Peripheral arterial testing before lower extremity amputation among Medicare beneficiaries, 2000 to 2010

Racial, Socioeconomic, and Geographic Disparities in Preamputation Vascular Care for Patients With Chronic Limb-Threatening Ischemia

BACKGROUND

Black patients, those with low socioeconomic status (SES), and those living in rural areas have elevated rates of major lower extremity amputation, which may be related to a lack of subspecialty chronic limb-threatening ischemia care. We evaluated the association between race, rurality, SES, and preamputation vascular care.

METHODS

Among patients aged 66 to 86 years with fee-for-service Medicare who underwent major lower extremity amputation for chronic limb-threatening ischemia from July 2010 to December 2019, we compared the proportion who received vascular care in the 12 months before amputation by race (Black versus White), rurality, and SES (dual eligibility for Medicaid versus no dual eligibility) using multivariable logistic regression adjusting for clinical and demographic covariates.

RESULTS

Among 73 237 patients who underwent major lower extremity amputation, 40 320 (55.1%) had an outpatient vascular subspecialist visit, 60 109 (82.1%) had lower extremity arterial testing, and 28 345 (38.7%) underwent lower extremity revascularization in the year before amputation. Black patients were less likely to have an outpatient vascular specialist visit (adjusted odds ratio [adjOR], 0.87 [95% CI, 0.84-0.90]) or revascularization (adjOR, 0.90 [95% CI, 0.86-0.93]) than White patients. Compared with patients without low SES or residing in urban areas, patients with low SES or residing in rural areas were less likely to have an outpatient vascular specialist visit (adjOR, 0.62 [95% CI, 0.60-0.64]; low SES versus nonlow SES; adjOR, 0.82 [95% CI, 0.79-0.85]; rural versus urban), lower extremity arterial testing (adjOR, 0.78 [95% CI, 0.75-0.81]; low SES versus nonlow SES; adjOR, 0.90 [95% CI, 0.0.86-0.94]; rural versus urban), or revascularization (adjOR, 0.65 [95% CI, 0.63-0.67]; low SES versus nonlow SES; adjOR, 0.89 [95% CI, 0.86-0.93]; rural versus urban).

CONCLUSIONS

Black race, rural residence, and low SES are associated with failure to receive subspecialty chronic limb-threatening ischemia care before amputation. To reduce disparities in amputation, multilevel interventions to facilitate equitable chronic limb-threatening ischemia care are needed.

Association Between Diagnosis-to-Limb Revascularization Time and Clinical Outcomes in Outpatients With Chronic Limb-Threatening Ischemia: Insights From the CLIPPER Cohort

BACKGROUND

The extent and consequences of ischemia in patients with chronic limb-threatening ischemia (CLTI) may change rapidly, and delays from diagnosis to revascularization may worsen outcomes. We sought to describe the association between time from diagnosis to endovascular lower extremity revascularization (diagnosis-to-limb revascularization [D2L] time) and clinical outcomes in outpatients with CLTI.

METHODS AND RESULTS

In the CLIPPER cohort, comprising patients between 66 and 86 years old diagnosed with CLTI betweeen 2010 and 2019, we used Medicare claims data to identify patients who underwent outpatient endovascular revascularization within 180 days of diagnosis. We described the risk-adjusted association between D2L time and clinical outcomes. Among 1 130 065 patients aged between 66 and 86 years with CLTI, 99 221 (8.8%) underwent outpatient endovascular lower extremity revascularization within 180 days of their CLTI diagnosis. Among patients with D2L time <30 days, there was no association between D2L time and all-cause death or major lower extremity amputation. However, among patients with D2L time >30 days, each additional 10-day increase in D2L time was associated with a 2.5% greater risk of major amputation (hazard ratio, 1.025 [95% CI, 1.014-1.036]). There was no association between D2L time and all-cause death.

CONCLUSIONS

A delay of >30 days from CLTI diagnosis to lower extremity endovascular revascularization was associated with an increased risk of major lower extremity amputation among patients undergoing outpatient endovascular revascularization. Improving systems of care to reduce D2L time could reduce amputations.

Treatment Variability Among Patients Hospitalized for Chronic Limb-Threatening Ischemia: An Analysis of the 2016 to 2018 US National Inpatient Sample

BACKGROUND

Little is known about treatment variability across US hospitals for patients with chronic limb-threatening ischemia (CLTI).

METHODS AND RESULTS

Data were collected from the 2016 to 2018 National Inpatient Sample. All patients aged ≥18 years, admitted to nonfederal US hospitals with a primary diagnosis of CLTI, were identified. Patients were classified according to their clinical presentation (rest pain, skin ulceration, or gangrene) and were further characterized according to the treatment strategy used. The primary outcome of interest was variability in CLTI treatment, as characterized by the median odds ratio. The median odds ratio is defined as the likelihood that 2 similar patients would be treated with a given modality at 1 versus another randomly selected hospital. There were 15 896 (weighted n=79 480) hospitalizations identified where CLTI was the primary diagnosis. Medical therapy alone, endovascular revascularization ± amputation, surgical revascularization ± amputation, and amputation alone were used in 4057 (25%), 5390 (34%), 3733 (24%), and 2716 (17%) patients, respectively. After adjusting for both patient- and hospital-related factors, the median odds ratio (95% CI) for medical therapy alone, endovascular revascularization ± amputation, surgical revascularization ± amputation, any revascularization, and amputation alone were 1.28 (1.19-1.38), 1.86 (1.77-1.95), 1.65 (1.55-1.74), 1.37 (1.28-1.45), and 1.42 (1.27-1.55), respectively.

CONCLUSIONS

Significant variability in CLTI treatment exists across US hospitals and is not fully explained by patient or hospital characteristics.

