Regional variation in outcomes for lower extremity vascular disease in the Vascular Quality Initiative

Association between Asian race and perioperative outcomes after carotid revascularization varies with Asian procedure density

OBJECTIVE

Postoperative outcomes following carotid revascularization are understudied in Asian patients. We aimed to assess whether disease severity and postoperative outcomes following carotid revascularization differ between Asian and White patients, and whether this varies with Asian procedure density.

METHODS

We analyzed the Vascular Quality Initiative Carotid Endarterectomy and Carotid Artery Stenting datasets from 2003 to 2021. Regions were divided into tertiles based on Asian procedure density. Propensity scores were used to match Asian and White patients based on patient factors and procedure type. The primary outcome variable was a collapsed composite of in-hospital ipsilateral stroke/death/myocardial infarction. χ2 tests were used to assess association between Asian race and disease severity, center and surgeon volume, and 1-year outcomes. Logistic and Cox regressions were performed between the matched cohorts.

RESULTS

A total of 1766 Asian and 159,608 White patients underwent carotid revascularization, and we identified 2704 patients (1352 Asian and 1352 White) in the matched cohorts. Among propensity matched patients, all-comer Asian patients more commonly had >80% ipsilateral stenosis (63% vs 52%; P < .001) and a moderate/severe preoperative Rankin score (7.6% vs 5.1%; P = .007). The rate of in-hospital stroke/death/myocardial infarction was higher in Asian patients (2.6% vs 1.3%; P = .012), and this disparity was more pronounced in the lowest tertile of Asian procedure density (4.3% vs 0.5%; P < .001). Logistic regression in the propensity-matched cohort demonstrated Asian race was associated with lower odds of intervention at highest volume centers (odds ratio [OR], 0.3; 95% confidence interval [CI], 0.2-0.3; P < .001) and by highest volume surgeons (OR, 0.3; 95% CI, 0.3-0.4; P < .001). Asian race was associated with higher odds of in-hospital stroke/death/myocardial infarction (OR, 2.0; 95% CI, 1.1-3.8; P = .031), and there was a significant interaction between Asian procedure density and the relationship between Asian race and this outcome (interaction P = .001). After accounting for center and surgeon volume, the association of Asian race and the composite outcome was mitigated (OR, 1.5; 95% CI, 0.7-3.3; P = .300). Cox regression between the matched cohorts demonstrated that Asian race was associated with lower 1-year mortality (hazard ratio, 0.5; 95% CI, 0.3-0.7; P = .001) and higher risk of 1-year reintervention (hazard ratio, 16; 95% CI, 1.8-142; P = .013).

CONCLUSIONS

Asian patients are more likely to present with a higher degree of carotid stenosis, higher preoperative risk, and experience worse perioperative outcomes. The association of Asian race with perioperative stroke/death/myocardial infarction varies with Asian procedure density and is also confounded by center and surgeon volume. These results highlight the importance of understanding referral patterns and cultural effects on outcomes disparities in Asian patients.

Intra-arterial Fractional Flow Reserve Measurements Provide an Objective Assessment of the Functional Significance of Peripheral Arterial Stenoses

OBJECTIVE

Peripheral arterial stenoses (PAS) are commonly investigated with duplex ultrasound (DUS) and angiography, but these are not functional tests. Fractional flow reserve (FFR), a pressure based index, functionally assesses the ischaemic potential of coronary stenoses, but its utility in PAS is unknown. FFR in the peripheral vasculature in patients with limb ischaemia was investigated.

METHODS

Patients scheduled for angioplasty and or stenting of isolated iliac and superficial femoral artery stenoses were recruited. Resting trans-lesional pressure gradient (Pd/Pa) and FFR were measured after adenosine provoked hyperaemia using an intra-arterial 0.014 inch flow and pressure sensing wire (ComboWire XT, Philips). Prior to revascularisation, exercise ABPI (eABPI) and DUS derived peak systolic velocity ratio (PSVR) of the index lesion were determined. Calf muscle oxygenation was measured using blood oxygenation level dependent cardiovascular magnetic resonance prior to and after revascularisation.

RESULTS

Forty-one patients (32, 78%, male, mean age 65 ± 11 years) with 61 stenoses (iliac 32; femoral 29) were studied. For lesions < 80% stenosis, resting Pd/Pa was not influenced by the degree of stenosis (p = .074); however, FFR was discriminatory, decreasing as the severity of stenosis increased (p = .019). An FFR of < 0.60 was associated with critical limb threatening ischaemia (area under the curve [AUC] 0.87; 95% CI 0.75 - 0.95), in this study performing better than angiographic % stenosis (0.79; 0.63 - 0.89), eABPI (0.72; 0.57 - 0.83), and PSVR (0.65; 0.51 - 0.78). FFR correlated strongly with calf oxygenation (rho, 0.76; p < .001). A greater increase in FFR signalled resolution of symptoms and signs (ΔFFR 0.25 ± 0.15 vs. 0.13 ± 0.09; p = .009) and a post-angioplasty and stenting FFR of > 0.74 predicted successful revascularisation (combined sensitivity and specificity of 95%; AUC 0.98; 0.91 - 1.00).

CONCLUSION

This pilot study demonstrates that FFR can objectively measure the functional significance of PAS that compares favourably with visual and DUS based assessments. Its role as a quality control adjunct that confirms optimal vessel patency after angioplasty and or stenting also merits further investigation.

Amputation Rates and Associated Social Determinants of Health in the Most Populous US Counties

Importance

Social Determinants of Health (SDOH) have been found to be associated with health outcome disparities in patients with peripheral artery disease (PAD). However, the association of specific components of SDOH and amputation has not been well described.

Objective

To evaluate whether individual components of SDOH and race are associated with amputation rates in the most populous counties of the US.

Design, Setting, and Participants

In this population-based cross-sectional study of the 100 most populous US counties, hospital discharge rates for lower extremity amputation in 2017 were assessed using the Healthcare Cost and Utilization Project State Inpatient Database. Those data were matched with publicly available demographic, hospital, and SDOH data. Data were analyzed July 3, 2022, to March 5, 2023.

Main outcome and Measures

Amputation rates were assessed across all counties. Counties were divided into quartiles based on amputation rates, and baseline characteristics were described. Unadjusted linear regression and multivariable regression analyses were performed to assess associations between county-level amputation and SDOH and demographic factors.

