Comparative study of Björk-Shiley and Starr-Edwards prostheses for aortic valve replacement

Thirty-nine patients received aortic valve replacement prostheses. The 19 patients who received Starr-Edwards (SE) caged-ball valve prostheses and the 20 patients who received Björk-Shiley (BS) tilting-disc valve prostheses were followed up for a mean period of 20 and 19 mo, respectively. The cumulative mortality rate was 5.3% in the SE group and 15% in the BS group. The clinical improvement was more remarkable in the BS than in the SE series. Major thromboembolic complications developed in three patients in each group, and two patients in each group developed infectious endocarditis. Tests for intravascular hemolysis indicated a higher rate in the SE than in the BS group. The serum haptoglobin levels were 39 +/- 22 and 102 +/- 63 g/dl (mean +/- SD), respectively (P less than 0.001). The hemoglobin level was 12.4 +/- 1.8 g/dl in the SE group and 13.4 +/- 0.6 g/dl in the BS group (P less than 0.03). The BS tilting-disc valve caused less hemolysis and the smaller size led to greater clinical improvement.