How TAVR device type may impact outcomes in patients with excessive cusp calcification
Self-expanding and balloon-expandable transcatheter aortic valve replacement (TAVR) devices are associated with comparable five-year mortality rates in patients with excessive cusp calcification, according to new findings published in American Heart Journal.[1] When it comes to other outcomes, however, each treatment option appears to be associated with its own specific risks.
“Excessive aortic valve cusp calcification increases the risk of adverse procedural events, including transcatheter heart valve underexpansion, malpositioning or migration, stroke, conduction disturbances, paravalvular regurgitation (PVR), coronary obstruction and annular rupture,” according to first author Daijiro Tomii, MD, a cardiologist with Bern University Hospital, and colleagues. “Additionally, excessive leaflet calcification may be associated with unfavorable bioprosthetic hemodynamics and an increased risk of late adverse events.”
Tomii et al. tracked data from 271 matched pairs of patients treated with either a self-expanding TAVR valve from Medtronic or a balloon-expandable TAVR valve from Edwards Lifesciences. All patients presented with excessive cusp calcification and underwent treatment from 2007 to 2023. Data came from the SwissTAVI Registry.
Excessive cusp calcification was defined by the research team as a total aortic valve leaflet calcium volume of ≥235 mm3. A total of 1,345 patients with a mean aortic valve complex calcium volume of 540.6 mm3 were included in this analysis, though the team primarily focused on the 271 matched pairs using propensity score matching.
Technical and device success rates were comparable between the two groups. While suboptimal undersizing was more common for patients treated with a self-expanding TAVR valve, suboptimal oversizing was more common with the use of a balloon-expandable TAVR valve. Self-expanding valves had a lower mean transprosthetic gradient (8 mmHg) than balloon-expandable valves (11.2 mmHg).
Also, balloon-expandable TAVR valves were linked to higher rates of annular rupture (2.2%) and cardiac tamponade (1.8%) than the self-expanding TAVR valves (0% for both outcomes).
“These findings suggest that TAVR with balloon-expandable valves in the context of excessive aortic valve calcification carries a substantial procedural risk and warrants careful evaluation of bailout options,” the authors wrote.
Another key takeaway was the higher rates of permanent pacemaker implantation (22.6% vs. 15.5%) and PVR (69.7% vs. 58.1%) for self-expanding TAVR valves.
“Previous studies have suggested that the negative effect of even mild PVR accumulates over time, resulting in an increased risk of adverse events at five years,” the group explained. “Similarly, new permanent pacemaker implantation may also have an adverse effect on long-term clinical outcomes due to atrioventricular and inter/intraventricular dyssynchrony, although currently available data is conflicting.”
Meanwhile, after five years, all-cause mortality was seen in 45.1% of patients with a self-expanding valve and 50.2% of patients with a balloon expandable valve. Cardiovascular death, on the other hand, was seen in 34.9% of patients in the self-expanding group and 39.5% of the balloon-expandable group. There were no statistically significant differences in long-term risks of stroke, myocardial infarction or bleeding events.
“Future studies are warranted to investigate the relationship between bioprosthetic type and the pathophysiology of bioprosthetic degeneration,” the group concluded. “In the meantime, a tailored approach, integrating patient’s clinical characteristics (e.g., advanced coronary artery disease requiring coronary revascularization, impaired left ventricular systolic function), other anatomic considerations (annulus size, angulation of aortic valve plane, left ventricular outflow tract calcification, coronary height, and sinus of Valsalva dimensions), and procedural expertise with each type of device, is key to optimal device selection and life-time management.”
Michael has more than 19 years of experience as a professional writer and editor. He has written at length about cardiology, radiology, artificial intelligence and other key healthcare topics.