Revascularization of intermittent claudicants leads to more chronic limb-threatening ischemia and higher amputation rates

Endovascular therapy in intermittent claudication: Impact of IVUS guidance on treatment decisions

Conservative therapy is favored over revascularization for patients with peripheral arterial disease (PAD) and intermittent claudication (IC) owing to the better long-term results. The adjunctive use of intravascular ultrasound (IVUS) significantly improves endovascular therapy. However, data on IVUS and IC is scarce. Therefore, the aim of this investigation was to determine the safety and efficacy of IVUS in patients with IC and to evaluate discrepancies compared to angiography and potential consequences for treatment.This was a single-center prospective cohort study. Twenty patients with IC and femoropopliteal disease eligible for endovascular therapy were enrolled. Procedural data and discrepancies between IVUS and angiography were recorded.In total, 30 lesions were treated. IVUS-based measurements yielded substantially higher reference vessel diameters (RVD) and lesion lengths compared to DSA alone (RVD: 5.37 ± 0.71 mm vs. 4.74 ± 0.63 mm, p<.001, lesion length: 62.4 ± 41.4 mm vs. 42.18 ± 30.2 mm, p<.001). In 24 of 30 lesions (80%), a significant discrepancy in RVD (defined as difference >0.5 mm) and lesion length (defined as >20 mm) was determined between IVUS and standard DSA. Subsequently, IVUS assessment led to upsizing in 14 of 30 lesions (47%) and downsizing in 3 of 30 lesions (10%). On average, IVUS led to the selection of considerably larger balloons (5.25 ± 0.62 vs. 4.74 ± 0.63, p<.004) and device length (78.97 ± 44.19 mm vs. 42.18 ± 30.2, p<.001). Serious adverse events did not occur. Technical success was achieved in all cases.IVUS is safe and provides advantages regarding the evaluation of IC by depicting RVD and lesion length more reliably than standard DSA. More precise assessment of lesions resulted in the use of significantly larger devices. · The safety and efficacy of IVUS are confirmed for the distinct cohort of patients with IC.. · IVUS provides advantages for the evaluation of IC by depicting RVD and lesion length more reliably than standard DSA.. · More precise assessment of stenoses resulted in the selection of significantly larger devices, hence suggesting substantial clinical impact.. Hartung V, Augustin AM, Gruschwitz P et al. Endovascular therapy in intermittent claudication: Impact of IVUS guidance on treatment decisions. Fortschr Röntgenstr 2024; DOI 10.1055/a-2379-8857.

Co-Morbidity Differences Associated With Long-Term Amputation and Repeat Revascularization Rates After Femoropopliteal Artery Intervention for Intermittent Claudication by Sex, Race, and Ethnicity

Use of peripheral vascular intervention (PVI) for intermittent claudication (IC) continues to expand, but there is uncertainty whether baseline demographics, procedural techniques and outcomes differ by sex, race, and ethnicity. This study aimed to examine amputation and revascularization rates up to 4 years after femoropopliteal (FP) PVI for IC by sex, race, and ethnicity. Patients who underwent FP PVI for IC between 2016 and 2020 from the PINC AI Healthcare Database were analyzed. The primary outcome was any index limb amputation, assessed by Kaplan-Meier estimate. Secondary outcomes included index limb major amputation, repeat revascularization, and index limb repeat revascularization. Unadjusted and adjusted hazard ratios (HRs) were estimated using Cox proportional hazard regression models. This study included 19,324 patients with IC who underwent FP PVI, with 41.2% women, 15.6% Black patients, and 4.7% Hispanic patients. Women were less likely than men to be treated with atherectomy (45.1% vs 47.8%, p = 0.0003); Black patients were more likely than White patients to receive atherectomy (50.7% vs 44.9%, p <0.001), and Hispanic patients were less likely than non-Hispanic patients to receive atherectomy (41% vs 47%, p = 0.0004). Unadjusted rates of any amputation were similar in men and women (6.4% for each group, log-rank p = 0.842), higher in Black patients than in White patients (7.8% vs 6.1%, log-rank p = 0.007), and higher in Hispanic patients than in non-Hispanic patients (8.8% vs 6.3%, log-rank p = 0.031). After adjustment for baseline characteristics, Black race was associated with higher rates of repeat revascularization (adjusted HR 1.13, 95% confidence interval 1.04 to 1.22) and any FP revascularization (adjusted HR 1.10, 95% confidence interval 1.01 to 1.20). No statistical difference in amputation rate was observed among comparison groups. Women and men with IC had similar crude and adjusted amputation and revascularization outcomes after FP PVI. Black patients had higher repeat revascularization and any FP revascularization rates than did White patients. Black and Hispanic patients had higher crude amputation rates, but these differences were attenuated by adjustment for baseline characteristics. Black patients were more likely to receive atherectomy and had higher rates of any repeat revascularization and specifically FP revascularization. Further study is necessary to determine whether these patterns are related to disease-specific issues or practice-pattern differences among different populations.

Infrapopliteal Peripheral Vascular Interventions for Claudication are Performed Frequently in the USA and Are Associated with Poor Long Term Outcomes

OBJECTIVE

Infrapopliteal peripheral vascular interventions (PVIs) for claudication are still performed in the USA. This study aimed to evaluate whether infrapopliteal PVI is associated with worse long term outcomes than isolated femoropopliteal PVI for treatment of claudication.