Results

Amputation discharge data were available for 76 of the 100 most populous counties in the United States. Within these counties, 15.3% were African American, 8.6% were Asian, 24.0% were Hispanic, and 49.6% were non-Hispanic White; 13.4% of patients were 65 years or older. Amputation rates varied widely, from 5.5 per 100 000 in quartile 1 to 14.5 per 100 000 in quartile 4. Residents of quartile 4 (vs 1) counties were more likely to be African American (27.0% vs 7.9%, P < .001), have diabetes (10.6% vs 7.9%, P < .001), smoke (16.5% vs 12.5%, P < .001), be unemployed (5.8% vs 4.6%, P = .01), be in poverty (15.8% vs 10.0%, P < .001), be in a single-parent household (41.9% vs 28.6%, P < .001), experience food insecurity (16.6% vs 12.9%, P = .04), or be physically inactive (23.1% vs 17.1%, P < .001). In unadjusted linear regression, higher amputation rates were associated with the prevalence of several health problems, including mental distress (β, 5.25 [95% CI, 3.66-6.85]; P < .001), diabetes (β, 1.73 [95% CI, 1.33-2.15], P < .001), and physical distress (β, 1.23 [95% CI, 0.86-1.61]; P < .001) and SDOHs, including unemployment (β, 1.16 [95% CI, 0.59-1.73]; P = .03), physical inactivity (β, 0.74 [95% CI, 0.57-0.90]; P < .001), smoking, (β, 0.69 [95% CI, 0.46-0.92]; P = .002), higher homicide rate (β, 0.61 [95% CI, 0.45-0.77]; P < .001), food insecurity (β, 0.51 [95% CI, 0.30-0.72]; P = .04), and poverty (β, 0.46 [95% CI, 0.32-0.60]; P < .001). Multivariable regression analysis found that county-level rates of physical distress (β, 0.84 [95% CI, 0.16-1.53]; P = .03), Black and White racial segregation (β, 0.12 [95% CI, 0.06-0.17]; P < .001), and population percentage of African American race (β, 0.06 [95% CI, 0.00-0.12]; P = .03) were associated with amputation rate.

Conclusions and Relevance

Social determinants of health provide a framework by which the associations of environmental factors with amputation rates can be quantified and potentially used to guide interventions at the local level.

Performance of the Emergency Surgery Score in Nonelective Lower-Extremity Endovascular Procedures

INTRODUCTION

Multiple studies have validated the Emergency Surgery Score (ESS) as a tool which reliably predicts outcomes after emergency general surgery. The purpose of this study was to assess the performance of the ESS for lower-extremity endovascular procedures in nonelective setting (neLEE).

METHODS

The American College of Surgeons' National Surgical Quality Improvement Program database was retrospectively analyzed for patients undergoing neLEE between 2015 and 2019. The performance of the ESS in predicting mortality in each procedure was assessed using receiver operating characteristic analyses.

RESULTS

Four thousand five hundred and eighty three patients underwent neLEE with median age 68 (±12.3 SD), with 1802 females (39.3%). The ESS correlated with 30-day mortality (area under the curve [AUC] was 0.729), discharge to rehab (AUC 0.638), renal failure (AUC 0.667), postintervention ventilation requirement (AUC 0.680), and stroke (AUC 0.656). The predictive ability of the ESS decreased with increasing age, with the ESS performing best for patients between 60 and 69 y in age (AUC 0.735) and worst for patients above 80 y (AUC 0.650). A Cochran-Armitage test showed linear trend towards increased 30-day mortality among the quartiles with increasing ESS (P < 0.001), with patients with ESS ≥10 having 10 times odds of increased 30-day mortality compared to reference quartile of patients with ESS ≤4 on multivariate analysis.

CONCLUSIONS

The ESS score is associated with 30-day mortality and other complications after neLEE procedures. It can potentially be used as a predictive tool for preoperative risk stratification and can also be used for equitably evaluating standards and outcomes after lower extremity endovascular procedures.

Risk stratification with explainable machine learning for 30-day procedure-related mortality and 30-day unplanned readmission in patients with peripheral arterial disease

Predicting 30-day procedure-related mortality risk and 30-day unplanned readmission in patients undergoing lower extremity endovascular interventions for peripheral artery disease (PAD) may assist in improving patient outcomes. Risk prediction of 30-day mortality can help clinicians identify treatment plans to reduce the risk of death, and prediction of 30-day unplanned readmission may improve outcomes by identifying patients who may benefit from readmission prevention strategies. The goal of this study is to develop machine learning models to stratify risk of 30-day procedure-related mortality and 30-day unplanned readmission in patients undergoing lower extremity infra-inguinal endovascular interventions. We used a cohort of 14,444 cases from the American College of Surgeons National Surgical Quality Improvement Program database. For each outcome, we developed and evaluated multiple machine learning models, including Support Vector Machines, Multilayer Perceptrons, and Gradient Boosting Machines, and selected a random forest as the best-performing model for both outcomes. Our 30-day procedure-related mortality model achieved an AUC of 0.75 (95% CI: 0.71-0.79) and our 30-day unplanned readmission model achieved an AUC of 0.68 (95% CI: 0.67-0.71). Stratification of the test set by race (white and non-white), sex (male and female), and age (≥65 years and <65 years) and subsequent evaluation of demographic parity by AUC shows that both models perform equally well across race, sex, and age groups. We interpret the model globally and locally using Gini impurity and SHapley Additive exPlanations (SHAP). Using the top five predictors for death and mortality, we demonstrate differences in survival for subgroups stratified by these predictors, which underscores the utility of our model.

Vascular surgery patients in intensive care: a bi-national cohort study over 15 years

BACKGROUND

To describe the characteristics and outcomes of patients admitted to Intensive Care following vascular surgery, and their subsequent usage of Intensive Care resources, over a 15-year period in Australia and New Zealand.

METHODS

This was a retrospective, bi-national study of 69 676 adult patients admitted to 179 Intensive Care Unit (ICUs) following vascular surgery between January 2005 and December 2019, using the Australian and New Zealand Intensive Care Society Adult Patient Database.

RESULTS

The proportion of ICU bed days used by vascular surgery patients decreased during the study period from 3.6% in 2005 to 2.9% in 2019 (P < 0.001). The cohort had a median age of 73 years, and were most frequently admitted after a carotid endarterectomy (22%) or elective open aneurysm repair (20%). A total of 5.2% of patients did not survive to discharge. Mean annual adjusted mortality decreased during the study period from 6.1% in 2005 to 3.7% in 2019 (P < 0.001). Multiple factors were associated with higher mortality, including gender, hospital case volume and hospital type.

