Effect of the preservation of annulo-papillary continuity on leftventricular ejection fraction after mitral valve replacement. A clinicalrandomized study on patients affected by rheumatic valve disease

This perspective study has been designed to evaluate the modificationsinduced on left ventricular contractility by the interruption of annulo-papillary continuity during mitral valve replacement in patients withrheumatic valve disease. Patients with associated cardiac diseases were notadmitted to the study. Sixty-nine patients entered the trial, each patientwas randomly assigned to mitral valve replacement either with preservationof the annulo-papillary continuity (PAPC) or with excision of all thechordae (EC). Patients with mitral stenosis (MS) and combined mitraldisease (MS & R) were considered separately. The four groups weresimilar regarding preoperative characteristics including the radioisotopicleft ventricular ejection fraction (LVEF). All the patients had the mitralvalve replaced with a bileaflet prosthesis fixed by interrupted mattresssutures in the supra-annular position; the methods of anesthesia,cardiopulmonary bypass and myocardial preservation were similar in allpatients. In the patients of the two EC groups a complete excision of themitral valve was performed. In the patients of the PAPC groups a modifiedMiki's technique was used to preserve annulo-papillary continuity; in eightcases with heavy calcification of the subvalvular apparatus, after totalexcision of the mitral valve, PTFE sutures were used to reconnect theannulus to the papillary muscles. After 6 months' follow-up, 2D and Dopplerechocardiography was completed in each patient to confirm the absence ofany prosthetic leakage and left ventricular outflow tract obstruction.(LVOT).