Prevalence and correlates of mitral regurgitation in the current era: an echocardiography study of a Chinese patient population

OBJECTIVE: Little is known about the prevalence of mitral regurgitation (MR) in China until now. The objective of the study was to survey the prevalence, correlates and causes of MR in a large Chinese patient population in the current era. METHODS: This study retrospectively analysed the echocardiographic database of the subjects visiting our heart centre from 2010 to 2012. RESULTS: A total of 134,874 cases were included into the analysis. Of these cases 42.44%, 1.63%, 1.44% had mild MR(+), moderate MR(2+) and severe MR(3+/4+), respectively. The rate of MR increased with age. The rate of severe MR was 22.14% in subjects with a left ventricular ejection fraction (LVEF) < 30%, 13.0% in subjects with a LVEF of 30-44%, 15.74% in subjects with left ventricular end-systolic diameter (LVSD) of 50-59 mm, and 27.28% in those with LVSD ≥ 60 mm. The aetiology of 1,948 cases of severe MR was as follows: 972 (49.9%) patients had primary causes, of whom 55 had rheumatic heart disease, 96 had infectious endocarditis, 141 had papillary muscle dysfunction and 608 had degenerative disease, and the other 976 patients had secondary MR. CONCLUSION: MR is common in subjects referring to our heart centre in China. Severe MR is frequent in patients with decreased LVEF or an enlarged left ventricle or atrium. Degenerative disease and secondary changes are the most common causes for severe MR.