Effect of chronic kidney disease induced calcification on peripheral vascular perfusion using near-infrared spectroscopic imaging

Low-cost techniques that can detect the presence of vascular calcification (VC) in chronic kidney disease (CKD) patients could improve clinical outcomes. In this study, we established a near-infrared spectroscopy-based imaging technique to determine changes in peripheral hemodynamics due to CKD-induced VC. Mice were fed a high-adenine diet with either normal or high levels of phosphate to induce CKD with and without VC, respectively. The mice tail was imaged to evaluate hemodynamic changes in response to occlusion. The rate of change in oxyhemoglobin in response to occlusion showed a statistically significant difference in the presence of VC in the mice.

A Review of Healthcare Disparities Relevant to Interventional Radiology

Racial, ethnic, and gender disparities have received focused attention recently, as they became more visible in the COVID era. We continue to learn more about how healthcare disparities manifest for our patients and, more broadly, the structural underpinnings that result in predictable outcomes gaps. This review summarizes what we know about disparities relevant to interventional radiologists. The prevalence and magnitude of disparities are quantified and discussed where relevant. Specific examples are provided to demonstrate how factors like gender, ethnicity, social status, geography, etc. interact to create inequities in the delivery of interventional radiology (IR) care. Understanding and addressing health disparities in IR is crucial for improving real-world patient outcomes and reducing the economic burden associated with ineffective and low-value care. Finally, the importance of intentional mentorship, outreach, education, and equitable distribution of high-quality healthcare to mitigate these disparities and promote health equity in interventional radiology is discussed.

Development and Description of a National Cohort of Patients With Chronic Limb-Threatening Ischemia

Background

Chronic limb-threatening ischemia (CLTI) is a common condition with high rates of morbidity and mortality. Despite extensive literature documenting poor outcomes in patients with CLTI, as well as racial, ethnic, socioeconomic, and geographic disparities in these outcomes, process measures for high-quality CLTI care have not been developed. We developed the Chronic Limb threatening Ischemia Process PERformace (CLIPPER) cohort to develop and test the validity of CLTI care quality measures.

Methods

Using inpatient and outpatient claims data from patients with fee-for-service Medicare from 2010 to 2019, we created a coding algorithm to identify patients with CLTI. To qualify for a CLTI diagnosis, patients had to have either diagnostic codes for peripheral artery disease and for ulceration, infection, or gangrene on the same inpatient or outpatient claim or a CLTI-specific diagnostic code. Patients were also required to have a procedural code indicating arterial vascular testing within 6 months before or after the earliest qualifying CLTI diagnostic code(s). We describe baseline characteristics and long-term outcomes of this cohort.

Results

The final cohort comprised 1,130,065 patients diagnosed with CLTI between 2010 and 2019. Mean (±SD) age of the cohort was 75 ± 5.8 years; 48.4% were women, and 14.6% were Black. Within 30 days of CLTI diagnosis, 20.4% of patients underwent either percutaneous or surgical revascularization. Within 6 months, 3.3% of patients underwent major amputation; 16.7% of patients died within 1 year and 50.3% within 5 years.

Conclusions

We described the development of a cohort of fee-for-service Medicare patients with CLTI using inpatient and outpatient Medicare claims data. CLIPPER will be a resource for developing a set of process measures that can be captured from administrative claims data, with plans to describe their association with limb outcomes and corresponding racial, ethnic, socioeconomic, sex-based, and geographic variability.

Impact of neighborhood social disadvantage on the presentation and management of peripheral artery disease

OBJECTIVE

Studies examining the relationship between socioeconomic disparities and peripheral artery disease (PAD) often focus on individual social health determinants and fail to account for the complex interplay between factors that ultimately impact disease severity and outcomes. Area deprivation index (ADI), a validated measure of neighborhood adversity, provides a more comprehensive assessment of social disadvantage. Therefore, we examined the impact of ADI on PAD severity and its management.

METHODS

We identified all patients who underwent infrainguinal revascularization (open or endovascular) or amputation for symptomatic PAD in the Vascular Quality Initiative registry between 2003 and 2020. An ADI score of 1 to 100 was assigned to each patient based on their residential zip code, with higher ADI scores corresponding with increasing adversity. Patients were categorized by ADI quintiles (Q1-Q5). The outcomes of interest included indication for procedure (claudication, rest pain, or tissue loss) and rates of revascularization (vs primary amputation). Multinomial logistic regression was used to evaluate for an independent association between ADI quintile and these outcomes.

RESULTS

Among the 79,973 patients identified, 9604 (12%) were in the lowest ADI quintile (Q1), 14,961 (18.7%) in Q2, 19,800 (24.8%) in Q3, 21,735 (27.2%) in Q4, and 13,873 (17.4%) in Q5. There were significant trends toward lower rates of claudication (Q1: 39% vs Q5: 34%, P < .001), higher rates of rest pain (Q1: 12.4% vs Q5: 17.8%, P < .001) as the indication for intervention, and lower rates of revascularization (Q1: 80% vs Q5: 69%, P < .001) with increasing ADI quintiles. In adjusted analyses, there was a progressively higher likelihood of presenting with rest pain vs claudication, with patients in Q5 having the highest probability when compared with those in Q1 (relative risk: 2.0; 95% confidence interval: 1.8-2.2; P < .001). Patients in Q5, when compared with those in Q1, also had a higher likelihood of presenting with tissue loss vs claudication (relative risk: 1.4; 95% confidence interval: 1.3-1.6; P < .001). Compared with patients in Q1, patients in Q2-Q5 had a lower likelihood of undergoing any revascularization procedure.

