Two major studies on transfemoral aortic valve replacement technologies will be among the late-breaking clinical trials presented at the annual meeting of the American College of Cardiology March 9-11.
The results come at a key time, when surgeons are starting to consider transfemoral aortic valve replacement (TAVR) for low-risk as well as high-risk patients, said ACC.13 Cochair Dr. Mark G. Davies.
Other highlights among the late-breakers at the meeting include studies on biodegradable versus durable stents, statins to prevent kidney injury during percutaneous coronary intervention (PCI), short-acting antiplatelet therapy, new drugs that may reduce the size or long-term effects of heart attacks, ranolazine therapy to reduce angina in patients with diabetes, using digitalis in older patients with heart failure, and more.
He and a roster of other ACC officials provided these highlights:
• PARTNER trial: Two-year data from the Placement of Aortic Transcatheter Valve (PARTNER) trial already have suggested that results with TAVR were reasonably comparable to results with surgical aortic valve replacement (SAVR), though perhaps with increased risk of early stroke after TAVR. "But the one Achilles heel that everyone is worried about is that there will be more early strokes in TAVR," said Dr. Davies, a senior member at the Methodist Hospital Research Institute, Houston.
Three-year data from the PARTNER trial, to be presented at the meeting, should show whether the level of valvular regurgitation is increasing or not – important findings that will change practices, he said. "This is significant because we’re entering an era of entertaining these technologies for what’s considered normal or low-risk patients who might avoid a surgical aortic revascularization," said Dr. Davies. For hospitals, "it will be interesting to see if the cost-effectiveness is carried out to 3 years," he added.
• PARTNER II: This trial used a second-generation Edwards Sapien XT transcatheter heart valve and delivery system, which has a lower profile compared with the first-generation device.
The Food and Drug Administration required the Sapien and Edwards investigators to compare the newer version against SAVR before taking it to market, according to ACC Vice President Dr. Patrick T. O’Gara, director of clinical cardiology at Brigham and Women’s Hospital, Boston.
"Most investigators and clinicians in this area are keen to hear the results of this trial, and I think most anticipate that a lower-profile device will be an improvement," he said.
• NEXT trial: Enthusiasm for a potential future of biodegradable stent products rides on hopes that biodegradable polymers might cause less arterial injury and stent thrombosis, "although it seems to me very difficult to beat very low rates of stent thrombosis with present-generation drug-eluting stents," Dr. O’Gara said. This large Japanese trial comparing a biodegradable stent polymer and a durable stent polymer in more than 3,000 patients is a major data source. The NOBORI Biolimus-Eluting Versus XIENCE/PROMUS Everolimus-Eluting Stent (NEXT) trial likely will contribute "very important information in this growing field," he said.
• DKCRUSH-III trial: A highly technical and impressively large study in China compared two interventional strategies in more than 400 patients with unprotected left main bifurcation lesions. Historically, interventionalists have been challenged by management of lesions at the distal end of the left main coronary artery and extending to the origins of the left anterior descending (LAD) artery and the circumflex artery, he said. "Manipulation of the left main in this particular area is fraught with complications and relatively high rates of recurrent events."
The prospective, multicenter Comparison of Double Kissing Crush Versus Culotte Stenting for Unprotected Distal Left Main Bifurcation Lesions (DKCRUSH-III) study randomized patients to intervention with stents placed in the LAD and circumflex arteries or to high-pressure balloons being placed in those arteries and inflated simultaneously.
• CHAMPION PHOENIX trial: Results of previous studies of the experimental antiplatelet drug cangrelor have been neutral or positive, but none of the studies were as large as the Clinical Trial Comparing Cangrelor to Clopidogrel Standard Therapy in Subjects Who Require Percutaneous Coronary Intervention (CHAMPION PHOENIX), which boasts nearly 11,000 patients. Preliminary results of the phase III trial suggested that this intravenously administered P2Y2-receptor inhibitor outperformed clopidogrel in patients requiring PCI in a composite endpoint of death, MI, ischemia-driven revascularization, and stent thrombosis at 48 hours.
The potential advantage of cangrelor is its very rapid onset and rapid offset of effects. "I think there is very keen expectation to hear the results of this trial as to whether or not this medication should be considered in the armamentarium at the time of PCI," Dr. O’Gara said.