2016 AHA/ACC Guideline on the Management of Patients With Lower Extremity Peripheral Artery Disease: Executive Summary: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines

Functional Assessment of Intermediate Vascular Disease

Interventional treatment in various vascular beds has advanced tremendously. However, there are several problems to be considered. We searched the literature and tried to analyze major parts of it. One is safety and applicability of coronary proven methods in other vascular beds. An unresolved problem is the functional assessment of intermediate lesions, as far as various target organs have quite different circulation from the coronary one and the functional tests should be modified in order to be applicable and meaningful. In the majority of the acute vascular syndromes, the culprit lesion is of intermediate size on visual assessment. On the other hand, a procedurally successfully managed high-degree stenosis is not always followed by clinical and prognostic benefit. In vascular beds, where collateral network naturally exists, the readings from the functional assessment are complicated and thus the decision for interventional treatment is even more difficult. Here come into help the functional assessment and imaging with IVUS, OCT, high-resolution MRI, and contrast enhanced CT or SPECT. The focus of the current review is on the functional assessment of intermediate stenosis in other vascular beds, unlike the coronary arteries.

Clinical Impact of the Ankle-Brachial Index in Patients Undergoing Successful Percutaneous Coronary Intervention

BACKGROUND

Several studies have reported a relationship between clinical outcomes and the ankle-brachial index (ABI) in different populations. However, the relationship in Japanese patients or in patients undergoing percutaneous coronary intervention (PCI) has not been examined well.

METHODS AND RESULTS

The subjects were 1,857 patients who underwent PCI from July 2007 to May 2010 and in whom the carotid and renal arteries and abdominal aorta were examined simultaneously by ultrasonography and ABI. We investigated the relationship between ABI and major adverse cardiovascular events (MACE: all-cause death, myocardial infarction, and stroke). The median follow-up was 1,322 days (interquartile range: 1,092-1,566 days). Patients with low (<0.9), borderline (0.9-1.0) and high ABI (>1.4) had significantly higher incidence of MACE at 4 years (31%, 15%, 10%, and 29% for the low, borderline, normal, and high groups, respectively; log-rank P<0.0001) and all-cause mortality at 4 years (22%, 12%, 6.9%, and 29%, respectively; P<0.0001) compared with the normal ABI group (1.0≤ABI≤1.4). The adjusted hazard ratios for MACE were 2.35 (1.72-3.20), 1.27 (0.89-1.80) and 1.87 (0.81-3.79) for low, borderline and high ABI, respectively.

CONCLUSIONS

This study suggested that ABI provides additional information for cardiovascular disease risk stratification in Japanese patients undergoing PCI, even it is borderline ABI.

Directional Atherectomy Followed by a Paclitaxel-Coated Balloon to Inhibit Restenosis and Maintain Vessel Patency: Twelve-Month Results of the DEFINITIVE AR Study

Background—

Studies assessing drug-coated balloons (DCB) for the treatment of femoropopliteal artery disease are encouraging. However, challenging lesions, such as severely calcified, remain difficult to treat with DCB alone. Vessel preparation with directional atherectomy (DA) potentially improves outcomes of DCB.

Methods and Results—

DEFINITIVE AR study (Directional Atherectomy Followed by a Paclitaxel-Coated Balloon to Inhibit Restenosis and Maintain Vessel Patency—A Pilot Study of Anti-Restenosis Treatment) was a multicenter randomized trial designed to estimate the effect of DA before DCB to facilitate the development of future end point-driven randomized studies. One hundred two patients with claudication or rest pain were randomly assigned 1:1 to DA+DCB (n=48) or DCB alone (n=54), and 19 additional patients with severely calcified lesions were treated with DA+DCB. Mean lesion length was 11.2±4.0 cm for DA+DCB and 9.7±4.1 cm for DCB (P=0.05). Predilation rate was 16.7% for DA+DCB versus 74.1% for DCB; postdilation rate was 6.3% for DA+DCB versus 33.3% for DCB. Technical success was superior for DA+DCB (89.6% versus 64.2%; P=0.004). Overall bail-out stenting rate was 3.7%, and rate of flow-limiting dissections was 19% for DCB and 2% for DA+DCB (P=0.01). One-year primary outcome of angiographic percent diameter stenosis was 33.6±17.7% for DA+DCB versus 36.4±17.6% for DCB (P=0.48), and clinically driven target lesion revascularization was 7.3% for DA+DCB and 8.0% for DCB (P=0.90). Duplex ultrasound patency was 84.6% for DA+DCB, 81.3% for DCB (P=0.78), and 68.8% for calcified lesions. Freedom from major adverse events at 1 year was 89.3% for DA+DCB and 90.0% for DCB (P=0.86).

