Five-Year Safety and Effectiveness of Paclitaxel Drug-Coated Balloons Alone or With Provisional Bare Metal Stenting for Real-World Femoropopliteal Lesions: IN.PACT Global Study Subgroup Analysis

BACKGROUND

The treatment of complex infra-inguinal disease with drug-coated balloons (DCBs) is associated with a significant number of patients undergoing provisional stenting to treat a suboptimal result. To determine the potential long-term impact of DCB treatment with provisional bare metal stenting in complex lesions in real-world patients, a post hoc analysis was performed on data from the IN.PACT Global Study (The IN.PACT Global Clinical Study for the Treatment of Comprehensive Superficial Femoral and/or Popliteal Artery Lesions Using the IN.PACT Admiral Drug-Eluting Balloon). Five-year outcomes were compared between participants who were stented after DCB treatment versus those treated with DCB alone.

METHODS

The IN.PACT Global Study enrolled 1535 participants with intermittent claudication and/or ischemic rest pain caused by femoropopliteal lesions; 1397 patients were included in this subgroup analysis (353 stented and 1044 nonstented). Effectiveness was assessed as freedom from clinically driven target lesion revascularization through 60 months. The primary safety composite end point was defined as freedom from device- and procedure-related death through 30 days, and freedom from major target limb amputation and clinically driven target vessel revascularization through 60 months.

RESULTS

Lesions in the stented group were longer (15.37 versus 10.98 cm; P<0.001) and had more total occlusions (54.7% versus 28.6%; P<0.001) compared with the nonstented group. The 5-year Kaplan-Meier estimated freedom from clinically driven target lesion revascularization was similar between groups (66.8% stented versus 70.0% nonstented group, log-rank P=0.22). The safety composite end point was achieved in 64.5% stented versus 68.2% nonstented participants (log-rank P=0.19) as estimated by the Kaplan-Meier method. No significant difference was observed in the cumulative incidence of major adverse events (49.1% stented versus 45.0% nonstented; log-rank P=0.17), including all-cause death (19.6% stented versus 19.3% nonstented, log-rank P=0.99).

CONCLUSIONS

In this real-world study, revascularization of complex femoropopliteal artery lesions with DCB angioplasty alone or DCB followed by provisional bare metal stenting in certain lesions achieved comparable long-term safety and clinical effectiveness.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT01609296.

Paclitaxel-coated balloons for femoropopliteal peripheral arterial disease: final five-year results of the IN.PACT Global Study

BACKGROUND

Numerous randomised controlled trials (RCTs) have demonstrated the superiority of paclitaxel drug-coated balloons (DCBs) over non-coated angioplasty balloons for treatment of femoropopliteal peripheral arterial disease (PAD). There is a paucity of clinical evidence in more complex patients who are often excluded from RCTs and long-term data up to 5 years are very limited in PAD revascularisation studies.

AIMS

This is a report of the 5-year outcomes from the prospective, single-arm, international IN.PACT Global Study. The IN.PACT Admiral DCB was evaluated for femoropopliteal atherosclerotic disease treatment in a real-world patient population.

METHODS

In total, 1,535 patients were enrolled at 64 international sites. The prespecified clinical cohort included 1,406 patients with claudication or rest pain. Patients were evaluated up to 5 years for the occurrence of adverse events and clinically driven target lesion revascularisations (CD-TLR).

RESULTS

The mean lesion length was 12.1±9.5 cm in 1,774 lesions, 18.0% had in-stent restenosis, 35.5% were total occlusions and 68.7% were calcified. Per independent clinical events committee adjudication, the Kaplan-Meier estimate of freedom from CD-TLR up to 5 years was 69.4%, and the restricted mean survival time to first CD-TLR was 1,470.1 days. Outcomes were similar for males and females; freedom from CD-TLR was 69.1% in females and 69.6% in males (p=0.602). The cumulative incidence of major adverse events for the clinical cohort was 45.9% and freedom from all-cause mortality with the vital status update was 78.9% up to 5 years.

CONCLUSIONS

The IN.PACT Admiral DCB demonstrated safe and durable outcomes in real-world participants with complex femoropopliteal disease.

CLINICALTRIALS

gov: NCT01609296.

Characteristics and Outcomes of Patients With Diabetes Mellitus Undergoing Peripheral Vascular Intervention for Infrainguinal Symptomatic Peripheral Artery Disease

PURPOSE

Patients with diabetes mellitus (DM) are known to be at higher risk for peripheral artery disease (PAD), amputations, and major adverse cardiovascular events, though it is unclear whether they are at any higher risk for repeat intervention. LIBERTY 360 offered an opportunity to study a real-world cohort of patients who underwent distal superficial femoral artery endovascular revascularizations. We aimed to describe patients with DM, their outcomes following peripheral vascular intervention, and the effect of DM on outcomes in the LIBERTY 360 cohort.

METHODS

LIBERTY 360 is a prospective, multi-center, non-randomized, mono-industry funded observational study of patients undergoing endovascular revascularization. Outcomes included 30-day and 1-year all-cause mortality, major amputation, target vessel/lesion revascularization, and a composite of those events. A multivariable regression model including DM was constructed to examine the effect of DM on outcomes. Multivariable survival estimates were made using Cox proportional hazards models.

RESULTS

A total of 1,204 patients were enrolled, of whom 727 had DM (60.4%). Patients with DM had significantly more comorbidities and a third required insulin for DM management. Patients with DM had more severe disease based on Rutherford classification at baseline. After adjusting for comorbidities and disease severity, DM patients had more frequent major amputations at 1 year (5.2% versus 1.2%; HR 2.71, 95%CI 1.05-6.98, p = 0.040). The 1-year rates of all-cause mortality and target vessel/lesion revascularization were not significantly higher for patients with DM.