CONCLUSIONS

Among patients who underwent infrainguinal revascularization or amputation in the Vascular Quality Initiative, those with higher neighborhood adversity had more advanced disease at presentation and lower rates of revascularization. Further work is needed to better understand neighborhood factors that are contributing to these disparities in order to identify community-level targets for improvement.

Socioecological model-based design and implementation principles of lower limb preservation programs as partners for limb-loss rehabilitation programs- A mini-review

People with lower limb loss, especially of dysvascular etiology, are at substantial risk for both ipsilateral and contralateral reamputation. Additionally, while not as well documented for reamputation, there is recognition that amputation incidence is influenced by not only sociodemographic factors such as sex, race, socioeconomic status, but also by system factors such as service access. A systems strategy to address this disparity within the field of limb-loss rehabilitation is for Limb-loss Rehabilitation Programs (LRP) to partner with medical specialists, mental health professionals, and Limb Preservation Programs (LPP) to provide comprehensive limb care. While LPPs exist around the nation, design principles for such programs and their partnership role with LRPs are not well established. Using a socioecological model to incorporate hierarchical stakeholder perspectives inherent in the multidisciplinary field of limb care, this review synthesizes the latest evidence to focus on LPP design and implementation principles that can help policymakers, healthcare organizations and limb-loss rehabilitation and limb-preservation professionals to develop, implement, and sustain robust LPP programs in partnership with LRPs.

Trends in the incidence rates of lower limb amputation due to nondiabetic peripheral artery disease in a large industrial city in Western Siberia, Russia: A review from 1996 to 2019

BACKGROUND

lower limb amputation (LLA) is a growing problem in the population with and without diabetes mellitus. Monitoring the incidence rates of LLA is important for health care planning and has implications for the future problems of medical and social care.

OBJECTIVE

This study aimed to determine the trends in incidence rates of LLA due to nondiabetic peripheral artery disease in Novokuznetsk, Western Siberia, Russia.

STUDY DESIGN

An observational study.

METHODS

Data on all transtibial and transfemoral amputations performed in inpatient facilities in Novokuznetsk from 1996 to 2019 were derived from the regional Register of patients with limb amputations. The rates were calculated per 100,000 population.

RESULTS

A total of 2448 persons with amputations due to nondiabetic peripheral artery disease were included in this study (3191 amputations). The overall incidence rate of LLA in Novokuznetsk increased from 14.6 in 1996 to 30.4 in 2019. The proportion of persons older than 60 years increased from 15.5% in 1996 to 20.3% in 2019.

CONCLUSION

The expected aging of the population and increasing incidence of LLA are relevant issues in Russia. These findings can contribute to improving healthcare services and the development of prevention programs to reverse the alarming trend.

Disparities in Advanced Peripheral Arterial Disease Presentation by Socioeconomic Status

Background

Diabetes and peripheral arterial disease (PAD) often synergistically lead to foot ulceration, infection, and gangrene, which may require lower limb amputation. Worldwide there are disparities in the rates of advanced presentation of PAD for vulnerable populations. This study examined rates of advanced presentations of PAD for unemployed patients, those residing in low Index of Economic Resources (IER) areas, and those in rural areas of Australia.

Methods

A retrospective study was conducted at a regional tertiary care centre (2008–2018). To capture advanced presentations of PAD, the proportion of operative patients presenting with complications (gangrene/ulcers), the proportion of surgeries that are amputations, and the rate of emergency to elective surgeries were examined. Multivariable logistic regression adjusting for year, age, sex, Charlson Comorbidity Index, and sociodemographic variables was performed.

Results

In the period examined, 1115 patients underwent a surgical procedure for PAD. Forty-nine per cent of patients had diabetes. Following multivariable testing, the rates of those requiring amputations were higher for unemployed (OR 1.99(1.05–3.79), p = 0.036) and rural patients (OR 1.83(1.21–2.76), p = 0.004). The rate of presentation with complications was higher for unemployed (OR 7.2(2.13–24.3), p = 0.001), disadvantaged IER (OR 1.91(1.2–3.04), p = 0.007), and rural patients (OR 1.73(1.13–2.65), p = 0.012). The rate of emergency to elective surgery was higher for unemployed (OR 2.32(1.18–4.54), p = 0.015) and rural patients (OR 1.92(1.29–2.86), p = 0.001).

Conclusions

This study found disparities in metrics capturing delayed presentations of PAD: higher rates of presentations with complications, higher amputation rates, and increased rates of emergency to elective surgery, for patients of low socioeconomic status and those residing in rural areas. This suggests barriers to appropriate, effective, and timely care exists for these patients.

Orthopedic Surgery Referral Pattern Analysis per Demographic Factors Among Patients Diagnosed With Severe Peripheral Artery Disease in Terms of Partial or Total Limb Amputation

Introduction: Peripheral artery disease (PAD) signifies the obstruction of blood vessels in the lower extremities due to harmful buildup of fatty material. Patients may present to their primary care provider complaining of lower extremity pain, especially during exercise. Primary care providers must weigh the severity of patients’ disease process to determine if an orthopedic surgery referral is needed based on an extensive history as well as analysis of demographic factors that may influence their risk of morbidity and mortality. We aimed to objectively present these demographic factors with numeric values in terms of influence.

Methods: We utilized the Cerner Health Facts database to analyze 63 million unique patient encounters from 2000 to 2018. The database is categorized as Institutional Review Board (IRB) exempt due to its de-identified presentation. In an outcome-based approach, we were able to calculate referral patterns based on entered demographic parameters.

Results: A patient’s age, census region, marital status, previous history of PAD/critical limb ischemia (CLI), history of surgeries, race, facility type, and urban/rural status presented as predictors of seeing a surgeon during a patient encounter.