Conclusions—

DA+DCB treatment was effective and safe, but the study was not powered to show significant differences between the 2 methods of revascularization in 1-year follow-up. An adequately powered randomized trial is warranted.

Clinical Trial Registration—

http://www.clinicaltrials.gov. Unique Identifier: NCT01366482.

Peripheral vascular disease assessment in the lower limb: a review of current and emerging non-invasive diagnostic methods

BACKGROUND

Worldwide, at least 200 million people are affected by peripheral vascular diseases (PVDs), including peripheral arterial disease (PAD), chronic venous insufficiency (CVI) and deep vein thrombosis (DVT). The high prevalence and serious consequences of PVDs have led to the development of several diagnostic tools and clinical guidelines to assist timely diagnosis and patient management. Given the increasing number of diagnostic methods available, a comprehensive review of available technologies is timely in order to understand their limitations and direct future development effort.

MAIN BODY

This paper reviews the available diagnostic methods for PAD, CVI, and DVT with a focus on non-invasive modalities. Each method is critically evaluated in terms of sensitivity, specificity, accuracy, ease of use, procedure time duration, and training requirements where applicable.

CONCLUSION

This review emphasizes the limitations of existing methods, highlighting a latent need for the development of new non-invasive, efficient diagnostic methods. Some newly emerging technologies are identified, in particular wearable sensors, which demonstrate considerable potential to address the need for simple, cost-effective, accurate and timely diagnosis of PVDs.

Feasibility of using thermal response to Ka band millimeter wave heating to assess skin blood flow

OBJECTIVE

Implementation of clinical guidelines for diagnosing peripheral artery disease will demand screening many millions of patients who are considered at-risk. This will require faster, easier screening technologies to identify patients with compromised blood flow to the extremities.

APPROACH

The feasibility of using surface temperature response to K_a band (26.5-40 GHz) near-field irradiation to assess skin blood flow was explored using an animal model. Ears of domestic rabbits were subjected to low-power continuous wave radio frequency heating from an open-ended waveguide (WR-28) at f  =  35 GHz. Three flow conditions were evaluated: (1) a baseline flow condition, (2) occluded flow and (3) reactive hyperemia. Surface temperatures were monitored continuously by means of an infrared thermography camera during each 2 min exposure.

MAIN RESULTS

Ensemble average results showed significant differences (p  <  .05) at exposure times 30, 60, 90 and 120 s between baseline and occluded conditions, and between baseline and reactive hyperemia conditions. The occluded condition (N  =  12) resulted in an average temperature increase of 21.4 °C  ±  3.9 after 2 min, compared with an average increase of 12.1 °C  ±  1.6 for baseline conditions (N  =  9) and 4.7 °C  ±  3.6 for post-occlusion/hyperemic conditions (N  =  8).

SIGNIFICANCE

Results are compared with the results of a simple two parameter mathematical model. These results suggest a method for non-invasive skin blood flow assessment to screen for peripheral artery disease and associated risk of cardiovascular events.

Peripheral arterial disease: Changes in clinical outcomes and therapeutic strategies in two cohorts, from 2002 to 2008 and from 2008 to 2014. A population-based study

Background

The aim of our study was to evaluate whether treatments for peripheral artery disease changed in two different cohorts identified in 2002 and 2008, and whether this had an impact on mortality and major clinical outcomes after six years of follow-up.