CONCLUSIONS

Diabetes mellitus was associated with increased major amputations at 1 year following endovascular revascularization after accounting for demographics, comorbidities, and PAD-related characteristics. Further research is needed to determine which aspects of PAD and DM are most strongly associated with poor outcomes following lower extremity revascularization.

Prediction Model for Freedom from TLR from a Multi-study Analysis of Long-Term Results with the Zilver PTX Drug-Eluting Peripheral Stent

Purpose

Develop a prediction model to determine the impact of patient and lesion factors on freedom from target lesion revascularization (ffTLR) for patients who are candidates for Zilver PTX drug-eluting stent (DES) treatment for femoropopliteal lesions.

Methods

Patient factors, lesion characteristics, and TLR results from five global studies were utilized for model development. Factors potentially associated with TLR (sex, age, diabetes, hypertension, hypercholesterolemia, renal disease, smoking status, Rutherford classification, lesion length, reference vessel diameter (RVD), popliteal involvement, total occlusion, calcification severity, prior interventions, and number of runoff vessels) were analyzed in a Cox proportional hazards model. Probability of ffTLR was generated for three example patient profiles via combinations of patient and lesion factors. TLR was defined as reintervention performed for ≥ 50% diameter stenosis after recurrent clinical symptoms.

Results

The model used records from 2227 patients. The median follow-up time was 23.9 months (range: 0.03–60.8). The Kaplan–Meier estimates for ffTLR were 90.5% through 1 year and 75.2% through 5 years. In a multivariate analysis, sex, age, Rutherford classification, lesion length, RVD, total occlusion, and prior interventions were significant factors. The example patient profiles have predicted 1-year ffTLRs of 97.4, 92.3, and 86.0% and 5-year predicted ffTLRs of 92.8, 79.5, and 64.8%. The prediction model is available as an interactive web-based tool (https://cooksfa.z13.web.core.windows.net).

Conclusions

This is the first prediction model that uses an extensive dataset to determine the impact of patient and lesion factors on ffTLR through 5 years and provides an interactive web-based tool for expected patient outcomes with the Zilver PTX DES.

Clinical Trial Registrations

Zilver PTX RCT unique identifier: NCT00120406; Zilver PTX single-arm study unique identifier: NCT01094678; Zilver PTX China study unique identifier: NCT02171962; Zilver PTX US post-approval study unique identifier: NCT01901289; Zilver PTX Japan post-market surveillance study unique identifier: NCT02254837.

Levels of Evidence

Zilver PTX RCT: Level 2, randomized controlled trial; Single-arm study: Level 4, large case series; China study: Level 4, case series; US post-approval study: Level 4, case series Japan PMS study: Level 4, large case series.

Electronic supplementary material

The online version of this article (10.1007/s00270-020-02648-6) contains supplementary material, which is available to authorized users.

The impact of chronic kidney disease on outcomes following peripheral vascular intervention

Background

Patients with chronic kidney disease (CKD) have worsened clinical outcomes following percutaneous coronary intervention; however, limited evidence exists in patients undergoing peripheral vascular intervention (PVI).

Purpose

We aimed to assess the effect of CKD on outcomes following PVI for symptomatic peripheral artery disease.

Methods

Using patients from the LIBERTY 360 study, we compared the rates of 30 day and 1 year major adverse vascular events (MAVE), a composite of all‐cause mortality, major amputation, and target vessel/lesion revascularization, between patients with and without CKD (estimated glomular filtration rate less than 60) following PVI. Multivariable adjustment was performed to assess for independent association between CKD and outcomes.

Results

Among 1189 patients enrolled, 378 patients (31.8%) had CKD. At 1 year, patients with CKD had higher rates of MAVE (34.6% vs 25.6%), all‐cause mortality (11.9% vs 5.5%), and major amputation (5.9% vs 2.6%) when compared with patients without CKD (all P < .05). After adjustment, patients with CKD had higher risks of 1‐year MAVE (HR 1.30, 95% CI 1.04‐1.64; P = .023) and all‐cause mortality (HR 1.88, 95% CI 1.22‐2.91; P = .005) when compared with patients without CKD. There was no statistically significant difference in risk of major amputations (HR 1.70, 95% CI 0.91‐3.17; P = .094).

Conclusions

Despite high procedural success and low amputation rates, patients with CKD remain at greater risk for MAVE and all‐cause mortality after PVI. Further research is needed to determine treatment strategies to mitigate substantial mortality risk in this vulnerable population.

Mortality and Paclitaxel-Coated Devices: An Individual Patient Data Meta-Analysis

BACKGROUND

Paclitaxel-containing devices (PTXDs) significantly reduce reintervention in patients with symptomatic femoropopliteal peripheral artery disease. A recent aggregate-data meta-analysis reported increased late mortality in patients with peripheral artery disease treated with PTXDs. We performed an individual patient data meta-analysis to evaluate mortality.

METHODS

Manufacturers of US Food and Drug Administration-approved and commercially available devices in the United States provided deidentified individual patient data for independent analysis. Cox proportional hazards 1-stage meta-analysis models using intention-to-treat methods were used for the primary analysis. A secondary analysis of recovered missing vital status data was performed. The impact of control crossover to PTXDs, cause-specific mortality, and drug dose mortality were assessed.

RESULTS

A total of 2185 subjects and 386 deaths from 8 PTXD trials with 4-year median follow-up were identified. The primary analysis indicated a 38% (95% CI, 6% to 80%) increased relative mortality risk, corresponding to 4.6% absolute increase, at 5 years associated with PTXD use. Control and treatment arm loss to follow-up and withdrawal were 24% and 23%, respectively. With inclusion of recovered vital status data, the excess relative mortality risk was 27% (95% CI, 3%-58%). This observation was consistent across various scenarios, including as-treated analyses, with no evidence of increased risk over time with PTXDs. Mortality risk tended to be increased for all major causes of death. There were no subgroup differences. No drug dose-mortality association was identified.