CONCLUSIONS

Between 2005 and 2019 survival for vascular surgery patients requiring ICU admission in Australia and New Zealand improved. During the same time the proportion of ICU bed days used by these patients decreased.

pH/Thermosensitive dual-responsive hydrogel based sequential delivery for site-specific acute limb ischemia treatment

Acute limb ischemia (ALI) is the most severe manifestation of peripheral artery disease, accompanied by pH/temperature-microenvironment changes in two different phases. In the acute phase, temperature and pH are significantly decreased, and reactive oxygen species (ROS) are excessively generated owing to the sharp reduction of blood perfusion. Afterwards, in the chronic phase, although the temperature gradually recovers, angiogenesis is delayed due to chronic vascular injury, skeletal muscle cell apoptosis and endothelial cell dysfunction. Current therapeutic strategies mainly focus on recanalization; however, their effects on scavenging ROS in the acute phase and promoting angiogenesis in the chronic phase are quite limited. Herein, an injectable pH and temperature dual-responsive poloxamer 407 (PF127)/hydroxymethyl cellulose (HPMC)/sodium alginate (SA)-derived hydrogel (FHSgel), encapsulating melatonin and diallyl trisulfide-loaded biodegradable hollow mesoporous silica nanoparticles (DATS@dHMSNs), is developed, which can intelligently respond to the different phases of ALI. In the acute phase of ischemia, the decreased pH results in the rapid release of melatonin to scavenge excessive ischemia-induced ROS. On the other hand, in the chronic repair phase, the recovered temperature triggers the sustained release of DATS@dHMSNs from the FHSgel, thus generating hydrogen sulfide (H₂S) to enhance the angiogenesis and microcirculation reconstruction of ischemic limbs.

A systematic review of racial/ethnic disparities in pharmacotherapy and surgical treatment outcomes in peripheral arterial disease among African American/non-Hispanic Black, non-Hispanic White and Hispanic patients

Background

Lower extremity peripheral arterial disease (PAD) is associated with significant morbidity and mortality in racial/ethnic diverse populations. However, limited data exist on treatment outcome disparities in racial/ethnic diverse populations, particularly in AA/NHB populations.

Objective

The aim of this systematic review is to analyze disparities in the outcomes of PAD treatments, particularly pharmacotherapy and surgery, among racial/ethnic groups in the US.

Methods

A comprehensive search of original investigations pertaining to PAD treatments between 2015 and 2021 was performed. Quality assessment of the studies was also completed.

Results

Fourteen studies were included. Thirteen studies reported differences in treatment outcomes for surgical intervention, and one study reported differences for concurrent surgical and pharmacotherapy. NHB and Hispanic/Latinx ethnicities were associated with decreased overall and perioperative mortality in four studies. Six studies noted increased amputation risk among racial/ethnic diverse populations. Only one study noted significant survival benefit by race/ethnicity. Three studies noted increased risk of major adverse limb events and post-operative complications. One study noted increased limb patency after intervention in racial/ethnic cohorts. Overall, all studies reported high methodological quality with adequate assessment of outcomes and follow-up of cohort.

Conclusion

In this analysis, the predominant intervention reported is surgical. Overall, racial/ethnic populations are less likely to experience PAD-associated mortality but are more likely to experience adverse events. Further studies are necessary to include all racial/ethnic diverse populations in assessing PAD therapeutic intervention outcomes. Moreover, targeted public health efforts are necessary to increase PAD educational awareness, community-driven risk modification, and patient-centered care planning.

Rates of intervention for claudication versus chronic limb-threatening ischemia in Canada and United States

BACKGROUND

Previous studies have demonstrated important geographic variations in peripheral artery disease (PAD) management despite existing guidelines. We assessed differences in patient characteristics, procedural technique, and outcomes for PAD interventions in Canada vs. United States.

METHODS

The Vascular Quality Initiative (VQI) was used to identify all patients who underwent endovascular intervention or surgical bypass for PAD between 2010-2019 in Canada and United States. Independent t-test and chi-square test were performed to assess differences between countries in terms of demographic, clinical, and procedural characteristics. The primary outcome was the percentage of interventions performed for claudication vs. chronic limb-threatening ischemia (CLTI). Perioperative outcomes were in-hospital mortality and index limb amputation. The long-term outcome was 1-year amputation-free survival. Univariate/multivariate logistic regression and Cox proportional hazards analysis were performed to investigate associations between region and outcomes.

RESULTS

246,770 US patients and 3,467 Canadian patients underwent revascularization for PAD during the study period. There was a higher proportion of endovascular interventions in the US (75.9% vs. 69.2%, OR 1.41 [95% CI 1.31 - 1.51], p < 0.001). American patients were younger with more comorbidities, including hypertension, diabetes, and coronary artery disease. The percentage of interventions performed for claudication was significantly higher in the US (42.3% vs. 35.7%, OR 1.31 [95% CI 1.22 - 1.44], p < 0.001). This persisted after controlling for demographic, clinical, and procedural characteristics (adjusted OR 1.05 [95% CI 1.01 - 1.10], p = 0.02). Perioperative outcomes were similar between countries after adjustment for baseline differences: in-hospital mortality (adjusted OR 1.07 [95% CI 0.69 - 1.62], p = 0.75) and index limb amputation (adjusted OR 0.67 [95% CI 0.43 - 1.07], p = 0.09). However, 1-year amputation-free survival was higher in the US (84.1% vs. 71.0%, HR 1.61 [95% CI 1.47 - 1.76], p < 0.001). Multivariable Cox proportional hazards analysis demonstrated that the factor most strongly associated with index limb amputation or death at 1-year was intervention for CLTI (HR 1.56 [95% CI 1.54 - 1.58], p < 0.001).

CONCLUSIONS

There are significant variations in PAD management between US and Canada. In particular, a higher proportion of interventions are performed for claudication rather than CLTI in the US compared to Canada. This is an important contributor to the higher 1-year amputation-free survival rate in US patients. Reasons for these differences should be assessed by future studies and evidence-based care may be standardized by targeted quality improvement projects.

Participation in a Chronic Limb Threatening Ischemia Randomized Trial Is Inversely Correlated With Regional Amputation Rate in Limb Threatening Ischemia Patients

OBJECTIVE

The National Health Service demonstrated that regions of the United Kingdom with the highest number of patients enrolled in research studies had the lowest risk-adjusted mortality when patients were admitted to the hospital. Our goal was to investigate if this correlation was evident for patients with chronic limb threatening ischemia (CLI) treated in the United States (US). Accordingly, we examined correlations among sites participating in the Best Endovascular versus best Surgical Therapy in patients with Critical (BEST-CLI) trial, a multicenter, National Institute of Health-sponsored, international randomized controlled trial (RCT) comparing revascularization strategies in patients with CLI, and regional rates of major amputation from CLI.

METHODS

We measured regional participation in the BEST-CLI trial by evaluating trial participation and enrollment rosters. To determine regional rates of lower limb amputation, we queried the Medicare database (2007-2016) for patients with concurrent peripheral arterial disease (PAD) and diabetes, then assessed how many had lower extremity amputations. Correlation of regional amputation rates with distribution of BEST-CLI sites in four US geographical regions was calculated using Pearson's correlation coefficients. Simple regression equations were used to calculate the significance of these correlation coefficients.

