Histopathological Characterization of Mitral Valvular Lesions from Patients with Rheumatic Heart Disease

Mitral valve thickening in acute rheumatic fever as a predictor of late valvar dysfunction

Background

Rheumatic heart disease (RHD) complicating acute rheumatic fever (ARF) remains an important health problem in developing countries. No definitive diagnostic test for ARF exists and the role of Doppler echocardiography (DEC) for long-term prognostic evaluation following ARF is not well established.

Objective

To investigate the prognostic value of DEC in patients with ARF as a predictor of chronic valve dysfunction.

Methods

Prospectively enrolled patients with clinical ARF had a DEC performed soon after diagnosis and repeated at 1, 3, 6 and 12 months and thereafter at every 1–2 years. We defined chronic valve dysfunction by ≥ 3 of the following: increased valve thickening, commissure fusion, subvalvular thickening, reduced leaflet mobility, non-trivial mitral and/or aortic regurgitation. We performed univariate analysis and developed multivariate logistic regression models to identify variables that may influence evolution to RHD. p <0.05 was considered significant.

Results

We evaluated 70(57% men) patients, 10.8±5.6 years-old during the ARF episode and followed for 95±26 months. Chronic valve dysfunction was identified in 36(51.4%) which fulfilled criteria for RHD and 10(27.8%) of them died or underwent valve surgery. Univariate analysis showed that mitral valve thickening and presence of mitral regurgitation at baseline DEC, were associated with RHD(p<0.01). Multivariate logistic regression showed that only mitral valve thickness either as a continuous (Odds-Ratio:5.8;95%CI:1.7–19.7) or as a categorical variable (Odds-Ratio:4.04;95%CI:1.06–15.3) was an independent predictor of chronic valve dysfunction.

Conclusions

Mitral leaflets thickening documented at the time of diagnosis of ARF is a consistent prognostic marker for the subsequent evolution to RHD.