CONCLUSIONS

This individual patient data meta-analysis, based on the most complete available data set of mortality events from PTXD randomized controlled trials, identified an absolute 4.6% increased mortality risk associated with PTXD use.

Mortality Assessment of Paclitaxel-Coated Balloons: Patient-Level Meta-Analysis of the ILLUMENATE Clinical Program at 3 Years

BACKGROUND

A recent summary-level meta-analysis comprising randomized, controlled trials (RCTs) of femoropopliteal paclitaxel-coated balloon and stent intervention identified excess late mortality in the paclitaxel-treated patients.

METHODS

We evaluated the safety of the Stellarex drug-coated balloon (DCB) for femoropopliteal artery disease with an independently performed meta-analysis of patient-level data from all patients in the Stellarex femoropopliteal clinical program. To compare mortality after DCB or uncoated percutaneous transluminal angioplasty (PTA), we aggregated data from 2 RCTs comprising 419 patients treated with DCB and 170 patients treated with PTA. In an additional analysis, data were aggregated from 6 poolable Stellarex DCB studies (2 RCTs, 3 single-arm studies, and 1 registry). All serious adverse events including deaths were adjudicated by a blinded, third-party, independent Clinical Events Committee. Kaplan-Meier estimates in the RCTs were compared with restricted mean survival time. Predictors of death were assessed with hazard ratios (HRs) and Cox proportional hazards modeling.

RESULTS

Baseline characteristics were similar in the patients treated with DCB and PTA in the pooled RCT analysis, with the exception that the DCB cohort was younger (67.4±9.7 versus 69.4±9.4 years, P=0.02), smoked more frequently (86.6% versus 78.8%, P=0.02), and were less often treated for recurrent lesions (8.8% versus 14.7%, P=0.04). In the RCTs, patients treated with DCB had all-cause mortality rates that were not different from those of patients treated with PTA (Kaplan-Meier estimates 1.8±0.7% versus 1.3±0.9%, 6.5±1.2% versus 5.9±1.9%, and 9.3±1.5% versus 9.9±2.4% at 1, 2, and 3 years, respectively, P=0.86). All-cause mortality rates were similar in a 1906-patient pooled nonrandomized DCB data set (Kaplan-Meier estimates of 2.1%, 4.9%, and 7.0% at 1, 2, and 3 years, respectively). Clinical Events Committee-adjudicated causes of death were balanced between the DCB and PTA cohorts. Multivariable Cox modeling identified age (HR, 1.06; 95% CI, 1.04-1.08; P<0.001), diabetes mellitus (HR, 1.42; 95% CI, 1.01-2.00; P=0.04), congestive heart failure (HR, 1.88; 95% CI, 1.12-3.16; P=0.02), and renal insufficiency (HR, 2.00; 95% CI, 1.33-3.01; P<0.001) as predictors of mortality. Paclitaxel exposure was unrelated to mortality (HR, 1.04; 95% CI, 0.98-1.10; P=0.23).

CONCLUSIONS

The mortality rates for patients treated with the DCB and uncoated PTA were indistinguishable over 3-year follow-up. Additional patient-level, adequately powered meta-analyses with larger RCT data sets will be needed to confirm the generalizability of these findings.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifiers: NCT02110524, NCT01858363, NCT01858428, NCT03421561, NCT01912937, NCT01927068, and NCT02769273.

Paclitaxel-Coated Zilver PTX Drug-Eluting Stent Treatment Does Not Result in Increased Long-Term All-Cause Mortality Compared to Uncoated Devices

Purpose

Patient-level data from two large studies of the Zilver PTX drug-eluting stent (DES) with long-term follow-up and concurrent non-drug comparator groups were analyzed to determine whether there was an increased mortality risk due to paclitaxel.

Methods

Data from the Zilver PTX randomized controlled trial (RCT) and Zilver PTX and bare metal stent (BMS) Japan post-market surveillance studies were analyzed. Five-year follow-up is complete in both DES studies; follow-up for the BMS study was limited to 3 years and is complete. Kaplan–Meier analyses assessed mortality. A Cox proportional hazards model identified significant factors related to mortality.

Results

In the RCT, there were 336 patients treated with the DES and 143 patients treated with percutaneous transluminal angioplasty (PTA) or BMS. In Japan, there were 904 DES patients and 190 BMS patients. There was no difference in all-cause mortality for the DES compared to PTA/BMS in the RCT (19.1% DES versus 17.1% PTA/BMS through 5 years, p = 0.60) or Japan (15.8% DES versus 15.3% BMS through 3 years, p = 0.89). Cox proportional hazard models revealed that age, tissue loss, and congestive heart failure were significantly associated with mortality in the RCT, and critical limb ischemia, age, renal failure, and gender were significantly associated with mortality in Japan (all p < 0.05). Neither treatment with Zilver PTX (p = 0.46 RCT, p = 0.49 Japan) nor paclitaxel dose (p = 0.86 RCT, p = 0.07 Japan) was associated with mortality.

Conclusion

Analyses of the Zilver PTX patient-level data demonstrated no increase in long-term all-cause mortality.

Level of Evidence

Zilver PTX RCT: Level 1, randomized controlled trial; Japan PMS studies: Level 3, post-market surveillance study.

Electronic supplementary material

The online version of this article (10.1007/s00270-019-02324-4) contains supplementary material, which is available to authorized users.

Pedal access: Put the "pedal to the metal" or drive with caution?

Pedal artery access is associated with few acute complications. Pedal access differs from radial access by often being and associated with the atherosclerotic process being treated. Long-term patency of pedal artery access is necessary before routine adoption.

Drug-coated balloons versus drug-eluting stents in the femoropopliteal artery: comparing apples to oranges?

