Predictive factors for better bypass patency and limb salvage after prosthetic above-knee bypass reconstruction

Six-year outcomes of a phase II study of human-tissue engineered blood vessels for peripheral arterial bypass

Objective

The human acellular vessel (HAV) was evaluated for surgical bypass in a phase II study. The primary results at 24 months after implantation have been reported, and the patients will be evaluated for ≤10 years.

Methods

In the present report, we have described the 6-year results of a prospective, open-label, single-treatment arm, multicenter study. Patients with advanced peripheral artery disease (PAD) requiring above-the-knee femoropopliteal bypass surgery without available autologous graft options had undergone implantation with the HAV, a bioengineered human tissue replacement blood vessel. The patients who completed the 24-month primary portion of the study will be evaluated for ≤10 years after implantation. The present mid-term analysis was performed at the 6-year milestone (72 months) for patients followed up for 24 to 72 months.

Results

HAVs were implanted in 20 patients at three sites in Poland. Seven patients had discontinued the study before completing the 2-year portion of the study: four after graft occlusion had occurred and three who had died of causes deemed unrelated to the conduit, with the HAV reported as functional at their last visit. The primary results at 24 months showed primary, primary assisted, and secondary patency rates of 58%, 58%, and 74%, respectively. One vessel had developed a pseudoaneurysm deemed possibly iatrogenic; no other signs of structural failure were reported. No rejections or infections of the HAV occurred, and no patient had required amputation of the implanted limb. Of the 20 patients, 13 had completed the primary portion of the study; however, 1 patient had died shortly after 24 months. Of the remaining 12 patients, 3 died of causes unrelated to the HAV. One patient had required thrombectomy twice, with secondary patency achieved. No other interventions were recorded between 24 and 72 months. At 72 months, five patients had a patent HAV, including four patients with primary patency. For the entire study population from day 1 to month 72, the overall primary, primary assisted, and secondary patency rate estimated using Kaplan-Meier analysis was 44%, 45%, and 60% respectively, with censoring for death. No patient had experienced rejection or infection of the HAV, and no patient had required amputation of the implanted limb.

Conclusions

The infection-resistant, off-the-shelf HAV could provide a durable alternative conduit in the arterial circuit setting to restore the lower extremity blood supply in patients with PAD, with remodeling into the recipient's own vessel over time. The HAV is currently being evaluated in seven clinical trials to treat PAD, vascular trauma, and as a hemodialysis access conduit.

Perioperative inflammatory status predicts mid-term outcomes in patients undergoing femoropopliteal paclitaxel-coated balloon angioplasty

OBJECTIVE

To evaluate the association of perioperative inflammatory status, as determined using the neutrophil-to-lymphocyte ratio (NLR) and high-sensitivity C-reactive protein (hs-CRP) level, with the efficacy of femoropopliteal paclitaxel-coated balloon (PCB) angioplasty.

METHODS

The data of 122 patients (138 limbs) were retrospectively analyzed (median follow-up time, 21 months). The pre- and postoperative NLRs and hs-CRP levels were evaluated to determine their predictive value for mid-term primary patency and clinically driven target lesion revascularization (CD-TLR) during follow-up. Cox regression and Kaplan-Meier survival analyses were performed to investigate the predictive value of the inflammatory parameters and clinical risk factors.

RESULTS

The study population had a median age of 67.2±9.2 years, and 85.2±3% were men. Approximately 18.0±3% of the cases were classified under Rutherford grade II; 52.5±4%, grade III; 24.6±3%, grade IV; 4.1±1%, grade V; and 0.8±0.7%, grade VI. The 12- and 24-month cumulative patency rates were 81.2±27.0% and 60.4±30.1%, respectively, and the freedom from CD-TLR rates were 90.8±19.1% and 82.5±28.3%, respectively. Severe lesion calcification was identified as an independent risk factor for CD-TLR (hazard ratio [HR]=1.51, 95% confidence interval [CI]=1.05-3.01), while hypertension was found as a protective factor for primary patency (HR=0.54, 95% CI=0.30-0.93). The patients with Trans-Atlantic Inter-Society Consensus (TASC) C/D lesions had more than a 2-fold increased adjusted risk of both primary patency loss and CD-TLR compared with those with TASC A/B lesions (HR=2.44 for primary patency loss; HR=2.51 for CD-TLR). The perioperative NLRs and hs-CRP levels were stratified into three grades. The patients with a higher preoperative hs-CRP level (>9.2 vs. 0.6-9.2 vs. <0.6 mg/L by each tertile) had a 2.4-fold increased adjusted risk of primary patency loss compared with those with a lower preoperative hs-CRP level. The patients with a higher hs-CRP level on the first postoperative day (>13.0 vs. 7.7-13.0 vs. <7.7 mg/L by each tertile) had a 1.8-fold increased adjusted risk of primary patency loss compared with those with a lower hs-CRP level. In contrast, the patients with a higher NLR at 4-6 hours postoperatively (>3.6 vs. 2.5-3.6 vs. <2.5 by each tertile) showed better primary patency (adjusted HR=0.57) than did those with a lower NLR. A higher hs-CRP level on the first postoperative day was the only inflammatory marker associated with a high risk of CD-TLR (adjusted HR=2.37).

