Prognostic impacts of biological valve size on long-term outcomes of primary surgical aortic valve replacement for aortic stenosis.

Abstract

Objectives: We clarified associations between biological valve sizes selected during primary surgical aortic valve replacement (SAVR) and its long-term outcomes.

Methods: In total, 754 consecutive patients with aortic stenosis who underwent primary biological SAVR were classified into three groups based on valve size: 19-mm (n=246), 21-mm (n=262), and ≥23-mm (n=246). Severe prosthesis-patient mismatch (PPM) was defined as measured indexed effective orifice area ≤0.65 cm²/m² if body mass index (BMI) is <30 kg/m² and ≤0.55 cm²/m² if BMI is ≥30 kg/m². The mean observation period was 6.6±4.0 years (4996 patient-years).

Results: Patients with 19-mm valve were older (19-mm: 74±7.8 years vs. 21-mm: 72±8.0 years vs. ≥23-mm: 69±10 years), predominantly female (91% vs. 55% vs. 13%), and had smaller body surface area (BSA) (1.39±0.12 m² vs. 1.53±0.15 m² vs. 1.67±0.16 m²). The incidence of post-SAVR severe PPM was 15%, 5.8%, and 5.0%, respectively (p< 0.001 for all). However, a mixed-effects model demonstrated that left ventricular (LV) mass index regressed equivalently (interaction effect=0.189). During follow-up, 142 (19%) mortalities and 41 (5.4%) aortic valve reinterventions (31 redo-SAVR and 10 valve-in-valve) were observed, without difference in 10-year all-cause mortality rate (21% vs. 33% vs. 27%, p=0.438). Fine-Gray regression model identified age at surgery (adjusted hazard ratio 0.4 per 10-year, p<0.001) and use of 19-mm valve (adjusted hazard ratio 4.0, p<0.001) as independent associates with aortic valve reinterventions.

Conclusions: Despite a higher incidence of severe PPM and aortic reintervention after primary SAVR, use of a 19-mm biological valve can be justified for elderly patients with small BSA, as evidenced by equivalent long-term survival and LV mass regression to those with larger valves.