Analysis of CoreValve Trial Supports TAVR Versus SAVR for Intermediate-Risk Patients

August 19, 2016—In a study by Michael J. Reardon, MD, et al, the investigators concluded that self-expanding transcatheter aortic valve replacement (TAVR) compares favorably with surgical aortic valve replacement (SAVR) in high-risk patients with predictive scores that are traditionally considered intermediate risk. The study is available online ahead of print in the Journal of the American Medical Association: Cardiology (JAMA: Cardiology).

The investigators evaluated outcomes from the multicenter randomized noninferiority CoreValve United States pivotal high-risk trial in patients with a Society of Thoracic Surgeons (STS) risk score of 7% or less.

According to the investigators, the background of the study is that the STS Predicted Risk of Mortality (STS PROM) has trended downward in both the United States TAVR trials and the STS/American College of Cardiology Transcatheter Valve Therapy Registry. The investigators hypothesized that if the STS PROM alone is sufficient to define decreased risk, the contribution to survival based on the degree of invasiveness of the TAVR procedure will decrease, making it more difficult to show improved survival and benefit over SAVR.

The trial, which was performed at 45 sites in the United States, was composed of patients with severe aortic stenosis who were at increased surgical risk based on their STS PROM score and other risk factors. Eligible patients were randomly assigned (1:1) to self-expanding TAVR or to SAVR.

As summarized in JAMA: Cardiology, patients were retrospectively stratified by the overall median STS PROM score (7%), analyzed clinical outcomes, and quality of life using the Kansas City Cardiomyopathy Questionnaire (KCCQ) in patients with an STS PROM score of 7% or less.

The mean (standard deviation [SD]) ages were 81.5 (7.6) years for the TAVR group and 81.2 (6.6) years for the SAVR group. More than half of the patients were male (57.9% in the TAVR group and 55.8% in the SAVR group). 

Of 750 patients who underwent attempted implantation, 383 (202 TAVR and 181 SAVR) had an STS PROM of 7% or less (median [interquartile range]: TAVR, 5.3% [4.3%–6.1%]; SAVR, 5.3% [4.1%–5.9%]). 

Two-year all-cause mortality for TAVR versus SAVR was 15% (95% confidence interval [CI], 8.9–10) versus 26.3% (95% CI, 19.7–33) (log-rank, P = .01). The 2-year rate of stroke for TAVR versus SAVR was 11.3% versus 15.1% (log-rank, P = .5). 

Quality of life by the KCCQ summary score showed significant and equivalent increases in both groups at 2 years (mean [SD] TAVR, 20 [25]; SAVR, 18.6 [23.6]; P = .71; both P < .001, compared with baseline). Medical benefit, defined as alive with a KCCQ summary score of at least 60 and a < 10-point decrease from baseline, was similar between groups at 2 years (TAVR, 51%; SAVR, 44.4%; P = .28), reported the investigators in JAMA: Cardiology.