MRI as a Predictor of Outcomes in Patients Undergoing Mitral Valve Surgery

Mitral regurgitation is a common disease which can lead to heart failure and death if left untreated. The only known therapy for mitral regurgitation is correction of the mitral valve, most commonly performed by surgical repair or replacement. According the STS database, there were 15,748 lone mitral valve surgeries in 2014. The number of mitral valve surgeries has been increasing with a 23% increase between the years 2010 and 2014. Based on the ACC/AHA guidelines for the management of mitral valve disease, quantifying the severity of mitral regurgitation is central to determining which patients are appropriate for correction of their mitral valve by surgery. Specifically, once the diagnosis of severe MR is made, patients are considered appropriate for mitral valve surgery in almost all clinical circumstances. However, there is a significant mortality and morbidity associated with mitral valve surgery. In the STS database, 30 day mortality was \~2% for repair and \~5% for replacement. This data does not take into account long-term mortality and morbidity from re-operation and life-long anti-coagulation as well as changes in quality of life. The most common diagnostic tool to assess the severity of MR is echocardiography. Several studies have shown that echocardiography parameters used to quantify and qualify MR have high inter-observer and intra-observer variability, calling the accuracy of these parameters into question. Furthermore, studies have shown that there is a significant degree of discordance between echocardiography and MRI when assessing MR, particularly among patients referred for mitral valve surgery. In a recent study, quantification of mitral regurgitant volume MRI was found to be more accurate than echocardiography in patients who underwent mitral valve surgery. All 38 patients who underwent mitral valve surgery in this study were deemed appropriate according the ACC/AHA guidelines based on echocardiographic findings. However, more than 2/3rds of patients who underwent mitral valve surgery in this study did not have severe MR by MRI. Thus, we propose this prospective multicenter trial to assess: 1) the severity of MR by MRI in patients undergoing mitral valve surgery. 2) the impact of mitral valve surgery on quality of life and healthcare costs in the context of MR severity by MRI, 3) assess patient outcomes post surgery in the context of MR severity by MRI and 4) the likelihood of valve replacement vs. repair according to MR severity by MRI.