Risk factor analysis for acute type A aortic dissection after aortic valve replacement.

Previous aortic valve replacement (AVR) is considered to be an independent risk factor for late acute type A aortic dissection (AAAD). However, the predictors of late AAAD at the time of AVR have not been characterized. A total of 285 patients who underwent isolated AVR were followed for 7.6 ± 8.1 years (mean ± SD). These 285 patients were divided into two groups. Group A consisted of 275 patients who did not develop late aortic complications after AVR, and group B consisted of 10 patients (3.5%) who developed late AAAD after AVR. The mean time interval between initial AVR and developing late AAAD was 6.1 ± 5.2 years. The diameter of the ascending aorta at the time of AVR was significantly greater in group B than those of group A (47.7 ± 4.6 vs. 35.6 ± 6.3 mm; P < 0.001). Univariate analysis identified other predictors as well: aortic regurgitation (P = 0.029), systemic hypertension (P < 0.001), thinning or fragility of the aortic wall (P < 0.001), and male sex (P = 0.039). Aortic regurgitation combined with systemic hypertension, male sex, and thinned or fragile aortic walls in patients with ascending aortic dilatation (≥45 mm diameter) at the time of AVR may be predisposing factors for postsurgical aortic complications. These patients should be considered for concomitant replacement of the ascending aorta unless the patient has a high operative risk or older age.