Degenerative or rheumatic: after all, what is the most prevalent etiology of mitral regurgitation in developing countries?

Abstract

Abstract Introduction Mitral regurgitation (MR) is the most prevalent valve disease in Europe, mostly degenerative. In Brazil, on the other hand, there are few recent epidemiological data and previous studies show a higher prevalence of rheumatic disease. However, a change in the epidemiological profile of valve disease has recently been observed, largely due to the increase in life expectancy and decrease in the incidence of rheumatic fever. This study aims to evaluate patients with MR in a tertiary hospital in Brazil, emphasizing the etiological analysis. Methods Patients with moderate or severe MR on echocardiogram performed between 07/01/2018 and 06/30/2020 in a Brazilian Cardiology hospital were retrospectively evaluated, including 2,017 cases. Clinical data (age, sex, symptoms and comorbidities) were analyzed, in addition to complementary tests, such as electrocardiogram and echocardiogram. Results A total of 2,017 cases were included, of which 1,966 (97.5%) had severe MR. The mean age was 65 years and 52% were female. In this cohort, 924 patients (45.8%) had primary MR, while 1093 (54.2%) had secondary causes. Among the primary etiologies (N=1093), degenerative was the most prevalent, responding to 51.3% (n=474), followed by rheumatic disease, present in 34.5% of the patients (n=319). The other primary etiologies observed were calcific (94 patients = 4.7%), infective endocarditis (15 patients = 0.7%) and congenital (10 patients = 0.5%). In the comparative analysis between degenerative and rheumatic MR, a statistically significant difference was observed in age and gender. Patients diagnosed with rheumatic MR were younger - mean age: 58 years (standard deviation 49-68) compared to 67 years in patients with degenerative mitral disease (standard deviation 58-76 years). Most patients with rheumatic disease were female (N=255, 79.9%), with percentages almost twice as high as those observed in degenerative MR (N=192 - 40.5%). Secondary causes (N=1,093) were composed of dilated etiology in 859 patients (78.6%), ischemic (140 patients - 12.8%) and atrial functional (55 patients - 5%). Conclusion In agreement with the current epidemiological change in valvular heart disease, we could also observe an important change in the etiology of MR in Brazil, with a reduction in the burden of rheumatic disease and greater expressiveness of mitral prolapse.