IRQ Articles

Abstracts from the current literature 

01-16-2020 12:59 PM

By Ripal T. Gandhi, MD, FSIR, and Suvranu Ganguli, MD, FSIR  Winter 2020

This column alerts SIR members to abstracts that may have an impact on their practice and how they converse with referring clinicians. If you would like to suggest abstracts you feel should be included, email us at or

A prospective, single-arm, multicenter trial of catheter-directed mechanical thrombectomy for intermediate-risk acute pulmonary embolism: The FLARE Study.

JACC Cardiovasc Interv. 2019 May 13;12(9):859-869. doi: 10.1016/j.jcin.2018.12.022.

Tu T, Toma C, Tapson VF, Adams C, Jaber WA, Silver M, Khandhar S, Amin R, Weinberg M, Engelhardt T, Hunter M, Holmes D, Hoots G, Hamdalla H, Maholic RL, Lilly SM, Ouriel K, Rosenfield K; FLARE Investigators.

Objectives: The aim of this study was to evaluate the safety and effectiveness of percutaneous mechanical thrombectomy using the FlowTriever System (Inari Medical, Irvine, California) in a prospective trial of patients with acute intermediate-risk pulmonary embolism (PE).

Background: Catheter-directed thrombolysis has been shown to improve right ventricular (RV) function in patients with PE. However, catheter-directed thrombolysis increases bleeding risk and many patients with PE have relative and absolute contraindications to thrombolysis.

Methods: Patients with symptomatic, CT-documented PE and RV/left ventricular (LV) ratios ≥0.9 were eligible for enrollment. The primary effectiveness endpoint was core laboratory-assessed change in RV/LV ratio. The primary safety endpoint comprised device-related death, major bleeding, treatment-related clinical deterioration, pulmonary vascular injury or cardiac injury within 48 h of thrombectomy.

Results: From April 2016 to October 2017, 106 patients were treated with the FlowTriever System at 18 U.S. sites. Two patients (1.9%) received adjunctive thrombolytics and were analyzed separately. Mean procedural time was 94 min; mean intensive care unit stay was 1.5 days. Forty-three patients (41.3%) did not require any intensive care unit stay. At 48 h post procedure, average RV/LV ratio reduction was 0.38 (25.1%; p < 0.0001). Four patients (3.8%) experienced six major adverse events, with one patient (1.0%) experiencing major bleeding. One patient (1.0%) died, of undiagnosed breast cancer, through 30-day follow-up.

Conclusions: Percutaneous mechanical thrombectomy with the FlowTriever System appears safe and effective in patients with acute intermediate-risk PE, with significant improvement in RV/LV ratio and minimal major bleeding. Potential advantages include immediate thrombus removal, absence of thrombolytic complications, and reduced need for postprocedural critical care.

Five-year outcomes of a randomized trial of treatments for varicose veins.

N Engl J Med. 2019 Sep 5;381(10):912-922. doi: 10.1056/NEJMoa1805186.

Brittenden J, Cooper D, Dimitrova M, Scotland G, Cotton SC, Elders A, MacLennan G, Ramsay CR, Norrie J, Burr JM, Campbell B, Bachoo P, Chetter I, Gough M, Earnshaw J, Lees T, Scott J, Baker SA, Tassie E, Francis J, Campbell MK.

Background: Endovenous laser ablation and ultrasound-guided foam sclerotherapy are recommended alternatives to surgery for the treatment of primary varicose veins, but their long-term comparative effectiveness remains uncertain.

Methods: In a randomized, controlled trial involving 798 participants with primary varicose veins at 11 centers in the United Kingdom, we compared the outcomes of laser ablation, foam sclerotherapy and surgery. Primary outcomes at 5 years were disease-specific quality of life and generic quality of life, as well as cost-effectiveness based on models of expected costs and quality-adjusted life-years (QALYs) gained that used data on participants’ treatment costs and scores on the EuroQol EQ-5D questionnaire.

