Coronary artery bypass grafting (CABG) alone in moderate ischemic mitral regurgitation: is CABG really enough?

The randomized study described by Michler and co-authors recently appeared in NEJM reports the results of the 2-year outcomes of surgical treatment of moderate ischemic mitral regurgitation (IMR) (1). This paper nourishes and expands the discussion about functional or “secondary” mitral regurgitation occurring as a consequence of an active reversible ischemia or a complete infarction and reopens the debate arisen in the previous study of the Cardiothoracic Surgical Trials Network (CTSN) about the optimal treatment of IMR. Advances in the management of cardiovascular risk factors and acute coronary syndromes permit to effectively identify around 1.6 to 2.8 million patients in the United States suffering by functional IMR after a heart attack; about 10% of these patients suffer from an IMR of moderate entity. Despite the increase in the immediate survival, the lack of an optimized surgical treatment is responsible for a high rate of IMR recurrence (2) after surgery, transforming this pathological phenomenon into a chronic disease, with enormous societal implications