Suggested objective performance goals and clinical trial design for evaluating catheter-based treatment of critical limb ischemia

Revascularization for chronic limb-threatening ischaemia

Trials hampered by poor definitions

Impact of angiosome-oriented revascularization on clinical outcomes in critical limb ischemia patients without concurrent wound infection and diabetes

PURPOSE

To investigate the impact of angiosome-oriented revascularization on clinical outcomes in critical limb ischemia (CLI) patients excluding those with both diabetes and wound infection.

METHODS

Using a retrospective multicenter database, a propensity score matching analysis was performed of 539 consecutive CLI patients (375 men; mean age 71±11 years) without concurrent wound infection and diabetes who underwent balloon angioplasty of isolated infrapopliteal lesions. Propensity score matching produced 2 groups of 182 patients each who underwent angiosome-oriented direct revascularization (123 men; mean age 72±11 years) or indirect revascularization (125 men; mean age 72±11 years). The groups were compared for wound healing rate, freedom from major adverse limb events (MALE), and amputation-free survival (AFS).

RESULTS

In the overall population, indirect revascularization was performed in 36.6% (n=197). In the propensity matching analysis, the complete wound healing rate at 12 months was higher in the direct group than the indirect revascularization patients (75% vs. 64%, p=0.01), while freedom from MALE (p=0.99) and AFS (p=0.17) were not significantly different at up to 24 months. In multivariate analysis, indirect revascularization had an independent negative impact on wound healing (adjusted hazard ratio 0.7, p=0.008).

CONCLUSION

After propensity matching analysis for CLI patients other than those with both diabetes and wound infection, the wound healing rate was higher after direct revascularization than after indirect revascularization, whereas MALE and AFS were not significantly different.

Preliminary Report of Endovascular Treatment for Critical Limb Ischemia Patients with Connective Tissue Disease: Cases Series and Review of the Literature

Only few studies have addressed the surgical revascularization in patients with both connective tissue disease (CTD) and critical limb ischemia (CLI), and the evidence for the endovascular treatment (EVT) is lacking in such patients. The main purpose of this study is to assess our outcome of EVT in patients with CTD and ischemic leg ulcers and review the current situation of the revascularization in such patients. Medical records of 10 consecutive patients with coexistent CTD and CLI-related leg ulcers (in 11 limbs) treated endovascularly at our institution between 2009 and 2013 were reviewed retrospectively. The patients had rheumatoid arthritis (n = 5), systemic lupus erythematosus (n = 1), progressive systemic scleroderma (n = 3), or polyarteritis nodosa (n = 1). EVT was technically successful in all the cases. No procedure-related morbidity or mortality occurred. During the mean follow-up period of 26 months, there were no major amputations, and sustained clinical improvement (ulcer healing and reduction in Rutherford category) was observed in eight limbs. The overall 1-year rates of amputation-free survival and freedom from reintervention were 89 and 81%, respectively. In our series of patients with CTD and ischemic leg ulcers, EVT had acceptable outcomes and may be recommended as a safe and reasonably effective initial treatment option for such patients.

The BEST-CLI trial: a multidisciplinary effort to assess which therapy is best for patients with critical limb ischemia

Critical limb ischemia (CLI) is the most severe form of peripheral arterial disease and is associated with a significant risk of limb loss. It is currently treated with limb revascularization by a variety of specialists. Although both open vascular bypass and endovascular therapy are offered to patients with infrainguinal peripheral arterial disease and CLI, significant disagreement exists as to which therapy works best in candidates for both types of intervention. Persistent clinical equipoise in combination with a paucity of comparative effectiveness data to guide treatment of CLI has led to a multidisciplinary effort to organize the Best Endovascular versus Best Surgical Therapy in patients with CLI (BEST-CLI) trial. The BEST-CLI trial is a pragmatic, multicenter, open label, randomized trial that compares best endovascular therapy with best open surgical treatment in patients eligible for both treatments. This trial is highly innovative in both its design and its collaborative nature. BEST-CLI aims to provide urgently needed clinical guidance for CLI management by using (1) a pragmatic design comparing the effectiveness of established techniques while allowing for the introduction of newer therapies as they become available; (2) a novel primary end point that includes limb amputation rates, repeat intervention, and mortality; (3) a multidisciplinary structure that fosters cooperation among interventional cardiologists, interventional radiologists, vascular surgeons, and vascular medicine specialists; and (4) novel techniques to evaluate the cost-effectiveness and quality-of-life outcomes of the 2 treatment strategies being tested.

Efficacy of intravascular ultrasound in femoropopliteal stenting for peripheral artery disease with TASC II class A to C lesions

PURPOSE

To investigate whether use of intravascular ultrasound (IVUS) improves primary patency following nitinol stenting for TASC II (TransAtlantic Inter-Society Consensus) A-C femoropopliteal lesions.

METHODS

Using a retrospective multicenter database of 1198 limbs from 965 patients (695 men; mean age 72±9 years) with TASC II A-C lesions (28% critical limb ischemia) treated by provisional stenting from April 2004 to December 2011, primary patency rate was compared between 234 propensity score-matched pairs with vs. without IVUS use.

RESULTS

IVUS was used in 22% (n=268) of the overall population. It was more likely to be used in cases with generally more complicated femoropopliteal lesions (e.g., more severe TASC II class, longer lesion length, and narrower reference diameter). Analysis of the 234 propensity score-matched pairs (mean follow-up 1.9±1.5 years; 142 events) revealed higher 5-year primary patency with than without IVUS use (65%±6% vs. 35%±6%, p<0.001). IVUS resulted in significantly better assisted primary patency (p<0.001), secondary patency (p=0.004), freedom from any reintervention (p<0.001), freedom from any adverse limb event (p<0.001), and event-free survival (p<0.001).

CONCLUSION

IVUS use in femoropopliteal stenting for TASC II A-C lesions appears to be associated with higher primary patency rate.