CONCLUSION

Perioperative inflammatory status serves as a valuable prognostic parameter for assessing the potential risk stratification of outcomes after PCB angioplasty.

Statins and Peripheral Arterial Disease: A Narrative Review

Peripheral arterial disease (PAD) is a highly prevalent atherosclerotic condition. In patients with PAD, the presence of intermittent claudication leads to a deterioration in quality of life. In addition, even in asymptomatic cases, patients with PAD are at high risk of cardiac or cerebrovascular events. Treatment of PAD is based on lifestyle modifications; regular exercise; smoking cessation; and control of cardiovascular risk factors, including hypercholesterolemia. A growing number of studies have shown that statins reduce cardiovascular risk and improve symptoms associated with PAD. Current guidelines recommend the use of statins in all patients with PAD in order to decrease cardiovascular events and mortality. However, the prescribing of statins in patients with PAD is lower than in those with coronary heart disease. This review provides relevant information from the literature that supports the use of statins in patients with PAD and shows their potential benefit in decreasing lower limb complications as well as cardiovascular morbidity and mortality.

Effects of Statin Therapy and Dose on Cardiovascular and Limb Outcomes in Peripheral Arterial Disease: A Systematic Review and Meta-analysis

OBJECTIVE

Statin therapy is indicated in patients with peripheral arterial disease (PAD). National Institute for Health and Care Excellence guidelines suggest the use of "high intensity" statins, although evidence with PAD specific data are lacking. The effect of statin therapy and dose on outcomes in PAD is investigated.

DATA SOURCES

Studies measuring statin use in PAD patients and outcomes were identified based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria. The EMBASE and MEDLINE databases were interrogated from January 1957 until February 2020. Twenty-two observational cohort studies and two randomised control trials were included (n = 268 611).

REVIEW METHODS

Pooled estimates of dichotomous outcome data were calculated using the odds/hazard ratios (OR/HR) and 95% confidence interval (CI). Meta-analysis was conducted using the inverse variance or Mantel-Haenszel method. Outcomes included all cause mortality (ACM), cardiovascular mortality (CVM), major adverse cardiac events (MACE), and amputation. Subgroup analysis was performed on studies comparing patients taking high dose vs. combined low and moderate doses of statins. The GRADE criteria assessed the quality of evidence for outcomes.

RESULTS

Statin therapy (vs. no statins) was significantly protective for ACM: OR 0.68 (95% CI 0.60 - 0.76) (number needed to treat [NNT] = 48), HR 0.74 (95% CI 0.70 - 0.78) (NNT = 10 - 91); MACE: OR 0.84 (95% CI 0.78 - 0.92) (NNT = 53), HR 0.78 (95% CI 0.65 - 0.93) (NNT = 167); and amputations: OR 0.59 (95% CI 0.33 - 1.07) (NNT = 333), HR 0.74 (95% CI 0.62 - 0.89) (NNT = 50). High doses of statins (vs. combined low and moderate doses) were significantly better protective against ACM OR 0.69 (95% CI 0.43 - 1.09) (NNT = 17), HR 0.74 (95% CI 0.62 - 0.89) (NNT = 16 - 200) but work less significantly for MACE OR 0.77 (95% CI 0.49 - 1.21) (NNT = 25). Amputations were less frequent in patients on high doses HR 0.78 (95% CI 0.69 - 0.90) (NNT = 53 - 1 000).

CONCLUSION

Higher dosing of statins confers a significant improvement in patient outcomes, especially ACM and amputations, although the quality of the evidence was variable. Such findings require confirmation in larger, PAD specific trials.

Systems Approach to Discovery of Therapeutic Targets for Vein Graft Disease: PPARα Pivotally Regulates Metabolism, Activation, and Heterogeneity of Macrophages and Lesion Development

Supplemental Digital Content is available in the text.

Vein graft failure remains a common clinical challenge. We applied a systems approach in mouse experiments to discover therapeutic targets for vein graft failure.

