How did the self-expanding supraannular valve compare with the balloon-expandable valve in this trial?

Herrmann et al. conducted a trial in which the self-expanding supraannular valve was compared with the balloon-expandable valve in patients with symptomatic severe aortic stenosis and a small aortic-valve annulus who were undergoing transcatheter aortic-valve replacement (TAVR).

Clinical Pearls

Q: Have the different types of TAVR prostheses been compared in randomized trials?

A: On the basis of multiple prospective randomized trials comparing TAVR with surgery, TAVR has emerged as the dominant treatment method for most patients with symptomatic severe aortic stenosis. Despite differences in their design, hemodynamic characteristics, and implantation techniques, different types of TAVR prostheses have been compared in relatively few randomized trials. In observational studies and randomized trials, the self-expanding supraannular valve has been shown to have better hemodynamic properties than balloon-expandable valves.

Q: What are the post-TAVR risks faced by patients with a small aortic annulus?

A: Patients with a small aortic annulus are an important subgroup of symptomatic patients with aortic stenosis, predominantly women, who undergo TAVR. Patients with a small annulus are at particular risk for high residual gradients and prosthesis–patient mismatch, which are associated with major adverse cardiovascular events, including death, heart failure, and reduced quality of life. Findings from a large national database showed that a mean echocardiographic gradient of greater than 22.5 mm Hg was associated with increased 5-year mortality. Severe prosthesis–patient mismatch after TAVR is also associated with reduced survival. Finally, impaired hemodynamic performance is associated with reduced valve durability.

Morning Report Questions

Q: How did the self-expanding supraanular valve compare with the balloon-expandable valve in this trial?

A: The two powered coprimary end points, both of which were assessed through 12 months, were a clinical outcome composite of death, disabling stroke, or rehospitalization for heart failure and a composite end point of bioprosthetic-valve dysfunction. Among patients who underwent TAVR, a self-expanding supraannular valve was noninferior to a balloon-expandable valve with respect to clinical outcomes and was superior with respect to bioprosthetic-valve dysfunction through 12 months. The Kaplan–Meier estimate of the percentage of patients with a first coprimary end-point was 9.4% in the self-expanding valve group and 10.6% in the balloon-expandable valve group (difference, −1.2 percentage points; 90% CI, −4.9 to 2.5; P<0.001 for noninferiority; hazard ratio, 0.90; 95% CI, 0.56 to 1.43). The Kaplan–Meier estimate of the percentage of patients with bioprosthetic-valve dysfunction through 12 months was 9.4% in the self-expanding valve group and 41.6% in the balloon-expandable valve group (difference, −32.2 percentage points; 95% CI, −38.7 to −25.6; P<0.001).

Q: What were some additional results of this trial?

A: The self-expanding valve was also superior to the balloon-expandable valve with respect to several hypothesis-tested secondary end points: mean gradient, effective orifice area, hemodynamic structural valve dysfunction, and bioprosthetic-valve dysfunction in women through 12 months, as well as moderate or severe prosthesis–patient mismatch at 30 days. No apparent differences in safety outcomes were found between the groups.