Results of mechanical prosthetic valve replacement in active valvular endocarditis

To evaluate the results of mechanical prosthetic valve replacement for active endocarditis 71 patients were reviewed. They were treated surgically between 1988 and 1993 in our institution. Mechanical valves were used in 54 patients (group 1) and bioprosthetic valves were used in 17 patients (group 2). In terms of demographic, clinical and surgical variables prior to operation groups were statistically the same. Follow up ranged from 2-63 months averaged 21 months. This study was carried out to: asses cardiac status postoperatively and assess the rate of mortality, recurrency and reoperations.

Evaluation of cardiac status was assessed on the basis of symptoms and findings by examination, ECG, X-ray, echocardiography, and laboratory tests. Data analysis was done by means of statistical tests like: Student's "t"-test, Fisher exact test, one sided test of difference between two percentages, Kaplan Meyer survival analysis and Cox test.

4-year mortality was 20% in group 1 comparing to 28,6% in group 2, when early mortality were 13% in group 1 comparing to 17% in group 2. These differences were not significant. The recurrency rate was 8,5% in group 1 comparing to 28,6% in group 2 which was statistically significant (p=0.028). Especially early recurrency rates differed significantly between groups and were 4,2% in group 1 comparing to 21% in group 2 (p=0.022). The reoperations rate was 4,2% in group 1 comparing to 21% in group 2 which was statistically significant (p=0.022). Clinical status showed satisfactory values and significant improvement in both groups, slightly better after mechanical valve replacement.

It is concluded that mechanical valve is recommended for valve replacement in active valvular endocarditis first of all due to low recurrency and reoperation rate.