Conclusion: Our results found numerous aforementioned demographic factors to be associated with orthopedic surgery referral patterns. This is significant as proper reconciliation of these factors may help reduce patient morbidity in terms of amputation reduction and reduce patient mortality associated with this surgery or complications.

Sex-related differences in outcome after endovascular revascularization for lower extremity artery disease

Background: Sex-related differences may influence the outcome of endovascular revascularization (EVR) in patients with lower extremity arterial disease (LEAD) even under optimized healthcare supply. Patients and methods: LEAD patients who underwent EVR at the Department of Cardiology I - Coronary and Peripheral Vascular Disease, Heart Failure, University Hospital Muenster, Germany between 2014 and 2016 were included into the retrospective study. Detailed information on risk factors and co-morbidities, medication, LEAD related measures, and interventional parameters were assessed. Outcome defined as technical success rate, complications, and mortality was analyzed up to 12 months follow-up. Results: In total, 165 female and 437 male LEAD patients were included. Women and men presented with comparable severity of LEAD in terms of critical limb threatening ischemia (46.2%), wound status (34.9%), and amputation rate (9.6%, all n.s.) at index. Intake of platelet inhibitors (65.8% female vs. 70.0% male), oral anticoagulants (21.3% vs. 25.4%), and statins (65.6% vs. 76.0%) was observed less frequently in female patients. Against the background of high technical success (85%), in-hospital death (0.8%), severe adverse cardiac (MCE; 1.7%), and limb events (MALE; 6.1%) occurred at low rates in either sex. Adjusted long-term mortality was not affected by patients' sex (female HR 0.755; p=0.312). Conclusions: Despite critical LEAD stages in every second patient, EVR was performed safe with high technical success rates in female and male patients. Long-term outcomes were observed at comparatively low rates in both sexes at the specialized vascular center. During aftercare, supply with statin therapy turned out improvable particularly in female LEAD patients.

Geographic and Socioeconomic Disparities in Major Lower Extremity Amputation Rates in Metropolitan Areas

Background Rates of major lower extremity amputation in patients with peripheral artery disease are higher in rural communities with markers of low socioeconomic status, but most Americans live in metropolitan areas. Whether amputation rates vary within US metropolitan areas is unclear, as are characteristics of high amputation rate urban communities. Methods and Results We estimated rates of major lower extremity amputation per 100 000 Medicare beneficiaries between 2010 and 2018 at the ZIP code level among ZIP codes with ≥100 beneficiaries. We described demographic characteristics of high and low amputation ZIP codes, and the association between major amputation rate and 3 ZIP code-level markers of socioeconomic status-the proportion of patients with dual eligibility for Medicaid, median household income, and Distressed Communities Index score-for metropolitan, micropolitan, and rural ZIP code cohorts. Between 2010 and 2018, 188 995 Medicare fee-for-service patients living in 31 391 ZIP codes with ≥100 beneficiaries had a major lower extremity amputation. The median (interquartile range) ZIP code-level number of amputations per 100 000 beneficiaries was 262 (75-469). Though nonmetropolitan ZIP codes had higher rates of major amputation than metropolitan areas, 78.2% of patients undergoing major amputation lived in metropolitan areas. Compared with ZIP codes with lower amputation rates, top quartile amputation rate ZIP codes had a greater proportion of Black residents (4.4% versus 17.5%, P<0.001). In metropolitan areas, after adjusting for clinical comorbidities and demographics, every $10 000 lower median household income was associated with a 4.4% (95% CI, 3.9-4.8) higher amputation rate, and a 10-point higher Distressed Communities Index score was associated with a 3.8% (95% CI, 3.4%-4.2%) higher amputation rate; there was no association between the proportion of patients eligible for Medicaid and amputation rate. These findings were comparable to the associations identified across all ZIP codes. Conclusions In metropolitan areas, where most individuals undergoing lower extremity amputation live, markers of lower socioeconomic status and Black race were associated with higher rates of major lower extremity amputation. Development of community-based tools for peripheral artery disease diagnosis and management targeted to communities with high amputation rates in urban areas may help reduce inequities in peripheral artery disease outcomes.

Utilization Rates of Diagnostic and Therapeutic Vascular Procedures Among Patients Undergoing Lower Extremity Amputations in a Rural Community Hospital: A Clinicopathological Correlation

Background:

Significant geographical variations exist in amputation rates and utilization of diagnostic and therapeutic vascular procedures before lower extremity amputations in the United States. The purpose of this study was to evaluate the rates of diagnostic and therapeutic vascular procedures in the year prior to amputation in a contemporary population and correlate with pathological findings of the amputation specimens.

Methods:

A retrospective analysis was conducted of non-traumatic amputations from 2011 to 2017 at a rural community hospital. We reviewed the proportion of patients undergoing diagnostic (ankle brachial index with duplex ultrasound, computerized tomography angiogram and invasive angiogram) and therapeutic (endovascular and surgical revascularization) vascular procedures in the year prior to amputation. Prevalence of tissue viability and osteomyelitis were evaluated in all amputated specimens and atherosclerotic vascular disease (ASVD) was evaluated in major amputations. We also analyzed primary amputation rates among different subgroups.

Results:

698 patients were included with 248 (36%) major amputations and 450 (64%) minor amputations. Any diagnostic procedure was performed in 59% of the major amputations and 49% of the minor amputations (P = 0.01). Any therapeutic revascularization procedure was performed in 34% of the major amputations and 28% of the minor amputations (P = 0.08). The pathology of major amputation specimens revealed severe ASVD in 57% and mild-moderate ASVD in 27% of specimens. Tissue viability was significantly higher in major amputations (90% vs 30%, P = 0.04) and osteomyelitis was significantly higher in minor amputations (50% vs 14%, P = 0.03). Primary amputations were performed in 66% of major amputations, 72% of minor amputations, 81% with mild to moderate ASVD and 54% with severe ASVD.

