Impact of small prosthetic valve size on operative mortality in elderly patients after aortic valve replacement for aortic stenosis: Does gender matter?

Abstract

Objective: Ideal management of the elderly patient with a small aortic root remains controversial. This retrospective analysis was performed to determine whether small prosthetic valve size is related to outcome in patients 70 years of age or older undergoing aortic valve replacement for aortic stenosis. Methods: Between December 1991 and July 1998, 366 patients 70 years of age or older (median age 77 years, range 73-81 years, 49% male) underwent isolated aortic valve replacement or aortic valve replacement with coronary bypass grafting with standard Carpentier-Edwards bovine pericardial valves (Baxter Healthcare Corp, Edwards Division, Santa Ana, Calif) (n = 277; 76%) or St Jude Medical mechanical valves (St Jude Medical, Inc, St Paul, Minn) (n = 89; 24%). Propensity scoring and multivariable regression models were used to evaluate the risks associated with implantation of 19-mm valves. Results: Operative mortality was 16.7% (17/102) in patients who received 19-mm valves and 3% (8/264) among those receiving ≥21-mm valves (P ≤ .0005). The univariable odds ratio for operative death for 19-mm versus ≥21-mm valves was 6.4 (95% CI 2.7, 15.4; P ≤ .0005). In the final multivariable model, receipt of a 19-mm valve alone was not a statistically significant predictor of operative death (odds ratio 2.1; 95% CI 0.7, 6.4; P = .21). However, the combination of male sex and 19-mm valve resulted in a significant risk of operative death (4/9 patients; odds ratio 17.5; 95% CI 2.2, 139; P = .007). Use of a 19-mm valve was not related to late death in either the univariable (hazard ratio 1.0; 95% CI 0.5, 2.0; P = .95) or the multivariable analysis (hazard ratio 0.7; 95% CI 0.3, 1.8; P = .51). Conclusions: Implantation of a standard 19-mm aortic valve in elderly men with aortic stenosis may be associated with an increased risk of operative mortality. A higher performance valve and/or a root enlargement procedure should be considered in men with a measured 19-mm anulus. (J Thorac Cardiovasc Surg 1999;118:815-22)