Superficial femoral and popliteal artery disease are commonly involved in the development of symptomatic PAD. As time has gone on drug coated stents and drug coated balloons have supplanted the plain balloon angioplasty corner stone of therapy with superiority proven in randomized trials. Device approval trials are typically characterized by simple lesions that are less common than the longer complex disease. Registry data has demonstrated benefit of both technologies though drug coated balloons typically require a significant amount of adjunctive stenting in more complex disease. Recently published randomized data is starting to help proceduralists define when each therapy may be more optimal.

Design and rationale of a randomized noninferiority trial to evaluate the SurVeil drug-coated balloon in subjects with stenotic lesions of the femoropopliteal artery - the TRANSCEND study

BACKGROUND

Drug-coated balloons (DCBs), developed to reduce restenosis after percutaneous intervention in peripheral arterial disease (PAD), have been shown to be safe and efficacious, particularly in treating PAD affecting the femoropopliteal segment. The SurVeil DCB uses an excipient intended to optimize both the uniformity and transfer of paclitaxel to the vessel wall, allowing for efficient drug loading and lower systemic exposure than currently available DCBs, Heretofore, clinical outcomes have not previously been compared to other DCBs.

STUDY DESIGN AND OBJECTIVES

This prospective, multicenter, international, randomized, single-blind, trial will compare 1:1 the SurVeil DCB with the IN.PACT Admiral DCB for treatment of patients with Rutherford classification 2 to 4 due to femoral and/or popliteal arterial disease. The trial will randomize 446 subjects (with reference vessel diameter 4-7 mm and total lesion length ≤180 mm). Subjects will be followed for 60 months. The primary efficacy endpoint is 1 year primary patency, defined as composite freedom from clinically-driven target-lesion revascularization (TLR) and binary restenosis (core lab-adjudicated duplex ultrasound peak systolic velocity ratio ≥2.4, or ≥50% stenosis via angiography). The primary safety endpoint is composite freedom from device- and procedure-related death through 30 days and freedom from target limb major amputation and clinically-driven target vessel revascularization through 12 months. The primary analysis is a test of noninferiority of the SurVeil vs. IN.PACT Admiral on the primary efficacy and safety endpoints according to absolute deltas of 15.0% and 10.0%, respectively.

CONCLUSION

The Randomized And Controlled Noninferiority Trial to Evaluate Safety and Clinical Efficacy of the SurVeil DCB in the Treatment of Subjects with Stenotic Lesions of the Femoropopliteal Artery Compared to the Medtronic IN.PACT Admiral (TRANSCEND) study will assess safety and efficacy of the SurVeil DCB relative to a commonly used DCB.

Drug-Coated Balloon Treatment of Femoropopliteal Lesions Typically Excluded From Clinical Trials: 12-Month Findings From the IN.PACT Global Study

PURPOSE

To report a post hoc analysis comparing outcomes between subjects who would have been included in the IN.PACT SFA randomized controlled trial vs those who would have been excluded.

METHODS

The 1406 subjects enrolled in the IN.PACT Global Study ( ClinicalTrials.gov identifier NCT01609296) were retrospectively assigned to a standard-use group (n=281) based on the inclusion and exclusion criteria from the randomized IN.PACT SFA trial; the remaining 1125 patients were assigned to the broader-use group. Freedom from clinically-driven target lesion revascularization (CD-TLR) was evaluated at 12 months. The composite primary safety endpoint was freedom from 30-day device- and procedure-related death plus freedom from 12-month target limb major amputation and clinically-driven target vessel revascularization (CD-TVR). Functional outcomes were evaluated with dedicated questionnaires.

RESULTS

Compared with the standard-use cohort, the broader-use lesions were longer, more calcified, and had more popliteal involvement, bilateral disease, and in-stent restenosis (p<0.001 for all). Freedom from 12-month CD-TLR by Kaplan-Meier analysis was 96.6% for the standard-use group and 91.6% for the broader-use group (p=0.005). The safety endpoint was 96.2% in the standard-use group and 91.0% in the broader-use group (p=0.003). The 12-month CD-TLR (3.4% standard-use vs 8.5% broader-use, p=0.004) and CD-TVR (4.2% standard-use vs 9.1% broader-use, p=0.008) were increased in the broader-use group. Twelve-month all-cause mortality was not increased (3.8% standard-use vs 3.4% broader-use, p=0.852).

CONCLUSION

Post hoc analysis of the IN.PACT Global Study of real-world patients demonstrated consistent outcomes with significant clinical improvement to 12 months in subjects with complex lesions typically excluded from a randomized controlled trial.

Percutaneous Endovascular Aortic Aneurysm Repair for Abdominal Aortic Aneurysm

PURPOSE OF REVIEW

This review discusses the benefits of a completely percutaneous approach to endovascular aortic aneurysm repair (EVAR), and provides an outline as to how this is performed by a multidisciplinary team of cardiologists and cardiovascular surgeons at a quaternary care community hospital.

RECENT FINDINGS

Percutaneous endovascular aortic aneurysm repair (PEVAR) as compared to EVAR utilizing surgical femoral artery exposure is associated with a significant reduction in operation time, length of stay, access site complications, patient discomfort, and procedural cost. Furthermore, PEVAR may be the preferred approach in patients presenting with aneurysm rupture, as the avoidance of general anesthesia has been associated with improved 30-day mortality. Assuming no contraindication based on vascular anatomy, clinical status, or patient preference, these findings suggest that in properly selected patients, PEVAR should be the primary method for abdominal aortic aneurysm repair in both stable and unstable patients.