Evaluation and treatment of patients with lower extremity peripheral artery disease: consensus definitions from Peripheral Academic Research Consortium (PARC)

The lack of consistent definitions and nomenclature across clinical trials of novel devices, drugs, or biologics poses a significant barrier to accrual of knowledge in and across peripheral artery disease therapies and technologies. Recognizing this problem, the Peripheral Academic Research Consortium, together with the U.S. Food and Drug Administration and the Japanese Pharmaceuticals and Medical Devices Agency, has developed a series of pragmatic consensus definitions for patients being treated for peripheral artery disease affecting the lower extremities. These consensus definitions include the clinical presentation, anatomic depiction, interventional outcomes, surrogate imaging and physiological follow-up, and clinical outcomes of patients with lower-extremity peripheral artery disease. Consistent application of these definitions in clinical trials evaluating novel revascularization technologies should result in more efficient regulatory evaluation and best practice guidelines to inform clinical decisions in patients with lower extremity peripheral artery disease.

The prognostic value of the serum eicosapentaenoic acid to arachidonic acid ratio in relation to clinical outcomes after endovascular therapy in patients with peripheral artery disease caused by femoropopliteal artery lesions

BACKGROUND

The EPA/AA ratio has emerged as a predictor of mortality endpoints in cardiac disease; however, its prognostic value in peripheral artery disease (PAD) patients is unclear. We assessed the serum eicosapentaenoic acid (EPA) to arachidonic acid (AA) ratio in patients with PAD caused by femoropopliteal artery lesions, to determine whether it predicts clinical outcomes after endovascular therapy (EVT).

METHODS AND RESULTS

We obtained serum EPA/AA ratios from 132 consecutive patients with PAD caused by femoropopliteal artery lesions before EVT. Patients were divided into two groups using the median value of serum EPA/AA ratios of the entire cohort; LOW group with the levels ≤0.30 (n = 66) and HIGH group >0.30 (n = 66). The incidence of major adverse events (MAE), including major adverse limb events (MALE) and death from any cause, was determined. At a median follow-up interval of 24 months, MALE occurred in 40 patients (30.3%) and 11 patients (8.3%) died. Kaplan-Meier curve analysis demonstrated the survival probability from MAE was significantly worse in patients with EPA/AA ratio under the median (long-rank test χ(2) = 16.4; p < 0.001). Multivariate Cox regression analysis showed critical limb ischemia (hazard ratio [HR]: 3.44; 95% confidence interval [CI]: 1.84 to 6.46; p < 0.001) and the preprocedural serum EPA/AA ratios ≤0.30 (HR: 2.74; 95% CI: 1.33 to 5.65; p = 0.006) independently predicted MAE after EVT.

CONCLUSIONS

Lower serum EPA/AA ratios appear to be associated with a greater risk of MALE and death from any cause after EVT in patients with PAD caused by femoropopliteal artery lesions.

Postprocedural Skin Perfusion Pressure Correlates With Clinical Outcomes 1 Year After Endovascular Therapy for Patients With Critical Limb Ischemia

BACKGROUND

Although skin perfusion pressure (SPP) is widely used clinically to predict probability of wound healing, correlation between clinical outcomes and SPP has not been systematically studied.

METHODS

This subanalysis of the prospective multicenter OLIVE registry of patients who received infrainguinal endovascular therapy (EVT) for critical limb ischemia (CLI) assessed the association between clinical outcomes and postoperative SPP in 211 consecutive patients. Logistic regression analysis was performed, with amputation-free survival (AFS), modified major adverse limb events (MALEs), and complete wound healing as dependent variables and postprocedural SPP as independent variable.

RESULT

Pre- and postprocedural SPP was 28 ± 11 and 46 ± 18 mm Hg, respectively. In logistic regression analysis, postprocedural SPP correlated with 1-year AFS (P = .018), modified MALEs (P < .001), and wound healing (P = .022).

CONCLUSION

Postprocedural SPP correlates with clinical outcomes after EVT for patients with CLI.

The impact of chronic renal insufficiency on vascular surgery patient outcomes

Renal insufficiency is associated with an increased incidence of poor outcomes, including cardiovascular events and death, in the general population. Renal dysfunction appears to have a particularly negative impact in patients undergoing vascular surgery and endovascular therapy. Although the exact mechanism is unknown, increased levels of inflammatory and biochemical modulators associated with adverse cardiovascular outcomes, as well as endothelial dysfunction, appear to play a role in the association between renal insufficiency and adverse outcomes. Outcomes after the surgical and endovascular treatment of abdominal aortic aneurysms, carotid disease, and peripheral arterial disease are all negatively affected by renal insufficiency. Patients with renal dysfunction may warrant intervention for the treatment of critical limb ischemia and symptomatic carotid stenosis, given the comparatively worse outcomes associated with medical management. Open repair of aortic aneurysms and carotid intervention for asymptomatic disease in patients with severe renal dysfunction should be performed with significant caution, as the risks of repair may outweigh the benefits in this population. Further study is needed to better delineate the risks of medical management for these conditions in patients with coexisting severe renal dysfunction. Lastly, current guidelines for the management of vascular diseases, including objective performance goals for critical limb ischemia, are likely not applicable in patients with severe renal insufficiency.

Effect of repetitive intra-arterial infusion of bone marrow mononuclear cells in patients with no-option limb ischemia: the randomized, double-blind, placebo-controlled Rejuvenating Endothelial Progenitor Cells via Transcutaneous Intra-arterial Supplementation (JUVENTAS) trial

BACKGROUND

Patients with severe limb ischemia may not be eligible for conventional therapeutic interventions. Pioneering clinical trials suggest that bone marrow-derived cell therapy enhances neovascularization, improves tissue perfusion, and prevents amputation. The objective of this trial was to determine whether repetitive intra-arterial infusion of bone marrow mononuclear cells (BMMNCs) in patients with severe, nonrevascularizable limb ischemia can prevent major amputation.

