Aortic valve replacement with the Starr-Edwards ball-valve prosthesis. Indications and results

The results of aortic valve replacement with the Starr-Edwards prosthesis are reviewed in 86 patients. The total early and late mortality rate was 24 per cent. This fell to 13 per cent in 1964, and can be expected to decline further. Nearly all survivors are greatly improved by surgery. Detailed follow-up of 6 months to 3 years is available in 50 patients. All but one had symptoms prior to operation, and hemodynamic study preoperatively demonstrated gross abnormalities in most. Sixty-six per cent became asymptomatic, whereas mild limitation to exercise persisted in another 40 per cent. Angina pectoris disappeared in 32 of 34 instances. Sixty-eight per cent had a normal or only slightly enlarged heart after operation. Electrocardiographic evidence of left ventricular hypertrophy disappeared in 58 per cent. Postoperative hemodynamic studies usually demonstrated some mild residual hemodynamic abnormality, probably attributable to irreversible myocardial damage resulting from long-standing left ventricular hypertrophy and/or dilatation. Postoperative complications included regurgitation around the prosthesis, which was rarely of hemodynamic consequence, bacterial endocarditis (rare), traumatic hemolytic anemia (rare), and systemic arterial embolization. Thromboembolism remains the major unsolved problem of aortic valve replacement, and anticoagulant drugs have not been proved to be of value in preventing this. Indications for aortic valve replacement are discussed in terms of the current mortality rate and incidence of complications, the proved clinical and hemodynamic benefits, and the natural history of the various types of aortic lesions. All symptomatic patients with aortic stenosis, and all Class III or IV patients with aortic regurgitation are candidates for surgery. In addition, surgery is recommended in relatively asymptomatic patients with aortic stenosis who have a transvalvular peak systolic gradient of more than 70 mm. Hg, and in those with aortic regurgitation if there is gross cardiac enlargement, angina pectoris, or abnormal left heart dynamics. The possibility of underestimating the hemodynamic severity of a mixed aortic valve lesion was discussed.