Design Strategies for Global Clinical Trials of Endovascular Devices for Critical Limb Ischemia (CLI) - A Joint USA-Japanese Perspective

For more than 10 years, the Harmonization by Doing (HBD) program, a joint effort by members from academia, industry and regulators from the United States of America (USA) and Japan, has been working to increase timely regulatory approval for cardiovascular devices through the development of practical global clinical trial paradigms. Consistent with this mission and in recognition of the increasing global public health effects of critical limb ischemia (CLI), academic and government experts from the USA and Japan have developed a basic framework of global clinical trials for endovascular devices for CLI. Despite differences in medical and regulatory environments and complex patient populations in both countries, we developed a pathway for the effective design and conduct of global CLI device studies by utilizing common study design elements such as patients' characteristics and study endpoints, and minimizing the effect of important clinical differences. Some of the key recommendations for conducting global CLI device studies are: including patients on dialysis; using a composite primary endpoint for effectiveness that includes 6-month post-procedure therapeutic success and target vessel patency; and using a 30-day primary safety endpoint of perioperative death and major adverse limb events. The proposed approach will be uniquely beneficial in facilitating both the initiation and interpretation of CLI studies and accelerating worldwide CLI device development and innovation.

Full Drug-Eluting Stent Jacket: Two-Year Results of a Single-Center Experience With Zilver PTX Stenting for Long Lesions in the Femoropopliteal Arteries

Purpose: To evaluate the 1- and 2-year patency and reintervention rates with the Zilver PTX drug-eluting stent (DES) in long complex femoropopliteal disease. Methods: A retrospective review was conducted of 89 consecutive patients (mean age 68.7±9.8 years; 86 men) with femoropopliteal occlusive disease (Rutherford category 2–6) treated with the Zilver PTX between December 2012 and December 2013. Mean lesion length for the entire cohort was 24.2±11.3 cm (median 24.0, range 4–48). The patient population was dichotomized into a short lesion (≤20 cm) group (n=41; mean lesion length 13.3±5.6 cm) and the full DES jacket (>20 cm) group (n=48; mean lesion length 33.0±6.5 cm). Primary endpoints were duplex-derived restenosis (peak systolic velocity ratio >2.5), clinically driven reintervention, and major amputation. Results: The incidence of restenosis was lower in the short lesion group at 1 year (19% vs 40% for the longer lesions, p=0.050) and 2 years (39% vs 54%, respectively; p=0.331). The short lesion group had significantly lower rates of reintervention at both 1 year (2% vs 21% in long lesions, p=0.009) and 2 years (12% vs 33%, p=0.019). Conclusion: Treatment of femoropopliteal lesions >20 cm with the Zilver PTX appears to be a clinically effective therapy for patients with symptomatic peripheral artery disease. However, there is an increase in restenosis and a need for reintervention that continues to progress up to 2 years.

Helical Centerline Stent Improves Patency: Two-Year Results From the Randomized Mimics Trial

BACKGROUND

Reintervention in the femoropopliteal artery is frequent and a major driver of cost-effectiveness. High wall shear generated by swirling blood flow is associated with reduced occurrence of atherosclerosis and restenosis. This trial investigated the clinical and hemodynamic outcomes of the BioMimics 3D self-expanding tubular nitinol stent with helical centerline geometry compared with a straight stent in the femoropopliteal artery.

METHODS AND RESULTS

In a prospective, multicenter, randomized controlled trial, 76 patients with symptomatic peripheral arterial disease were randomized 2:1 to receive a helical or a straight stent. An independent core laboratory adjudicated angiographic and ultrasound parameters. The primary safety end point was freedom from a composite of all death, target limb amputation, and target lesion revascularization at 30 days. The primary effectiveness end point was freedom from clinically driven target lesion revascularization at 6 months. Patency was a secondary end point. Subjects were followed up for 2 years from intervention. The primary safety (1-sided P<0.01) and efficacy (1-sided P<0.001) end points for the helical stent were met. The proportion of patients treated with the helical stent who maintained patency at 12 and 24 months was 80% and 72%, respectively, compared with 71% and 55% for the control group. The difference was significant through 24 months (P=0.05). Freedom from clinically driven target lesion revascularization for the helical compared with straight stent was 91% versus 92% at 12 months and 91% versus 76% at 24 months.

CONCLUSIONS

Both groups had similar safety outcomes and clinically driven target lesion revascularization to 2 years. However, after placement of a BioMimics 3D helical stent, there was improved patency to 2 years.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT02163863.

The Italian stallions of CLI "value care" delivery

Critical Limb ischemia with long segment occlusive disease typically reserved for surgery can be treated with a high degree of success in expert centers via an endovascular approach Nitinol woven stents appear to have high patency with proper deployment in all PAD groups Increased early expense that is associated with decreased re-intervention can be cost effective.

A Quantitative Angiographic Comparison of Restenotic Tissue Following Placement of Drug-Eluting Stents and Bare Metal Stents in Symptomatic Patients With Femoropopliteal Disease

PURPOSE

To evaluate the patterns of in-stent restenosis (ISR) within femoropopliteal bare metal stents (BMS) and drug-eluting stents (DES) as determined by quantitative angiographic analysis.

METHODS

Utilizing results from independent core laboratory angiographic imaging analysis, quantitative assessment of the restenotic tissue burden was evaluated in 33 patients with symptomatic femoropopliteal ISR, including 20 lesions in 19 patients (mean age 71.5±8.1 years; 11 men) treated with DES and 14 lesions in 14 patients (mean age 70.6±9.2 years; 9 men) treated with BMS.

RESULTS

The average time to target lesion revascularization was similar (8.7 months) for the DES and BMS groups. The DES group had significantly less recurrent disease burden (17.1%) compared with the BMS group (27.8%, p=0.03), representing a 39% relative reduction.

CONCLUSION

Reduced restenotic tissue after endovascular intervention is associated with improved hemodynamics and fewer clinical symptoms and may explain the reduced need for reintervention in restenotic lesions initially treated with DES as compared with BMS. Further study of treatment failure modes may lead to improved device selection criteria to treat patients with peripheral artery disease.