Conclusion:

Diagnostic and therapeutic vascular procedures appear under-utilized for patients undergoing lower extremity amputations at a rural community hospital. ASVD rates and tissue viability imply that revascularization could be of significant benefit to avoid major amputation.

Model-Based Algorithms for Detecting Peripheral Artery Disease Using Administrative Data From an Electronic Health Record Data System: Algorithm Development Study

Background

Peripheral artery disease (PAD) affects 8 to 10 million Americans, who face significantly elevated risks of both mortality and major limb events such as amputation. Unfortunately, PAD is relatively underdiagnosed, undertreated, and underresearched, leading to wide variations in treatment patterns and outcomes. Efforts to improve PAD care and outcomes have been hampered by persistent difficulties identifying patients with PAD for clinical and investigatory purposes.

Objective

The aim of this study is to develop and validate a model-based algorithm to detect patients with peripheral artery disease (PAD) using data from an electronic health record (EHR) system.

Methods

An initial query of the EHR in a large health system identified all patients with PAD-related diagnosis codes for any encounter during the study period. Clinical adjudication of PAD diagnosis was performed by chart review on a random subgroup. A binary logistic regression to predict PAD was built and validated using a least absolute shrinkage and selection operator (LASSO) approach in the adjudicated patients. The algorithm was then applied to the nonsampled records to further evaluate its performance.

Results

The initial EHR data query using 406 diagnostic codes yielded 15,406 patients. Overall, 2500 patients were randomly selected for ground truth PAD status adjudication. In the end, 108 code flags remained after removing rarely- and never-used codes. We entered these code flags plus administrative encounter, imaging, procedure, and specialist flags into a LASSO model. The area under the curve for this model was 0.862.

Conclusions

The algorithm we constructed has two main advantages over other approaches to the identification of patients with PAD. First, it was derived from a broad population of patients with many different PAD manifestations and treatment pathways across a large health system. Second, our model does not rely on clinical notes and can be applied in situations in which only administrative billing data (eg, large administrative data sets) are available. A combination of diagnosis codes and administrative flags can accurately identify patients with PAD in large cohorts.

Outcome of patients with chronic limb-threatening ischemia with and without revascularization

Summary: Background: Patients with chronic critical limb-threatening ischemia (CLTI) are at high risk of amputation and death. Despite the general recommendation for revascularization in CTLI in the guidelines, the underlying evidence for such a recommendation is limited. The aim of our study was to assess the outcome of patients with CLTI depending on the use of revascularization in a retrospective real-world cohort. Patients and methods: Administrative data of the largest German Health insurance (BARMER GEK) were provided for all patients that were hospitalized for the treatment of CLTI Rutherford category (RF) 5 and 6 between 2009 and 2011. Patients were followed-up until December 31st, 2012 for limb amputation and death in relation to whether patients did (Rx +) or did not have (Rx −) revascularization during index-hospitalization. Results: We identified 15,314 patients with CLTI at RF5 (n = 6,908 (45.1%)) and RF6 (n = 8,406 (54.9%)), thereof 7,651 (50.0%) underwent revascularization (Rx +) and 7,663 (50.0%) were treated conservatively (Rx −). During follow-up (mean 647 days; 95% CI 640–654 days) limb amputation (46.5% Rx− vs. 40.6% Rx+, P < 0.001) and overall mortality (48.2% Rx− vs. 42.6% Rx+, P < 0.001) were significantly lower in the subgroup Rx+. Conclusions: In a real-world setting, only half of CLTI were revascularized during the in-hospital treatment. Though, revascularization was associated with significantly better observed short- and long-term outcome. These data do not allow causal conclusion due to lack of data on the underlying reason for applied or withheld revascularization and therefore may involve a relevant selection bias.

Multidisciplinary Care for Critical Limb Ischemia: Current Gaps and Opportunities for Improvement

Critical limb ischemia (CLI), defined as ischemic rest pain or nonhealing ulceration due to arterial insufficiency, represents the most severe and limb-threatening manifestation of peripheral artery disease. A major challenge in the optimal treatment of CLI is that multiple specialties participate in the care of this complex patient population. As a result, the care of patients with CLI is often fragmented, and multidisciplinary societal guidelines have not focused specifically on the care of patients with CLI. Furthermore, multidisciplinary care has the potential to improve patient outcomes, as no single medical specialty addresses all the facets of care necessary to reduce cardiovascular and limb-related morbidity in this complex patient population. This review identifies current gaps in the multidisciplinary care of patients with CLI, with a goal toward increasing disease recognition and timely referral, defining important components of CLI treatment teams, establishing options for revascularization strategies, and identifying best practices for wound care post-revascularization.

Association of Race with Long-Term Outcomes in Patients Undergoing Popliteal and Infra-Popliteal Percutaneous Peripheral Arterial Interventions

BACKGROUND

Race-related differences in clinical features, presentation, treatment and outcomes of patients with various cardiovascular diseases have been reported in previous studies. However, the long-term outcomes in black versus white patients with popliteal and/or infra-popliteal peripheral arterial disease (PAD) undergoing percutaneous peripheral vascular interventions (PVI) are not well known.