METHODS

A retrospective analysis of fee for service claims in a national administrative database was conducted using 100% of the Medicare fee for service claims between 2017 and 2019 to capture all Medicare beneficiaries who underwent an index infra-inguinal PVI for claudication. Hierarchical Cox proportional hazards models were performed to assess the association of infrapopliteal PVI with conversion to chronic limb threatening ischaemia (CLTI), repeat PVI, and major amputation.

RESULTS

In total, 36 147 patients (41.1% female; 89.7% age ≥ 65 years; 79.0% non-Hispanic White ethnicity) underwent an index PVI for claudication, of whom 32.6% (n = 11 790) received an infrapopliteal PVI. Of these, 61.4% (n = 7 245) received a concomitant femoropopliteal PVI and 38.6% (n = 4 545) received an isolated infrapopliteal PVI. The median follow up time was 3.5 years (interquartile range 2.7, 4.3). Patients receiving infrapopliteal PVI had a higher three year cumulative incidence of conversion to CLTI (26.0%; 95% confidence interval [CI] 24.9 - 27.2% vs. 19.9%; 95% CI 19.1 - 20.7%), repeat PVI (56.0%; 95% CI 54.8 - 57.3% vs. 45.7%; 95% CI 44.9 - 46.6%), and major amputation (2.2%; 95% CI 1.8 - 2.6% vs. 1.3%; 95% CI 1.1 - 1.5%) compared with patients receiving isolated femoropopliteal PVI. After adjusting for patient and physician level characteristics, the risk of conversion to CLTI (adjusted hazard ratio [aHR] 1.31, 95% CI 1.23 - 1.39), repeat PVI (aHR 1.12, 95% CI 1.05 - 1.20), and major amputation (aHR 1.72, 95% CI 1.42 - 2.07) remained significantly higher for patients receiving infrapopliteal PVI. An increasing number of infrapopliteal vessels treated during the index intervention was associated with increasingly poor outcomes (p < .001 for trend).

CONCLUSION

Infrapopliteal PVI for claudication is associated with worse long term outcomes relative to isolated femoropopliteal PVI.

Hypercholesterolemia impairs collateral artery enlargement by ten-eleven translocation 1-dependent hematopoietic stem cell autonomous mechanism in a murine model of limb ischemia

Objective

The extent of collateral artery enlargement determines the risk of limb loss due to peripheral arterial disease. Hypercholesterolemia impairs collateral artery enlargement, but the underlying mechanism remains poorly characterized. This study tests the hypothesis that hypercholesterolemia impairs collateral artery enlargement through a ten-eleven translocation 1 (Tet1)-dependent hematopoietic stem cell (HSC)-autonomous mechanism that increases their differentiation into proinflammatory Ly6Chi monocytes and restricts their conversion into proangiogenic Ly6Clow monocytes.

Methods

To test our hypothesis, we induced limb ischemia and generated chimeric mouse models by transplanting HSCs from either wild-type (WT) mice or hypercholesterolemic mice into lethally irradiated WT recipient mice.

Results

We found that the lethally irradiated WT recipient mice reconstituted with HSCs from hypercholesterolemic mice displayed lower blood flow recovery and collateral artery enlargement that was nearly identical to that observed in hypercholesterolemic mice, despite the absence of hypercholesterolemia and consistent with an HSC-autonomous mechanism. We showed that hypercholesterolemia impairs collateral artery enlargement by a Tet1-dependent mechanism that increases HSC differentiation toward proinflammatory Ly6Chi monocytes and restricts the conversion of Ly6Chi monocytes into proangiogenic Ly6Clow monocytes. Moreover, Tet1 epigenetically reprograms monocyte gene expression within the HSCs. Restoration of Tet1 expression in HSCs of hypercholesterolemic mice restores WT collateral artery enlargement and blood flow recovery after induction of hindlimb ischemia.

Conclusions

These results show that hypercholesterolemia impairs collateral artery enlargement by a novel Tet1-dependent HSC-autonomous mechanism that epigenetically reprograms monocyte gene expression within the HSCs.

Socioeconomic factors predict successful supervised exercise therapy completion

OBJECTIVE

Supervised exercise therapy (SET) for patients with intermittent claudication (IC) can lower the risk of progression to chronic limb-threatening ischemia and amputation, while preserving and restoring functional status. Despite supporting evidence, it remains underutilized, and among those who initiate programs, attrition rates are extremely high. We hypothesize that socioeconomic factors may represent significant barriers to SET completion.

METHODS

Patients with IC referred to SET at a multi-hospital, single-institution health care system (2018-2022) from a prospectively maintained database were retrospectively analyzed. Our primary endpoint was SET program completion and graduation, defined as completion of 36 sessions. Our secondary endpoints were vascular intervention within 1 year of referral and change in ankle-brachial index (ABI). Baseline demographics were assessed using standard statistical methods. Predictors of SET graduation were analyzed using multivariable logistic regression generating adjusted odds ratios (aORs) with 95% confidence intervals (CIs). Change in ABI was analyzed using t-test between subgroups. Reasons for attrition were tabulated. Patient Health Questionnaire-9 (PHQ-9), metabolic equivalent level, Vascular QOL, Duke Activity Status, and ABI were analyzed using paired t-tests across the entire cohort.

