assuming the latter to be "basal"--that is, responsive only to changes in demographics and medical knowledge.

MATERIALS AND METHODS

We analyzed 100% procedure-specific claims for services provided to Medicare Part B beneficiaries during 6 years over an 8-year span (2000-2007). We extracted all Current Procedural Terminology codes for lower extremity vascular noninvasive physiologic studies, peripheral arterial stent placement, and transluminal angioplasty. Utilization volumes were adjusted per 100,000 beneficiaries. Compound annual growth rates were calculated.

RESULTS

Utilization of both noninvasive physiologic and revascularization services increased steadily over the study period. Growth rates of diagnostic services provided by interventional radiologists (7%) and vascular surgeons (8%) were slightly higher than the basal rate (7%), with cardiologists (14%) at the top of the list. For revascularization procedures, vascular surgery showed the greatest growth (28%), a rate more than twice that of cardiology (13%); radiology experienced a decrease in volumes (-2%).

CONCLUSION

Self-referring specialists are screening large volumes of Medicare beneficiaries for lower extremity PAD at an accelerated rate compared with testing done by those who do not self-refer. Similar trends exist for endovascular interventions.

Low rehospitalization rate for vascular surgery patients

OBJECTIVES

Reducing rehospitalization rates has been proposed to improve care, reduce costs, and as a pay-for-performance criterion. Recent review of Medicare claims data indicates that vascular surgery patients have among the highest rates of 30-day rehospitalization at 23.9%.

METHODS

We retrospectively examined all live patient discharges (n = 799) from the vascular surgery service at a single university hospital over 12 months. Planned and unplanned 30-day rehospitalizations were distinguished, and predictors of unplanned 30-day rehospitalization were determined. To identify whether patients were readmitted to other hospitals, a prospective study of patient discharges (n = 66) over 1 month was also performed.

RESULTS

Ninety-five (11.9%) of the 799 patient discharges from the vascular surgery service were rehospitalized within 30 days. Of these, 71 were unplanned; therefore, the unplanned rehospitalization rate was 8.9%. The most common causes of unplanned 30-day rehospitalization were related to wound complications. Diabetes (P = .039) predicted unplanned 30-day rehospitalization by multivariate analysis. Patients with the diagnosis of critical limb ischemia (14.9%) and patients undergoing open lower extremity revascularization (14.6%) had the highest rates of unplanned 30-day rehospitalization. In the prospective portion of this study, no patient was readmitted to any other hospital.

CONCLUSIONS

Relatively low 30-day rehospitalization was accomplished in vascular surgery patients at a single university hospital. Moreover, planned rehospitalizations accounted for approximately 25% of readmissions in vascular surgery patients. Strategies designed to reduce rehospitalization in diabetics may be warranted.

Quality of Life and Functional Status After Revascularization or Conservative Treatment in Patients With Intermittent Claudication

Revascularization of patients with intermittent claudication (IC) is recommended only for selected patients who have chronic pain or disabling disease. However, improvement in the quality of life (QoL) could justify more widespread use.

Objectives: To determine the effect of conservative treatment and revascularization on the QoL and physical performance of selected patients with IC.

Patients and Methods: This nonrandomized, parallel group, follow-up study included 83 patients with IC at Fontaine stage II. On the basis of interventional opportunities and the risks and benefits, combined with the preference of the patient, 47 patients were treated conservatively and 41 were revascularized. The patients were examined at inclusion and 3 months later. The evaluations included the QoL measure Short Form 36 (SF-36), the Walking Impairment Questionnaire (WIQ), pain-free and maximal walking distance (treadmill at 3 km/h, no incline), maximal isometric knee-extension strength and endurance, and ankle—brachial blood pressure index (ABI).

Results: At baseline, the SF-36 and WIQ scores and the ABI were significantly lower in the patients selected for revascularization. After revascularization, all dimensions of QoL and functional status increased significantly in the patients who underwent revascularisation compared with the patients treated conservatively. The difference in the change in the physical component summary of SF-36 was 29.4% (P < .001), in the total WIQ 63.6% (P = .0002), and in the pain-free and maximal walking distances 313% (P < .001) and 135% (P < .001), respectively. After adjustment for age, smoking, ABI, body mass index (BMI), and baseline values, the differences remained statistically significant.

Conclusion: Revascularization above the knee increased QoL, functional status, and walking distance significantly in patients with moderate IC.

Analysis of large databases in vascular surgery

Large databases can be a rich source of clinical and administrative information on broad populations. These datasets are characterized by demographic and clinical data for over 1000 patients from multiple institutions. Since they are often collected and funded for other purposes, their use for secondary analysis increases their utility at relatively low costs. Advantages of large databases as a source include the very large numbers of available patients and their related medical information. Disadvantages include lack of detailed clinical information and absence of causal descriptions. Researchers working with large databases should also be mindful of data structure design and inherent limitations to large databases, such as treatment bias and systemic sampling errors. Withstanding these limitations, several important studies have been published in vascular care using large databases. They represent timely, "real-world" analyses of questions that may be too difficult or costly to address using prospective randomized methods. Large databases will be an increasingly important analytical resource as we focus on improving national health care efficacy in the setting of limited resources.

The impact of socioeconomic factors on outcome and hospital costs associated with femoropopliteal revascularization

INTRODUCTION

Within the context of healthcare system reform, the cost efficacy of lower extremity revascularization remains a timely topic. The impact of an individual patient's socioeconomic status represents an under-studied aspect of vascular care, especially with respect to longitudinal costs and outcomes. The purpose of this study is to examine the relationship between socioeconomic status and clinical outcomes as well as inpatient hospital costs.