RESULTS

Of 9,231,909 CLI patients, 342,406 underwent amputation in the Medicare dataset. Amputation rates per 1000 CLI patients differed by region (South 40.42, Midwest 40.12, West 34.81, Northeast 31.14). There were 116 US vascular centers, selected by volume and expertise that participated in BEST-CLI with the following distribution: South (n = 30, 26%), Midwest (n = 26, 22%), West (n = 29, 25%), and Northeast (n = 31, 27%). There was a negative correlation between the number of amputations per 1000 for Medicare CLI patients with diabetes and PAD and the number of BEST-CLI sites in the region which trended toward significance (Pearson R= -0.61, P = 0.39).

CONCLUSIONS

Amputation rate among Medicare CLI patients is inversely correlated with US BEST-CLI site distribution. Higher participation in clinical research, especially within large RCTs, may be a marker of optimal PAD management.

Lower Extremity Peripheral Artery Disease: Contemporary Epidemiology, Management Gaps, and Future Directions: A Scientific Statement From the American Heart Association

Lower extremity peripheral artery disease (PAD) affects >230 million adults worldwide and is associated with increased risk of various adverse clinical outcomes (other cardiovascular diseases such as coronary heart disease and stroke and leg outcomes such as amputation). Despite its prevalence and clinical importance, PAD has been historically underappreciated by health care professionals and patients. This underappreciation seems multifactorial (eg, limited availability of the first-line diagnostic test, the ankle-brachial index, in clinics; incorrect perceptions that a leg vascular disease is not fatal and that the diagnosis of PAD would not necessarily change clinical practice). In the past several years, a body of evidence has indicated that these perceptions are incorrect. Several studies have consistently demonstrated that many patients with PAD are not receiving evidence-based therapies. Thus, this scientific statement provides an update for health care professionals regarding contemporary epidemiology (eg, prevalence, temporal trends, risk factors, and complications) of PAD, the present status of diagnosis (physiological tests and imaging modalities), and the major gaps in the management of PAD (eg, medications, exercise therapy, and revascularization). The statement also lists key gaps in research, clinical practice, and implementation related to PAD. Orchestrated efforts among different parties (eg, health care providers, researchers, expert organizations, and health care organizations) will be needed to increase the awareness and understanding of PAD and improve the diagnostic approaches, management, and prognosis of PAD.

Variation in treatment and outcomes for patients with chronic limb-threatening ischaemia in New South Wales, Australia

BACKGROUND

Chronic limb-threatening ischaemia (CLTI) carries significant amputation and mortality risks. Australian population-based outcomes for CLTI are inadequately known. This study aimed to distinguish factors associated with outcomes in the first 2 years after CLTI surgery.

METHODS

By linking routinely collected health administrative and mortality data from New South Wales, this population-based cohort study identified patients with ischaemic rest pain, gangrene or ulceration undergoing vascular surgery in public hospitals between 2010 and 2012. The primary outcome was 2-year amputation-free survival (AFS), and secondary outcomes included readmission and reoperation rates. Multivariable regression analysis identified prognostic factors adjusted for patient, hospital and geographic factors.

RESULTS

Primary CLTI surgery was performed on 4898 patients. Almost half the cohort had minor amputations without concurrent revascularization (2398, 49%), and the remaining patients had open (652, 13%) or endovascular (1848, 38%) surgery. At 2-years, the AFS rate was 72%. Significant disparity was seen between age groups, with the 2-year AFS 71% in patients aged 75 years or older, compared to 95% in patients aged less than 75 years (P < 0.001). Place of residence or hospital training status did not significantly influence AFS or readmission, but non-training hospitals had higher rates of reoperation.

CONCLUSION

This population-based cohort study demonstrated variable outcomes for patients with CLTI, particularly with respect to older age, admission acuity and comorbidity. Results may guide service improvements however further research is needed into how population-wide health initiatives can address age-related disparities in CLTI.

Trends and causes of readmission following peripheral vascular intervention in patients with peripheral vascular disease

OBJECTIVES

To study the risk factors associated with 30-readmission postperipheral vascular intervention (PVI) in peripheral artery disease (PAD).

BACKGROUND

There has been a paucity of data regarding the trend and predictors of PVI readmission.

METHODS

We performed an observational cohort study of patients admitted with peripheral vascular disease for PVI using the NRD for the years 2010-2014. PVI was defined as angioplasty, atherectomy, and/or stenting of lower limb vessels.

RESULTS

A total of 453,278 patients (30-day readmission n = 97,235). The mean age of study population was 68.6 ± 12.2 years and included 43.8% women. The 30-day readmission post-PVI was 21.5% (p = .034). Cardiovascular causes constitute 44% of readmission. Chronic limb ischemia and intermittent claudication were two most common cardiovascular causes constituting 11.7 and 4.9% cases of readmissions. Other cardiac causes of readmissions included heart failure (4.64%), dysrhythmias (1.4%), and acute myocardial infarction (1.7%). The high-risk factors for of all-cause 30-day readmission were hypertension, CLI, diabetes, renal failure, dyslipidemia, smoking, chronic pulmonary disease, and atrial fibrillation (p < .005). Length-of-stay was greater than 5 days for 56.2 and 75.4% paid by Medicare.

CONCLUSIONS

Our study shows an average yearly readmission rate of 21.5% post-PVI. Chronic comorbidities and prolonged hospitalization were associated with higher risk of readmission.

Incidence of Major Atherothrombotic Vascular Events among Patients with Peripheral Artery Disease after Revascularization

BACKGROUND

Patients with peripheral artery disease (PAD) treated with lower extremity revascularization are at increased risk of major atherothrombotic vascular events (acute limb ischemia (ALI), major non-traumatic lower-limb amputation, myocardial infarction (MI), ischemic stroke, and cardiovascular (CV)-related death). This study assessed the incidence of major atherothrombotic vascular events, venous thromboembolism (VTE) events and rates of subsequent lower extremity revascularizations in the real-world among patients with PAD after revascularization.

METHODS

Patients aged ≥50 years with PAD who underwent peripheral revascularization were identified from Optum Clinformatics Data Mart claims database (Q1/2014-Q2/2019). The first lower extremity revascularization after PAD diagnosis was defined as index date. Incidence rates of major atherothrombotic vascular events (i.e., composite of ALI, major non-traumatic lower-limb amputation, MI, ischemic stroke, and CV-related death) and VTE were assessed during follow-up as the number of events divided by patient-years of observation (censored at the first event). Rates of subsequent revascularizations and VTE were estimated overall and compared between patients with major atherothrombotic vascular events and those without.

