A comparative study in patients with Omnicarbon and Björk-Shiley heart valve replacement

To compare the Omnicarbon heart valve and the Björk-Shiley spherical valve, operative results, hemodynamic parameters and late results were examined after mitral valve replacement. There were no early deaths, and 6 late deaths in the Omnicarbon valve (2.9% per patient-year). The actuarial survival rate at 6 years was 82.1 +/- 4.8% and freedom from valve-related complications was 86.4 +/- 2.2%. Pressure gradients and effective mitral valve areas at rest calculated by Gorlin's formula were satisfactory in both valve. Cardiac index (l/min/m2) was slightly changed according to the pacer-induced tachycardia, but there was a significant decrease in 160 bpm in the Omnicarbon valve (2.01 vs 2.39, p < 0.05). Peak pressure gradients and pressure half time by Doppler echocardiography, revealed the same trends as those of the Björk-Shiley valve during tachycardiac exercise, though regurgitant flow was detected in 7 patients in 160 bpm in the Omnicarbon valve, while in 2 in the Björk-Shiley valve (28% vs 10%, p = ns). Phonocardiographic study demonstrated that aortic closure to mitral opening click (AC-OpC) interval and Q wave of the electrocardiogram to mitral closing click (Q-CC) interval, which were related to the mitral valve gradients, fell within the normal range in both valves. However, the Björk-Shiley valve compared favorable to the Omnicarbon valve in the AC-OpC interval (70.9 msec vs 76.8 msec, p < 0.05). Hemolysis was of no clinical importance in the intact function of the Omnicarbon valve.(ABSTRACT TRUNCATED AT 250 WORDS)