METHODS AND RESULTS

The Rejuvenating Endothelial Progenitor Cells via Transcutaneous Intra-arterial Supplementation (JUVENTAS) trial is a randomized, double-blind, placebo-controlled clinical trial in 160 patients with severe, nonrevascularizable limb ischemia. Patients were randomly assigned to repetitive (3 times; 3-week interval) intra-arterial infusion of BMMNC or placebo. No significant differences were observed for the primary outcome, ie, major amputation at 6 months, with major amputation rates of 19% in the BMMNC versus 13% in the placebo group (relative risk, 1.46; 95% confidence interval, 0.62-3.42). The safety outcome (all-cause mortality, occurrence of malignancy, or hospitalization due to infection) was not significantly different between the groups (relative risk, 1.46; 95% confidence interval, 0.63-3.38), neither was all-cause mortality at 6 months with 5% versus 6% (relative risk, 0.78; 95% confidence interval, 0.22-2.80). Secondary outcomes quality of life, rest pain, ankle-brachial index, and transcutaneous oxygen pressure improved during follow-up, but there were no significant differences between the groups.

CONCLUSIONS

Repetitive intra-arterial infusion of autologous BMMNCs into the common femoral artery did not reduce major amputation rates in patients with severe, nonrevascularizable limb ischemia in comparison with placebo. The general improvement in secondary outcomes during follow-up in both the BMMNC and the placebo group, as well, underlines the essential role for placebo-controlled design of future trials.

CLINICAL TRIAL REGISTRATION URL

http://www.clinicaltrials.gov. Unique identifier: NCT00371371.

Clinical Outcomes of SMART Versus Luminexx Nitinol Stent Implantation for Aortoiliac Artery Disease: A Propensity Score-Matched Multicenter Study

BACKGROUND

Endovascular therapy for aortoiliac (AI) lesions using stents is widely accepted. However, the long-term outcome of 2 different types of nitinol stents for AI lesions is unknown. The aim of this study was to examine the long-term outcome of the SMART and Luminexx nitinol stents for the treatment of de novo AI lesions.

METHODS

This study was a multicenter retrospective analysis of a prospectively maintained database. The study enrolled consecutive patients undergoing primary stenting for de novo AI artery stenosis between January 2005 and December 2009. A total of 1503 lesions in 1229 patients treated with SMART or Luminexx primary stenting were enrolled. The primary end point was primary patency, secondary end points were the primary assisted patency, secondary patency, and major adverse limb events (MALEs), which included major amputation and major reintervention. To minimize the differences between the groups, a propensity score matching analysis was performed, and 284 lesions per group were analyzed to identify outcomes.

RESULTS

After the propensity score matching analysis, the lesion length was 60 ± 37 and 57 ± 31 mm (P = .275), and the reference vessel diameter was 8.2 ± 1.5 and 8.3 ± 1.5 mm (P = .482) in the SMART and Luminexx groups, respectively. The primary patency at 3 years was not significantly different between the groups (83.5% vs 82.2%, P = .842, respectively). The assisted primary patency and secondary patency rates were also not significantly different (91.7% vs 93.2%, P = .340, 99.2% vs 98.8%, P = .922). In addition, the MALE rate was not significantly different between the groups (98.3% vs 97.3%, P = .821).

CONCLUSION

The current data suggest that the use of nitinol stents for the AI artery provided good long-term patency and freedom from MALE for 3 years of follow-up, regardless of whether SMART or Luminexx stents were used.

Drug-eluting balloon versus standard balloon angioplasty for infrapopliteal arterial revascularization in critical limb ischemia: 12-month results from the IN.PACT DEEP randomized trial

BACKGROUND

Drug-eluting balloons (DEB) may reduce infrapopliteal restenosis and reintervention rates versus percutaneous transluminal angioplasty (PTA) and improve wound healing/limb preservation.

OBJECTIVES

The goal of this clinical trial was to assess the efficacy and safety of IN.PACT Amphirion drug-eluting balloons (IA-DEB) compared to PTA for infrapopliteal arterial revascularization in patients with critical limb ischemia (CLI).

METHODS

Within a prospective, multicenter, randomized, controlled trial with independent clinical event adjudication and angiographic and wound core laboratories 358 CLI patients were randomized 2:1 to IA-DEB or PTA. The 2 coprimary efficacy endpoints through 12 months were clinically driven target lesion revascularization (CD-TLR) and late lumen loss (LLL). The primary safety endpoint through 6 months was a composite of all-cause mortality, major amputation, and CD-TLR.

RESULTS

Clinical characteristics were similar between the 2 groups. Significant baseline differences between the IA-DEB and PTA arms included mean lesion length (10.2 cm vs. 12.9 cm; p = 0.002), impaired inflow (40.7% vs. 28.8%; p = 0.035), and previous target limb revascularization (32.2% vs. 21.8%; p = 0.047). Primary efficacy results of IA-DEB versus PTA were CD-TLR of 9.2% versus 13.1% (p = 0.291) and LLL of 0.61 ± 0.78 mm versus 0.62 ± 0.78 mm (p = 0.950). Primary safety endpoints were 17.7% versus 15.8% (p = 0.021) and met the noninferiority hypothesis. A safety signal driven by major amputations through 12 months was observed in the IA-DEB arm versus the PTA arm (8.8% vs. 3.6%; p = 0.080).

CONCLUSIONS

In patients with CLI, IA-DEB had comparable efficacy to PTA. While primary safety was met, there was a trend towards an increased major amputation rate through 12 months compared to PTA. (Study of IN.PACT Amphirion™ Drug Eluting Balloon vs. Standard PTA for the Treatment of Below the Knee Critical Limb Ischemia [INPACT-DEEP]; NCT00941733).

Angiosome-directed revascularization for critical limb ischemia

The angiosome hypothesis states that the surface of the lower extremity is supplied by arteries consistently corresponding to regions of the foot. There is limited and conflicting evidence suggesting that angiosome-directed interventions improve wound healing and limb salvage. As peripheral arterial disease progresses, collaterals may develop that confound a predetermined angiosome map. In selecting a revascularization target vessel for patients with tissue loss, good surgical judgment should prevail, including consideration of the angiosome concept to optimize tissue healing.

