Comparison of Outcomes Between Low-Risk Aortic Valve Replacement Trials and a Surgical Registry.

Importance: It remains unknown whether outcomes of the Placement of Aortic Transcatheter Valves 3 (PARTNER 3) and Evolut Low Risk trials are comparable with surgical outcomes in nontrial settings, considering the added risk of concomitant cardiac operations. Objective: To compare 30-day mortality and stroke incidences of patients in the surgical aortic valve replacement (SAVR) arm of low-risk trials with those of similar patients in the US Society of Thoracic Surgeons Adult Cardiac Surgery Database (STS ACSD). Design, Setting, and Participants: A cross-sectional sampling study was conducted of adults in the STS ACSD with severe aortic stenosis at low surgical risk for AVR who underwent SAVR during the years low-risk AVR trials (PARTNER 3 and Evolut Low Risk) were enrolling (calendar years 2016-2018). After trial exclusion criteria were applied, 1000 samples were created, each including 1000 patients selected from the STS ACSD according to the likelihood-based selection probabilities to achieve similar STS predicted risk of mortality (PROM) distribution to the trial participants. The distribution of 30-day mortality and stroke rates among these samples were compared with the results from the trials. The analysis was conducted between October 2, 2023, and May 27, 2024. Main Outcomes and Measures: The main outcomes were 30-day postoperative mortality and stroke. Results: Among 25 811 patients at low risk undergoing SAVR, the mean (SD) age was 71 (7) years, including 650 220 men (65%). The probability-based sampling yielded a trial-like sample with STS PROM (mean [SD], 1.9% [0.6%]) and concomitant coronary artery bypass graft surgery frequencies of 13%, comparable with the trials. Among the sampled cohorts, the mean (SD) 30-day mortality rate was 1.39% (0.38%) which was not significantly different from the mortality rate in PARTNER 3 (1.1%) (P = .83) and Evolut Low Risk (1.3%) (P = .65). The stroke rate was 1.25% (0.36%), significantly lower than PARTNER 3 (2.4%) (P = .002) and Evolut Low Risk (3.4%) (P < .001). Conclusions and Relevance: In this cross-sectional study, the national samples of low-risk trial-like patients undergoing SAVR during the trial enrollment period had similar 30-day mortality but a lower incidence of stroke compared with the SAVR arm of both low-risk trials. These findings overall suggest that the low-risk trial findings may be generalizable to the broader national SAVR cohort.