Methods

Using administrative health databases of the largest region in Northern Italy, we identified patients admitted to hospital for peripheral artery disease in 2002 and 2008. Both cohorts were followed for six years. All cause death, acute coronary syndrome, stroke and major amputations, cardiovascular prevention drugs and revascularization procedures were collected. Incidence of events was plotted using adjusted cumulative incidence function estimates. The risk, for each outcome, was compared between 2002–2008 and 2008–2014 using a multivariable Fine and Gray’s semiparametric proportional subdistribution hazards model.

Results

In 2002 and 2008, 2885 and 2848 patients were identified. Adjusting for age, sex, Charlson comorbidity index and severity of peripheral artery disease we observed a significant reduction (in 2008 vs. 2002) in the risk of acute coronary syndrome (28%), stroke (27%) and major amputation (17%). No change was observed in the risk of death. The percentages of patients with peripheral artery revascularizations, during the hospital stay, increased: 43.8% in 2002 vs. 49.0% in 2008, p < 0.001. From 2002 to 2008 there was a significant absolute increase in the prescription of lipid-lowering drugs (+18%), antiplatelets (+7.2%) and angiotensin-converting enzyme inhibitors/angiotensin receptor blockers (+11.8%), p < 0.001.

Conclusions

In six years of follow-up we observed a reduction in risk of major cardiovascular events in 2008–2014 in comparison with the 2002–2008 cohort. Increasing use of revascularization interventions and cardiovascular prevention drugs could have contributed to the better prognosis.

Myocardial injury after endovascular revascularization in critical limb ischemia predicts 1-year mortality: a prospective observational cohort study

BACKGROUND

Patients with critical limb ischemia (CLI) are at increased risk of cardiovascular complications and mortality. To determine (1) incidence of myocardial injury following endovascular revascularization, and (2) relationship between myocardial injury with 1-year mortality and major adverse cardiovascular events (MACE; i.e., composite of myocardial infarction, stroke, and death).

METHODS AND RESULTS

Single-center, prospective cohort study of CLI patients ≥ 45 years of age, who underwent endovascular revascularization with overnight hospitalization. High-sensitive troponins T (hsTnTs) were measured on admission, 3-6 h after endovascular revascularization and the subsequent morning. Myocardial injury after endovascular revascularization was defined as an hsTnT ≥ 14 ng/L with a relative increase ≥ 30% from the baseline value. We also evaluated other myocardial injury hsTnT thresholds (i.e., ≥ 30, ≥ 40, ≥ 60, and ≥ 80 ng/L). 239 consecutive patients (56% male, mean age 71.5 ± 10.1 years) were included; one patient was lost to follow-up. At 1 year, there were 34 deaths (14.2%), and 48 MACE (20.5%). Myocardial injury with the hsTnT threshold of 14 ng/L and relative increase by ≥ 30% from the baseline level occurred in 61 patients (25.5%). Myocardial injury was independently associated with 1-year mortality ([aHR], 2.44; 95% CI 1.18-5.06, for hsTnT ≥ 14 ng/L to aHR, 3.34; 95% CI 1.29-8.65 for hsTnT ≥ 80 ng/L). Myocardial injury was also independently associated with 1-year MACE ([AOR] 2.89; 95% CI 1.41-5.92 for hsTnT ≥ 14 ng/L to AOR, 6.69; 95% CI 2.17-20.68 for hsTnT ≥ 80 ng/L). 85.2% patients who had myocardial injury did not have ischemic clinical symptoms or electrocardiography changes. In sensitive analysis with exclusion of symptomatic patients that developed myocardial injury for the hsTnT ≥ 14 ng/L threshold, both the 1-year mortality (aHR: 2.19; CI 1.02-4.68; p = 0.04), and 1-year MACE (OR 2.25; CI 1.06-4.77; p = 0.036) remained significant.

CONCLUSIONS

Myocardial injury is common following endovascular revascularization for CLI and associated with the risk of 1-year mortality and MACE.

Patient Experience of Recovery After Major Leg Amputation for Arterial Disease

Objectives:

To date, studies of vascular amputees primarily examine quantitative outcomes following limb loss. Less is known about the patient’s perspective after major lower limb amputation. Here, we define and describe the postamputation recovery period.

