Beating Heart Mitral Valve Replacement in Secondary Mitral Regurgitation with Poor Left Ventricular Function Literature Review

Abstract

The poor early and mid-term prognosis of secondary mitral regurgitation (MR) with impaired left ventricular function after restrictive annuloplasty with cardioplegic arrest has opened the way for transcatheter repair. The indication for surgery is only incontestable when concomitant coronary revascularization is required. Beating heart mitral valve surgery without aortic clamping has been promoted as an alternative to the technique of cardioplegic arrest. Its potential advantage is the elimination of ischemic reperfusion injury and its impact on myocardial function. On the other hand a randomized study confirmed that for ischemic MR, mitral valve replacement (MVR) reduces the rate of MR recurrence and re-hospitalization compared to restrictive annuloplasty. We performed a review of the literature to assess the strength of the evidence supporting the efficacy of beating heart MVR without aortic clamping compared to the conventional technique for secondary MR with poor left ventricular function. In a randomized study of patients with chronic severe mitral regurgitation and left ventricular dysfunction, beating heart MVR was associated with better LV function, reduction of cardiac enzymes early postoperatively, reduced duration of mechanical ventilation, and ICU than MVR using warm blood cardioplegic arrest. This together with the absence of related perioperative mortality and the major complications suggests that this technique is safe and beneficial to LV function. This finding has been verified by a multitude of other observational studies which have shown that the benefit of this technique is more palpable in cases of redo mitral surgery or in cases of MR with poor left ventricular function.