RESULTS

Fifty-two patients met inclusion criteria: mean age 67.85 ± 10.69 years, 19 females (36.54%), mean baseline ABI of 0.77 ± 0.16. The co-pays for 100% of patients were fully covered by primary and secondary insurance plans. Twenty-one patients (40.38%) completed SET. On multivariable analysis, residence in a ZIP code with median household income <$47,000 (aOR, 0.10; 95% CI, 0.01-0.76; P = .03) and higher body mass index (aOR, 0.81; 95% CI, 0.67-0.99; P = .04) were significant barriers to SET graduation. There were no differences in ABI change or vascular intervention within 1 year between graduates and non-graduates. Non-graduates reported transportation challenges (25.00%), lack of motivation (20.83%), and illness/functional limitation (20.83%) as primary reasons for SET attrition. Metabolic Equivalent Level (P ≤ .01) and Duke Activity Status scores (P = .04) were significantly greater after participating in a SET program.

CONCLUSIONS

Although SET participation improves lower extremity and functionality outcomes, only 40% of referred patients completed therapy in our cohort. Our findings suggest that both socioeconomic and functional factors influence the odds of completing SET programs, indicating a need for holistic pre-referral assessment to facilitate enhanced program accessibility for these populations.

Revascularization for claudication: Changing the natural history of a benign disease!

OBJECTIVE

The benign natural history of intermittent claudication was first documented in 1960 and has been reconfirmed in several subsequent studies. Excellent outcomes in patients with intermittent claudication can be achieved with exercise therapy and optimal medical management. Professional society guidelines have clearly stated that revascularization procedures should be performed only in patients with incapacitating claudication who have failed conservative therapy. Despite these guidelines, revascularization procedures, primarily percutaneous interventions, have been increasingly utilized in patients with claudication. Many of these patients are not even offered an attempt at medical therapy, and those who are often do not undergo a full course of treatment. Many studies document significant reintervention rates following revascularization, which are associated with increased rates of acute and chronic limb ischemia that may result in significant rates of amputation. The objectives of this study were to compare outcomes of conservative therapy to those seen in patients undergoing revascularization procedures and to determine the impact of revascularization on the natural history of claudication.

METHODS

Google Scholar and PubMed were searched for manuscripts on the conservative management of claudication and for those reporting outcomes following revascularization for claudication.

RESULTS

Despite early improvement in claudication symptoms following revascularization, multiple studies have demonstrated that long-term outcomes following revascularization are often no better than those obtained with conservative therapy. High reintervention rates (up to 43% for tibial atherectomies) result in high rates of both acute and chronic limb ischemia as compared with those patients undergoing medical therapy. In addition, amputation rates as high as 11% on long-term follow-up are seen in patients undergoing early revascularization. These patients also have a higher incidence of adverse cardiovascular events such as myocardial infarctions compared with patients treated medically.

CONCLUSIONS

Revascularization procedures negatively impact the natural history of claudication often resulting in multiple interventions, an increase in the incidence of acute and chronic limb ischemia, and an increased risk of amputation. Accordingly, informed consent requires that all patients undergoing early revascularization must be appraised of the potential negative impact of revascularization on the natural history of claudication.

Perspectives on Lower Extremity Peripheral Artery Disease: A Qualitative Study of Early Diagnosis and Treatment and the Impact of Health Disparities

Lower-extremity peripheral artery disease (PAD), the accumulation of atherosclerotic plaque in the arteries of the legs, causes substantial morbidity and mortality. Frequent under- and delayed diagnosis result in poor outcomes, disproportionately affecting individuals from racial and ethnic minority groups. To understand barriers to early detection and treatment and factors contributing to disparities, American Medical Group Association (AMGA) conducted roundtable discussions and semistructured interviews in 2021. Eighteen participants discussed PAD evaluation, diagnosis, early medical management, and disparities in care. A qualitative case study approach and data reduction methods were used to generate themes, draw conclusions, and make actionable recommendations. Identified themes included lack of (1) prioritization of PAD for population health; (2) engagement of primary care providers in early evaluation and referral; (3) "ownership" of lower-extremity PAD within health systems; and (4) focus on disparities in care. Participant solutions included (1) financial impact of early PAD management, in the context of value-based payment; (2) embedding an advanced practice provider into a vascular surgery practice to facilitate evaluation and provide medical therapy; and (3) leveraging care coordination, multidisciplinary clinics, and telehealth technology to provide comprehensive care for patients with PAD and address disparities. A deliberate focused effort is necessary to close gaps and the accompanying disparities in early evaluation, diagnosis, and treatment for people with lower-extremity PAD. The authors describe 3 models that can be emulated to improve care for this high-risk population. With improved reimbursement and better medical therapies, now is the time to focus on early diagnosis and management of PAD.

Outcomes of lower extremity revascularization in octogenarians and nonagenarians for intermittent claudication

OBJECTIVE

Revascularization for intermittent claudication (IC) due to infrainguinal peripheral arterial disease (PAD) is dependent on durability and expected benefit. We aimed to assess outcomes for IC interventions in octogenarians and nonagenarians (age ≥80 years) and those younger than 80 years (age <80 years).

METHODS

The Vascular Quality Initiative was queried (2010-2020) for peripheral vascular interventions (PVIs) and infrainguinal bypasses (IIBs) performed to treat IC. Baseline characteristics, procedural details, and outcomes were analyzed (comparing age ≥80 years and age <80 years).