Randomized Trial of Stent versus Surgery for Asymptomatic Carotid Stenosis

BACKGROUND

Previous clinical trials have suggested that carotid-artery stenting with a device to capture and remove emboli ("embolic protection") is an effective alternative to carotid endarterectomy in patients at average or high risk for surgical complications.

METHODS

In this trial, we compared carotid-artery stenting with embolic protection and carotid endarterectomy in patients 79 years of age or younger who had severe carotid stenosis and were asymptomatic (i.e., had not had a stroke, transient ischemic attack, or amaurosis fugax in the 180 days before enrollment) and were not considered to be at high risk for surgical complications. The trial was designed to enroll 1658 patients but was halted early, after 1453 patients underwent randomization, because of slow enrollment. Patients were followed for up to 5 years. The primary composite end point of death, stroke, or myocardial infarction within 30 days after the procedure or ipsilateral stroke within 1 year was tested at a noninferiority margin of 3 percentage points.

RESULTS

Stenting was noninferior to endarterectomy with regard to the primary composite end point (event rate, 3.8% and 3.4%, respectively; P=0.01 for noninferiority). The rate of stroke or death within 30 days was 2.9% in the stenting group and 1.7% in the endarterectomy group (P=0.33). From 30 days to 5 years after the procedure, the rate of freedom from ipsilateral stroke was 97.8% in the stenting group and 97.3% in the endarterectomy group (P=0.51), and the overall survival rates were 87.1% and 89.4%, respectively (P=0.21). The cumulative 5-year rate of stroke-free survival was 93.1% in the stenting group and 94.7% in the endarterectomy group (P=0.44).

CONCLUSIONS

In this trial involving asymptomatic patients with severe carotid stenosis who were not at high risk for surgical complications, stenting was noninferior to endarterectomy with regard to the rate of the primary composite end point at 1 year. In analyses that included up to 5 years of follow-up, there were no significant differences between the study groups in the rates of non-procedure-related stroke, all stroke, and survival. (Funded by Abbott Vascular; ACT I ClinicalTrials.gov number, NCT00106938.).

Durable Clinical Effectiveness With Paclitaxel-Eluting Stents in the Femoropopliteal Artery: 5-Year Results of the Zilver PTX Randomized Trial

Background—

This randomized controlled trial evaluated clinical durability of Zilver PTX, a paclitaxel-coated drug-eluting stent (DES), for femoropopliteal artery lesions. Outcomes compare primary DES versus percutaneous transluminal angioplasty (PTA), overall DES (primary and provisional) versus standard care (PTA and provisional Zilver bare metal stent [BMS]), and provisional DES versus provisional BMS.

Methods and Results—

Patients with symptomatic femoropopliteal artery disease were randomly assigned to DES (n=236) or PTA (n=238). Approximately 91% had claudication; 9% had critical limb ischemia. Patients experiencing acute PTA failure underwent secondary randomization to provisional BMS (n=59) or DES (n=61). The 1-year primary end points of event-free survival and patency showed superiority of primary DES in comparison with PTA; these results were sustained through 5 years. Clinical benefit (freedom from persistent or worsening symptoms of ischemia; 79.8% versus 59.3%, P<0.01), patency (66.4% versus 43.4%, P<0.01), and freedom from reintervention (target lesion revascularization, 83.1% versus 67.6%, P<0.01) for the overall DES group were superior to standard care in nonrandomized comparisons. Similarly, clinical benefit (81.8% versus 63.8%, P=0.02), patency (72.4% versus 53.0%, P=0.03), and freedom from target lesion revascularization (84.9% versus 71.6%, P=0.06) with provisional DES were improved over provisional BMS. These results represent >40% relative risk reduction for restenosis and target lesion revascularization through 5 years for the overall DES in comparison with standard care and for provisional DES in comparison with provisional BMS.

Conclusions—

The 5-year results from this large study provide long-term information previously unavailable regarding endovascular treatment of femoropopliteal artery disease. The Zilver PTX DES provided sustained safety and clinical durability in comparison with standard endovascular treatments.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00120406.

Treating on the edge

Treatment of stent graft edge restenosis can be successfully treated but optimal treatment has not been identified. The practice of continued duplex surveillance for stent grafts appears to be important. Randomized trials comparing drug technology and to properly sized stent graft extension will be needed.

Abstract 69: Can Patient or Arterial Characteristics Guide the Choice between Carotid Angioplasty and Carotid Endarterectomy? The Carotid Revascularization Endarterectomy versus Stenting Trial (CREST)

Background: We have previously reported that carotid artery stenting (CAS) carries a higher stroke risk than carotid endarterectomy (CEA) in patients over the age of 70. The question arises if advanced age is a surrogate for other factors? If so, can those factors be separately identified such that advanced chronological age alone would not be considered a contra-indication for CAS? Here we consider whether the CAS/CEA choice could be guided by other factors known in the clinical center at the time of patient evaluation, independent of age, in order to provide optimal 4-year outcomes.

Methods: Demographic factors (age, sex and race), symptomatic status, patient risk factors (hypertension, diabetes, dyslipidemia, smoking), and arterial characteristics (percent stenosis) were available on 2,502 patients. Additional detailed arterial characteristics (ulcerated plaque, distal tortuosity, sequential lesions, circumferential calcification) were available on 1141 CAS and 438 CEA patients. Potential differential treatment efficacy was assessed by the addition of factor-by-treatment interaction terms to a proportional hazard model containing established predictors of outcome (treatment, symptomatic status, sex, age and age-by-treatment interaction).

Results: No other factor was found to mitigate advanced age with evidence of additional treatment effect modification of 4-year outcome (p > 0.10).

Discussion: Beyond the previously described differential treatment efficacy by age, there were no other patient or arterial characteristic detected to identify patient subgroups that would differentially benefit from the choice of CAS versus CEA. Our inability to identify factors to guide treatment choices could be due to the low number of stroke and death events, incomplete information regarding arterial characteristics in the CEA population, or the potential exclusion of “high risk” groups (such as those with severe arterial tortuosity) from the study.