METHODS

A retrospective femoropopliteal revascularization database, which included socioeconomic factors (household income, education level, and payor status), in addition to standard demographic, clinical, anatomical, and procedural variables were analyzed over a 3-year period. Patients were stratified by income level (low income [LI] <200% federal poverty level [$42,400 for a household of 4], and higher income [HI] >200% federal poverty level) and revascularization technique (open vs endovascular) and analyzed for the endpoints of primary assisted patency, amortized cost-per-day of patency, and limb salvage. Data were analyzed with univariate and multivariate techniques.

RESULTS

A total of 187 cases were identified with complete data for analysis, 146 in the LI and 41 in the HI cohorts. LI patients differed from HI patients by mean age (66.2 +/- 1.0 vs 61.8 +/- 1.5 years, P = .04), high school graduate rate (51.4% vs 85.4%, P < .001), presence of tissue loss (30.1% vs 14.6%, P = .05), female gender (43.7% vs 22.0%, P = .01) and preoperative statin use (45.8% vs 75.6%, P < .001). There were no differences with respect to other comorbidities including smoking status, presence of diabetes, renal insufficiency, anatomic factors or treatment modality (open vs endovascular). Ninety-seven patients underwent endovascular revascularization. The following outcomes were noted in the endovascular subset of LI and HI patients respectively: primary assisted patency (66% vs 71%, P = NS) and 12-month cost-per-day of patency ($166.30 +/- 77.40 vs $22.45 +/- 12.45, P = .05). Ninety-eight patients underwent open revascularization, with the following outcomes in LI and HI patients respectively: primary assisted patency (78% vs 86%, P = NS) and 12-month cost-per-day of patency ($319.43 +/- 225.44 vs $40.47 +/- 4.63, P = .07). Of the 77 patients with critical limb ischemia, 19 underwent eventual amputation. Multivariate analysis demonstrated that income above 100% of the federal poverty line was protective against limb loss (odds ratio 0.06, 95% confidence interval 0.01-0.51, P < .001).

CONCLUSION

Income level correlates with advanced presentation, advanced age, and lack of statin use. Although primary assisted patency rate is not affected by income status, an increased cost-per-day of patency and inferior limb salvage is found in lower income patients.

Angiography underestimates peripheral atherosclerosis: lumenography revisited

PURPOSE

To compare angiograms, considered the gold standard for diagnostic imaging of peripheral arterial disease (PAD), to the corresponding histological sections of popliteal and tibial vessels obtained after amputation to determine if angiography fails to define atheroma burden in "normal appearing" arteries in patients with PAD.

METHODS

Between 2004 and 2006, 69 patients underwent amputation of a lower extremity for severe tissue loss, gangrene, or pedal sepsis precluding limb salvage. Popliteal and tibial vessels were harvested, perfusion-fixed, and analyzed histologically. Thirty-four of these patients had pre-amputation angiography during attempted salvage procedures. Angiograms with patent or minimally diseased vessel segments (n = 19) were assessed for stenoses, diameter, and calcification by 3 vascular surgeons (n = 72 evaluations). These results were compared to corresponding cross-sectional histological slides (n = 66) in a blinded manner.

RESULTS

Angiograms performed prior to above-knee (n = 9) or below-knee (n = 10) amputation revealed 24 stenoses with a mean (+/-SD) diameter-reducing stenosis of 19.5%+/-15.2%. Corresponding histological cross sections revealed greater linear stenoses measured via boundaries of the internal elastic lamina (IEL stenosis, 28.9%+/-20.2%, p = 0.003 versus angiography) or via boundaries of the external elastic membrane (vessel stenosis, 43.1%+/-15.2%, p<0.0001). Stenosis calculated by area methods (IEL area) were greater and measured 39.2%+/-24.2% (p<0.0001) and 60.9%+/-15.2% (vessel area, p<0.0001). Popliteal arteries had greater discrepancy in stenosis measurement than tibial arteries (18.5%+/-14.6% versus 34.9%+/-21.0%, p = 0.0005). However, evaluations of tibial arteries for concentricity of plaque (44% versus 69%, p = 0.08) and calcification grade (1.6 versus 2.2, p = 0.002) by angiography were discordant with histological analyses. Measurement of arterial diameter by histology for popliteal arteries (6.2+/-0.9 mm) and tibial arteries (3.1+/-0.7 mm) was greater than angiographic diameter determination (p<0.001).

CONCLUSION

Angiography provides information on luminal characteristics of peripheral arteries but severely underestimates the extent of atherosclerosis in patients with PAD even in "normal appearing" vessels.

A Population-Level Analysis: The Influence of Hospital Type on Trends in Use and Outcomes of Lower Extremity Angioplasty

Objective The use of infrainguinal percutaneous transluminal angioplasty (PTA) has increased, but patterns of use have not been well studied. Academic institutions (AIs) and nonacademic institutions (NAIs) may have developed different practice patterns and may have different associated outcomes.

Methods A retrospective statewide population-based administrative database was evaluated for patients undergoing PTA (1997-2004).

Results A total of 1718 patients underwent PTA for claudication (51.9%), rest pain (12.1%), and ulceration or gangrene (23.1%). The use of infrainguinal stents (62.4% vs 60.8%), elective procedures (76.3% vs 79.8%), in-hospital death (1.6% vs 2.2%), 30-day mortality (2.1% vs 3.3%), readmission rates (17.1% vs 15.9%), and reintervention rates after readmission (38.5% vs 42.9%) were similar between groups. Increased use of PTA was noted in AIs versus NAIs (239.5% vs 53.9%). AIs were significantly less likely to perform PTA for rest pain (7.5% vs 14.4%, P < .05).

Conclusion AIs had a more recent increase in the use of PTA, but less often used PTA for patients with rest pain compared with NAIs. Both center types had higher than expected 30-day readmission and reintervention rates. Further understanding of the implementation and associated outcomes of PTA is required.