BACKGROUND - In low surgical risk patients with symptomatic severe aortic stenosis, the PARTNER 3 (Safety and Effectiveness of the SAPIEN 3 Transcatheter Heart Valve in Low Risk Patients With Aortic Stenosis) trial demonstrated superiority of transcatheter aortic valve replacement (TAVR) versus surgery for the primary endpoint of death, stroke, or re-hospitalization at 1 year.

OBJECTIVES - This study determined both clinical and echocardiographic outcomes between 1 and 2 years in the PARTNER 3 trial.

METHODS - This study randomly assigned 1,000 patients (1:1) to transfemoral TAVR with the SAPIEN 3 valve versus surgery (mean Society of Thoracic Surgeons score: 1.9%; mean age: 73 years) with clinical and echocardiography follow-up at 30 days and at 1 and 2 years. This study assessed 2-year rates of the primary endpoint and several secondary endpoints (clinical, echocardiography, and quality-of-life measures) in this as-treated analysis.

RESULTS - Primary endpoint follow-up at 2 years was available in 96.5% of patients. The 2-year primary endpoint was significantly reduced after TAVR versus surgery (11.5% vs. 17.4%; hazard ratio: 0.63; 95% confidence interval: 0.45 to 0.88; p = 0.007). Differences in death and stroke favoring TAVR at 1 year were not statistically significant at 2 years (death: TAVR 2.4% vs. surgery 3.2%; p = 0.47; stroke: TAVR 2.4% vs. surgery 3.6%; p = 0.28). Valve thrombosis at 2 years was increased after TAVR (2.6%; 13 events) compared with surgery (0.7%; 3 events; p = 0.02). Disease-specific health status continued to be better after TAVR versus surgery through 2 years. Echocardiographic findings, including hemodynamic valve deterioration and bioprosthetic valve failure, were similar for TAVR and surgery at 2 years.

CONCLUSIONS - At 2 years, the primary endpoint remained significantly lower with TAVR versus surgery, but initial differences in death and stroke favoring TAVR were diminished and patients who underwent TAVR had increased valve thrombosis. (Safety and Effectiveness of the SAPIEN 3 Transcatheter Heart Valve in Low Risk Patients With Aortic Stenosis [PARTNER 3]; NCT02675114)