Heparin-bonded, expanded polytetrafluoroethylene-lined stent graft in the treatment of femoropopliteal artery disease: 1-year results of the VIPER (Viabahn Endoprosthesis with Heparin Bioactive Surface in the Treatment of Superficial Femoral Artery Obstructive Disease) trial

PURPOSE

To evaluate the performance of a heparin-bonded, expanded polytetrafluoroethylene (ePTFE)-lined nitinol endoprosthesis in the treatment of long-segment occlusive disease of the femoropopliteal artery (FPA) and to identify factors associated with loss of patency.

MATERIALS AND METHODS

In a single-arm, prospective, 11-center study (VIPER [Gore Viabahn Endoprosthesis with Heparin Bioactive Surface in the Treatment of Superficial Femoral Artery Obstructive Disease] trial), 119 limbs (113 patients; 69 men; mean age, 67 y), including 88 with Rutherford category 3-5 disease and 72 with Inter-Society Consensus for the Management of Peripheral Arterial Disease (TASC II) C or D lesions of the FPA, underwent stent graft implantation. The mean lesion length was 19 cm; 56% of lesions were occlusions. Follow-up evaluations included color duplex ultrasonography in all patients, with patency defined as a peak systolic velocity ratio< 2.5.

RESULTS

At 12 months, Rutherford category and ankle-brachial index (ABI) were significantly improved (mean category improvement, 2.4; ABI increased from 0.6±0.2 to 0.9±0.19; P<.0001). Primary and secondary patency rates were 73% and 92%. The primary patency for devices oversized<20% at the proximal landing zone was 88%, whereas the primary patency for devices oversized by>20% was 70% (P = .047). Primary patency was not significantly affected by device diameter (5 vs 6 vs 7 mm) or lesion length (≤20 cm vs>20 cm). The 30-day major adverse event rate was 0.8%.

CONCLUSIONS

The heparin-bonded, ePTFE/nitinol stent graft provided clinical improvement and a primary patency rate of 73% at 1 year in the treatment of long-segment FPA disease. Careful sizing of the device relative to vessel landing zones is essential for achieving optimal outcomes.

The Role of Drug-coated Balloons in Infrapopliteal Intervention

The goal of infrapopliteal endovascular therapy is the re-establishment of straight-line flow to the foot with adequate perfusion of tissue. This treatment should be the first method in properly selected patients to relieve ischemic rest pain, heal ulcers and prevent limb loss, improving quality of life. Percutaneous angioplasty (PTA) continues to be the cornerstone of infrapopliteal therapy. Metal stents are reserved for suboptimal PTA. Although data are accumulating that may eventually guide the use of alternative devices such as lasers, excisional, and rotational atherectomy, drug-eluting stents or drug-coated balloons, we currently lack adequate evidence demonstrating improved outcomes. Endovascular therapy has expanded to include patients with severe co-morbidities such as renal failure and complex occlusive disease. Despite advances in below-the-knee (BTK) angioplasty balloons and a focus on angioplasty technique, current PTA results demonstrate one-year restenosis rates up to 80 %, depending on lesion complexity. Drug-coated balloons have demonstrated superior patency in the superficial femoral artery and it is yet to be determined if this technology can achieve improved patency and the clinical outcomes in the infrapopliteal region.

The Role of Drug-coated Balloons in Infrapopliteal Intervention

The goal of infrapopliteal endovascular therapy is the re-establishment of straight-line flow to the foot with adequate perfusion of tissue. This treatment should be the first method in properly selected patients to relieve ischaemic rest pain, heal ulcers and prevent limb loss, improving quality of life. Percutaneous angioplasty (PTA) continues to be the cornerstone of infrapopliteal therapy. Metal stents are reserved for suboptimal PTA. Although data are accumulating that may eventually guide the use of alternative devices such as lasers, excisional and rotational atherectomy, drug-eluting stents or drug-coated balloons, we currently lack adequate evidence demonstrating improved outcomes. Endovascular therapy has expanded to include patients with severe co-morbidities such as renal failure and complex occlusive disease. Despite advances in below-the-knee (BTK) angioplasty balloons and a focus on angioplasty technique, current PTA results demonstrate one-year restenosis rates up to 80 %, depending on lesion complexity. Drug-coated balloons have demonstrated superior patency in the superficial femoral artery and it is yet to be determined if this technology can achieve improved patency and the clinical outcomes in the infrapopliteal region.

Safety and effectiveness of the INVATEC MO.MA proximal cerebral protection device during carotid artery stenting: results from the ARMOUR pivotal trial

OBJECTIVE

The multicenter ARMOUR (ProximAl PRotection with the MO.MA Device DUring CaRotid Stenting) trial evaluated the 30-day safety and effectiveness of the MO.MA Proximal Cerebral Protection Device (Invatec, Roncadelle, Italy) utilized to treat high surgical risk patients undergoing carotid artery stenting (CAS).

BACKGROUND

Distal embolic protection devices (EPD) have been traditionally utilized during CAS. The MO.MA device acts as a balloon occlusion "endovascular clamping" system to achieve cerebral protection prior to crossing the carotid stenosis.

METHODS

This prospective registry enrolled 262 subjects, 37 roll-in and 225 pivotal subjects evaluated with intention to treat (ITT) from September 2007 to February 2009. Subjects underwent CAS using the MO.MA device. The primary endpoint, myocardial infarction, stroke, or death through 30 days (30-day major adverse cardiac and cerebrovascular events [MACCE]) was compared to a performance goal of 13% derived from trials utilizing distal EPD.

RESULTS

For the ITT population, the mean age was 74.7 years with 66.7% of the cohort being male. Symptomatic patients comprised 15.1% and 28.9% were octogenarians. Device success was 98.2% and procedural success was 93.2%. The 30-day MACCE rate was 2.7% [95% CI (1.0-5.8%)] with a 30-day major stroke rate of 0.9%. No symptomatic patient suffered a stroke during this trial.

