CardioSource WorldNews Interventions May/June 2016 | Page 29

recommend extended DAPT after DES placement, increasing bleeding risk, requiring good patient compliance, and added cost. Bioresorbable vascular scaffolds (BVS) were proposed as an answer to this dilemma. Efforts to develop the devices began more than 20 years ago, but the world first learned of their clinical use in 2000. The “disappearing” stent became commercially available 11 years later, when Abbott’s Absorb™ BVS became the first of its kind to be approved for use in Europe. The everolimus-eluting device, made of a poly-L-lactide polymer, won its approval based on results of clinical trials demonstrating that the stent restored blood flow by opening a blocked vessel, providing support to that vessel until it dissolved after about 2 years. Since then, the BVS concept has hit a few snags. Yes, the conformability and superior flexibility of BVS allows for minimal changes of vessel geometry and along with the eventual absorption of the lumenprotruding struts attenuate the unfavorable hemodynamic changes typical of rigid stents. Plus, elimination of late-acquired malapposition (an established trigger of stent thrombosis) or edge-related vascular responses in the long term are additional theoretical benefits of BVS. On the other hand, strut thickness is larger compared with new-generation DES, leading to suboptimal crossing profiles, limiting the ability to treat complex (e.g., excessively tortuous or calcified) lesions or to implant overlapping BVS, resulting in inferior immediate, post-procedural angiographic Stents Disappear but Questions Do Not outcomes of device performance. Compared with bare-metal stents (BMS), drugRecent randomized trials have raised concerns eluting stents (DES) decrease the risk of restenosis about the possibility of higher stent thrombosis without increasing the risk of death and MI. How(ST) with BVS. Thus, Alok Saurav, MD, et al. of ever, unlike their bare-metal counterparts they are associated with hypersensitivity reactions, delayed Creighton University Medical Center, Omaha, NE, conducted a meta-analysis of five randomized and healing, and incomplete endothelialization, which three observational trials, including data on 2,760 may increase the risk of late and very late stent BVS patients and 2,212 receiving DES. He presentthrombosis. And, of course, current guidelines ed the data at CRT.16. All patients were on DAPT for at least 1 year. They reported a strong TAVR: A Revolution in trend towards higher ‘definite ST’ Evolution (RR: 1.8; p = 0.06). Clinical outcomes were similar for death (RR: Josep Rodés-Cabau, MD, Quebec Heart & 0.74; p = 0.57), cardiac death (RR: Lung Institute at Laval University talks about his 0.83; p = 0.66), TVR (RR: 1.0; JACC Interventions commentary on the conp = 0.95); and ischemia-driven TVR tinuing evolution of the TAVR revolution. This (RR: 1.0; p = 0.6). The difference? interview was taped at CRT.16. That would be MI, which was JACC Interventions commentary: interventions. significantly higher with BVS (RR: onlinejacc.org/article.aspx?articleID = 2483103 1.35; p = 0.049). loon PVI in 762 symptomatic patients. There was a 90-day blanking period after the procedure, only after which were endpoint events counted. The rates of the primary efficacy endpoint (the first documented AF recurrence, occurrence of atrial flutter or atrial tachycardia, use of antiarrhythmic drugs, or repeat ablation) were 34.6% for RFA ablation and 35.9% for cryoballoon (p < 0.001 for noninferiority). There was no difference, either, in the occurrence of the primary safety endpoint (a composite of death, cerebrovascular events, or serious treatment-related adverse events; hazard ratio, 0.78; p = 0.24). What does it mean that cryoballoon ablation was noninferior to RFA (and safety was similar between approaches)? The study was presented by KarlHeinz Kuck, MD, PhD, St. Georg Hospital, Hamburg, Germany. He said, “Radiofrequency ablation for atrial fibrillation is the most challenging procedure in cardiology, but with the cryoballoon, it becomes a very simple procedure. So, with a single-step approach, we s