RESULTS

Of the 38,439 patients included, 6,675 (17.4%) had a major atherothrombotic vascular event during a median follow-up of 1.0 year. The composite major atherothrombotic vascular and VTE incidence rates were 13.81/100 patient years and 1.77/100 patient years, respectively, and 40.2% of patients experienced subsequent revascularizations. Patients with a post-revascularization major atherothrombotic vascular event had significantly higher rates of subsequent revascularizations (64.6% vs. 35.1%, standardized difference [SD] ≥10%) and VTE (4.6% vs. 2.1%, SD ≥10%) versus those without.

CONCLUSION

One-in-six PAD patients aged ≥50 years who underwent peripheral revascularization experienced a major atherothrombotic vascular event within one year, and consequently, experienced higher rates of subsequent revascularizations compared with those without a major atherothrombotic vascular event post-revascularization. These findings highlight the need to improve strategies to prevent major atherothrombotic vascular events after revascularization.

Quantifying the risk-adjusted hospital costs of postoperative complications after lower extremity bypass in patients with claudication

OBJECTIVE

Increasing evidence has shown that the risks associated with surgical revascularization for intermittent claudication outweigh the benefits. The aim of our study was to quantify the cost of care associated with perioperative complications after elective lower extremity bypass (LEB) in patients presenting with intermittent claudication.

METHODS

All patients undergoing first-time LEB for claudication in the Healthcare Database (2009-2015) were included. The primary outcome was in-hospital postoperative complications, including major adverse limb events (MALE), major adverse cardiac events (MACE), acute kidney injury, and wound complications. The overall crude hospital costs are reported, and a generalized linear model with log link and inverse Gaussian distribution was used to calculate the predicted hospital costs for specific complications.

RESULTS

Overall, 7154 patients had undergone elective LEB for claudication during the study period. The median age was 66 years (interquartile range, 59-73 years), 67.5% were male, and 75.3% were white. Two thirds of patients (61.2%) had Medicare insurance, followed by private insurance (26.9%), Medicaid (7.7%), and other insurance (4.2%). In-hospital complications occurred in 8.5% of patients, including acute kidney injury in 3.0%, MALE in 2.8%, wound complications in 2.3%, and MACE in 1.0%. The overall median crude hospital cost was $11,783 (interquartile range, $8911-$15,767) per patient. The incremental increase in cost associated with a postoperative complication was significant, ranging from $6183 (95% confidence interval, $4604-$7762) for MALE to $10,485 (95% confidence interval, $6529-$14,441) for MACE after risk adjustment.

CONCLUSIONS

Postoperative complications after elective LEB for claudication are not uncommon and increase the in-hospital costs by 46% to 78% depending on the complication. Surgical revascularization for claudication should be used sparingly in carefully selected patients.

Reducing Nontraumatic Lower-Extremity Amputations by 20% by 2030: Time to Get to Our Feet: A Policy Statement From the American Heart Association

Nontraumatic lower-extremity amputation is a devastating complication of peripheral artery disease (PAD) with a high mortality and medical expenditure. There are ≈150 000 nontraumatic leg amputations every year in the United States, and most cases occur in patients with diabetes. Among patients with diabetes, after an ≈40% decline between 2000 and 2009, the amputation rate increased by 50% from 2009 to 2015. A number of evidence-based diagnostic and therapeutic approaches for PAD can reduce amputation risk. However, their implementation and adherence are suboptimal. Some racial/ethnic groups have an elevated risk of PAD but less access to high-quality vascular care, leading to increased rates of amputation. To stop, and indeed reverse, the increasing trends of amputation, actionable policies that will reduce the incidence of critical limb ischemia and enhance delivery of optimal care are needed. This statement describes the impact of amputation on patients and society, summarizes medical approaches to identify PAD and prevent its progression, and proposes policy solutions to prevent limb amputation. Among the actions recommended are improving public awareness of PAD and greater use of effective PAD management strategies (eg, smoking cessation, use of statins, and foot monitoring/care in patients with diabetes). To facilitate the implementation of these recommendations, we propose several regulatory/legislative and organizational/institutional policies such as adoption of quality measures for PAD care; affordable prevention, diagnosis, and management; regulation of tobacco products; clinical decision support for PAD care; professional education; and dedicated funding opportunities to support PAD research. If these recommendations and proposed policies are implemented, we should be able to achieve the goal of reducing the rate of nontraumatic lower-extremity amputations by 20% by 2030.

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.

The Society for Vascular Surgery Alternative Payment Model Task Force report on opportunities for value-based reimbursement in care for patients with peripheral artery disease

The Society for Vascular Surgery Alternative Payment Model (APM) Taskforce document explores the drivers and implications for developing objective value-based reimbursement plans for the care of patients with peripheral arterial disease (PAD). The APM is a payment approach that highlights high-quality and cost-efficient care and is a financially incentivized pathway for participation in the Quality Payment Program, which aims to replace the traditional fee-for-service payment method. At present, the participation of vascular specialists in APMs is hampered owing to the absence of dedicated models. The increasing prevalence of PAD diagnosis, technological advances in therapeutic devices, and the increasing cost of care of the affected patients have financial consequences on care delivery models and population health. The document summarizes the existing measurement methods of cost, care processes, and outcomes using payor data, patient-reported outcomes, and registry participation. The document also evaluates the existing challenges in the evaluation of PAD care, including intervention overuse, treatment disparities, varied clinical presentations, and the effects of multiple comorbid conditions on the cost potentially attributable to the vascular interventionalist. Medicare reimbursement data analysis also confirmed the prolonged need for additional healthcare services after vascular interventions. The Society for Vascular Surgery proposes that a PAD APM should provide patients with comprehensive care using a longitudinal approach with integration of multiple key medical and surgical services. It should maintain appropriate access to diagnostic and therapeutic advancements and eliminate unnecessary interventions. It should also decrease the variability in care but must also consider the varying complexity of the presenting PAD conditions. Enhanced quality of care and physician innovation should be rewarded. In addition, provisions should be present within an APM for high-risk patients who carry the risk of exclusion from care because of the naturally associated high costs. Although the document demonstrates clear opportunities for quality improvement and cost savings in PAD care, continued PAD APM development requires the assessment of more granular data for accurate risk adjustment, in addition to largescale testing before public release. Collaboration between payors and physician specialty societies remains key.