METHODS AND RESULTS

We retrospectively evaluated long-term outcomes in 696 patients (263 blacks and 433 whites) who underwent PVI for popliteal and/or infra-popliteal PAD at our institution between 2007 and 2012. When compared to white patients, black patients were younger (70 ± 11 vs. 72 ± 11; P = 0.002) and had more comorbidities: higher creatinine (2.04 ± 2.08 vs. 1.33 ± 1.16; P < 0.0001) with more ESRD (19% vs. 6%; P < 0.0001) and more diabetes (64% vs. 55%; P = 0.004). At mean follow-up of 36 ± 20 months, there was no statistically significant difference between black and white patients either in all-cause mortality (29% vs. 32%; P = 0.38) or in major amputation (4.4% vs. 4.2%; P = 0.88), respectively. In a multi-variate Cox proportional hazard model, repeat ipsilateral percutaneous revascularization or bypass were lower in black patients (HR = 0.64 [95% CI 0.46-0.89]; P = 0.007) and major adverse vascular events (MAVE) were lower in black patients as well (HR = 0.7 [95% CI 0.56-0.89]; P = 0.003).

CONCLUSION

Black patients undergoing popliteal or infra-popliteal PVI had similar mortality and major amputation, but lower repeat revascularization and MAVE compared to white patients. These data support the use of PVI in minorities despite higher baseline comorbidities and call for more research to understand the mechanisms underlying the high mortality irrespective of race.

Trends in Rates of Lower Extremity Amputation Among Patients With End-stage Renal Disease Who Receive Dialysis

IMPORTANCE

Patients with end-stage renal disease (ESRD) who receive dialysis are at high risk of lower extremity amputation. Recent studies indicate decreasing rates of lower extremity amputation in non-ESRD populations, but contemporary data for patients with ESRD who receive dialysis are lacking.

OBJECTIVES

To assess rates of lower extremity amputation among patients with ESRD who receive dialysis during a recent 15-year period; to analyze whether those rates differed by age, sex, diabetes, or geographic region; and to determine 1-year mortality rates in this population after lower extremity amputation.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective study of 3 700 902 records obtained from a US national registry of patients with ESRD who receive dialysis assessed cross-sectional cohorts for each calendar year from 2000 through 2014. Adult patients with prevalent ESRD treated with hemodialysis or peritoneal dialysis covered by Medicare Part A and B on January 1 of each cohort year were included. Data analysis was conducted from August 2017 to April 2018.

EXPOSURES

Age, sex, diabetes, and hospital referral region.

MAIN OUTCOMES AND MEASURES

Annual rates per 100 person-years of nontraumatic major (above- or below-knee) and minor (below-ankle) amputations.

RESULTS

For each annual cohort, there were fewer women (47.5% in 2000, 46.2% in 2005, 44.9% in 2010, and 44.0% in 2014) than men, more than half the patients were white individuals (58.1% in 2000, 56.9% in 2005, 56.9% in 2010, and 56.7% in 2014), and a small proportion were employed (13.9% in 2000, 15.1% in 2005, 16.1% in 2010, and 16.5% in 2014). The rate of lower extremity amputations for patients with ESRD who receive dialysis decreased by 51.0% from 2000 to 2014, driven primarily by a decrease in the rate of major amputations (5.42 [95% CI, 5.28-5.56] in 2000 vs 2.66 [95% CI, 2.59-2.72] per 100 person-years in 2014). Patients with diabetes had amputation rates more than 5 times as high as patients without diabetes. Patients younger than 65 years had higher adjusted amputation rates than older patients, and men had consistently higher adjusted amputation rates than women. Adjusted 1-year mortality rates after lower extremity amputation for patients with ESRD who receive dialysis decreased from 52.2% (95% CI, 50.9%-53.4%) in 2000 to 43.6% (95% CI, 42.5%-44.8%) in 2013. In general, amputation rates decreased among all regions from 2000 to 2014, but regional variability persisted across time despite adjustment for differences in patient demographics and comorbid conditions.

CONCLUSIONS AND RELEVANCE

Although rates of lower extremity amputations among US patients with ESRD who receive dialysis decreased by 51% during a recent 15-year period, mortality rates remained high, with nearly half of patients dying within a year after lower extremity amputation. Our results highlight the need for more research on ways to prevent lower extremity amputation in this extremely high-risk population.

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.

Risk of major amputation or death among patients with critical limb ischemia initially treated with endovascular intervention, surgical bypass, minor amputation, or conservative management

AIMS

Patients with critical limb ischemia (CLI) have an increased risk of major amputation. The initial treatment approach for CLI may significantly impact the subsequent risk of major amputation or death. The objective of this study was to describe the initial treatment approaches of patients with CLI and the limb outcomes associated with each approach.

METHODS

Data from MarketScan Commercial and Medicare Supplemental Databases from January 2006-December 2014 was utilized. Cohorts of CLI patients were defined as follows: (1) peripheral vascular intervention (PVI); (2) peripheral vascular surgery (PVS); (3) minor amputation without concomitant PVI or PVS (MinAMP); and (4) Patients without PVI, PVS, or MinAMP (conservative therapy). The odds of major amputation or inpatient death were estimated using the Cox proportional hazards model. For those patients requiring a major amputation, the incremental expenditures per member per month (PMPM) were estimated using a gamma log-link model.

RESULTS

Conservative therapy was associated with significantly higher odds of major amputation or inpatient death compared to patients who underwent minor amputation (1.59-times), PVI (2.08-times), or PVS (2.12-times). Patients treated with an initial strategy of minor amputation also had higher odds of major amputation or inpatient death compared to PVS (1.31-times) or PVI (1.33-times). The estimated incremental expenditures PMPM for patients with a major amputation was $5,165.

CONCLUSIONS

Revascularization reduces the risk of a major amputation or inpatient death for patients with CLI when compared to conservative therapy. Major amputation is also associated with significantly higher healthcare expenditures.