RESULTS

There were 84,210 PVIs (12.1% age ≥80 years and 87.9% age <80 years) and 10,980 IIBs (7.4% age ≥80 years and 92.6% age <80 years) for IC. For PVI, patients aged ≥80 years more often underwent femoropopliteal (70.7% vs 58.1%) and infrapopliteal (19% vs 9.3%) interventions, and less often iliac interventions (32.1% vs 48%) (P < .001 for all). Patients aged ≥80 years had more perioperative hematomas (3.5% vs 2.4%) and 30-day mortality (0.9% vs 0.4%) (P < .001). At 1-year post-intervention, the age ≥80 years cohort had fewer independently ambulatory patients (80% vs 91.5%; P < .001). Kaplan-Meier analysis showed patients aged ≥80 years had lower reintervention/amputation-free survival (81.4% vs 86.8%), amputation-free survival (87.1% vs 94.1%), and survival (92.3% vs 96.8%) (P < .001) at 1-year after PVI. Risk adjusted analysis showed that age ≥80 years was associated with higher reintervention/amputation/death (hazard ratio [HR], 1.22; 95% confidence interval [CI], 1.1-1.35), amputation/death (HR, 1.85; 95% CI, 1.61-2.13), and mortality (HR, 1.92; 95% CI, 1.66-2.23) (P < .001 for all) for PVI. For IIB, patients aged ≥80 years more often had an infrapopliteal target (28.4% vs 19.4%) and had higher 30-day mortality (1.3% vs 0.5%), renal failure (4.1% vs 2.2%), and cardiac complications (5.4% vs 3.1%) (P < .001). At 1 year, the age ≥80 years group had fewer independently ambulatory patients (81.7% vs 88.8%; P = .02). Kaplan-Meier analysis showed that the age ≥80 years cohort had lower reintervention/amputation-free survival (75.7% vs 81.5%), amputation-free survival (86.9% vs 93.9%), and survival (90.4% vs 96.5%) (P < .001 for all). Risk-adjusted analysis showed age ≥80 years was associated with higher amputation/death (HR, 1.68; 95% CI, 1.1-2.54; P = .015) and mortality (HR, 1.85; 95% CI, 1.16-2.93; P = .009), but not reintervention/amputation/death (HR, 1.1; 95% CI, 0.85-1.44; P = .47) after IIB.

CONCLUSIONS

Octogenarians and nonagenarians have greater perioperative morbidity and long-term ambulatory impairment, limb loss, and mortality after PVI and IIB for claudication. Risks of intervention on elderly patients with claudication should be carefully weighed against the perceived benefits of revascularization. Medical and exercise therapy efforts should be maximized in this population.

An audit of secondary prevention for peripheral arterial disease in primary care - scope for improved collaboration between vascular surgery and general practitioners

BACKGROUND

Symptomatic peripheral arterial disease (PAD) is a common cause for referral from primary care to vascular surgery. Best medical therapy (BMT), encompassing anti-platelets, statins, smoking cessation, blood pressure and glycaemic control, is a cornerstone of PAD management. However, these easily modifiable risk factors are often left unaddressed between referral and clinic review.

METHODS

A prospective audit of electronic 'Healthlink' referrals by GPs to the vascular department for symptomatic PAD between July 2021 and June 2022 was performed. Referrals were individually reviewed for demographics, symptoms, medical history, smoking status and medications. An information leaflet on BMT was posted to all GP practices in the Soalta region as part of an educational intervention, with plans to re-audit after 6 months.

RESULTS

One-hundred-and-seventy referrals were analysed. The median age was 68.5 years (range 33-94) and 69% (n = 117) were male. The typical vasculopath comorbidity profile was noted. Fifty-two percent (n = 88) were referred with claudication-type pain and 25% (n = 43) with critical limb ischaemia (CLI). Twenty-eight percent (n = 33) were active smokers and 31% (n = 36) had no smoking status documented. Regarding BMT, only 34.5% (n = 40) and 52% (n = 60) were on anti-platelets and statins, respectively. Suspected CLI was not significantly associated with BMT prescription at referral (p = 0.664). Only eleven referral letters mentioned risk factor optimisation.

CONCLUSIONS

Our first-cycle results identified significant scope for improvement in community-based risk factor modification for PAD referrals. We aim to continue supporting and educating our colleagues that effective medical management can start safely in primary care and further explore the barriers preventing this.

Current Medical Therapy and Revascularization in Peripheral Artery Disease of the Lower Limbs: Impacts on Subclinical Chronic Inflammation

Peripheral artery disease (PAD), coronary artery disease (CAD), and cerebrovascular disease (CeVD) are characterized by atherosclerosis and inflammation as their underlying mechanisms. This paper aims to conduct a literature review on pharmacotherapy for PAD, specifically focusing on how different drug classes target pro-inflammatory pathways. The goal is to enhance the choice of therapeutic plans by considering their impact on the chronic subclinical inflammation that is associated with PAD development and progression. We conducted a comprehensive review of currently published original articles, narratives, systematic reviews, and meta-analyses. The aim was to explore the relationship between PAD and inflammation and evaluate the influence of current pharmacological and nonpharmacological interventions on the underlying chronic subclinical inflammation. Our findings indicate that the existing treatments have added anti-inflammatory properties that can potentially delay or prevent PAD progression and improve outcomes, independent of their effects on traditional risk factors. Although inflammation-targeted therapy in PAD shows promising potential, its benefits have not been definitively proven yet. However, it is crucial not to overlook the pleiotropic properties of the currently available treatments, as they may provide valuable insights for therapeutic strategies. Further studies focusing on the anti-inflammatory and immunomodulatory effects of these treatments could enhance our understanding of the mechanisms contributing to the residual risk in PAD and pave the way for the development of novel therapies.