Methods:

Qualitative study using purposive, maximum variation sampling on the variables of amputation level and times since surgery. We first conducted structured interviews with 20 participants (median age: 65 years, range: 45-88 years; 85% male; below knee amputation n = 14; above knee amputation n = 6; median time from amputation to interview = 16 months, range: 4-51 months). Findings were validated via a focus group with 5 amputees. Data were coded, analyzed, and interpreted by 2 reviewers.

Results:

All participants expressed the desire to have an active role in the decision to undergo amputation, even while acknowledging that limb salvage options were exhausted. Following amputation, participants described a 6-month recovery period when they learned to modify daily activities to accommodate their new functional and psychological needs. Participants defined recovery as when they had regained functional independence, which was described as a level of mobility that allowed them to perform daily activities with minimal assistance. Concerns that participants felt were poorly addressed included uncontrolled pain, feeling unprepared to live with an amputation, and questions about prosthetics. Two of the 5 focus group participants stated a preference for amputation earlier in the treatment course.

Conclusions:

Postamputation recovery has an early (up to 6 months) and late phase (after 6 months) and concludes when amputees regain what they perceive as independence. Patients desire to participate in amputation decision-making; in this study, some would have preferred amputation earlier in their clinical course. Attention to the domains that impact quality of life, and fostering a shared decision-making process, are opportunities to enhance postamputation recovery.

Utilization and in-hospital outcomes associated with atherectomy in the treatment of peripheral vascular disease: An observational analysis from the National Inpatient Sample

Objective Percutaneous revascularization for patients with peripheral arterial disease has become a treatment of choice for many symptomatic patients. The presence of severe arterial calcification presents many challenges for successful revascularization. Atherectomy is an adjunctive treatment option for patients with severe calcification undergoing percutaneous intervention. We sought to analyze the impact of atherectomy on in-hospital outcomes, length of stay, and cost in the percutaneous treatment of peripheral arterial disease. Methods Patients with lower extremity peripheral arterial disease undergoing percutaneous revascularization were assessed, utilizing the National Inpatient Sample (2012-2014) and appropriate International Classification of Diseases, 9th Revision, Clinical Modification diagnostic and procedural codes. Patients who were not treated with atherectomy ( n = 51,037) were compared to those treated with atherectomy ( n = 11,408). Propensity score-matched analysis was performed to address baseline differences. Results After performing propensity score-matched analysis, 11,037 patients were included in each group. Utilization of atherectomy was associated with lower in-hospital mortality (2% vs. 1.4% p = 0.0006). All secondary outcomes were lower when using atherectomy except acute renal failure. Length of stay was slightly lower when using atherectomy (7.2 vs. 7.0 days, p = 0.0494). However, median cost was higher in patients treated with atherectomy ($21,589 vs. $24,060, p = <0.0001). Conclusion The use of atherectomy was associated with significantly decreased in-hospital mortality, adverse events, and length of stay. Though, cost associated with atherectomy use is increased, this is offset by decreased in-hospital adverse outcomes. Appropriate use of atherectomy devices is an important tool in revascularization of peripheral arterial disease in select patients.

Prevalence of peripheral arterial disease among diabetic patients in Santo Domingo, Dominican Republic and associated risk factors

Introduction

Peripheral arterial disease (PAD) is a major risk factor of coronary artery disease and a major complication of atherosclerosis. Peripheral arterial disease can be diagnosed with simple and low cost techniques. There are major risk factors of PAD that have been studied for different countries. However, no such study has been done for the Dominican Republic. We conducted a cross-sectional study to determine the prevalence of PAD and the risk factors among patients with diabetes in Santo Domingo, Dominican Republic.

Material and methods

Six hundred randomly chosen patients with previously diagnosed diabetes were enrolled in our study. Their blood pressure and ankle brachial index were calculated and a questionnaire was provided to gather information regarding gender, age, weight, ethnicity, known duration of diabetes along with any history of smoking, hypertension and hyperlipidemia. A physical examination was also done to assess for any active diabetic ulcers, previous foot ulcers and non-traumatic amputation. A microfilament test was conducted to check for peripheral neuropathy.