Serum apolipoprotein A-I concentration differs in coronary and peripheral artery disease

Coronary artery and peripheral artery diseases represent different clinical outcomes of atherosclerosis and despite sharing common risk factors the ultimate reasons determining disease presentation are still unclear. The present study sought to define and compare the serum lipid and apolipoprotein profiles of patients undergoing coronary artery bypass grafting and those treated invasively for symptomatic lower extremity peripheral artery disease. Altogether 218 coronary and 280 peripheral artery disease patients treated between 2013 and 2014 in the Tampere University Hospital, Tampere, Finland, with available lipid measurements within two years prior to the intervention were retrospectively analysed. The Extended Friedewald formula neural network model was used to obtain apolipoprotein and lipoprotein subfraction values. Patients undergoing coronary artery bypass surgery had a clear male predominance (82% versus 53%, p < 0.001), lower median age (69 versus 74 years, p < 0.001) and a lower prevalence of smoking (18% versus 32%, p = 0.001) and pulmonary disease (12% versus 20%, p = 0.023) compared to peripheral artery disease patients. There were some differences in the serum lipid profiles between the study groups in the univariable analyses. When controlling for the statistically significant differences in age, sex, urgency of treatment and comorbidities between the groups in a multivariable logistic regression model, higher serum concentrations of apolipoprotein A-I were significantly and independently associated with coronary artery disease (OR 1.11 for 0.01 g/L increase, p = 0.044). In conclusion, patients undergoing coronary artery bypass grafting appear to have higher apolipoprotein A-I levels when compared to patients treated for peripheral artery disease.

A systematic review and meta-analysis of risk factors for and incidence of 30-day readmission after revascularization for peripheral artery disease

OBJECTIVE

Readmission to the hospital after revascularization for peripheral artery disease (PAD) is frequently reported. No consensus exists as to the exact frequency and risk factors for readmission. This review aimed to determine the incidence of and risk factors for 30-day readmission after revascularization for PAD.

METHODS

PubMed/Medline (Ovid), Scopus, Web of Science, the Cochrane Library, and CINAHL were searched systematically from inception until May 20, 2018. Studies were eligible for inclusion if they included patients with diagnosed PAD undergoing revascularization and reported the readmission rate and a statistical evaluation of the association of at least one risk factor with readmission. Studies were excluded if data for other procedures could not be distinguished from revascularization. Two authors undertook study selection independently with the final inclusion decision resolved through consensus. The PRISMA and Meta-analyses of Observational Studies in Epidemiology guidelines were followed regarding data extraction and quality assessment, which was performed by two authors independently. Data were pooled using a random effects model.

RESULTS

The primary outcome was readmission within 30 days of revascularization. Fourteen publications reporting the outcomes of 526,008 patients were included. Reported readmission rates ranged from 10.9% to 30.0% with a mean of 16.4% (95% confidence interval [CI], 15.1%-17.9%). Meta-analyses suggested the following risk factors had a significant association with readmission: female sex (odds ratio [OR], 1.13; 95% CI, 1.05-1.21), black race (OR, 1.36; 95% CI, 1.28-1.46), dependent functional status (OR, 1.72; 95% CI, 1.43-2.06), critical limb ischemia (OR, 2.12; 95% CI, 1.72-2.62), emergency admission (OR, 1.75; 95% CI, 1.43-2.15), hypertension (OR, 1.39; 95% CI, 1.26-1.54), heart failure (OR, 1.82; 95% CI, 1.50-2.20), chronic pulmonary disease (OR, 1.19; 95% CI, 1.08-1.32), diabetes (OR, 1.47; 95% CI, 1.32-1.63), chronic kidney disease (OR, 1.93; 95% CI, 1.62-2.31), dialysis dependence (OR, 2.08; 95% CI, 1.75-2.48), smoking (OR, 0.83; 95% CI, 0.78-0.89), postoperative bleeding (OR, 1.70; 95% CI, 1.23-2.35), and postoperative sepsis (OR, 4.13; 95% CI, 2.02-8.47).

CONCLUSIONS

Approximately one in six patients undergoing revascularization for PAD are readmitted within 30 days of their procedure. This review identified multiple risk factors predisposing to readmission, which could potentially serve as a way to target interventions to reduce readmissions.

Using the epidemiology of critical limb ischemia to estimate the number of patients amenable to endovascular therapy

Critical limb ischemia represents the advanced stage of peripheral artery disease, a health problem with increasing prevalence. Critical limb ischemia is associated with significant mortality, limb loss, pain, and diminished health-related quality of life. Public awareness and early diagnosis are necessary for an effective treatment with early risk factor modification, smoking cessation, and exercise therapy. Herein, we present an overview of the epidemiology as well as the clinical stages of the disease, and estimate that there are 6.5 million patients with critical limb ischemia in the US, Europe, and Japan based on global population-based studies. At least 75% of these patients, accounting for approximately 4.8 million patients, are amenable to endovascular therapy.

Major Adverse Limb Events and 1-Year Outcomes After Peripheral Artery Revascularization

BACKGROUND

Revascularization is important for symptom treatment and limb salvage in peripheral artery disease, yet little data exist on the incidence of post-procedure major adverse limb events (MALE) and longer-term outcomes.

OBJECTIVES

This study sought to characterize hospitalizations and outpatient endovascular revascularizations after peripheral artery revascularization, assess temporal trends for outcomes, and identify factors associated with subsequent MALE hospitalization.

METHODS

Patients undergoing peripheral artery revascularization between January 1, 2009, and September 30, 2014, in the Premier Healthcare Database were examined for the primary outcome of 1-year MALE hospitalization. Secondary outcomes included 1-year outpatient endovascular revascularization and limb-related, cardiovascular, and all-cause inpatient hospitalizations. Multivariable logistic regression was used to identify factors associated with 1-year MALE hospitalization.

RESULTS

Among 381,415 revascularized patients, within 1 year post-index revascularization, 10.3% (n = 10,182) had a hospitalization for MALE, 11.0% (n = 42,056) had an outpatient endovascular revascularization, 18.8% (n = 71,663) had a limb-related hospitalization, 12.8% (n = 48,875) had a cardiovascular hospitalization, and 38.9% (n = 148,457) had any inpatient hospitalization. Over the study period, limb-related, cardiovascular, and all-cause hospitalizations decreased, whereas rates of outpatient endovascular revascularizations increased. Male sex, black race, Medicare and Medicaid insurance, diabetes, renal insufficiency, heart failure, smoking, baseline critical or acute limb ischemia, surgical revascularization, and noncardiology operator specialty were significantly associated with increased risk of MALE hospitalization.

CONCLUSIONS

In contemporary practice, hospitalization for MALE occurs in 1 in 10 patients within 1 year after peripheral revascularization and is associated with patient and procedural factors. These data may inform efforts to improve post-procedure outcomes and limb-related clinical trial design.

Temporal trends and hospital costs associated with an endovascular-first approach for acute limb ischemia

OBJECTIVE

Recent studies suggest similar perioperative outcomes for endovascular and open surgical management of acute limb ischemia (ALI). We sought to describe temporal trends, patient factors, and hospital costs associated with contemporary ALI management.

METHODS

We used the weighted National Inpatient Sample to estimate primary ALI cases requiring open or endovascular intervention (2005-2014). We used multivariable regression models to examine temporal trends, patient factors, and hospital costs associated with endovascular-first vs open-first management.