Optimal management of infrainguinal arterial occlusive disease

Peripheral arterial occlusive disease is becoming a major health problem in Western societies as the population continues to age. In addition to risk of limb loss, the complexity of the disease is magnified by its intimate association with medical comorbidity, especially cardiovascular and cerebrovascular disease. Risk factor modification and antiplatelet therapy are essential to improve long-term survival. Surgical intervention is indicated for intermittent claudication when a patient’s quality of life remains unacceptable after a trial of conservative therapy. Open reconstruction and endovascular revascularization are cornerstone for limb salvage in patients with critical limb ischemia. Recent advances in catheter-based technology have made endovascular intervention the preferred treatment approach for infrainguinal disease in many cases. Nevertheless, lower extremity bypass remains an important treatment strategy, especially for reasonable risk patients with a suitable bypass conduit. In this review, we present a summary of current knowledge about peripheral arterial disease followed by a review of current, evidence-based medical and surgical therapy for infrainguinal arterial occlusive disease.

Failure of patients with peripheral arterial disease to accept the recommended treatment results in worse outcomes

BACKGROUND

Strategies available to facilitate decision making for patients with peripheral arterial disease (PAD) include a Markov-based decision analysis (DA) model and the Lower Extremity Grading System (LEGS) score. Both have suggested inferior outcomes when the actual treatment received (ATX) differs from that predicted. This study focuses on patient outcomes when such discordance exists.

METHODS

All patients referred for symptomatic lower extremity PAD over a 3-year period were evaluated using the DA model and the LEGS score. Calculated quality of life (cQOL) values were assigned before treatment based on patient symptom, perfusion, and amputation status and at follow-up (range 1.000 [perfect health] to .000 [death]). The primary outcome of cQOL was compared according to whether the ATX matched that proposed by the surgeon or predicted by the DA model or LEGS score. Secondary outcomes for revascularized patients included major adverse limb event with perioperative death (MALE + POD) and amputation-free survival (AFS).

RESULTS

Among 375 procedures in 345 consecutive patients, the greatest improvement in cQOL at last follow-up (median 16 months) was observed with endovascular (0.23 ± 0.16, n = 93) or open (0.21 ± 0.17, n = 137) revascularization compared with primary amputation (0.10 ± 0.07, n = 23) or medical therapy (0.04 ± 0.09, n = 122). Multivariate regression showed discordance with the surgeon's recommendation (P < 0.05) and/or the DA model (P < 0.05) to be independent predictors of improvement failure. ATX did not always agree with that proposed by the surgeon (89% agree, κ = 0.84), the DA model (68% agree, κ = 0.53), or the LEGS score (53% agree, κ = 0.32). Improvement in cQOL was greatest when ATX was concordant with treatment proposed by the surgeon (0.18 vs. 0.08, P < 0.01), the DA model (0.19 vs. 0.13, P < 0.01), or the LEGS score (0.23 vs. 0.10, P < 0.01). Patient refusal to follow the surgeon's recommendations and continued smoking were associated with minimal improvement (cQOL ranges 0.05-0.07 and 0.00-0.02, respectively), while pursuing a less morbid procedure was associated with greater improvement (cQOL range 0.28-0.38). Among revascularized patients, MALE + POD was lower at 36 months after endovascular than open surgery (21% ± 5% vs. 36% ± 4%, P < 0.05), while AFS was not significantly different. Only discordance with the surgeon's recommendation was an independent predictor of MALE + POD, possibly because of limitations in sample subset size.

CONCLUSIONS

Mean cQOL improved most with direct revascularization, especially when the treatment received matched that predicted by the models or proposed by the surgeon. Type of treatment received was an independent predictor of agreement of treatment with recommendations. Patient refusal to follow the recommended treatment as well as the strategy not to revascularize claudicants who persist in smoking were associated with much less patient benefit from treatment.

Contemporary outcomes with percutaneous vascular interventions for peripheral critical limb ischemia in those with and without poly-vascular disease

Given the very ill nature of patients with critical limb ischemia (CLI), the use of percutaneous vascular interventions (PVIs) for limb salvage may or may not be efficacious; in particular, for those with polyvascular arterial disease. Herein, we reviewed large, multi-institutional outcomes of PVI in polyvascular and peripheral arterial disease (PAD) patients with CLI. An 18-hospital consortium collected prospective data on patients undergoing endovascular interventions for PAD with 6-month follow-up from January 2008 to December 2011. The patient cohort included 4459 patients with CLI; of those, 3141 patients had polyvascular (coronary artery disease, cerebrovascular disease and PAD) disease, whereas 1318 patients suffered from only PAD. All patients were elderly and with significant comorbidities. The mean ankle–brachial index (ABI) was 0.44 and was not different between those with and without polyvascular disease. Polyvascular patients had more femoropopliteal and infra-inguinal interventions and less aortoiliac interventions than PAD patients. Pre- and post-procedural cardioprotective medication use was less in the PAD patients as compared with polyvascular patients. Vascular complications requiring surgery were higher in PAD patients whereas other access complications were similar between groups. At 6-month follow-up, death was more common in the polyvascular group (6.7% vs 4.1%, p<0.001) as was repeat PVI, but no difference was found in the amputation rate. Considering the group as a whole at the 6-month follow-up, predictors of amputation/death included age (HR=1.01; 95% CI=1.002–1.02), anemia (HR=2.6; 95% CI=2.1–3.2), diabetes mellitus (HR=1.6; 95% CI=1.3–1.9), congestive heart failure (HR=1.6; 95% CI=1.4–1.9), and end-stage renal failure (HR=1.9; 95% CI=1.5–2.3), while female sex was protective (HR=0.7; 95% CI=0.6–0.8). In conclusion, from examination of this large, multicenter, multi-specialist practice registry, patients with polyvascular disease had higher 6-month mortality than PAD patients, but this was not a factor in 6-month limb amputation outcomes. This study also underscores that PAD patients still lag in cardioprotective medication use as compared with polyvascular patients.