Results: Quality-of-life questionnaires were completed by 595 (75%) of the 798 trial participants. After adjustment for baseline scores and other covariates, scores on the Aberdeen Varicose Vein Questionnaire (on which scores range from 0 to 100, with lower scores indicating a better quality of life) were lower among patients who underwent laser ablation or surgery than among those who underwent foam sclerotherapy (effect size [adjusted differences between groups] for laser ablation vs. foam sclerotherapy, -2.86; 95% confidence interval [CI], -4.49 to -1.22; P<0.001; and for surgery vs. foam sclerotherapy, -2.60; 95% CI, -3.99 to -1.22; P<0.001). Generic quality-of-life measures did not differ among treatment groups. At a threshold willingness-to-pay ratio of £20,000 ($28,433 in U.S. dollars) per QALY, 77.2% of the cost-effectiveness model iterations favored laser ablation. In a two-way comparison between foam sclerotherapy and surgery, 54.5% of the model iterations favored surgery.

Conclusions: In a randomized trial of treatments for varicose veins, disease-specific quality of life 5 years after treatment was better after laser ablation or surgery than after foam sclerotherapy. The majority of the probabilistic cost-effectiveness model iterations favored laser ablation at a willingness-to-pay ratio of £20,000 ($28,433) per QALY. (Funded by the National Institute for Health Research; CLASS Current Controlled Trials number, ISRCTN51995477.)

Long-distance tele-robotic-assisted percutaneous coronary intervention: A report of first-in-human experience.

EClinical Medicine (Published by The Lancet), Volume 14, September 2019, Pages 53–58.

Patel TM, Shah SC, Pancholy SB.

Background: Robotic-assisted percutaneous coronary intervention (R-PCI) has been successfully employed in the United States since 2011. Performing R-PCI from a remote location has never been reported but if feasible would extend availability of treatment to many patients with coronary artery disease (CAD) who would otherwise go without.

Objective: To assess the feasibility of remote tele-R-PCI with the operator 20 miles away from the patients.

Methods: Five patients with single, type A coronary artery lesions treatable by PCI consented to participate. The primary endpoint was procedural success with no major adverse cardiac events (MACE) before discharge. Procedural success was defined as achieving<10% diametric stenosis of the occluded target vessel utilizing tele-R-PCI balloon angioplasty and stent deployment (CorPath GRX®, Corindus Vascular Robotics, USA) without converting to in-lab manual PCI by an on-site standby team. Procedural, angiographic and safety data were collected as were questionnaire scores from the remote operator evaluating the robot-network composite, image clarity and overall confidence in the procedure.

Results: The primary endpoint was achieved in 100% of patients. No procedural complications or adverse events occurred, and all patients were discharged the following day without MACE. The operator scores were favorable with the operators rating the procedure as equivalent to an in-lab procedure.

Conclusions: Performing long-distance tele-R-PCI in patients with CAD is feasible with predictably successful outcomes if reliable network connectivity and local cardiac catheterization facilities are available.

Mortality assessment of paclitaxel-coated balloons: Patient-level meta-analysis of the ILLUMENATE clinical program at 3 years.

Circulation. 2019 Oct;140(14):1145-1155. doi: 10.1161/CIRCULATIONAHA.119.040518. Epub 2019 Sep 30.

Gray WA, Jaff MR, Parikh SA, Ansel GM, Brodmann M, Krishnan P, Razavi MK, Vermassen F, Zeller T, White R, Ouriel K, Adelman MA, Lyden S.

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 two RCTs comprising 419 patients treated with DCB and 170 patients treated with PTA. In an additional analysis, data were aggregated from six poolable Stellarex DCB studies (two RCTs, three single-arm studies and one 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 vs. 69.4±9.4 years, P=0.02), smoked more frequently (86.6% vs. 78.8%, P=0.02) and were less often treated for recurrent lesions (8.8% vs. 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% vs. 1.3±0.9%, 6.5±1.2% vs. 5.9±1.9%, and 9.3±1.5% vs. 9.9±2.4% at 1, 2 and 3 years, respectively, P=0.86). All-cause mortality rates were similar in a 1,906-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.

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