Early and long-term outcome of aortic valve replacement with homograft versus mechanical prosthesis--8-year follow-up study

Abstract

Background: Aortic valve disease is an important and frequent clinical problem with a mortality rate as high as 50-80% in a 5-year natural history of patients with severe aortic valve disease. Biological or mechanical prosthesis implantation is the only way to improve prognosis.

Hypothesis: The aim of our study was to assess the clinical outcome of aortic valve replacement according to the underlying valve pathology and the type of replacement device, that is, aortic homografts versus mechanical prostheses.

Methods: The study group consisted of 143 patients with a mean follow-up period of 4.1 +/- 2.7 years. All patients had annual clinical and Doppler echocardiographic evaluation.

Results: Total 8-year mortality was 4.9% (7/143) including early mortality of 1.4%. Eight-year survival probability was not significantly higher in the homograft than in the mechanical prosthesis recipients. No differences were found among subgroups with aortic stenosis, insufficiency, and combined disease. Overall early and late complication rate (13.3 and 24.8%, respectively) was similar in homograft and mechanical valve recipients. The most common late complications were ventricular arrhythmia (10%) (Lown class I-III), predominantly in the homograft recipients (17.7 vs. 3.7%), and heart failure (9.2%), more frequent in mechanical valve recipients (14.8 vs. 1.6%). Thromboembolic events occurred in 6.3%, infective endocarditis in 4.2% (more common in mechanical valve recipients), serious bleeding in 3.7% (only in mechanical valve recipients). There was no significant difference in early and late complication rate among subgroups (aortic stenosis, insufficiency, and combined disease). Of the patients studied, 91.6% improved in functional status after surgery, with significantly better outcome in homograft recipients. The type of preexisting valve disease did not influence clinical improvement.

Conclusion: Early and late mortality as well as estimated probability of survival and hemodynamic improvement at 8-year follow-up after aortic valve replacement are independent of the type of implanted valve. Complication rate does not depend upon the type of preexisting valve pathology, but severe late complications are more common after mechanical valve implantation than after homograft implantation.