Advanced Chronic Venous Insufficiency

Introduction:

Intervention for advanced chronic venous insufficiency is considered an appropriate standard of care. However, outcomes vary among patients who present in advanced clinical stages of disease. The main objectives of this study were to determine whether racial disparity exists at initial presentation and response to intervention.

Methods:

A retrospective database was created to include all radiofrequency ablation procedures performed by a single surgeon from January 14, 2009, through May 25, 2011. Demographics, clinical traits, race, procedure, and outcomes were analyzed. Stepwise model selection reduced candidate baseline factors to a final parsimonious model, which was analyzed using analysis of variance.

Results:

The database consisted of 300 patients with a predominant female (n = 215, 85%) base and 85 (15%) males, with a mean age distribution of 53 years. The mean body mass index was 30.2. Racial distribution revealed Asian (n = 9, 3.3%), Pacific Islander (n = 1, 0.4%), African American (n = 37, 13.6%), and Caucasian (CAU, n = 225, 82.7%). African Americans presented with more advanced clinical stages than the CAU group—C2: African American 21.6%, CAU 36.7%; C4: African American 35%, CAU 24.3%; and C6: African American 35.1%, CAU 7.5%. African Americans demonstrated a higher preoperative venous clinical severity score (VCSS) than their CAU counterparts. Postprocedural decrease in VCSS score was lower in African Americans than their CAU counterparts.

Conclusion:

African American patients present with more advanced venous insufficiency than CAUs. Postprocedural analysis reveals not only slower ulcer healing times but also higher ulcer recurrence rates.

Critical Limb Ischemia: An Expert Statement

Critical limb ischemia (CLI), the most advanced form of peripheral artery disease, is associated with significant morbidity, mortality, and health care resource utilization. It is also associated with physical, as well as psychosocial, consequences such as amputation and depression. Importantly, after a major amputation, patients are at heightened risk of amputation on the contralateral leg. However, despite the technological advances to manage CLI with minimally invasive technologies, this condition often remains untreated, with significant disparities in revascularization and amputation rates according to race, socioeconomic status, and geographic region. Care remains disparate across medical specialties in this rapidly evolving field. Many challenges persist, including appropriate reimbursement for treating complex patients with difficult anatomy. This paper provides a comprehensive summary that includes diagnostic assessment and analysis, endovascular versus open surgical treatment, regenerative and adjunctive therapies, and other important aspects of CLI.

Low Rates of Revascularization and High In-Hospital Mortality in Patients With Ischemic Lower Limb Amputation

Background:

To assess the nationwide contemporary burden of cardiovascular risk factors, comorbidities, and in-hospital mortality in patients with lower limb amputation (LLA) due to peripheral arterial disease and critical limb ischemia (CLI) in Germany.

Methods:

German nationwide data for 2005 and 2009 were analyzed regarding in-hospital rates of major and minor ischemic LLA, risk factors, comorbidities, surgical and endovascular revascularizations, and in-hospital mortality.

Results:

In 2005, a total of 22 479 major (7.8%) and 28 262 minor (9.8%) LLAs were performed with a relative decrease of −21.8% in major LLA, yet with a relative increase of +2% in minor LLA rate in 2009. The overall revascularization rate before amputation was 46% in 2005 and 57% in 2009. In-hospital mortality for non-CLI, minor, and major amputees was 3.3%, 4.6%, and 19.8%, respectively ( P < .001 for major vs minor LLA and non-CLI).

Conclusion:

The total number of ischemic LLA and amputation-related in-hospital mortality remains high in Germany in the 21st century. The poor outcome of patients with CLI might in part be due to underuse of revascularizations prior to amputation.

The LIBERTY study: Design of a prospective, observational, multicenter trial to evaluate the acute and long-term clinical and economic outcomes of real-world endovascular device interventions in treating peripheral artery disease

BACKGROUND

Most peripheral artery disease (PAD) clinical device trials are supported by commercial manufacturers and designed for regulatory device approval, with extensive inclusion/exclusion criteria to support homogeneous patient populations. High-risk patients with advanced disease, including critical limb ischemia (CLI), are often excluded leading to difficulty in translating trial results into real-world clinical practice. As a result, physicians have no direct guidance regarding the use of endovascular devices. There is a need for objectively assessed studies to evaluate clinical, functional, and economic outcomes in PAD patient populations.

STUDY DESIGN

LIBERTY is a prospective, observational, multicenter study sponsored by Cardiovascular Systems Inc (St Paul, MN) to evaluate procedural and long-term clinical and economic outcomes of endovascular device interventions in patients with symptomatic lower extremity PAD. Approximately 1,200 patients will be enrolled and followed up to 5 years: 500 patients in the "Claudicant Rutherford 2-3" arm, 600 in the "CLI Rutherford 4-5" arm, and 100 in the "CLI Rutherford 6" arm. The study will use 4 core laboratories for independent analysis and will evaluate the following: procedural and lesion success, rates of major adverse events, duplex ultrasound interpretations, wound status, quality of life, 6-minute walk test, and economic analysis. The LIBERTY Patient Risk Score(s) will be developed as a clinical predictor of outcomes to provide guidance for interventions in this patient population.

CONCLUSION

LIBERTY will investigate real-world PAD patients treated with endovascular revascularization with rigorous study guidelines and independent oversight of outcomes. This study will provide observational, all-comer patient clinical data to guide future endovascular therapy.

Trends in hospital treatments for peripheral arterial disease in the United States and association between payer status and quality of care/outcomes, 2007-2011

OBJECTIVE

This study sought to identify the temporal trends of presenting diagnoses and vascular procedures performed for peripheral arterial disease (PAD) along with the rates of procedures and in-hospital outcomes by payer status.

