Risk of Heart Failure Due to a Combination of Mild Mitral Regurgitation and Impaired Distensibility of the Left Ventricle in Patients with Old Myocardial Infarction

Abstract

Ischemic mitral regurgitation (MR) is a serious complication after myocardial infarction, and the incidence of heart failure (HF) increases as the severity of MR increases. However, little is known about the relationship between mild MR and HF in the patients with old myocardial infarction (OMI) and a normal ejection fraction (EF). We hypothesized that a combination of mild MR and impaired distensibility of the left ventricle may increase the risk of diastolic HF in the patients with OMI and a normal EF. The relationship between HF and mild MR was retrospectively investigated in 62 patients with OMI and EF of > 50% on echocardiography. Of the 62 patients, 47 (76%) did not have HF and 15 (24%) had HF. There was a significant difference in the incidence of mild MR between the patients with and without HF (p < 0.0001): of the 47 patients without HF, mild MR was detected in 19, but all 15 patients with HF had mild MR. However, there were no significant differences in age, gender, infarct sites, diseased coronary vessels, peak CK level, and observation period between the 2 groups. An increased E-wave and the ratio of the E-wave to the A-wave (E/A), a reduction of the E-wave deceleration time, and an increased brain natriuretic peptide (BNP) level were significantly noted in HF patients with mild MR compared with patients without HF. Even a mild MR may cause diastolic HF in patients with impaired distensibility of the left ventricle due to ischemic heart disease.