RESULTS

Of 116,451 admissions for ALI during the study period, 35.2% were treated by an endovascular-first approach. The percentage of admissions managed with an endovascular-first approach increased over time (P < .001). Independent predictors of endovascular-first management included younger age, male sex, renal insufficiency, and more recent calendar year of admission (P ≤ .02), whereas patients who underwent fasciotomy, those with Medicaid, and those admitted on a weekend were more likely to undergo open-first management (P ≤ .02). Endovascular-first management had higher mean hospital costs than open-first management ($29,719 vs $26,193; P < .001). After adjustment for patient, hospital, and admission characteristics, there was an increase of $981 in treatment costs per year in the endovascular-first group (95% confidence interval [CI], $571-$1392; P < .001), whereas the costs associated with an open-first approach remained relatively stable over time ($10 per year; 95% CI, -$295 to $315; P = .95; P < .001 for interaction). The risk-adjusted odds of in-hospital major amputation was similar in both groups (adjusted odds ratio, 0.99; 95% CI, 0.85-1.15; P = .88).

CONCLUSIONS

Use of an endovascular-first approach for the treatment of ALI has significantly increased over time. Although major amputation rates are similar for both approaches, the costs associated with an endovascular-first approach are increasing over time, whereas the costs of open surgery have remained stable. The cost-effectiveness of modern ALI management warrants further investigation.

A Strategy for Risk-adjusted Ranking of Surgeons and Practices Based on Patient-reported Outcomes After Elective Lumbar Surgery

STUDY DESIGN

This study retrospectively analyzes prospectively collected data.

OBJECTIVE

The primary aim of this study is to present a scheme for patient-reported outcome (PRO)-based, risk-adjusted rankings of spine surgeons and sites that perform elective lumbar surgery, using the Quality and Outcomes Database (QOD).

SUMMARY OF BACKGROUND DATA

There is currently no means of determining which spine surgeons or centers are positive or negative outliers with respect to PROs for elective lumbar surgery. This is a critical gap as we move toward a value-based model of health care in which providers assume more accountability for the effectiveness of their treatments.

METHODS

Random effects regression models were fit for the following outcomes, with QOD site as a fixed effect but surgeon ID as a random effect: Oswestry Disability Index, EQ-5D, back pain and leg pain, and satisfaction. Hierarchical Bayesian models were also fit for each outcome, with QOD site as a random effect and surgeon as a nested random effect.

RESULTS

Our study cohort consists of 8834 patients who underwent surgery by 124 QOD surgeons, for the degenerative lumbar diseases. Nonoverlapping Bayesian credible intervals demonstrate that the variance attributed to QOD site was greater than the nested variance attributed to surgeon ID for the included PROs.

CONCLUSION

This study presents a novel strategy for the risk-adjusted, PRO-based ranking of spine surgeons and practices. This can help identify positive and negative outliers, thereby forming the basis for large-scale quality improvement. Assuming adequate coverage of baseline risk adjustment, the choice of surgeon matters when considering PROs after lumbar surgery; however, the choice of site appears to matter more.

LEVEL OF EVIDENCE

3.

Regional variation in use and outcomes of combined carotid endarterectomy and coronary artery bypass

OBJECTIVE

In treating concomitant carotid and coronary disease, some recommend staged carotid endarterectomy (CEA) and coronary artery bypass grafting, whereas others favor the combined approach (CCAB). Pressure to reduce surgical variation and to improve quality is real, yet little is known about how geographic practice differences affect outcomes. Using the Vascular Quality Initiative (VQI), this study evaluated regional variation in use and outcomes of CCAB.

METHODS

All CCAB procedures in the VQI from 2003 to 2017 were reviewed and stratified into four regions, as defined by the United States Census Bureau. Primary outcomes included perioperative stroke, death, myocardial infarction (MI), and these as composite (SDM). A χ² analysis was performed.

RESULTS

There were 1495 CCAB procedures identified, representing 1.8% of the VQI CEAs. Regions included the following: Midwest (MW), 32%; Northeast (NE), 39%; South (S), 25%; and West (W), 4%. Most were male (70%) and white (92%). There was significant regional variation in proportional volume of CCABs to all CEAs (0.7% [W] to 2.5% [MW]; P < .001). Regional variation in patch use (78% [W] to 93% [MW]; P < .001), shunting (29% [W] to 71% [MW]; P < .001), and electroencephalography monitoring (13% [W] to 52% [NE]; P < .001) was also significant. Overall perioperative stroke was 3.6%; death, 3.0%; and SDM, 6.8%. No regional difference was seen in outcomes of mortality (1.5% [MW] to 4.2% [NE]; P = .05), stroke (2.8% [NE] to 4.4% [MW]; P = .52), and MI (0.6% [MW] to 1.8% [W]; P = .62). When the Bonferroni correction was used, there remained no difference in stroke, MI, or SDM across regions, but mortality became significant. Using the Society for Vascular Surgery guidelines for consideration of CCAB, the minority of patients fell within the symptomatic carotid stenosis (SYMP, 15%; n = 218) or severe (≥70%) asymptomatic bilateral carotid disease (BIL, 18%; n = 267) categories. The most common indication was asymptomatic unilateral severe carotid stenosis (UNI, 37%; n = 552). There were no differences in regional outcomes stratified by indication (SYMP, BIL, UNI). Overall, when SYMP and BIL were compared with UNI, UNI had lower rates of stroke (2.4% vs 4.9%; P = .03) but similar MI (0.7% vs 1.2%; P = .40) and mortality (2.2% vs 2.5%; P = .75).

CONCLUSIONS

Significant variation exists across VQI centers in the use of CCAB. Despite differences in volume and practices, regional perioperative outcomes are similar. UNI is the most commonly used indication and has lower stroke rates relative to SYMP and BIL. CCAB is performed well across the United States, but most patients fall outside of Society for Vascular Surgery guidelines.

Using the Society for Vascular Surgery Wound, Ischemia, and foot Infection classification to identify patients most likely to benefit from revascularization

BACKGROUND

The Society of Vascular Surgery Wound Ischemia foot Infection (WIfI) classification system for chronic limb-threatening ischemia was intended to predict 1-year major lower extremity amputation (LEA) risk and to identify which patients benefit most from revascularization. We aimed to identify which WIfI presentations benefited most from revascularization to explore whether a cluster analysis could identify a more data-driven WIfI score, and to quantify which component of the WIfI score was most strongly associated with 1-year LEA after revascularization.