BACKGROUND

Previous studies suggest that patients with Medicare, Medicaid, or lack of insurance receive poorer quality of care leading to worse outcomes.

METHODS

We analyzed 196,461,055 discharge records to identify all hospitalized patients with PAD records (n=1,687,724) from January 2007 through December 2011 in the Nationwide Inpatient Sample database.

RESULTS

The annual frequency of vascular procedures remained unchanged during the study period. Patients with Medicaid were more likely to present with gangrenes, whereas patients with Medicare were more likely to present with ulcers. After adjustment, patients with Medicare and Medicaid were more likely to undergo amputations when compared with private insurance/HMO (OR=1.13, 95% CI=1.10-1.16 and OR=1.24, 95% CI=1.20-1.29, respectively). Patients with both Medicare and Medicaid were less likely to undergo bypass surgery (OR=0.82, 95% CI=0.81-0.84 and OR=0.87, 95% CI=0.85-0.90, respectively), but more likely to undergo endovascular procedures (OR=1.18, 95% CI=1.17-1.20 and OR=1.03, 95% CI=1.01-1.06, respectively). Medicare and Medicaid status versus private insurance/HMO was associated with worse adjusted odds of in-hospital outcomes, including mortality after amputations, endovascular procedures, and bypass surgeries.

CONCLUSIONS

In this analysis, patients with Medicare and Medicaid had more comorbid conditions at baseline when compared with private insurance/HMO cohorts, were more likely to present with advanced stages of PAD, undergo amputations, and develop in-hospital complications. These data unveil a critical gap and an opportunity for quality improvement in the elderly and those with poor socioeconomic status.

Trends in Major Lower Limb Amputation Related to Peripheral Arterial Disease in Hungary: A Nationwide Study (2004-2012)

OBJECTIVES

To assess the trends of peripheral arterial disease associated major lower limb amputation in Hungary over a 9 year period (2004-2012) in the whole Hungarian population.

METHODS

This was a retrospective cohort study employing administrative health care data. Major amputations were identified in the entire Hungarian population during a 9 year period (2004-2012) using the health care administrative data. Direct standardization was used to eliminate the potential bias induced by the different age and sex structure of the compared populations. For external direct standardization, the ESP 2013 was chosen as reference.

RESULTS

76,798 lower limb amputations were performed. The number of major amputations was 38,200; these procedures affected 32,084 patients. According to case detection, 50.4% of the amputees were diabetic. The overall primary amputation rate was 71.5%. The annual crude and age adjusted major amputation rates exhibited no significant long-term pattern over the observation period. The major lower limb amputation incidence for the overall period was 42.3/10(5) in the total population and 317.9/10(5) in diabetic population.

CONCLUSION

According to this whole population based study from Hungary, the incidence of lower limb major amputation is high with no change over the past 9 years. An explanation for this remains to be determined, as the traditional risk factors in Hungary do not account for it. The characteristics of major amputation (the rate of primary amputation, the ratio of below to above knee amputation and the age of the affected population) underline the importance of screening, early detection, improved vascular care and an optimal revascularization policy. Standardization and validation of amputation detection methods and reporting is essential.

The persistence of gender and racial disparities in vascular lower extremity amputation: an examination of HCUP-NIS data (2002-2011)

The purpose of this study was to examine trends in racial and gender disparities in the severity of lower extremity amputation among individuals with peripheral artery disease (PAD) over the period of a decade (2002-2011). This is a longitudinal secondary analysis of data from the Healthcare Utilization Project Nationwide Inpatient Survey (HCUP-NIS) for the years 2002-2011. Level of amputation was determined from ICD-9-CM procedure and coded as either transfemoral (TF) or transtibial (TT). The main predictors were gender and race; covariates including age, race, income, insurance status and presence of vascular disease were incorporated as control variables in regression analysis. A total 121,587 cases of non-traumatic dysvascular amputations were identified. Female gender (odds ratio (OR) 1.35; 95% confidence interval (CI) 1.32, 1.39) and black race (OR 1.17; 95% CI 1.12, 1.23) are both significantly associated with increased odds for receiving TF amputation with no change in these odds over the decade of study. Other covariates with significant associations with TF amputation level include increased age (OR 1.03; 95% CI 0.99, 1.09), low income (OR 1.21; 95% CI 1.15, 1.27), Medicaid insurance (OR 1.36; 95% CI 1.29, 1.44), Medicare insurance (OR 1.27; 95% CI 1.21, 1.32), and cerebrovascular disease (OR 2.12; 95% CI 2.03, 2.23). In conclusion, although overall rates of amputation have decreased, disparities in level of amputation related to female gender and black race have not significantly changed over time. Higher-level amputation has significant consequences from a quality-of-life, medical and economic perspective.

Lower extremity amputation in peripheral artery disease: improving patient outcomes

Peripheral artery disease affects over eight million Americans and is associated with an increased risk of mortality, cardiovascular disease, functional limitation, and limb loss. In its most severe form, critical limb ischemia, patients are often treated with lower extremity (LE) amputation (LEA), although the overall incidence of LEA is declining. In the US, there is significant geographic variation in the performing of major LEA. The rate of death after major LEA in the US is approximately 48% at 1 year and 71% at 3 years. Despite this significant morbidity and mortality, the use of diagnostic testing (both noninvasive and invasive testing) in the year prior to LEA is low and varies based on patient, provider, and regional factors. In this review we discuss the significance of LEA and methods to reduce its occurrence. These methods include improved recognition of the risk factors for LEA by clinicians and patients, strong advocacy for noninvasive and/or invasive imaging prior to LEA, improved endovascular revascularization techniques, and novel therapies.