Indications for a "Surgery-First" Approach for the Treatment of Lower Extremity Arterial Disease

BACKGROUND

In recent years, there has been a tendency toward an "endovascular-first" approach for the treatment for femoropopliteal arterial disease. The purpose of this study is to determine if there are patients that are better served with an initial femoropopliteal bypass (FPB) rather than an endovascular attempt at revascularization.

METHODS

A retrospective analysis of all patients undergoing FPB between June 2006 - December 2014 was performed. Our primary endpoint was primary graft patency, defined as patent using ultrasound or angiography without secondary intervention. Patients with <1-year follow-up were excluded. Univariate analysis of factors significant for 5-year patency was performed using χ2 tests for binary variables. A binary logistic regression analysis incorporating all factors identified as significant by univariate analysis was used to identify independent risk factors for 5-year patency. Event-free graft survival was evaluated using Kaplan-Meier models.

RESULTS

We identified 241 patients undergoing FPB on 272 limbs. FPB indication was disabling claudication in 95 limbs, chronic limb-threatening ischemia (CLTI) in 148, and popliteal aneurysm in 29. In total, 134 FPB were saphenous vein grafts (SVG), 126 were prosthetic grafts, 8 were arm vein grafts, and 4 were cadaveric/xenografts. There were 97 bypasses with primary patency at 5 or more years of follow-up. Grafts patent at 5 years by Kaplan-Meier analysis were more likely to have been performed for claudication or popliteal aneurysm (63% 5-year patency) as compared with CLTI (38%, P < 0.001). Statistically significant predictors (using log rank test) of patency over time were use of SVG (P = 0.015), surgical indication of claudication or popliteal aneurysm (P < 0.001), Caucasian race (P = 0.019) and no history of COPD (P = 0.026). Multivariable regression analysis confirmed these 4 factors as significant independent predictors of 5-year patency. Of note, there was no statistical correlation between FPB configuration (above or below knee anastomosis, in-situ versus reversed saphenous vein) and 5-year patency. There were 40 FPBs in Caucasian patients without a history of COPD receiving SVG for claudication or popliteal aneurysm that had a 92% estimated 5-year patency by Kaplan-Meier survival analysis.

CONCLUSIONS

Long-term primary patency that was substantial enough to consider open surgery as a first intervention was demonstrated in Caucasian patients without COPD, having good quality saphenous vein, and who underwent FPB for claudication or popliteal artery aneurysm.

Long-Term Patient Outcomes After Femoropopliteal Peripheral Vascular Intervention in Patients With Intermittent Claudication

BACKGROUND

In patients with intermittent claudication (IC), short-term amputation rates from clinical trial data following lower extremity femoropopliteal (FP) peripheral vascular intervention (PVI) are <1% with unknown longer-term rates.

OBJECTIVES

The aim of this study was to identify revascularization and amputation rates following PVI in the FP segment and to assess 4-year amputation and revascularization rates after FP PVI for IC.

METHODS

From 2016 to 2020, 19,324 patients undergoing FP PVI for IC were included from the PINC AI Healthcare Database and evaluated by treatment level (superficial femoral artery [SFA], popliteal artery [POP], or both). The primary outcome was index limb amputation (ILA) assessed by Kaplan-Meier estimate. The secondary outcomes were index limb major amputation and repeat revascularization. HRs were estimated using Cox proportional hazard regression.

RESULTS

The 4-year index limb amputation rate following FP PVI was 4.3% (95% CI: 4.0-4.7), with a major amputation rate of 3.2% (95% CI: 2.9-3.5). After POP PVI, ILA was significantly higher than SFA alone (7.5% vs 3.4%) or both segment PVI (5.5%). In multivariate analysis, POP PVI was associated with higher ILA rates at 4 years compared with isolated SFA PVI (HR: 2.10; 95% CI: 1.52-2.91) and index limb major amputation (HR: 1.98; 95% CI: 1.32-2.95). Repeat FP revascularization rates were 15.2%; they were highest in patients undergoing both SFA and POP PVI (18.7%; P < 0.0001) compared with SFA (13.9%) and POP (17.1%) only.

CONCLUSIONS

IC patients undergoing FP PVI had 4-year rates of index limb repeat revascularization of 16.7% and ILA rates of 4.3%. Further risk factors for amputation requires further investigation.

Reprint of: Early peripheral vascular interventions for claudication are associated with higher rates of late interventions and progression to chronic limb threatening ischemia

OBJECTIVE

Despite societal guidelines that peripheral vascular intervention (PVI) should not be the first-line therapy for intermittent claudication, a significant number of patients will undergo PVI for claudication within 6 months of diagnosis. The aim of the present study was to investigate the association of early PVI for claudication with subsequent interventions.

METHODS

We evaluated 100% of Medicare fee-for-service claims to identify all beneficiaries with a new diagnosis of claudication from January 1, 2015 to December 31, 2017. The primary outcome was late intervention, defined as any femoropopliteal PVI performed >6 months after the claudication diagnosis (through June 30, 2021). Kaplan-Meier curves were used to compare the cumulative incidence of late PVI for claudication patients with early (≤6 months) PVI vs those without early PVI. A hierarchical Cox proportional hazards model was used to evaluate the patient- and physician-level characteristics associated with late PVIs.