Results

Eighty-four diabetic patients were diagnosed with PAD with a prevalence of 14% in Santo Domingo, Dominican Republic. Statistically significant associations (p < 0.05) was found for female gender, presence of active foot ulcers, history of past foot ulcer, non-traumatic amputation, hypertension, hyperlipidemia and peripheral neuropathy. Glycated hemoglobin (HbA_1c), age and smoking were not statistically significant in our study.

Conclusions

Diabetic patients who are either female, have active foot ulcers, a history of past foot ulcer, non-traumatic amputation, hypertension, hyperlipidemia or peripheral neuropathy are more at risk of developing PAD.

Color Doppler Ultrasonography Is a Useful Tool for Diagnosis of Peripheral Artery Disease in Type 2 Diabetes Mellitus Patients with Ankle-Brachial Index 0.91 to 1.40

BACKGROUND

The clinical utility of ankle-brachial index (ABI) is not clear in subjects with less severe or calcified vessel. Therefore, we investigated the usefulness of color Doppler ultrasonography for diagnosing peripheral artery disease (PAD) in type 2 diabetes mellitus (T2DM) subjects.

METHODS

We analyzed 324 T2DM patients who concurrently underwent ABI and carotid intima-media thickness (CIMT) measurements and color Doppler ultrasonography from 2003 to 2006. The degree of stenosis in patients with PAD was determined according to Jager's criteria, and PAD was defined as grade III (50% to 99% stenosis) or IV stenosis (100% stenosis) by color Doppler ultrasonography. Logistic regression analysis and receiver operating characteristic curve analysis were performed to evaluate the risk factors for PAD in patients with ABI 0.91 to 1.40.

RESULTS

Among the 324 patients, 77 (23.8%) had ABI 0.91 to 1.40 but were diagnosed with PAD. Color Doppler ultrasonography demonstrated that suprapopliteal arterial stenosis, bilateral lesions, and multivessel involvement were less common in PAD patients with ABI 0.91 to 1.40 than in those with ABI ≤0.90. A multivariate logistic regression analysis demonstrated that older age, current smoking status, presence of leg symptoms, and high CIMT were significantly associated with the presence of PAD in patients with ABI 0.91 to 1.40 after adjusting for conventional risk factors. CIMT showed significant power in predicting the presence of PAD in patients with ABI 0.91 to 1.40.

CONCLUSION

Color Doppler ultrasonography is a useful tool for the detection of PAD in T2DM patients with ABI 0.91 to 1.40 but a high CIMT.

Etiology of gastrointestinal bleeding in patients on dual antiplatelet therapy

OBJECTIVE

Dual antiplatelet therapy (DAPT) is associated with an increased risk of gastrointestinal (GI) bleeding and is thought to cause upper gastrointestinal bleeding (UGIB). However, recent reports indicate that the incidence of lower gastrointestinal bleeding (LGIB) in patients on DAPT may be increasing. We aimed to compare the endoscopic findings and etiology of GI bleeding between patients on DAPT compared with those not on DAPT.

METHODS

This was a retrospective, single-center, case-control study. Cases were 114 consecutive patients admitted with a first episode of GI bleeding while on DAPT who underwent detailed GI evaluation. We chose 114 controls who had GIB but were not on DAPT.

RESULTS

There was no significant difference in the incidence of UGIB or LGIB between the two groups (UGIB: 53.5% vs 51.3% and LGIB: 46.5% vs 48.7%, P = 0.10) or within groups (DAPT: 53.5% vs 46.5%, P = 0.30 and controls: 51.3% vs 48.7%, P = 0.80). Although the DAPT group had a lower prevalence of the usual UGIB risk factors, it had a higher likelihood of bleeding from varices or upper GI inflammation [odds ratio (OR) 3.54, 95% confidence interval (CI) 0.14-92.3; OR 13.98, 95% CI 1.40-140.36]. No etiology of bleeding was identified in a higher percentage of patients on DAPT than those who were not (22.8% vs 5.3%).

CONCLUSION

In patients with GI bleeding, the incidences of UGIB and LGIB are similar irrespective of their DAPT use.

