Ischemic mitral regurgitation (MR) following myocardial infarction is common and presages a doubling in mortality for those with at least mild regurgitation. The disorder reflects disease of the myocardium, rather than an abnormality of the valve itself. Surgical practice guidelines support intervention for severe symptomatic ischemic MR, but evidence is lacking to inform whether valvular repair or replacement is the superior surgical approach.
In this multicenter study, a total of 251 patients with severe ischemic MR were randomized to either mitral valve repair or chordal sparing replacement with concomitant revascularization as required. The primary end-point was the left ventricular end-systolic volume index (LVESVI) at 12 months, a parameter which is closely associated with long term outcomes. At 12 months, there was no significant difference in LVESI between patients treated with repair (54.6±25.0 mL per square meter) and replacement (60.7±31.5 mL per square meter). There was also no difference in mortality (14.3% vs. 17.6%, hazard ratio 0.79; 95% confidence interval, 0.42 to 1.47; P=0.45), major adverse cardiovascular event rates or quality of life indices between the two groups. A significantly higher rate of recurrence of moderate or severe MR was observed among patients treated with repair (32.6% vs. 2.3%, P<0.001).
In the consideration of repair versus replacement for ischemic MR, there has long been a presumed trade-off of lower surgical complication rates with repair balanced against the greater durability of valve replacement. The present study suggests the improved durability of valve replacement may significantly outweigh any potential short-term benefit of repair. Further long-term data on outcomes is awaited.
Summarized by Steven M. Bradley and Hussain Contractor
- Acker MA, Parides MK, Perrault LP, Moskowitz AJ, Gelijns AC, Voisine P, Smith PK, Hung JW, Blackstone EH, Puskas JD, Argenziano M, Gammie JS, Mack M, Ascheim DD, Bagiella E, Moquete EG, Ferguson TB, Horvath KA, Geller NL, Miller MA, Woo YJ, D’Alessandro DA, Ailawadi G, Dagenais F, Gardner TJ, O’Gara PT, Michler RE, Kron IL. Mitral-valve repair versus replacement for severe ischemic mitral regurgitation. N Engl J Med. 2014 Jan 2;370(1):23-32.