RESULTS

A total of 187,442 patients had a new diagnosis of claudication during the study period, of whom 6069 (3.2%) had undergone early PVI. After a median follow-up of 4.39 years (interquartile range, 3.62-5.17 years), 22.5% of the early PVI patients had undergone late PVI vs 3.6% of those without early PVI (P < .001). Patients treated by high use physicians of early PVI (≥2 standard deviations; physician outliers) were more likely to have received late PVI than were patients treated by standard use physician of early PVI (9.8% vs 3.9%; P < .001). Patients who had undergone early PVI (16.4% vs 7.8%) and patients treated by outlier physicians (9.7% vs 8.0%) were more likely to have developed CLTI (P < .001 for both). After adjustment, the patient factors associated with late PVI included receipt of early PVI (adjusted hazard ratio [aHR], 6.89; 95% confidence interval [CI], 6.42-7.40) and Black race (vs White; aHR, 1.19; 95% CI, 1.10-1.30). The only physician factor associated with late PVI was a majority of practice in an ambulatory surgery center or office-based laboratory, with an increasing proportion of ambulatory surgery center or office-based laboratory services associated with significantly increased rates of late PVI (quartile 4 vs quartile 1; aHR, 1.57; 95% CI, 1.41-1.75).

CONCLUSIONS

Early PVI after the diagnosis of claudication was associated with higher late PVI rates compared with early nonoperative management. High use physicians of early PVI for claudication performed more late PVIs than did their peers, especially those primarily delivering care in high reimbursement settings. The appropriateness of early PVI for claudication needs critical evaluation, as do the incentives surrounding the delivery of these interventions in ambulatory intervention suites.

Early peripheral vascular interventions for claudication are associated with higher rates of late interventions and progression to chronic limb threatening ischemia

OBJECTIVE

Despite societal guidelines that peripheral vascular intervention (PVI) should not be the first-line therapy for intermittent claudication, a significant number of patients will undergo PVI for claudication within 6 months of diagnosis. The aim of the present study was to investigate the association of early PVI for claudication with subsequent interventions.

METHODS

We evaluated 100% of Medicare fee-for-service claims to identify all beneficiaries with a new diagnosis of claudication from January 1, 2015 to December 31, 2017. The primary outcome was late intervention, defined as any femoropopliteal PVI performed >6 months after the claudication diagnosis (through June 30, 2021). Kaplan-Meier curves were used to compare the cumulative incidence of late PVI for claudication patients with early (≤6 months) PVI vs those without early PVI. A hierarchical Cox proportional hazards model was used to evaluate the patient- and physician-level characteristics associated with late PVIs.

RESULTS

A total of 187,442 patients had a new diagnosis of claudication during the study period, of whom 6069 (3.2%) had undergone early PVI. After a median follow-up of 4.39 years (interquartile range, 3.62-5.17 years), 22.5% of the early PVI patients had undergone late PVI vs 3.6% of those without early PVI (P < .001). Patients treated by high use physicians of early PVI (≥2 standard deviations; physician outliers) were more likely to have received late PVI than were patients treated by standard use physician of early PVI (9.8% vs 3.9%; P < .001). Patients who had undergone early PVI (16.4% vs 7.8%) and patients treated by outlier physicians (9.7% vs 8.0%) were more likely to have developed CLTI (P < .001 for both). After adjustment, the patient factors associated with late PVI included receipt of early PVI (adjusted hazard ratio [aHR], 6.89; 95% confidence interval [CI], 6.42-7.40) and Black race (vs White; aHR, 1.19; 95% CI, 1.10-1.30). The only physician factor associated with late PVI was a majority of practice in an ambulatory surgery center or office-based laboratory, with an increasing proportion of ambulatory surgery center or office-based laboratory services associated with significantly increased rates of late PVI (quartile 4 vs quartile 1; aHR, 1.57; 95% CI, 1.41-1.75).

CONCLUSIONS

Early PVI after the diagnosis of claudication was associated with higher late PVI rates compared with early nonoperative management. High use physicians of early PVI for claudication performed more late PVIs than did their peers, especially those primarily delivering care in high reimbursement settings. The appropriateness of early PVI for claudication needs critical evaluation, as do the incentives surrounding the delivery of these interventions in ambulatory intervention suites.

Identifying potentially avoidable femoral to popliteal expanded polytetrafluoroethylene bypass for claudication using cross-site blinded peer review

OBJECTIVE

The surgical treatment of claudication can be associated with significant morbidity and costs. There are growing concerns that some patients proceed to interventions without first attempting evidence-based nonoperative management. We used a direct, cross-site, blinded expert review to evaluate the appropriateness of the surgical treatment of claudication.

METHODS

We enlisted practicing vascular surgeons to perform retrospective clinical assessments of lower extremity bypass procedures in a statewide clinical registry. Cases were limited to elective, open, infrainguinal bypasses performed for claudication using prosthetic grafts. Reviewing surgeons were randomly assigned 10 cases from a sample of 139 anonymized bypass operations and instructed to evaluate procedural appropriateness based on their expert opinion and evidence-based guidelines for preoperative treatment, namely, antiplatelet, statin, cilostazol, exercise, and smoking cessation therapy as documented in the medical record. Ninety-day episode payments were estimated from a distinct but similar cohort of patients undergoing lower extremity bypass for claudication.

