Prognostic value of delayed enhancement cardiac magnetic resonance imaging in mitral valve repair

Background. The objective of this study was to examine the prognostic utility of cardiac magnetic resonance imaging (CMR) in patients with chronic mitral regurgitation undergoing mitral valve repair. Methods. This study is a prospectively enrolled observational cohort studyof 48 consecutive patients with chronic mitral regurgitation who had preoperative evaluation with CMRincluding delayed-enhancement CMR for assessment of myocardial fibrosis before undergoing mitral valve repair. Postoperative adverse clinical events were defined as intensive care unit readmission, needs of permanent cardiac pacemaker, and rehospitalization for cardiac reasons. Results. The cohort comprised 33 (69%) men with a mean age of 61 ± 13 years and mean left ventricular ejection fraction of 0.63 ± 0.12. Preoperative myocardial fibrosis was detected in 40% of the patients. Median fibrosis was 4% (interquartile range, 2% to 10%). Mean follow-up duration was 11 months (interquartile range, 1 to 24 months). Adverse clinical events occurred in 16 patients. In multivariate analysis, the presence of myocardial fibrosis was independently associated with postoperative adverse clinical events (hazard ratio, 4.775; 95% confidence interval, 1.100 to 20.729; p = 0.037). The addition of the presence of myocardial fibrosis to the preoperative characteristics model significantly improved overall predictive performance (p = 0.04). Conclusions. The presence of preoperative myocardial fibrosis assessed with delayed-enhancement CMR was an independent predictor of increased adverse clinical outcomes in patients with chronic mitral regurgitation undergoing mitral valve repair. Our findings suggest that in this population, preoperative delayed-enhancement CMR may be of clinical utility.