Validity of Ankle Brachial Index using Palpation Method in Screening for Peripheral Arterial Disease in Type 2 Diabetes Mellitus Patients at a Tertiary Hospital in the Philippines

Introduction

Peripheral Artery Disease (PAD) is a significant marker of cardiovascular disease and is prevalent but underdiagnosed. Ankle-Brachial Index (ABI) is the recommended screening test for PAD. However, not all clinics have a Doppler ultrasound. ABI by palpation offers a more feasible alternative.

Objective

This study aims to determine the validity of ABI measurement by palpation method in the screening of PAD.

Methodology

This prospective validation study utilized a cross-sectional analytic design. Three physicians performed the ABI by palpation method and their result was compared to the Doppler ABI. The accuracy indices for validation was computed per physician conducting the ABI by palpation and also as an average of all 3 palpation method readings. During the course of sampling, there were no patients with severe PAD found during the prospective period.

Results

The accuracy of Ankle Brachial Index using Palpation method yielded the following ranges, sensitivity between 63.16 % - 73.68%, specificity of 94.06% - 98.02%, PPV within 85.37% - 95.45%, and NPV within 80.73% - 86.84% in predicting PAD. The accuracy indices were clinically acceptable. Meanwhile, the raters’ usage of Ankle Brachial Index using Palpation method demonstrated a substantial agreement with ABI by Doppler Method performed by the angiologist (Cohen Kappa >0.60).

Conclusion

The ABI by palpation is a good screening tool for PAD, but the person performing it must be adequately trained to do the procedure. The procedure is affordable and convenient, and should be done routinely during clinic visits in the physical examination of patients with known risk factors for PAD.

Relationship between Mediterranean diet and asymptomatic peripheral arterial disease in a population of pre-menopausal women

BACKGROUND AND AIMS

The Mediterranean Diet (MedD) is considered a very healthy diet useful in the prevention of cardiovascular disease. The present study aims to evaluate adherence to MedD in unselected premenopausal women and its relation with ankle-brachial index (ABI), an index of preclinical atherosclerosis.

METHODS AND RESULTS

A group of 425 patients (age range 45-54 years) was investigated. They were enrolled only if they were asymptomatic for cardiovascular disease. Nutritional parameters were assessed by a self-administered food frequency validated questionnaire (116 items) completed by an interviewer administered 24 h diet recall. They all underwent ABI measurement. The mean MedD Score was 32.2 ± 6.1 (Q1-Q3 range 26-37) comparing with data from Italian population (46 ± 8.3) was significantly lower. Intake of food categories sources of antioxidants was higher in patients with a greater adherence to Med D and was mainly related to fruit and vegetables. Patients were categorized in quartile according to MedD Score and we evaluate the distribution of ABI index within quartile. 31.4% of women in Q1 (lower adherence to MedD) had an ABI lower than 0.9 compared to 18.3% of women in Q4 (higher adherence to MedD): p < 0.01. Obesity was more frequent in Q1 compared to Q4 and in women with lower ABI.

CONCLUSIONS

Women with a low MedD Score were more obese and showed instrumental sign of preclinical peripheral atherosclerosis. MedD rich in antioxidants from fruit, vegetables and nuts influenced the development of atherosclerosis and was associated with a lower incidence of asymptomatic atherosclerosis.

Short vs prolonged dual antiplatelet treatment upon endovascular stenting of peripheral arteries

INTRODUCTION

Peripheral artery disease (PAD) is a highly prevalent disorder with a substantial economical burden. Dual antiplatelet treatment (DAPT) upon endovascular stenting to prevent acute thrombotic reocclusions is an universally accepted practice for postinterventional management of PAD patients. However, the optimal period of time for DAPT upon endovascular stenting is not known.

METHODS

In the current nonrandomized, retrospective monocentric study, we evaluated the duration of DAPT upon endovascular stenting. A total of 261 endovascular SFA and iliac stenting procedures were performed on 214 patients and these patients were subdivided into a short (4-6 weeks) or a prolonged (8-12 weeks) DAPT regime group. More than 65% of the patients included were male, approximately 35% were diabetic, and 61% had a history of smoking. Of all the patients, 90% exhibited a Rutherford stage 2-3, and approximately half of the patients had a moderate-to-severe calcified target lesion with a length of >13 cm. Major safety end points were defined as any bleeding, compartment syndrome, and ischemic events. In addition to this, patency, all-cause mortality, as well as amputation were followed up over a period of 12 months upon intervention.

