Prosthesis-patient mismatch after surgical aortic valve replacement with aortic annular enlargement in small aortic annuli

OBJECTIVES: Aortic annular enlargement (AAE) during surgical aortic valve replacement (SAVR) is performed to facilitate implantation of larger prostheses in patients with small aortic annuli and mitigate prosthesis-patient mismatch (PPM). However, the clinical impact of residual PPM after AAE remains uncertain. METHODS: All adult patients who underwent SAVR with AAE for small aortic annuli were retrospectively identified from a prospectively maintained institutional database (2011-2024). PPM was defined based on indexed effective orifice area thresholds derived from published reference tables. The primary outcome was all-cause mortality, and secondary outcomes included heart failure (HF) hospitalization, and longitudinal echocardiographic performance. RESULTS: A total of 169 patients were identified (age 68 years [61-73], 119 female [70.4%]). Median STS risk was 2% [1-4%], and preoperative mean gradient was 45.0 mmHg [36.8-57.2]. Overall median valve size after AAE was 23 mm (21-25), and PPM occurred in 25 patients (14.8%), including 24 (14.2%) with moderate and 1 (0.6%) with severe PPM. Early outcomes were comparable between PPM and no-PPM groups: postoperative stroke 0 (0%) vs. 3 (2.1%, p > 0.999), and 30-day mortality 1 (4.0%) vs. 5 (3.5%, p > 0.999). Over 4 years follow-up, survival (HR 0.94, 95%CI 0.40-2.21, p = 0.896) and freedom from HF hospitalization (HR 1.16, 95%CI 0.45-2.95, p = 0.760) were similar. Echocardiographic trends showed no differences in LVEF (p = 0.123) or mean gradient (p = 0.879) during follow-up. CONCLUSIONS: In patients with small aortic annuli undergoing SAVR with annular enlargement, the incidence of PPM was low, and residual PPM did not adversely impact early postoperative outcomes, mid-term survival, or valve hemodynamics.