Final 5-Year OBSERVANT Results Compare TAVR and SAVR

July 9, 2019—Five-year outcomes from the Italian OBSERVANT study were published online by Marco Barbanti, MD, et al in Circulation: Cardiovascular Interventions.

Previously, OBSERVANT—an observational study of effectiveness of surgical aortic value replacement (SAVR) versus transcatheter aortic valve replacement (TAVR) procedures for severe aortic stenosis treatment—showed that mortality at 1 year is similar after transfemoral TAVR and SAVR for real-world propensity-matched patients with aortic stenosis at low and intermediate risk.

As summarized in Circulation: Cardiovascular Interventions, the unadjusted enrolled population (N = 7,618) between December 2010 and June 2012 included 5,707 patients treated by SAVR and 1,911 patients treated by TAVR. The propensity score method was applied to select two groups with similar baseline characteristics. All outcomes were adjudicated through a linkage with administrative databases.

The primary endpoints of this analysis were death from any cause and major adverse cardiac and cerebrovascular events at 5 years.

The matched population had a total of 1,300 patients (650 per group). For SAVR compared to transfemoral TAVR, the propensity score method generated a low-risk and intermediate-risk population (mean logistic EuroSCORE 2: 5.1 ± 6.2% vs 4.9 ± 5.1%; P = .485).

At 5 years, the investigators found the following:

• The rate of death from any cause was 35.8% for SAVR versus 48.3% for TAVR (hazard ratio, 1.38; 95% confidence interval [CI], 1.12–1.69; P = .002).
• The risk of major adverse cardiac and cerebrovascular events was increased with TAVR (54%) compared with SAVR (42.5%) (hazard ratio, 1.35; 95% CI, 1.11–1.63; P = .003).
• The cumulative incidence of cerebrovascular events, myocardial infarction, and coronary revascularization were similar in the study groups.

The investigators concluded that the results suggest that at 5 years, in a real-world population with severe aortic stenosis and at low and intermediate risk, SAVR is associated in with lower mortality and major adverse cardiac and cerebrovascular events rates than transfemoral TAVR performed using first-generation devices. These data need to be confirmed in randomized trials using new-generation TAVR devices, advised the investigators in Circulation: Cardiovascular Interventions.