Clinical and haemodynamic evaluation of mounted porcine heterograft in mitral position.

Abstract

Clinical and hemodynamic assessment was made of 24 patients with porcine heterograft mitral valve replacements. Patients (20) had a good clinical result and were studied electively and 4 patients had persistent symptoms caused either by poor left ventricular function, aortic paraprosthetic regurgitation, mitral paraprosthetic regurgitation or impaired left ventricular function with a rather small mitral valve area of 1.4 cm2. The mean left ventricular end-diastolic pressure was 17.8 .+-. 1.2 mmHg and the mean mitral valve diastolic gradient was 5.9 .+-. 1.0 mmHg. The larger prostheses had the smaller gradients. The average mitral valve area was 3.2 cm2 for 35 mm valves, 2.8 cm2 for 33 mm valves, 2.1 cm2 for 31 mm valves and 2.3 cm2 for 29 mm valves. Two patients showed significant mitral regurgitation on left ventricular cineangiography but in the remainder the valves were competent. An apical diastolic murmur was audible in 9 of 24 patients but there was no correlation between the presence of a murmur and the magnitude of the mitral valve gradient or mitral valve area. Patients (9) with soft apical systolic murmurs had no evidence of mitral regurgitation but 2 patients with louder murmurs had significant regurgitation. Apparently the hemodynamic indices seen with porcine heterograft valves are similar to those observed with other mitral valve prostheses. Though most patients have distinct symptomatic improvement significant hemodynamic abnormalities persist. Apical systolic and diastolic murmurs can be present with normal prosthetic valve function.