Antithrombotic therapy for postinterventional management of peripheral arterial disease

PURPOSE

Evidence on the use of antithrombotic pharmacotherapy in patients undergoing revascularization of lower extremities for symptomatic peripheral arterial disease (PAD) is reviewed.

SUMMARY

Individuals with PAD can experience leg pain, intermittent claudication, critical limb ischemia, and acute limb ischemia. In such patients, revascularization may be indicated to improve the quality of life and to prevent amputations. Antithrombotic therapy is often intensified in the postrevascularization period to prevent restenosis of the index artery and to counteract the prothrombotic state induced by the intervention. Therapeutic modalities include dual antiplatelet therapy (DAPT), anticoagulation, a combination of antiplatelet and anticoagulation therapy, and addition of cilostazol to single antiplatelet therapy. Subgroup analyses of data from randomized clinical trials provided low-quality evidence for the use of DAPT in patients with a below-knee prosthetic bypass graft and anticoagulation for those with a venous bypass graft. Cilostazol, when added to aspirin therapy, has been shown to prevent index vessel reocclusion after an endovascular intervention in patients at low risk for thrombosis in several small randomized trials.

CONCLUSION

There is a considerable paucity of high-quality evidence on the optimal antithrombotic regimen for patients undergoing lower extremity revascularization, with no particular therapy shown to consistently improve patient outcomes. The decision to initiate intensified antithrombotic therapy should include a close examination of its risk-benefit profile. The demonstrated benefit of such treatment is restricted to the prevention of index artery reocclusion, while an increased risk of bleeding may lead to significant morbidity and mortality.

Premature atherosclerotic peripheral artery disease: An underrecognized and undertreated disorder with a rising global prevalence

Premature atherosclerotic peripheral artery disease (PAD) of the lower extremities is characterized by disease diagnosis before the age of 50 years. The global prevalence of premature PAD has increased, and the disease is often underdiagnosed given heterogenous patient symptoms. Traditional cardiovascular risk factors like smoking, diabetes, hypertension, and hyperlipidemia as well as non-traditional risk factors like elevated lipoprotein(a), family history of PAD, hypercoagulability, and systemic inflammation are associated with premature PAD. Patients with premature PAD tend to have an aggressive vascular disease process, a high burden of cardiovascular risk factors, and other concomitant atherosclerotic vascular diseases like coronary artery disease. Prevention of cardiovascular events, improvement of symptoms and functional status, and prevention of adverse limb events are the main goals of patient management. In this review, we discuss the epidemiology, risk factors, clinical evaluation, and management of patients with premature PAD.

Midterm Results of a Japanese Prospective Multicenter Registry of Heparin-Bonded Expanded Polytetrafluoroethylene Grafts for Above-the-Knee Femoropopliteal Bypass

BACKGROUND

This study prospectively analyzed the midterm results of above-the-knee femoropopliteal bypass (AKb) using bioactive heparin-bonded expanded polytetrafluoroethylene (HB-ePTFE) graft in patients with femoropopliteal occlusive disease.Methods and Results:This prospective, multicenter, non-randomized study reviewed limbs undergoing AKb with HB-ePTFE graft for femoropopliteal lesion in 20 Japanese institutions between July 2014 and October 2017. Primary efficacy endpoints were primary, primary assisted, and secondary graft patency. Safety endpoints included any major adverse limb event and perioperative mortality. During the study period, 120 limbs of 113 patients (mean age, 72.7 years) underwent AKb with HB-ePTFE grafts. A total of 45 patients (37.5%) had critical limb ischemia and 17 (15.0%) were on hemodialysis (HD). Median duration of follow-up was 16 months (range, 1-36 months). Estimated 1- and 2-year primary, primary assisted, and secondary graft patency rates were 89.4% and 82.7%, 89.4% and 87.2%, and 94.7% and 92.5%, respectively. On univariate analysis of 2-year primary graft patency, having 3 run-off vessels, cuffed distal anastomoses, no coronary artery disease, and no chronic kidney disease requiring HD were significantly associated with favorable patency.

CONCLUSIONS

AKb using HB-ePTFE grafts achieved favorable 2-year graft patency. AKb using HB-ePTFE grafts may therefore be an acceptable, highly effective treatment option for femoropopliteal artery lesions.

Cardiovascular Outcomes After Lower Extremity Endovascular or Surgical Revascularization: The EUCLID Trial

BACKGROUND

Lower extremity revascularization (LER) is a common treatment in patients with peripheral artery disease (PAD), but long-term outcomes are poorly defined.

