Outcomes for Low-Risk Surgical Aortic Valve Replacement: A Benchmark for Aortic Valve Technology

Background: Two large, randomized trials are underway evaluating transcatheter aortic valve replacement (AVR) against conventional surgical AVR. We analyzed contemporary, real-world outcomes of surgical AVR in low-risk patients to provide a practical benchmark of outcomes and cost for evaluating current and future transapical AVR technology.

Methods: From 2010 to 2015, 2,505 isolated AVR operations were performed for severe aortic stenosis at 18 statewide cardiac institutions. Of these, 2,138 patients had a Society of Thoracic Surgeons predicted risk of mortality of less than 4%, and 1,119 met other clinical and hemodynamic criteria as outlined in the PARTNER 3 (The Placement of Transcatheter Aortic Valves) protocol. Patients with endocarditis, end-stage renal disease, ejection fraction of less than 0.45, bicuspid valves, and previous valve replacements were excluded. Outcomes of interest included operative death and postoperative adverse events.

Results: The median Society of Thoracic Surgeons predicted risk of mortality for the study-eligible patients was 1.44%, with a median age of 72 years (interquartile range [IQR], 65 to 78 years). Operative mortality was 1.3%, permanent stroke was 1.3%, and pacemaker requirement was 4.2%. The most common adverse events were transfusion of 2 or more units of red blood cells (18%) and atrial fibrillation (28%). The median length of stay was 6 days (IQR, 5 to 8 days). Median total hospital cost was $37,999 (IQR, $30,671 to $46,138). Examination of complications by age younger than 65 vs 65 or older demonstrated a significantly lower need for transfusion (11.2%, p < 0.001) and incidence of atrial fibrillation (17.1%, p < 0.001) but no difference in operative mortality (2.2% vs 0.9%, p = 0.1), major morbidity (10.4% vs 12.6%, p = 0.3), or total hospital costs.

Conclusions: Low-risk patients undergoing surgical AVR in the current era have excellent results. The most common complications were atrial fibrillation and bleeding. These real-world results should provide additional context for upcoming transcatheter clinical trial data.