RESULTS

Of 325 total reviews, surgeons stated they would not have recommended bypass in 134 reviews (41%) and deemed bypass inappropriate in 122 reviews (38%). The most common reason for inappropriateness was lack of preoperative medical and lifestyle therapy, which was present in 63% of reviews where bypass was deemed appropriate and 39% of reviews where bypass was deemed inappropriate (P < .001). Surgeons stated they would have recommended additional preoperative therapy in 65% of reviews where bypass was deemed inappropriate and 35% of reviews where bypass was deemed appropriate (P < .001). The mean total episode payments in a similar cohort of 1458 patients undergoing elective open lower extremity bypass for claudication were $31,301 ± $21,219. Extrapolating to the 325 reviews, the 134 reviews in which surgeons would not have recommended bypass were associated with potentially avoidable estimated total payments of $4,194,334, and the 122 reviews in which bypass was deemed inappropriate were associated with potentially avoidable estimated total payments of $3,818,722.

CONCLUSIONS

In this cross-site expert peer review study, 40% of lower extremity bypasses were deemed premature and, therefore, potentially avoidable, primarily owing to a lack of medical and lifestyle management before surgery. Reviews deemed inappropriate were associated with approximately $4 million in potentially avoidable costs. This approach could inform performance feedback among surgeons to help align clinical practice with evidence-based recommendations for the treatment of claudication.

MetfOrmin BenefIts Lower Extremities with Intermittent Claudication (MOBILE IC): randomized clinical trial protocol

BACKGROUND

Peripheral artery disease (PAD) affects over 230 million people worldwide and is due to systemic atherosclerosis with etiology linked to chronic inflammation, hypertension, and smoking status. PAD is associated with walking impairment and mobility loss as well as a high prevalence of coronary and cerebrovascular disease. Intermittent claudication (IC) is the classic presenting symptom for PAD, although many patients are asymptomatic or have atypical presentations. Few effective medical therapies are available, while surgical and exercise therapies lack durability. Metformin, the most frequently prescribed oral medication for Type 2 diabetes, has salient anti-inflammatory and promitochondrial properties. We hypothesize that metformin will improve function, retard the progression of PAD, and improve systemic inflammation and mitochondrial function in non-diabetic patients with IC.

METHODS

200 non-diabetic Veterans with IC will be randomized 1:1 to 180-day treatment with metformin extended release (1000 mg/day) or placebo to evaluate the effect of metformin on functional status, PAD progression, cardiovascular disease events, and systemic inflammation. The primary outcome is 180-day maximum walking distance on the 6-min walk test (6MWT). Secondary outcomes include additional assessments of functional status (cardiopulmonary exercise testing, grip strength, Walking Impairment Questionnaires), health related quality of life (SF-36, VascuQoL), macro- and micro-vascular assessment of lower extremity blood flow (ankle brachial indices, pulse volume recording, EndoPAT), cardiovascular events (amputations, interventions, major adverse cardiac events, all-cause mortality), and measures of systemic inflammation. All outcomes will be assessed at baseline, 90 and 180 days of study drug exposure, and 180 days following cessation of study drug. We will evaluate the primary outcome with linear mixed-effects model analysis with covariate adjustment for baseline 6MWT, age, baseline ankle brachial indices, and smoking status following an intention to treat protocol.

DISCUSSION

MOBILE IC is uniquely suited to evaluate the use of metformin to improve both systematic inflammatory responses, cellular energetics, and functional outcomes in patients with PAD and IC.

TRIAL REGISTRATION

The prospective MOBILE IC trial was publicly registered (NCT05132439) November 24, 2021.

Outcomes of Femoropopliteal Bypass for Lifestyle-Limiting Claudication in the Endovascular Era

INTRODUCTION

Outcomes after femoropopliteal bypass for intermittent claudication (IC) remain unclear in the endovascular era.

METHODS

A multi-institutional database was retrospectively queried for all femoropopliteal bypass procedures performed between 1995 and 2020. Demographics, operative details, and outcomes were documented. A statistical analysis included Kaplan-Meier curves and Cox proportional hazards ratios (HR).

RESULTS

A total of 282 patients underwent femoropopliteal bypass surgery for IC. Median age was 68 y (interquartile range, 61-73 y). Bypass conduits included great saphenous vein (GSV) (48.2%), prosthetic grafts (48.9%), and non-GSV autogenous grafts (2.8%). Distal bypass target was above-knee in 62.1% and below-knee in 37.9% of patients. The most common postoperative complications were wound infections (14.2%) followed by unplanned 30-d hospital readmissions (12.4%). Mortality rates were low at 0.4% (30 d) and 3.2% (1 y). Five-year primary patency rates trended highest for claudicants undergoing above-knee bypass with GSV conduit (log-rank P = 0.065). Five-year amputation-free survival rates were highest using GSV conduit regardless of distal bypass target (log-rank P = 0.017). On a multivariable analysis, age (HR 1.02 [1.00-1.04], P = 0.023) and active smoking (HR 1.48 [1.06-2.06], P = 0.021) were identified as risk factors for diminished primary graft patency. Risk factors for amputation-free survival included age (HR 1.03 [1.01-1.05], P < 0.001) and GSV conduit type (HR 0.65 [0.46-0.90], P = 0.011).

CONCLUSIONS

Femoropopliteal bypass among claudicants is associated with high rates of wound infection and hospital readmission. Active smoking portends worse outcomes in this population. These data may inform clinical decision-making regarding surgical intervention for claudication in the endovascular era.

