Kuyama N, Hamatani Y, Okada A, et al. - Researchers explored the clinical features as well as disease progression in degenerative mitral stenosis (DMS), in comparison with rheumatic mitral stenosis (RMS). Participants were 203 consecutive patients suffering from mitral stenosis (113 with DMS and 90 with RMS) who had echocardiography between January 2014 and December 2017. Significantly older age and higher prevalence of atherosclerotic comorbidities were noted in DMS vs RMS patients. A significant association of atherosclerotic comorbidities as well as of lower initial mean gradient with disease progression was found in DMS patients even following adjustment by age and gender. Overall, findings showed a slow but highly variable disease progression in DMS, similar to that of RMS. There was no correlation between baseline mitral annular calcification (MAC) severity and disease progression in DMS patients, this indicates that follow-up echocardiography is important irrespective of the MAC severity.