OBJECTIVES

The aim was to analyze LER in the EUCLID (Examining Use of tiCagreLor In paD) trial to determine predictors and cardiovascular outcomes.

METHODS

Patients were grouped according to whether they received a post-randomization LER (n = 1,738) or not (n = 12,147). All variables were assessed for significance in univariable and parsimonious multivariable models. The primary endpoint was myocardial infarction, ischemic stroke, or cardiovascular death; major adverse limb events (MALE) included acute limb ischemia or major amputation.

RESULTS

A post-randomization LER occurred in 12.5% of patients and was an endovascular LER in 74.7%. Endovascular LERs were performed more often in North America, whereas surgical procedures occurred more frequently in Europe. Independent factors predicting LER were prior and type of prior LER, geographic region, limb symptoms, diabetes, and smoking. A post-randomization LER was associated with an increased risk for the primary endpoint (hazard ratio: 1.60; 95% confidence interval: 1.35 to 1.90; p < 0.0001) and MALE (hazard ratio: 12.0; 95% confidence interval: 9.47 to 15.30; p < 0.0001). Event rates for the primary endpoint after LER were numerically higher in the surgical subgroup, but MALE were similar between surgical and endovascular LER.

CONCLUSIONS

In the EUCLID trial, LER was most often endovascular. Following LER, there was an increased hazard for the primary endpoint (with higher event rates in the surgical group) and a markedly increased risk for MALE events (with similar event rates between surgical and endovascular LER procedures). (A Study Comparing Cardiovascular Effects of Ticagrelor and Clopidogrel in Patients With Peripheral Artery Disease [EUCLID]; NCT01732822).

Statin loading in cardiovascular surgery: never too early to treat

PURPOSE OF REVIEW

The effects of statin loading before, during or after vascular interventions on cardiovascular and renal outcomes are discussed. Furthermore, the selection of optimal statin type and dose, according to current evidence or guidelines, is considered. The importance of treating statin intolerance and avoiding statin discontinuation is also discussed.

RECENT FINDINGS

Statin loading has been shown to beneficially affect cardiovascular outcomes, total mortality and/or contrast-induced acute kidney injury, in patients undergoing vascular procedures such as percutaneous coronary intervention (PCI), coronary artery bypass grafting (CABG), carotid endarterectomy (CEA), carotid artery stenting, endovascular aneurysm repair, open abdominal aortic aneurysms (AAA) repair and lower extremities vascular interventions. High-dose statin pretreatment is recommended for PCI and CABG according to current guidelines. Statin discontinuation should be avoided during acute cardiovascular events and vascular interventions; adequate measures should be implemented to overcome statin intolerance.

SUMMARY

Statin loading is an important clinical issue in patients with cardiac and noncardiac vascular diseases, including carotid artery disease, peripheral artery disease and AAA, undergoing vascular interventions. Cardiologists and vascular surgeons should be aware of current evidence and implement guidelines in relation to statin loading, discontinuation and intolerance.

Vein Versus Prosthetic Graft for Femoropopliteal Bypass Above the Knee: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Conflicting evidence exists surrounding which conduit material is preferable in above-knee femoropopliteal bypass surgery. We performed a systemic review of electronic information sources to identify randomized controlled trials (RCTs) comparing vein versus prosthetic grafts in above-knee femoropopliteal bypasses. Eight RCTs reporting 1271 grafts (608 saphenous vein and 663 prosthetic) in 1132 patients were included. At 5 years, the vein group had significantly higher primary patency (odds ratio [OR]: 1.73, 95% confidence interval [CI]: 1.17-2.55, P = 0.006), primary assisted patency (OR: 4.02, 95% CI: 2.84-5.70, P < 0.0001), and secondary patency (OR: 1.83, 95% CI: 1.20-2.80, P = 0.005) rates compared with the prosthetic group. The vein group required significantly fewer reinterventions (OR: 0.33, 95% CI: 0.18-0.60, P = 0.0003). There was no significant difference in 30-day mortality (risk difference: −0.01, 95% CI: −0.02 to 0.01, P = 0.34), 30-day morbidity (OR: 1.58, 95% CI: 0.61-4.06, P = 0.35), major amputation (OR: 0.71, 95% CI: 0.43-1.18, P = 0.19), or overall survival (OR: 0.95, 95% CI: 0.70-1.30, P = 0.76) when comparing vein versus prosthetic grafts. Our analysis supports the use of the saphenous vein in above-knee femoropopliteal bypass grafting owing to its superiority in primary, primary assisted, and secondary patency rates and less need for reintervention when compared with prosthetic grafts.

