EuroPCR 2013: From Cutting-Edge Devices to the Clinical Challenges
PARIS, France—Findings presented at EuroPCR 2013 last week spanned a broad range of topics relevant to clinicians, from late breaking results on novel technologies to the practical concerns of daily practice.
EuroPCR course director William Wijns, MD, PhD, of Cardiovascular Center Aalst (Aalst, Belgium), told TCTMD in an interview that the conference organizers had deliberately pursued a new path this year. “The entire program was revamped this year [to highlight] clinical situations or anatomic substrates that are particularly difficult to treat,” he said, especially those that require input from interventional radiologists, vascular surgeons, and interventional cardiologists. The idea is to “engage the 3 disciplines to talk with each other and collaborate.”
Another theme is that as the field advances, devices are becoming more flexible in meeting the needs of individual patients. “We have the opportunity to think more about the patient-driven indication than the device-mandated indication,” he said, citing debates over the ideal duration of dual antiplatelet therapy as an example.
Bioresorbable Technology Gains Momentum
As in past years, bioabsorbable devices were prominent at EuroPCR.
“There are 2 levels to this,” said Dr. Wijns. “I think the discussion for metallic drug-eluting stents, [regarding] any advantage of bioerodable polymers as a reservoir for drug release vs. biocompatible but durable polymers, is still going on. And it’s not surprising, because results are [already] good, so we’re looking for a small incremental gain here.
Fully bioabsorbable stents, however, are further along and the evidence continues to build, he continued. “A number of colleagues who have a large experience—I’m taking about several hundred implants for a single operator—are starting to have a good sense for what might be the advantage of using the scaffold other than the promise of it disappearing,” Dr. Wijns said, highlighting the potential advantage of being able to treat very long lesions or diffuse disease.
In addition to the Absorb BVS (Abbott Vascular, Santa Clara, CA), the DESolve stent (Elixir Medical, Sunnyvale, CA) recently gained CE mark approval in Europe, Dr. Wijns reported. New results for DESolve were presented at EuroPCR; in the DESolve Nx trial, the new DES showed low late lumen loss and good safety results at 6 months in patients with de novo coronary lesions.
BIOFLOW-II, meanwhile, pitted the Orsiro sirolimus-eluting, biodegradable-polymer stent (BIOTRONIK, Berlin, Germany) against the Xience Prime everolimus-eluting stent (Abbott Vascular, Santa Clara, CA). The newer device proved noninferior in terms of late lumen loss at 9 months, with both stent types showing low and comparable clinical event rates.
Long-term follow-up from the COMFORTABLE AMI trial shed light on dual antiplatelet therapy use with bioresorbable devices. One-year results, published in the Journal of the American Medical Association in August 2012, favored the Biomatrix biolimus-A9-eluting stent (Biosensors, Singapore) over a conventional BMS for the primary endpoint of MACE (composite of cardiac death, target vessel-related reinfarction, and ischemia-driven TLR).
The benefits continued to accrue after 1 year, even after dual antiplatelet therapy was discontinued by more than 80% of patients. Two-year follow-up, available in approximately 96% of the original cohort, again showed an advantage for Biomatrix in terms of MACE. The difference was driven by both target-vessel MI and clinically indicated TLR.
Early data from the PRAGUE-19 registry, slated for 3-year follow-up, suggest that implantation of bioresorbable vascular scaffolds (BVS) is feasible and safe in select patients with acute STEMI.
Researchers prospectively examined outcomes of 87 consecutive STEMI patients who underwent emergent coronary angiography at a single center. BVS implantation was the default treatment, though due to prespecified inclusion and exclusion criteria, both angiographic and clinical, the procedure was ultimately attempted in only 22 patients (25%).
All procedures but 1 were considered successful, and 19 of 21 patients had ideal procedural outcomes, with TIMI 3 flow, no residual stenosis, and no dissection. At 5 months, there were no deaths, strokes, or cases of clinical restenosis. One reinfarction occurred due to BVS thrombosis at 3 days after the patient had discontinued ticagrelor.
In the first-in-man BiOSS-LIM registry, a novel dedicated bifurcation stent demonstrated positive angiographic and clinical results. The BiOSS LIM stent (Balton, Warsaw, Poland) is a 316L stainless steel device coated with a biodegradable polymer (polylactide and polyglycolide) and sirolimus. It consists of 2 parts, with the proximal section larger in diameter than the distal section, and is designed to protect the carina from being crushed or damaged.
Emphasis on the Importance of Daily Choices
Several studies touched on the decisions made in daily practice.