METHODS

Composite multi-institutional nested cohort data from centers who previously validated WIfI were reviewed retrospectively. We collected each patient's WIfI component grades and whether LEA was performed. To examine the benefit of revascularization, the predicted LEA rates were subtracted from observed LEA rates. We used k-means cluster analysis to model predicted vs observed LEA rates after revascularization. Multivariable linear regression analysis was performed to quantify which WIfI score component(s) best predicted LEA.

RESULTS

Data from 10 centers, accumulated between 2005 and 2015 were collated (2878 limbs at risk; 314 LEAs performed). The subset of patients who underwent revascularization comprised the study base (1654 limbs; 169 LEAs). Of 64 potential WIfI grade combinations, 15 were never reported and were excluded from the analysis. By original WIfI stages, the observed LEA rate after revascularization was: stage 1, 10.8% (14/130); stage 2, 4.9% (5/103); stage 3, 5.1% (25/487); and stage 4, 13.4% (125/934). Based on the difference between predicted and observed LEA risk for those who underwent revascularization, the WIfI scores were placed into quartiles from greatest to no benefit of revascularization. Cluster analysis identified four clusters with the following 1-year LEA rates: cluster 1, 4.4% (46/1038); cluster 2, 14.8% (66/447); cluster 3, 28.1% (36/128); and cluster 4, 51.2% (21/41). The between sum of squares/total sum of squares was 93.9%. Multiple linear regression revealed the wound grade most strongly predicted LEA (F-value, 17.25; P < .001). Ischemia (F-value, 6.51; P = .001) and infection (F-value, 5.7; P = .003) were similarly associated with LEA risk. Interaction terms between each component of the WIfI score were not statistically significant.

CONCLUSIONS

WIfI can identify which patients with chronic limb-threatening ischemia are most likely to benefit from revascularization and may provide improved prognostication, risk stratification, and equitable outcome assessments. After revascularization, wound severity is most strongly associated with LEA risk. Ischemic and infectious grades confer additive, but not synergistic, risk. Future cluster analyses comparing specific WIfI presentations treated with and without revascularization will be required to further refine WIfI.

Preventing Major Amputations in Patients with Critical Limb Ischemia

PURPOSE OF REVIEW

This review summarizes the risks of lower extremity amputation associated with critical limb ischemia (CLI) and discusses current therapies that can prevent amputation in CLI.

RECENT FINDINGS

CLI remains an under-recognized condition associated with high rates of major amputation and disparities in care. Optimal medical therapy can reduce the risk of major adverse cardiovascular and limb events, but revascularization combined with close wound care remains the cornerstone of amputation prevention. Endovascular revascularization has become more common over time and has been associated with a reduction in amputation rates. Ongoing clinical trials will help inform best practices for revascularization strategies and techniques. Vascular care is inconsistent across the USA, with significant variation in access to care revascularization rates and rates of major amputation. Major amputation can be prevented in patients with CLI when optimal medical therapy, lifestyle modification, and revascularization are provided in a multidisciplinary setting.

Peripheral atherectomy practice patterns in the United States from the Vascular Quality Initiative

OBJECTIVE

Peripheral atherectomy has been shown to have technical success in single-arm studies, but clinical advantages over angioplasty and stenting have not been demonstrated, leaving its role unclear. We sought to describe patterns of atherectomy use in a real-world U.S. cohort to understand how it is currently being applied.

METHODS

The Vascular Quality Initiative was queried to identify all patients who underwent peripheral vascular intervention from January 2010 to September 2016. Descriptive statistics were performed to analyze demographics of the patients, comorbidities, indication, treatment modalities, and lesion characteristics. The intermittent claudication (IC) and critical limb ischemia (CLI) cohorts were analyzed separately.

RESULTS

Of 85,605 limbs treated, treatment indication was IC in 51% (n = 43,506) and CLI in 49% (n = 42,099). Atherectomy was used in 15% (n = 13,092) of cases, equivalently for IC (15%; n = 6674) and CLI (15%; n = 6418). There was regional variation in use of atherectomy, ranging from a low of 0% in one region to a high of 32% in another region. During the study period, there was a significant increase in the proportion of cases that used atherectomy (11% in 2010 vs 18% in 2016; P < .0001). Compared with nonatherectomy cases, those with atherectomy use had higher incidence of prior peripheral vascular intervention (IC, 55% vs 43% [P < .0001]; CLI, 47% vs 41% [P < .0001]), greater mean number of arteries treated (IC, 1.8 vs 1.6 [P < .0001]; CLI, 2.1 vs 1.7 [P < .0001]), and lower proportion of prior leg bypass (IC, 10% vs 14% [P < .0001]; CLI, 11% vs 17% [P < .0001]). There was lower incidence of failure to cross the lesion (IC, 1% vs 4% [P < .0001]; CLI, 4% vs 7% [P < .0001]) but higher incidence of distal embolization (IC, 1.9% vs 0.8% [P < .0001]; CLI, 3.0% vs 1.4% [P < .0001]) and, in the CLI cohort, arterial perforation (1.4% vs 1.0%; P = .01).

CONCLUSIONS

Despite a lack of evidence for atherectomy over angioplasty and stenting, its use has increased across the United States from 2010 to 2016. It is applied equally to IC and CLI populations, with no identifiable pattern of comorbidities or lesion characteristics, suggesting that indications are not clearly delineated or agreed on. This study places impetus on further understanding of the optimal role for atherectomy and its long-term clinical benefit in the management of peripheral arterial disease.

Regional variation in the cost of infrainguinal lower extremity bypass surgery in the United States

BACKGROUND

Lower extremity bypass (LEB) remains the gold standard revascularization procedure in patients with peripheral arterial disease. The cost of LEB substantially varies based on patient's characteristics and comorbidities. The aim of this study was to assess regional variation in infrainguinal LEB cost and to identify the specific health care expenditures per service that are associated with the highest cost in each region.

METHODS

We identified adult patients who underwent infrainguinal LEB in the Premier database between June 2009 and March 2015. Generalized linear regression models were used to report differences between regions in total in-hospital cost and service-specific cost adjusting for patient's demographics, clinical characteristics, and hospital factors.

RESULTS

A total of 50,131 patients were identified. The median in-hospital cost was $13,259 (interquartile range, $9308-$19,590). The cost of LEB was significantly higher in West and Northeast regions with a median cost of nearly $16,000. The high cost in the Northeast region was driven by the fixed (indirect) cost, whereas the driver of the high cost in the West region was the variable (direct) cost. The adjusted total in-hospital cost was significantly higher in all regions compared with the South (mean difference, West, $3752 [95% confidence interval (CI), 3477-4027]; Northeast, $2959 [95% CI, 2703-3216]; Midwest, 1586 [95% CI, 1364-1808]).

CONCLUSIONS

In this study, we show the marked regional variability in LEB costs. This disparity was independent from patient clinical condition and hospital factors. Cost inequality across the US represents a financial burden on both the patient and the health system.