CONCLUSIONS

The ARMOUR trial demonstrated that the MO.MA(R) Proximal Cerebral Protection Device is safe and effective for high surgical risk patients undergoing CAS. The absence of stroke in symptomatic patients is the lowest rate reported in any independently adjudicated prospective multicenter registry trial to date.

Carotid artery stenting in high surgical risk patients using the FiberNet embolic protection system: the EPIC trial results

OBJECTIVE

The multicenter EPIC (FiberNet Embolic Protection System in Carotid Artery Stenting Trial) single-arm trial evaluated the 30-day outcomes of a new design concept for embolic protection during carotid artery stenting (CAS).

BACKGROUND

Embolic protection filters available for use during CAS include fixed and over-the-wire systems that rely on embolic material capture within a "basket" structure. The FiberNet Embolic Protection System (EPS), which features a very low crossing profile, consists of a three-dimensional fiber-based filter distally mounted on a 0.014 inch guidewire with integrated aspiration during filter retrieval.

METHODS

The trial enrolled 237 patients from 26 centers. Demographics, clinical and lesion characteristics, as well as adverse events through a 30-day follow-up were recorded. The mean age of the patients was 74 years, 64% were male and 20% had symptomatic carotid artery disease.

RESULTS

The combined major adverse event (MAE) rate at 30 days for all death, stroke, and myocardial infarction was 3.0%. There were three major strokes (two ischemic and one hemorrhagic) and two minor strokes (both ischemic) for a 2.1% 30-day stroke rate. The procedural technical success rate was 97.5% and macroscopic evidence of debris was reported in 90.9% of the procedures.

CONCLUSIONS

The FiberNet EPS, used with commercially available stents, produced low stroke rates following CAS in high surgical risk patients presenting with carotid artery disease. The unique filter design including aspiration during retrieval may have contributed to the low 30-day stroke rate reported during CAS in patients considered at high risk for complications following carotid endarterectomy (CEA).

Evolving modalities for femoropopliteal interventions

Despite technical advances in balloon design and technique, there has been little improvement of primary patency rates after balloon-based endovascular interventions for all but focal femoropopliteal lesions. Improving on stainless steel models, nitinol stents have been associated with favorable short- and midterm primary patency rates; studies with longer-term follow-up will be required to learn whether restenosis is ongoing, with continued loss of primary patency. Studies in recent years have shown varying incidences of mechanical fatigue leading to nitinol stent fracture. Covered stents are designed to prevent the tissue infiltration and intimal hyperplasia that can lead to bare metal in-stent restenosis. Several clinical studies, mainly single-center registries, have demonstrated a general effectiveness of the Hemobahn/Viabahn polytetrafluoroethylene-covered stent-grafts, approved for femoral arterial occlusive disease, and have helped to distinguish indications for use and to delineate possible failure modes. A multicenter randomized trial, which has completed enrollment, will compare the Viabahn with self-expanding bare nitinol stents. The primary use of drug-eluting stents (DES) has become routine clinical practice for coronary artery disease. The 2-phase multicenter randomized double-blind SIROCCO trials have been completed, with results published through 24 months. Follow-up demonstrated the feasibility and safety of deploying sirolimus-eluting stents in the femoropopliteal segment but failed to show superior efficacy for DES versus bare nitinol stents. However, the restenosis rates with bare metal stents were unexpectedly low. A paclitaxel-eluting stent without a polymer coating is currently being evaluated in the recently enrolled Zilver PTX randomized trial and international registry. A polymer-based everolimus-eluting stent is being evaluated for femoropopliteal use in the nonrandomized European STRIDES trial. Balloons coated with paclitaxel have recently been evaluated for simple femoropopliteal disease with encouraging results through 2 years of follow-up. The bioabsorbable stent concept emerged in response to the potential issues with metal stents, but to date no investigational device has successfully overcome issues such as relatively low radial force and variable degradation rates.

The "art" of medicine and the "smokescreen" of the randomized trial off-label use of vascular devices

Once a device is approved for sale in the United States by the Food and Drug Administration (FDA), it can legally be used by doctors to treat any condition a physician determines is medically appropriate. Based on postmarket published data and physician procedural experience, this may even become the standard of care when an alternative device either does not exist or is inferior in performance, even before FDA approval. This right of physicians to practice medicine without FDA approval is Federal law. The off-label use of medical devices for the treatment of peripheral vascular disease has recently become the latest target by groups with interests that have little to do with patient care. This interference has begun to negatively impact the latitude necessary for physicians to best treat their patients.

Carotid stenting with embolic protection: evolutionary advances

Stroke is one of the most significant causes of death and morbidity worldwide. Atherosclerotic stenosis of the extracranial internal carotid artery has been invoked as a common causative factor for stroke in over 20% of patients. Although medical therapy can help to prevent the onset and progression of carotid arteriosclerosis, open surgical carotid endarterectomy has been the gold standard for treating severe blockage. Carotid artery stenting has recently demonstrated efficacy in stroke prevention from atherosclerosis, and in high-risk surgical subgroups, has been shown to be associated with a reduction in the risk of myocardial infarction. The controversy for carotid stenting surrounds the incidence of periprocedural stroke. Will embolic protection devices (EPDs) decrease this risk? EPDs continue to evolve with various engineering strategies directed at increasing the efficiency of protection. There are two major categories of EPDs: distal occlusion, either with balloons (e.g., Percusurge, Medtronic Corporation, MN, USA); or distal filtration (e.g., Angioguard, Cordis Corporation, NJ, USA). The second method is proximal protection (e.g., MoMA device, Invatec Corporation, Brescia, Italy). We review the results of trials currently evaluating carotid stenting with both distal and proximal embolic protection.