Stem cell trials for cardiovascular medicine: ethical rationale

Stem cell-based interventions provide new treatment prospects for many disease conditions, including cardiovascular disorders. Clinical trials are necessary to collect adequate evidence on (long-term) safety and efficacy of novel interventions such as stem cells, but the design and launch of clinical trials, from first-in-human studies to larger randomized controlled trials (RCTs), is scientifically and ethically challenging. Stem cells are different from traditional pharmaceuticals, surgical procedures, and medical devices in the following ways: the novelty and complexity of stem cells, the invasiveness of the procedures, and the novel aim of regeneration. These specifics, combined with the characteristics of the study population, will have an impact on the design and ethics of RCTs. The recently closed JUVENTAS trial will serve as an example to identify the (interwoven) scientific and ethical challenges in the design and launch of stem cell RCTs. The JUVENTAS trial has investigated the efficacy of autologous bone marrow cells in end-stage vascular patients, in a double-blind sham-controlled design. We first describe the choices, considerations, and experiences of the JUVENTAS team. Subsequently, we identify the main ethical and scientific challenges and discuss what is important to consider in the design of future stem cell RCTs: assessment of risks and benefits, the choice for outcome measures, the choice for the comparator, the appropriate selection of participants, and adequate informed consent. Additionally, the stem cell field is highly in the spotlight due to the (commercial) interests and expectations. This warrants a cautious pace of translation and scrupulous set up of clinical trials, as failures could put the field in a negative light. At the same time, knowledge from clinical trials is necessary for the field to progress. We conclude that in the scientifically and ethically challenging field of stem cell RCTs, researchers and clinicians have to maneuver between the Skylla of hyper accelerated translation without rigorously conducted RCTs and the Charybdis of the missed opportunity of valuable knowledge.

Safety and effectiveness of endovascular therapy for claudication in octogenarians

BACKGROUND

Advanced age (≥ 80 years) has been associated with adverse outcomes after lower extremity bypass for critical limb ischemia (CLI), but endovascular therapy (ET) is reported to have comparable safety across age groups. Here, we assess the safety and effectiveness of advanced age on outcomes after ET for lifestyle-limiting intermittent claudication (IC).

METHODS

A retrospective review of a prospectively maintained institutional database (2007-2012) identified all patients undergoing ET for IC. Demographics, procedural details, and outcomes were assessed via univariate analysis and multivariate Cox regression. Effectiveness was assessed across a panel of outcome metrics including the following: overall survival, freedom from major adverse limb event (MALE), and freedom from reintervention, amputation, or restenosis (RAS). Freedom from MALE + perioperative death (MALE + POD) was the primary safety end point.

RESULTS

Two hundred thirty-six patients underwent primary ET for 284 affected limbs. Of these, 46 interventions (16%) were performed in patients ≥ 80 years old. The average age of octogenarians treated was 84.4 years compared with 67.4 years among those aged <80 (P < 0.001). Compared with younger claudicants, octogenarians were less likely to have hypercholesterolemia (43.5% vs. 63.9%, P = 0.01) and more likely to deny a history of smoking (41.3% vs. 14.7%, P < 0.001). Octogenarians were also more likely to undergo interventions involving the popliteal artery (50% vs. 31.9%, P = 0.03). There were no other significant differences in demographics, comorbidities, TransAtlantic Inter-Society Consensus II classification, or treated arterial segment. Thirty-day freedom from MALE + POD was 100% in octogenarians and 99.6% in patients <80 years, with no difference between age groups. There were no differences in freedom from MALE, freedom from RAS, or overall survival at 1- and 3-year follow-up.

CONCLUSIONS

Although age >80 years has been identified as an independent risk factor for poor outcomes in the surgical treatment of CLI, our results suggest that ET for selected octogenarians with lifestyle-limiting claudication is as safe and effective as ET in younger patients. Advanced age alone should not prohibit consideration of ET for patients with IC.

Bone marrow aspirate injection for treatment of critical limb ischemia with comparison to patients undergoing high-risk bypass grafts

OBJECTIVE

Bone marrow cell therapy (BMCT) for patients with critical limb ischemia (CLI) is a potential treatment in candidates with poor options for standard revascularization procedures. Whereas clinical trials are ongoing, there are few comparative data to assess its efficacy compared with bypass.

METHODS

Patients with poor revascularization options underwent BMCT between 2011 and 2013. Outcomes were compared with those of a cohort of CLI patients undergoing infrainguinal bypass thought to be at high risk for graft failure (tissue loss, a tibial target, and a previous endovascular treatment or bypass). BMCT patients underwent harvest of bone marrow that was then concentrated and injected intramuscularly into the ischemic limb.

RESULTS

There were 20 BMCT patients and 35 high-risk bypass patients. All BMCT patients had either rest pain (80%) or tissue loss (80%). The majority (65%) had a prior intervention (bypass, 30%; endovascular, 58%) compared with high-risk bypass patients, all of whom had previous revascularization attempts (bypass, 43% [P = .35]; endovascular, 77% [P = .14]). Mean follow-up was 773 days after BMCT and 972 days after high-risk bypass. All patients tolerated BMCT without issues or complications. A second BMCT treatment was performed in 21% because of clinical deterioration. Wound healing occurred in 75% at 1.5 years, including patients receiving second injections, all of which resolved. Rest pain improved in 87.5% of patients. Pain completely resolved in 58% at 1.5 years. Ankle-brachial index improvement was 0.23 (±0.25). Three BMCT patients went on to amputation. One-year freedom from major amputation or death was 78% for BMCT vs 69% for high-risk bypass (P = .60).

CONCLUSIONS

BMCT is a potential option in CLI patients who are not candidates for bypass or endovascular intervention. Limb salvage is unexpectedly high in this population with few other options.

Defining utility and predicting outcome of cadaveric lower extremity bypass grafts in patients with critical limb ischemia

OBJECTIVE

Despite poor long-term patency, acceptable limb salvage has been reported with cryopreserved saphenous vein bypass (CVB) for various indications. However, utility of CVB in patients with critical limb ischemia (CLI) remains undefined. The purpose of this analysis was to determine the role of CVB in CLI patients and to identify predictors of successful outcomes.

METHODS

A retrospective review of all lower extremity bypass (LEB) procedures at a single institution was completed, and CVB in CLI patients were further analyzed. The primary end point was amputation-free survival. Secondary end points included primary patency and limb salvage. Life tables were used to estimate occurrence of end points. Cox regression analysis was used to determine predictors of limb salvage.

