Beating-heart versus conventional mitral valve replacement; a randomized clinical trial

Background: Various methods have been developed to overcome the deleterious effects of ischemia/ reperfusion injury that occurs after cardioplegic arrest. The aim of the study was to assess the safety, efficacy, and applicability of the beating-heart mitral valve replacement (MVR) compared to the conventional MVR. Methods: Forty patients scheduled for mitral valve replacement were randomly assigned into two groups, conventional MVR as the control group (n= 20) and beating-heart MVR with continuous antegrade coronary perfusion as the study group (n=20). Three patients in the beating-heart group were converted to the conventional technique because of the blood-flooded field and excluded from the analysis. Results: The preoperative clinical and echocardiographic variables were comparable between both groups. There was no significant difference between both groups regarding cardiopulmonary bypass time (79.4± 14 vs. 75.7± 10.9 minutes; p= 0.398) and total operative time (200± 55.6 vs. 183.9± 67.5 min; p= 0.458) in the conventional and beating-heart group, respectively. Serum troponin I level was significantly higher in the conventional MVR group 6 hours postoperatively (4.9±4 vs. 2.7±1.2 ng/ml; p= 0.036), while there was no significant difference between both groups regarding total CK and CK-MB (p= 0.565 & 0.597 respectively).  Eight patients (44%) in the conventional MVR group needed inotropic support compared to 3 patients (19%) in the beating-heart MVR group (P = 0.11). There was no operative mortality or major morbidity in both groups. At 6-months follow-up, there was no difference in NYHA class (1.3±0.3 vs. 1.2±0.3; p= 0.336) and the ejection fraction (60.0±6.3 vs. 63.2±6 %; p= 0.139) in the conventional vs. beating-heart group.  Conclusion: Beating-heart MVR is a safe alternative to the conventional method with comparable outcomes. There is a relatively blood-filled field compared to the conventional technique.