Underutilization of Medical Management of Peripheral Artery Disease Among Patients with Claudication Undergoing Lower Extremity Bypass

OBJECTIVE

First-line treatment of peripheral artery disease (PAD) involves medical therapy and lifestyle modification. Multiple professional organizations such as the Society for Vascular Surgery (SVS) and the American Heart Association/American College of Cardiology (AHA/ACC) make Class I recommendations for medical management including antiplatelet, statin, antihypertensive, and cilostazol medications, as well as lifestyle therapy including exercise and smoking cessation. Although evidence supports up-front medical and lifestyle management prior to surgical intervention, it is unclear how well this occurs in contemporary clinical practice. It is also unclear whether variability in first-line treatment prior to revascularization is associated with postoperative outcomes. This study examined the proportion of patients with claudication actively receiving evidence-based therapy prior to surgery in a statewide surgical registry.

METHODS

We conducted a retrospective cohort study of adult patients undergoing elective open lower extremity bypass for claudication from 2012-2021 within a statewide surgical quality registry. The primary exposure was optimal medical therapy defined as an antiplatelet agent, a statin, and an angiotensin-converting enzyme inhibitors (ACEI) or angiotensin II receptor blockers (ARB) (if the patient had hypertension) on the patient's home medication list on admission for surgery, all of which are Class I recommendations. Despite also being Class I recommendations, cilostazol was not included in the primary exposure due to its highly selective use and our inability to capture intolerance and/or contraindications which are common, and lifestyle therapies were not included as they were only recorded at the time of discharge rather than preoperatively. The primary outcomes were mortality, hospital readmission, amputation, wound complication, myocardial infarction (MI), non-patent bypass, and non-independent ambulatory status at 30 days and 1 year after surgery. Multivariable logistic regression was performed to estimate the association of receiving optimal vs. non-optimal medical therapy.

RESULTS

3,829 patients with claudication underwent bypass surgery during the study period, with a mean age of 64.8 (9.8) years, 2,690 (70.3%) males, and 1,873 (48.9%) current smokers. 1,822 (47.6%) patients were on optimal medical therapy prior to surgery. Additionally, at discharge, 66.5% of smokers received referral to smoking cessation therapy and 54.1% of patients received referral to exercise therapy. In a multivariable logistic regression, compared to patients not on optimal medical therapy, patients on optimal medical therapy prior to surgery had lower 30-day odds of mortality (aOR 0.45 [95% CI 0.26-0.78]) and MI (aOR 0.46 [95% CI 0.28-0.76]) and lower 1-year odds of mortality (aOR 0.57 [95% CI 0.39-0.82]), MI (aOR 0.48 [95% CI 0.32-0.74]), and readmission (aOR 0.79 [95% CI 0.64-0.96]).

CONCLUSION

Although medical and lifestyle management is recommended as first-line treatment for patients with PAD, only half of patients were on optimal medical therapy prior to surgery. Patients receiving optimal therapy had a lower risk of postoperative mortality, MI, and readmission. This suggests that not only are there significant opportunities to improve clinical utilization of evidence-based treatment of PAD, but that doing so can benefit patients postoperatively.

Update on the pathophysiology and medical treatment of peripheral artery disease

Approximately 6% of adults worldwide have atherosclerosis and thrombosis of the lower limb arteries (peripheral artery disease (PAD)) and the prevalence is rising. PAD causes leg pain, impaired health-related quality of life, immobility, tissue loss and a high risk of major adverse events, including myocardial infarction, stroke, revascularization, amputation and death. In this Review, I describe the pathophysiology, presentation, outcome, preclinical research and medical management of PAD. Established treatments for PAD include antithrombotic drugs, such as aspirin and clopidogrel, and medications to treat dyslipidaemia, hypertension and diabetes mellitus. Randomized controlled trials have demonstrated that these treatments reduce the risk of major adverse events. The drug cilostazol, exercise therapy and revascularization are the current treatment options for the limb symptoms of PAD, but each has limitations. Novel therapies to promote collateral and new capillary growth and treat PAD-related myopathy are under investigation. Methods to improve the implementation of evidence-based medical management, novel drug therapies and rehabilitation programmes for PAD-related pain, functional impairment and ischaemic foot disease are important areas for future research.

Principal predictors of major adverse limb events in diabetic peripheral artery disease: A narrative review

Background and aims

The increasing prevalence of diabetes mellitus is causing a massive growth of peripheral artery disease incidences, a disabling complication of diabetic atherosclerosis, which leads often to the amputation of the affected limb. Critical limb ischemia is the terminal disease stage, which requires a prompt intervention to relieve pain and save limbs. However, patients undergoing revascularization often suffer from cardiovascular, cerebrovascular and major adverse limb events with poor outcomes. Furthermore, the same procedure performed in apparently similar patients has various outcomes and lack of an outcome predictive support causes a high lower limb arterial revascularization rate with disastrous effects for patients. We collected the main risk factors of major adverse limb events in a more readable and immediate format of the topic, to propose an overview of parameters to manage effectively peripheral artery disease patients and to propose basics of a new predictive tool to prevent from disabling vascular complications of the disease.

Methods

Most recent and updated literature about the prevalence of major adverse limb events in peripheral artery disease was reviewed to identify possible main predictors.

Results

In this article, we summarized major risk factors of limb revascularization failure and disabling vascular complications collecting those parameters principally responsible for major adverse limb events, which provides physio-pathological explanation of their role in peripheral artery disease.

Conclusion

We evaluated and listed a panel of possible predictors of MALE (Major Adverse Limb Event) in order to contribute to the development of a predictive score, based on a summary of the main risk factors reported in scientific articles, which could improve the management of peripheral artery disease by preventing vascular accidents.