RESULTS

From 2000 to 2012, 1059 patients underwent LEB for various indications, of whom 81 received CVB for either ischemic rest pain or tissue loss. Mean age (± standard deviation) was 66 ± 10 years (male, 51%; diabetes, 51%; hemodialysis dependence, 12%), and 73% (n = 59) had history of failed ipsilateral LEB or endovascular intervention. None had sufficient autogenous conduit for even composite vein bypass. Infrainguinal CVB (infrapopliteal target, 96%; n = 78) was completed for multiple indications including Rutherford class 4 (42%; n = 34), class 5 (40%; n = 32), and class 6 (18%; n = 15). Eleven (14%) had CLI and concomitant graft infection (n = 8) or acute on chronic ischemia (n = 3). Intraoperative adjuncts (eg, profundaplasty, suprainguinal stent or bypass) were completed in 49% (n = 40) of cases. Complications occurred in 36% (n = 29), with 30-day mortality of 4% (n = 3). Median follow-up for CLI patients was 11.8 (interquartile range, 0.4-28.4) months with corresponding 1- and 3-year actuarial estimated survival (± standard error mean) of 84% ± 4% and 62% ± 6%. Primary patency of CVB for CLI was 27% ± 6% and 17% ± 6% at 1 and 3 years, respectively. Amputation-free survival was 43% ± 6% and 23% ± 6% at 1 and 3 years, respectively, and significantly higher for rest pain (59% ± 9%, 36% ± 10%) compared with tissue loss (31% ± 7%, 14% ± 7%; log-rank, P = .04). Freedom from major amputation after CVB for CLI was 57% ± 6% and 43% ± 7% at 1 and 3 years. Multivariable predictors of limb salvage for the CVB CLI cohort included postoperative warfarin (hazard ratio [HR], 0.4; 95% confidence interval [CI], 0.2-0.8), dyslipidemia (HR, 0.4; 95% CI, 0.2-0.9), and rest pain (HR, 0.4; 95% CI, 0.2-0.9). Predictors of major amputation included graft infection (HR, 3.1; 95% CI, 1.1-9.0).

CONCLUSIONS

In CLI patients with no autologous conduit and prior failed infrainguinal bypass, CVB outcomes are disappointing. CVB performs best in patients with rest pain, particularly those who can be anticoagulated with warfarin. However, it may be an acceptable option in patients with minor tissue loss or concurrent graft infection, but consideration should be weighed against the known natural history of nonrevascularized CLI and nonbiologic conduit alternatives, given potential cost implications.

Objective measurement of lower extremity function and quality of life after surgical revascularization for critical lower extremity ischemia

BACKGROUND

Outcomes of revascularization for critical limb ischemia (CLI) have historically been patency, limb salvage, and survival. Functional status and quality of life have not been well described. This study used functional and quality of life assessments to measure patient-centered outcomes after revascularization for CLI.

METHODS

The study observed 18 patients (age, 65 ± 11 years) prospectively before and after lower extremity bypass for CLI. Patients completed the Short Physical Performance Battery, which measures walking speed, leg strength, and balance, as well as performed a 6-minute walk, and calorie expenditure was measured by an accelerometer. Isometric muscle strength was assessed with the Muscle Function Evaluation chair (Metitur, Helsinki, Finland). Quality of life instruments included the 36-Item Short Form Health Survey and the Vascular Quality of Life questionnaire. Patients' preoperative status was compared with 4-month postoperative status.

RESULTS

Muscle Function Evaluation chair measurements of ipsilateral leg strength demonstrated a significant increase in knee flexion from 64 ± 62 N to 135 ± 133 N (P = .038) and nearly significant increase in knee extension from 120 ± 110 N to 186 ± 85 N (P = .062) and ankle plantar flexion from 178 ± 126 N to 267 ± 252 N (P = .078). In the contralateral leg, knee flexion increased from 71 ± 96 N to 149 ± 162 N (P = .028) and knee extension from 162 ± 112 N to 239 ± 158 N (P = .036). Absolute improvements were noted in 6-minute walk distance, daily calorie expenditure, and individual domains and overall Short Physical Performance Battery scores, and upper extremity strength decreased, although none were significant. The Vascular Quality of Life questionnaire captured significant improvement in all individual domains and overall score (P < .015). Significant improvement was noted only for bodily pain (P = .011) on the 36-Item Short Form Health Survey.

CONCLUSIONS

Despite lack of statistical improvement in most functional test results, revascularization for CLI results in improved patient-perceived leg function. Significant improvements in isometric muscle strength may explain the measured improvement in quality of life after revascularization for CLI.

Individual and composite study endpoints: separating the wheat from the chaff

We provide an overview of the individual and combined clinical endpoints and patient-reported outcomes typically used in clinical trials and prospective epidemiological investigations. We discuss the strengths and limitations associated with the utilization of aggregated study endpoints and surrogate measures of important clinical endpoints and patient-centered outcomes. We hope that the points raised in this overview will lead to the collection of clinically rich, relevant, measurable, and cost-efficient study outcomes.

Comparative effectiveness of endovascular and surgical revascularization for patients with peripheral artery disease and critical limb ischemia: systematic review of revascularization in critical limb ischemia

BACKGROUND

For patients with critical limb ischemia (CLI), the optimal treatment to enhance limb preservation, prevent death, and improve functional status is unknown. We performed a systematic review and meta-analysis to assess the comparative effectiveness of endovascular revascularization and surgical revascularization in patients with CLI.

METHODS

We systematically searched PubMed, Embase, and the Cochrane Database of Systematic Reviews for relevant English-language studies published from January 1995 to August 2012. Two investigators screened each abstract and full-text article for inclusion, abstracted the data, and performed quality ratings and evidence grading. Random-effects models were used to compute summary estimates of effects, with endovascular treatment as the control group.

RESULTS

We identified a total of 23 studies, including 1 randomized controlled trial, which reported no difference in amputation-free survival at 3 years (odds ratio [OR] 1.22, 95% CI 0.84-1.77) and all-cause mortality (OR 1.07, 0.73-1.56) between the 2 treatments. Meta-analysis of the observational studies showed a statistically nonsignificant reduction in all-cause mortality at 6 months (11 studies, OR 0.85, 0.57-1.27) and amputation-free survival at 1 year (2 studies, OR 0.76, 0.48-1.21) in patients treated with endovascular revascularization. There was no difference in overall death, amputation, or amputation-free survival at ≥2 years.

