Surgical management of moderate ischemic mitral valve regurgitation: Where do we stand?

Abstract

Ischemic mitral regurgitation (IMR) represents a common complication after myocardial infarction. The valve is anatomically normal and the incompetence is the result of papillary muscles displacement and annular dilatation, causing leaflets tethering. Functionally the leaflets present a restricted systolic motion due to tethering forces that displaces the coaptation surface toward the left ventricle apex. The patients present poor left ventricular function at the time of surgery and the severity of the mitral regurgitation increases the risk of mortality. Currently there is general agreement to treat surgically severe IMR nevertheless strong evidences for patient with moderate insufficiency remains poor and proper treatment debated. The most effective surgical approach for the treatment of IMR remains debated. Some authors demonstrated that coronary artery bypass graft (CABG) alone is beneficial in patients with IMR. Conversely, in most patients, moderate IMR will persist or worsen after CABG alone which translate in higher long-term mortality as a function of residual mitral regurgitation severity. A probable reason for this unclear surgical management of functional MR is due to the contemporary suboptimal results of reparative techniques. The standard surgical treatment of chronic IMR is CABG associated with undersized annuloplasty using complete ring. Though, the recurrence of mitral regurgitation remains high (> 30%) because of continous left ventricle remodeling. To get better long term results, in the last decade, several subvalvular procedures in adjunct to mitral anuloplasty have been developed. Among them, surgical papillary muscle relocation represents the most appreciated option capable to restore normal left ventricle geometry. In the next future new preoperative predictors of increased mitral regurgitation recurrence are certainly needed to find an individual time period of treatment in each patient with moderate IMR. Key words: Anatomy; Surgery; Cardiology; Valve; Mitral; Echocardiography Core tip: Moderate ischemic mitral regurgitation should always be considered in patients undergoing other cardiac surgery. Restrictive anuloplasty alone fails as valid treatment because often associated with persistence and high recurrence rate of mitral regurgitation due to continuous ventricular remodeling. Probably more aggressive repair procedures addressing the subvalvular mitral apparatus would help to find more durable results for this complex disease. In the next future new preoperative predictors of increased MR recurrence are certainly needed to find an individual time period of treatment in each patients with moderate ischemic mi- MINIREVIEWSSubmit a

Valve repair to avoid prosthetic valve pathology: Mid-term results in mitral valve repair

“…Nevertheless, this procedure results in a recurrence rate of 20 to 30% after two to four years. [16,17] Recent studies have demonstrated the results in favor of the ring annuloplasty in terms of early survival compared to valve replacement; however, no differences were observed between mid-term results in ischemic MR. [18] On the other hand, there is a controversy on whether ring annuloplasty is superior to valve replacement.…”

The Effect of Treatment Strategy of Chronic Ischemic Mitral Regurgitation on Long-Term Outcomes in Coronary Artery Bypass Grafting

“…IMR is an important complication of myocardial infarction and observed in 40% of patients with this condition. Regurgitation is caused by annular dilation and papillary muscle displacement in an anatomically normal valve [ 9 ] .…”

Chronic ischemic mitral valve regurgitation and surgical perspectives

“…There is an agreement among clinicians that severe IMR should be surgically treated, however treatment of moderate IMR is still a matter of debate[ 10 ]. Many changes have occurred in surgical approaches over the past years.…”