Early and 8 year results of aortic valve replacement: a clinical study of 232 patients.

The study concerns early and late results of aortic valve replacement (AVR) in 232 patients with aortic valve disease, using the Björk-Shiley tilting-disc prosthesis. Of the 232, 27 patients had some evidence of mitral valve disease with valvulotomy having been undertaken in 7 previously, and in 12 at the time of the aortic valve replacement. Patients who underwent simultaneous mitral valve replacement and/or aorta coronary artery bypass grafting are not included in this analysis. To establish predictions of early death and late survival the patients were divided into two groups (A and B), taking 6 pre-operative risk factors into consideration: systolic pressure gradient greater than or equal to 100 mmHg; NYHA class IV; depressed left ventricular function (heart failure); previous valvulotomy of the aortic valve; advanced age (greater than or equal to 70 years) and surgery during the acute stage of bacterial endocarditis. In group A, consisting of 132 patients with no preoperative risk factors, early mortality was 1.5% (2/132). In group B, with 1 or more risk factors, early mortality amounted to 15% (15/100), (P less than 0.01). Subdividing group B into patients with one of the first three risk factors and patients with two or three of these risk factors, mortality was 12% (9/73) and 27% (6/22), respectively. Actuarially determined survival curves showed an 8-year survival rate of 84.2% for patients in group A and 59.6% for patients belonging to group B. Corrected for early mortality, however, the difference in late mortality is not significant. Analysis showed that early mortality was related to myocardial preservation: results for coronary perfusion and cardioplegic arrest were similar, but results were far less good when hypothermic ischaemic arrest was applied. Late results were less favourable in patients who had prior mitral valve disease not requiring mitral valve replacement at the time of AVR, or in those who developed mitral valve disease. The results allow the authors to conclude that AVR is a relatively safe procedure with a low operative mortality and few postoperative complications in patients with no 'risk factors'.