CONCLUSIONS

The currently available literature suggests that there is no difference in clinical outcomes for patients with CLI treated with endovascular or surgical revascularization. There is a paucity of high-quality data available to guide clinical decision making, especially as it pertains to patient subgroups or anatomical considerations.

Endovascular techniques in limb salvage: infrapopliteal angioplasty

Critical limb ischemia (CLI) results from inadequate blood flow to supply and sustain the metabolic needs of resting muscle and tissue. Infragenicular atherosclerosis is the most common cause of CLI, and it is more likely to develop when multilevel or diffuse arterial disease coincides with compromised run-off to the foot. Reports of good technical and clinical outcomes have advanced the endovascular treatment options, which have gained a growing acceptance as the primary therapeutic strategy for CLI, especially in patients with significant risk factors for open surgical bypass. In fact, endovascular recanalization of below-the-knee arteries has proven to be feasible and safe, reduce the need for amputation, and improve wound healing. The distribution of various vascular territories or angiosomes in the foot has been recognized, and it appears advantageous to revascularize the artery supplying the territory directly associated with tissue loss. In addition, the targeted application and local delivery of drugs using drug-coated balloons (DCB) during angioplasty has the potential to improve patency rates compared to balloon angioplasty alone.

Surgical reconstruction versus peripheral intervention in patients with critical limb ischemia – a prospective multicenter registry in Japan: The SPINACH study design and rationale

Clinical evidence reflecting the recent development of treatments for patients with critical limb ischemia is mandatory to guide the decision-making process for the selection of revascularization procedures, including bypass or endovascular treatment. This paper describes the protocol for a clinical study that is designed and carried out by both vascular surgeons and interventional cardiologists collaboratively, and will investigate current treatment for critical limb ischemia in Japan. The registry aimed to recruit approximately 450 patients with critical limb ischemia, including approximately 150 patients who underwent bypass surgery and approximately 300 patients who underwent endovascular treatment in 23 institutions. The primary endpoint of this study is amputation-free survival at 36 months, and the secondary endpoints include major amputation, cardiovascular events, re-intervention, death, ulcer healing, and their composite outcomes. The SPINACH study aims to provide a suitable patient model for each revascularization procedure, bypass and endovascular treatment, and will expound on the role of each approach for critical limb ischemia treatment (Clinical trial registration UMIN000007050).

Cilostazol is associated with improved outcomes after peripheral endovascular interventions

OBJECTIVE

Although cilostazol is commonly used as an adjunct after peripheral vascular interventions, its efficacy remains uncertain. We assessed the effect of cilostazol on outcomes after peripheral vascular interventions using meta-analytic techniques.

METHODS

We searched MEDLINE (1946-2012), Cochrane CENTRAL (1996-2012), and trial registries for studies comparing cilostazol in combination with antiplatelet therapy to antiplatelet therapy alone after peripheral vascular interventions. Treatment effects were reported as pooled risk/hazard ratio (HR) with random-effects models.

RESULTS

Two randomized trials and four retrospective cohorts involving 1522 patients met inclusion criteria. Across studies, mean age ranged from 65 to 76 years, and the majority of patients were male (64%-83%); mean follow-up ranged from 18 to 37 months. Most interventions were in the femoropopliteal segment, and overall, 68% of patients had stents placed. Pooled estimates demonstrated that the addition of cilostazol was associated with decreased restenosis (relative risk [RR], 0.71; 95% confidence interval [CI], 0.60-0.84; P < .001), improved amputation-free survival (HR, 0.63; 95% CI, 0.47-0.85; P = .002), improved limb salvage (HR, 0.42; 95% CI, 0.27-0.66; P < .001), and improved freedom from target lesion revascularization (RR, 1.36; 95% CI, 1.14-1.61; P < .001). There was no significant reduction in mortality among those receiving cilostazol (RR, 0.73; 95% CI, 0.45-1.19; P = .21).

CONCLUSIONS

The addition of cilostazol to antiplatelet therapy after peripheral vascular interventions is associated with a reduced risk of restenosis, amputation, and target lesion revascularization in our meta-analysis of six studies. Consideration of cilostazol as a medical adjunct after peripheral vascular interventions is warranted, presuming these findings are broadly generalizable.

Results of infrapopliteal endovascular procedures performed in diabetic patients with critical limb ischemia and tissue loss from the perspective of an angiosome-oriented revascularization strategy

Our aim was to describe our experience with infrapopliteal endovascular procedures performed in diabetic patients with ischemic ulcers and critical ischemia (CLI). A retrospective study of 101 procedures was performed. Our cohort was divided into groups according to the number of tibial vessels attempted and the number of patent tibial vessels achieved to the foot. An angiosome anatomical classification of ulcers were used to describe the local perfusion obtained after revascularization. Ischemic ulcer healing and limb salvage rates were measured. Ischemic ulcer healing at 12 months and limb salvage at 24 months was similar between a single revascularization and multiple revascularization attempts. The group in whom none patent tibial vessel to the foot was obtained presented lower healing and limb salvage rates. No differences were observed between obtaining a single patent tibial vessel versus more than one tibial vessel. Indirect revascularization of the ulcer through arterial-arterial connections provided similar results than those obtained after direct revascularization via its specific angiosome tibial artery. Our results suggest that, in CLI diabetic patients with ischemic ulcers that undergo infrapopliteal endovascular procedures, better results are expected if at least one patent vessel is obtained and flow is restored to the local ischemic area of the foot.

Clinical efficacy of successful angioplasty in critical ischemia--a cohort study

BACKGROUND

To evaluate the impact of percutaneous angioplasty (PA), objectively assessed with duplex-ultrasound, on 3-year clinical outcome.

METHODS

Thirty-nine patients with atherosclerotic disease successfully treated by PA were included (40 limbs). All patients had critical ischemia with rest pain and ischemic ulcers due to infrainguinal obstructions alone. The patients were submitted to duplex ultrasound examination on the day before and on the first or second day after the procedure. Peak systolic velocities (PSV) were recorded in the anterior tibial, posterior tibial, and fibular arteries at the level of distal third of the leg. All patients were followed for 3 years. Comparison between groups with good and bad results were based on perioperative VPS gradient (GPSV) of the mean of the VPS in the 3 arteries. After 3 years, a good result was defined as a patient having no pain and complete healing of a previous ulcer or minor amputations.