RESULTS

Twelve months after endovascular stenting, primary patency in our cohort was comparable between the groups (83.94% short vs 79.8% long DAPT, P>0.05). Major bleeding occurred in 18 cases without any difference between the groups (P>0.05). In addition, during the 12-month follow-up, 6 (3.4%) patients in the short and 3 (3.5%) in the prolonged DAPT regime suffered a stroke/transient ischemic attack (P>0.05). In addition, there was no difference regarding mortality and amputation rate comparing short vs prolonged DAPT regime in a 12-month follow-up.

CONCLUSION

In the current cohort, prolonged DAPT after endovascular stenting had no beneficial effect on the outcome in a 12-month follow-up.

Advances in Percutaneous Therapies for Peripheral Artery Disease: Drug-Coated Balloons

PURPOSE OF REVIEW

This review paper provides a summary on the use of drug-coated balloons in peripheral artery disease. It covers the main drug-coated balloon (DCB) trials. It is divided into categories of lesions: superficial femoral artery and popliteal lesions, infra-popliteal lesions and in-stent restenosis. It also includes an overview of the future of DCBs, highlighting the main ongoing trials.

RECENT FINDINGS

The latest research on DCB focuses on newer types of DCBs, mainly paclitaxel-coated but with lower doses. Another area of latest DCB research is its use in superficial femoral artery and popliteal artery in-stent restenosis, with superior outcomes. Drug-coated balloons produce better outcomes than percutaneous transluminal angioplasty alone in de novo and in-stent restenosis lesions of superficial femoral artery and popliteal arteries. More data are needed to demonstrate efficacy and safety of DCBs in infrapopliteal disease. Newer DCBs and adjunctive therapy may provide improved outcomes for peripheral artery disease interventions.

Stellarex Drug-Coated Balloon for Treatment of Femoropopliteal Disease: Twelve-Month Outcomes From the Randomized ILLUMENATE Pivotal and Pharmacokinetic Studies

Supplemental Digital Content is available in the text.

Background:

Drug-coated balloons (DCBs) are a predominant revascularization therapy for symptomatic femoropopliteal artery disease. Because of the differences in excipients, paclitaxel dose, and coating morphologies, varying clinical outcomes have been observed with different DCBs. We report the results of 2 studies investigating the pharmacokinetic and clinical outcomes of a new DCB to treat femoropopliteal disease.

Methods:

In the ILLUMENATE Pivotal Study (Prospective, Randomized, Single-Blind, U.S. Multi-Center Study to Evaluate Treatment of Obstructive Superficial Femoral Artery or Popliteal Lesions With A Novel Paclitaxel-Coated Percutaneous Angioplasty Balloon), 300 symptomatic patients (Rutherford class 2–4) were randomly assigned to DCB (n=200) or standard angioplasty (percutaneous transluminal angioplasty [PTA]) (n=100). The primary safety end point was freedom from device- and procedure-related death through 30 days, and freedom from target limb major amputation and clinically driven target lesion revascularization through 12 months. The primary effectiveness end point was primary patency through 12 months. In the ILLUMENATE PK study (Pharmacokinetic Study of the Stellarex Drug-Coated Angioplasty Balloon), paclitaxel plasma concentrations were measured after last DCB deployment and at prespecified times (at 1, 4, 24 hours and at 7 and 14 days postprocedure) until no longer detectable.

Results:

In the ILLUMENATE Pivotal Study, baseline characteristics were similar between groups: 50% had diabetes mellitus, 41% were women, mean lesion length was 8.3 cm, and 44% were severely calcified. The primary safety end point was met (92.1% for DCB versus 83.2% for PTA, P=0.025 for superiority) and the primary patency rate was significantly higher with DCB (76.3% for DCB versus 57.6% for PTA, P=0.003). Primary patency per Kaplan-Meier estimates at day 365 was 82.3% for DCB versus 70.9% for PTA (P=0.002). The rate of clinically driven target lesion revascularization was significantly lower in the DCB cohort (7.9% versus 16.8%, P=0.023). Improvements in ankle-brachial index, Rutherford class, and quality of life were comparable, but the PTA cohort required twice as many revascularizations. Pharmacokinetic outcomes showed that all patients had detectable paclitaxel levels after DCB deployment that declined within the first hour (54.4±116.9 ng/mL to 1.4±1.0 ng/mL).

