CMR predictors of secondary moderate to severe mitral regurgitation and its additive prognostic role in previous myocardial infarction

Background: We aimed to determine predictors and the additive prognostic role of moderate to severe (MS) ischemic mitral regurgitation (MR) in myocardial infarction (MI). Methods: Four hundred twenty-two patients with previous MI underwent cardiac magnetic resonance (CMR) imaging for the assessment of left ventricular (LV) ejection fraction (EF), end-diastolic (EDV) and end-systolic volume (ESV), sphericity index, wall motion score index (WMSI), and late gadolinium enhancement (LGE). Echocardiography was performed to assess MR. Results: Thirty-eight had from moderate to severe MR (MS-MR group) and 384 did not (No MS-MR group). The S-MR group had higher LV volumes, sphericity index, WMSI, and LGE extent, and lower LVEF. At univariate logistic regression analysis, dilated volumes, SI >0.43, dyskinesia of inferolateral wall, papillary muscle (PM)-LGE, and LGE extent >16% were associated with MS-MR. At multivariate analysis, only SI (OR=5.7) and PM-LGE (OR=3) were independently associated with MS-MR. Considering only patients without LV dilatation, only dyskinesia in the inferolateral wall was a predictor of MS-MR (OR 34.8). Thirty cardiac events (cardiac death, appropriate implantable cardioverter-defibrillator firing, and resuscitated cardiac arrest) occurred during a median follow-up of 1,276 days. After adjusting the prognostic variables at univariate analysis by age (>65 years) and selecting those that were significant (EDV > 95 ml/m2, ESV >53 ml/m2, EF <30%, WMSI >1.65, LGE >12%, S-MR), only WMSI >1.65 and MS-MR remained an independent predictor of cardiac events. Conclusions: Increased WMSI and PM-LGE in the overall population and inferolateral dyskinesia in patients without ESV dilatation are predictors of MS-MR; MS-MR and elevated WMSI have independent negative prognostic value.