RESULTS

Mean age was 68.5±8.1 years with no difference in demographic characteristics (P>0.05). In 26 cases, the long-term result was good. Healing time ranged from 4 to 130 weeks (median 26.5). Bad long-term results were observed in 12 cases. Two lesions remained unhealed despite patent angioplasty. In 10 cases, a second procedure was carried out (repeat angioplasty in 6 and bypass in 4). TransAtlantic Inter-Society Consensus (TASC) II category A/B registered better clinical success then TASC II category C/D (P<0.05) at 1-year follow-up but not at 3 years (P=0.36). Two-year limb salvage was 92.5%±4.2%. Primary patency was 52.5%±9.5% at 3 years. GVPS was 21.9 cm/sec in the good results group and 24.7 cm/sec in the bad results group (P>0.05). The quality of the initial result, as measured by GPSV, was not associated with long-term success (P>0.05).

CONCLUSIONS

An initially successful procedure indicated by the degree of increased flow is not related to long-term durability and ulcer healing.

Clinical Predictors of Long-Term Outcomes in Patients With Critical Limb Ischemia Who have Undergone Endovascular Therapy

Clinical predictors of long-term outcomes in patients with critical limb ischemia (CLI) treated with endovascular therapy (EVT) remain unclear. In this study, clinical predictors of long-term outcomes in EVT-treated patients with CLI were investigated. In this prospective, observational study, we analyzed a total of 253 Taiwanese patients with CLI with 314 limbs who underwent EVT between 2005 and 2012. Cox models were used to estimate hazard ratios of death, limb loss, and sustained clinical success (SCS). Multivariate analysis showed that age, atrial fibrillation (AF), end-stage renal disease (ESRD), and albumin were significant predictors of mortality. Patients with coronary artery disease and low albumin levels had a significant risk of major limb amputation, while AF, ESRD, and albumin were significant, independent predictors of SCS. In addition to previously reported predictors, we showed that AF and malnutrition can be used to predict long-term outcome in EVT-treated patients with CLI.

Growing impact of restenosis on the surgical treatment of peripheral arterial disease

Background

Patients with peripheral arterial disease often experience treatment failure from restenosis at the site of a prior peripheral endovascular intervention (PVI) or lower extremity bypass (LEB). The impact of these treatment failures on the utilization and outcomes of secondary interventions is poorly understood.

Methods and Results

In our regional vascular quality improvement collaborative, we compared 2350 patients undergoing primary infrainguinal LEB with 1154 patients undergoing secondary infrainguinal LEB (LEB performed after previous revascularization in the index limb) between 2003 and 2011. The proportion of patients undergoing secondary LEB increased by 72% during the study period (22% of all LEBs in 2003 to 38% in 2011, P<0.001). In‐hospital outcomes, such as myocardial infarction, death, and amputation, were similar between primary and secondary LEB groups. However, in both crude and propensity‐weighted analyses, secondary LEB was associated with significantly inferior 1‐year outcomes, including major adverse limb event‐free survival (composite of death, new bypass graft, surgical bypass graft revision, thrombectomy/thrombolysis, or above‐ankle amputation; Secondary LEB MALE‐free survival = 61.6% vs primary LEB MALE‐free survival = 67.5%, P=0.002) and reintervention or amputation‐free survival (composite of death, reintervention, or above‐ankle amputation; Secondary LEB RAO‐free survival = 58.9% vs Primary LEB RAO‐free survival 64.1%, P=0.003). Inferior outcomes for secondary LEB were observed regardless of the prior failed treatment type (PVI or LEB).

Conclusions

In an era of increasing utilization of PVI, a growing proportion of patients undergo LEB in the setting of a prior failed PVI or surgical bypass. When caring for patients with peripheral arterial disease, physicians should recognize that first treatment failure (PVI or LEB) affects the success of subsequent revascularizations.

Safety and efficacy outcomes of infrapopliteal endovascular procedures performed in patients with critical limb ischemia according to the Society for Vascular Surgery objective performance goals

BACKGROUND

Objective performance goals (OPGs) are a set of standardized end points generated from well documented historical controls against which new therapeutic procedures may be compared in single-arm studies. Recently, the Society for Vascular Surgery suggested a set of OPGs designed from vein bypass controls that could be used to evaluate the safety and efficacy of endovascular devices applied to critical limb ischemia through a noninferiority analysis. Our aim is to analyze the results of infrapopliteal endovascular procedures performed in patients with critical limb ischemia according to these OPG end points.

METHODS

This is a retrospective study of 121 infrapopliteal endovascular procedures. The tibial intervention was combined with a femoropopliteal angioplasty in 70 procedures. Major adverse cardiovascular events (MACEs), major adverse limb events (MALEs), and major amputations at 30 days were recorded as safety outcomes. Freedom from any MALE or perioperative death (Freedom from MALE + POD) and amputation-free survival were calculated as primary efficacy end points at both 12 months and at 8 years. The 95% confidence intervals (CIs) of all the end points were calculated to perform a noninferiority comparison using OPGs as the reference.

RESULTS

The incidence of MACEs, MALEs, and amputation at 30 days were 5% (95% CI: 2-10% [OPG-MACE <10%]), 2.5% (95% CI: 0.5-7% [OPG-MALE <9%]), and 1.7% (95% CI: 0.2-6% [OPG-major amputation <4%]), respectively. We recorded a freedom from MALE + POD of 76% (95% CI: 67-83% [OPG-MALE + POD >67%]) and an amputation-free survival of 78% (95% CI: 69-85% [OPG-amputation-free survival >68%]) at 12 months. Freedom from MALE + POD and amputation-free survival at 8 years decreased to 60% (95% CI: 49-69%) and to 26% (95% CI: 11-44%), respectively.

CONCLUSIONS

Infrapopliteal endovascular procedures performed in everyday vascular surgery practice could meet the main OPG end points proposed for catheter-based treatment of critical limb ischemia.