Utilization of Vasculoprotective Therapy for Peripheral Artery Disease: A Systematic Review and Meta-analysis

INTRODUCTION

Practice guidelines recommend that patients with peripheral artery disease receive antiplatelets, statins, and angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs). We sought to quantify the rates of prescribing these therapies in patients with peripheral artery disease in the literature.

METHODS

We performed a systematic review and meta-analysis of treatment prescribing rates in observational studies containing peripheral artery disease patients published on or after the year 2000. We also assessed whether prescribing rates are increasing over time.

RESULTS

A total of 86 studies were available for analysis. The aggregate sample size across all studies was 332,555. The pooled estimates for utilization of antiplatelets, statins, and ACE inhibitors or ARBs were 75% (95% confidence interval [CI], 71%-79%), 56% (95% CI, 52%-60%), and 53% (95% CI, 49%-58%), respectively. Statin use was directly related to publication year (+2.0% per year, P < .001), but this was not the case for antiplatelets (P = .68) or ACE inhibitors or ARBs (P = .066).

CONCLUSIONS

Although some improvement in statin prescribing has occurred in recent years, major practice gaps exist in the treatment of peripheral artery disease. Effective measures to close these gaps should be implemented.

Statin therapy improved long-term prognosis in patients with major non-cardiac vascular surgeries: a systematic review and meta-analysis

OBJECTIVE

To investigate whether statin intervention will improve the long-term prognosis of patients undergoing major non-cardiac vascular surgeries.

METHODS

Major database searches for clinical trials enrolling patients undergoing major non-cardiac vascular surgeries, including lower limb revascularization, carotid artery surgeries, arteriovenous fistula, and aortic surgeries, were performed. Subgroup analyses, stratified by surgical types or study types, were employed to obtain statistical results regarding survival, patency rates, amputation, and cardiovascular and stroke events. Odds ratio (ORs) and 95% confidence intervals (CIs) were calculated by Review Manager 5.3. Sensitivity analysis, publication bias and meta-regression were conducted by Stata 14.0.

RESULTS

In total, 34 observational studies, 8 prospective cohort studies and 4 randomized controlled clinical trials (RCTs) were enrolled in the present analysis. It was demonstrated that statin usage improved all-cause mortality in lower limb, carotid, aortic and mixed types of vascular surgery subgroups compared with those in which statins were not used. Additionally, the employment of statins efficiently enhanced the primary and secondary patency rates and significantly decreased the amputation rates in the lower limb revascularization subgroup. Furthermore, for other complications, statin intervention decreased cardiovascular events in mixed types of vascular surgeries and stroke incidence in the carotid surgery subgroup. No significant publication bias was observed. The meta-regression results showed that the morbidity of cardiovascular disease or the use of aspirin might affect the overall estimates in several subgroups.

CONCLUSIONS

This meta-analysis demonstrated that statin therapy was associated with improved survival rates and patency rates and with reduced cardiovascular or stroke morbidities in patients who underwent non-cardiac vascular surgeries.

Neutrophil-lymphocyte ratio is a marker of survival and cardiac complications rather than patency following revascularization of lower extremities

The neutrophil-lymphocyte ratio (NLR), as a marker of inflammation, is associated with the severity of peripheral artery disease (PAD). The role of the NLR on predicting future complications after elective revascularization for patients with PAD remains unknown. We aimed to examine the role of the NLR in the development of major adverse limb events (MALE) and the long-term mortality of these patients. We evaluated 1708 revascularization procedures from May 2001 to December 2015 at the Veterans Affairs Western New York Healthcare System from a prospectively maintained vascular database that included demographics, comorbidities and pre-procedural medications. Peri-procedural laboratory findings including complete blood cell count and metabolic panel were further retrieved from the electronic health record. The NLR was calculated, and the patients were categorized into tertiles according to NLR cut-off points. Multivariate Cox regression analysis was performed to determine MALE and 10-year mortality. The primary endpoint of the study was MALE, and the secondary endpoint included 10-year mortality. A total of 1228 patients were included for final analyses. Patients in the third NLR tertile were more likely to experience MALE during the follow-up period ( p<0.001). In addition, fewer patients in tertile 3 survived over the follow-up period compared to tertiles 1 and 2 ( p<0.0001). Patients in tertile 3 tended to be older with a higher frequency of hypertension, diabetes, chronic kidney disease, coronary artery disease and congestive heart failure. Our multivariate analysis demonstrated that the NLR was independently associated with higher rates of MALE in the affected vessels following revascularization procedures. Similarly, the NLR was revealed to be an independent predictor of higher long-term mortality in these patients.