In particular, a new report from the Swedish Coronary Angiography and Angioplasty Registry (SCAAR) “was perhaps a bit provocative,” Dr. Wijns said. The analysis included more than 40,000 NSTE ACS patients and grabbed headlines by showing that bivalirudin may not be superior to heparin as a bleeding avoidance strategy in the absence of glycoprotein IIb/IIIa inhibitors.
After propensity-score adjustment, 30-day mortality favored heparin; the difference was reduced to a trend in favor of heparin after instrumental variable analysis to adjust for unknown confounders. Subgroup analysis maintained nonsignificant support for heparin, with the exception of female patients, those with diabetes, and those who underwent femoral PCI.
“Of course, we all remember the SCAAR scare,” Dr. Wijns commented, referring to findings published in the New England Journal of Medicine in 2007 that suggested higher late mortality with DES vs. BMS. Even so, he added, the most recent SCAAR analysis offers “a unique set of data, because it’s the entire country and everything is captured. So it’s truly real life, but of course it’s potentially confounded by selection bias. They did all the possible corrections, but you never know.” In short, he said, a large trial is justified to explore the ramifications.
Also at EuroPCR the randomized ELISA-3 trial, which also featured NSTE ACS patients, showed that early invasive treatment is not superior to a delayed strategy in an older high-risk population.
At 30 days, the primary composite endpoint of death, reinfarction, and recurrent ischemia did not differ between the early and delayed groups, though there was a trend favoring immediate intervention for recurrent ischemia. Both strategies resulted in similar biomarker results and bleeding. However, hospital stays were significantly shorter for patients treated earlier.
According to the RIPCORD trial, routine assessment of fractional flow reserve (FFR) at the time of diagnostic angiography could change the course of treatment for a substantial segment of patients with stable angina. Cardiologists at 10 centers were asked to decide on treatment plans involving medical therapy, PCI, CABG, or further evaluation for 200 patients based on angiography alone. After patients underwent FFR, the clinicians were asked to reassess their plans. In 26% of cases, FFR results changed the intended course of patient management.
In addition, the 4EVER study found that use of 4-Fr devices is feasible for the majority of endovascular interventions in superficial femoral artery (SFA) lesions, achieving technical success and primary patency that rivals 6-Fr devices.
A randomized study of nearly 400 patients with true bifurcation lesions, meanwhile, showed that predilatation of the side branch before provisional T-stenting improves coronary blood flow and has no adverse consequences.
From Novel Devices to New Approaches
Other presentations at EuroPCR spanned a diverse array of topics.
In the Mimics study, the BioMimics 3D stent (Veryan, Horsham, United Kingdom) helped improve clinical symptoms and walking distance at 12 months vs. a control stent in patients with femoropopliteal disease. The novel stent features a 3-D design that mimics the natural helical geometry of the human vascular system. It is intended to improve blood flow characteristics in the stented segment that may confer a vasoprotective effect and enhance biomechanical performance. The stent also is designed to promote swirling flow to elevate wall shear stress.
Two studies exploring new methods of delivering paclitaxel to treat PAD also were presented.
The nonrandomized ILLUMENATE trial enrolled 80 patients, all with SFA and/or popliteal artery disease, who received the novel Covidien EverCross paclitaxel-coated balloon (ev3, Plymouth, MN) with or without predilatation. Out of a planned follow-up duration of 24 months, the predilatation arm has completed 12 months and the direct DCB arm 1 month.
Both the predilatation and direct DCB groups achieved 100% procedural success. So far, the balloon has been safe and durable up to 12-month follow-up.
In addition, a single-center feasibility study of 18 patients tested an ultrasound system intended to enhance arterial delivery of paclitaxel, thereby reducing restenosis. At 6 months, the restenosis rate was 5.5%. There were no reports of death, MI, TLR, or amputation of the target leg.
Results from the PEPCAD China ISR trial indicated that using paclitaxel-eluting balloons to treat DES restenosis is a noninferior alternative to paclitaxel-eluting stents, obviating the need for additional stent layers.
And in the DEFLECT I trial, a unique embolic deflection device reduced the volume of new cerebral lesions after TAVR but failed to decrease their number compared with historical controls. The TriGuard embolic deflection device (Keystone Heart, Caesarea Business Park, Israel) is a nitinol mesh filter with a pore size of 250 µm designed to deflect cerebral emboli while allowing maximal blood flow during TAVR. Stabilizers maintain the filter’s positioning across all 3 cerebral vessels.
Finally, the latest data from the ORBIT II trial suggested that a novel atherectomy system designed to clear away hard plaque components may improve outcomes in patients with severely calcified coronary lesions.
Presentations at: EuroPCR; May 21-24, 2013; Paris, France.
- Dr. Wijns reports receiving research funding and honoraria from multiple drug and device companies as well as holding stock in Cardio3 Biosciences.