Mitral valve replacement: long-term results, with particular reference to changes in pulmonary vascular resistance.

The first 16 patients to have mitral valve replacement with the Starr-Edwards prosthesis at St. Bartholomew's Hospital, London, were reviewed from one to three years after operation. These patients had presented with serious mitral valve disease and there was a high incidence of severe dyspnoea and persistent congestive failure before operation. There were four operative deaths, and two survivors had poor results due to regurgitation alongside the prosthesis. The remaining 10 patients showed considerable improvement. Although no diuretics were given after operation there was little dyspnoea and congestive failure resolved. Anticoagulant therapy is given after operation, and there have been few embolic incidents. The pulmonary vascular resistance was raised to between 6 and 11 units before operation in six patients. There was no undue mortality in this group, and post-operative cardiac catheterization showed a considerable fall in resistance and an increase in cardiac output, suggesting resolution of the pulmonary vascular obstruction. Tricuspid incompetence in these patients disappeared post-operatively. We conclude that mitral valve replacement can restore a patient severely disabled by mitral valve disease to a nearly normal life. We do not regard pulmonary hypertension as a contraindication to operation.