Ischaemic Mitral Regurgitation and the Role of Surgical Intervention

The correct management of ischaemic mitral regurgitation (IMR) in patients presenting for coronary artery bypass grafting (CABG) remains contentious. Although it is generally agreed that severe MR in patients presenting for CABG should be corrected and that mild MR can be left alone, there is no consensus as to the correct treatment for those patients with moderate MR undergoing CABG. Further, there has never been a prospective randomised trial looking at this issue. The data from retrospective reviews is conflicting. The available evidence clearly shows an increase in cardiac morbidity in those patients undergoing revascularisation who are left with significant MR. However, those retrospective studies comparing patients who have a mitral valve procedure with their CABG to those who undergo CABG alone have not consistently shown a benefit. This may be due to the retrospective nature of these reports. But it may also be due to the type of repairs being performed which may not be adequately addressing the specific pathology involved. The aim of this paper therefore is to evaluate the available evidence to help guide decision making in the treatment of ischaemic MR. The underlying pathophysiology of this condition is outlined and the various types of repair being advocated are reviewed. Although there is no clear answer to the question of optimal management of IMR at present, what is clear is that a prospective trial is urgently needed to guide us with the treatment of this clinical problem.