Conclusions:

The data demonstrate superior safety and effectiveness of the Stellarex DCB in comparison with PTA, and plasma levels of paclitaxel fall to low levels within 1 hour.

Clinical Trial Registration:

URL: http://clinicaltrials.gov. Unique identifiers: NCT01858428 and NCT01912937.

Thirty-Day Readmissions After Endovascular or Surgical Therapy for Critical Limb Ischemia

Background:

Thirty-day readmission rates have gained increasing importance as a key quality metric. A significant number of patients are hospitalized for the management of critical limb ischemia (CLI), but limited data are available on the incidence, predictors, and causes of 30-day readmission after hospitalization for CLI.

Methods:

Hospitalizations for a primary diagnosis of CLI during which patients underwent endovascular or surgical therapy (revascularization and/or amputation) and were discharged alive were identified in the 2013 to 2014 Nationwide Readmissions Databases. Incidence, reasons, and costs of 30-day unplanned readmissions were determined. Hierarchical logistic regression models were used to identify independent predictors of 30-day readmissions.

Results:

We included 60 998 (national estimate, 135 110) index CLI hospitalizations (mean age, 68.9±11.9 years; 40.8% women; 24.6% for rest pain, 37.2% for ulcer, and 38.2% for gangrene). The 30-day readmission rate was 20.4%. Presentation with ulcer or gangrene, age ≥65 years, female sex, large hospital size, teaching hospital status, known coronary artery disease, heart failure, diabetes mellitus, chronic kidney disease, anemia, coagulopathy, obesity, major bleeding, acute myocardial infarction, vascular complications, and sepsis were identified as independent predictors of 30-day readmission. Mode of revascularization was not independently associated with readmissions. Infections (23.5%), persistent or recurrent manifestations of peripheral artery disease (22.2%), cardiac conditions (11.4%), procedural complications (11.0%), and endocrine issues (5.7%) were the most common reasons for readmission. The inflation-adjusted aggregate costs of 30-day readmissions for CLI during the study period were $624 million.

Conclusions:

Approximately 1 in 5 patients hospitalized for CLI and undergoing revascularization is readmitted within 30 days. Risk of readmission is influenced by CLI presentation, patient demographics, comorbidities, and in-hospital complications, but not by the mode of revascularization.

Redox regulation of ischemic limb neovascularization - What we have learned from animal studies

Mouse hindlimb ischemia has been widely used as a model to study peripheral artery disease. Genetic modulation of the enzymatic source of oxidants or components of the antioxidant system reveal that physiological levels of oxidants are essential to promote the process of arteriogenesis and angiogenesis after femoral artery occlusion, although mice with diabetes or atherosclerosis may have higher deleterious levels of oxidants. Therefore, fine control of oxidants is required to stimulate vascularization in the limb muscle. Oxidants transduce cellular signaling through oxidative modifications of redox sensitive cysteine thiols. Of particular importance, the reversible modification with abundant glutathione, called S-glutathionylation (or GSH adducts), is relatively stable and alters protein function including signaling, transcription, and cytoskeletal arrangement. Glutaredoxin-1 (Glrx) is an enzyme which catalyzes reversal of GSH adducts, and does not scavenge oxidants itself. Glrx may control redox signaling under fluctuation of oxidants levels. In ischemic muscle increased GSH adducts through Glrx deletion improves in vivo limb revascularization, indicating endogenous Glrx has anti-angiogenic roles. In accordance, Glrx overexpression attenuates VEGF signaling in vitro and ischemic vascularization in vivo. There are several Glrx targets including HIF-1α which may contribute to inhibition of vascularization by reducing GSH adducts. These animal studies provide a caution that excess antioxidants may be counter-productive for treatment of ischemic limbs, and highlights Glrx as a potential therapeutic target to improve ischemic limb vascularization.