Systematic review of the outcome of aortic valve replacement in patients with aortic stenosis.

BACKGROUND: After the establishment of aortic valve replacement procedure for aortic stenosis, there are heterogeneous studies and varying reports on outcome. An analysis that compares individual studies to summarize the overall effect is still lacking. This study systematically analyzes the change in left ventricular (LV) mass index and ejection fraction after aortic valve replacement in adult patients.
METHODS: We performed MEDLINE and bibliographic searches and included 27 articles published between 1980 and 2003 about the outcome of valve replacement in 1546 aortic stenosis patients. To allow comparisons, we stratified the patients into early (0-6 months), intermediate (7-24 months), and late (25-120 months) follow-up groups for the analysis of both LV mass regression and ejection fraction. We separately analyzed five articles that reported groups of patients with low preoperative ejection fraction.
RESULTS: Increase in ejection fraction after surgery is more pronounced in the patients that have low preoperative ejection fraction (28% +/- 4.3%(preop) vs 40% +/- 9.4%(6-41 months) follow-up). Patients with normal or high preoperative ejection fraction have variable outcomes. However, regression of LV mass is uniformly achieved regardless of age, sex, time of operation, or types of valve substitute. Furthermore, LV mass regresses predominantly within the first 6 months after surgery (g/m2, 181 +/- 25.8(preop) vs 124 +/- 27(6 months), 117 +/- 15(24 months), and 113 +/- 14(120 months) follow-up).
CONCLUSIONS: This systematic review supports the concept that aortic stenosis patients with LV dysfunction show a clear functional improvement after aortic valve replacement. Ventricles regress rapidly and reach their approximate final size within the first 6 months of surgery.