Background: Mitral annulus Calcification (MAC) is relatively common in mitral valve prolapse (MVP) population (≈20%). It is presumably the result of dystrophic calcification at sites of annular trauma secondary to excess tension exerted by the redundant hypermobile leaflets. Calcium extending beneath the leaflets might bring to their elevation, cause secondary traction on the chords, and predispose chordal rupture. We hypothesize that MAC in MVP may increase the risk of transformation into flail. Thus, we aim first to study the association between MAC and flail mitral valve in a population of patients with degenerative mitral valve disease (DMVD).
Methods: The study included consecutive patients with MVP who underwent echocardiography study between 2003-2012. Patients with prior mitral surgery, and\or current or past history of endocarditis were excluded. For each echocardiography study, the presence of MAC, its severity (severe: calcium thickness ≥5 mm) and the characterization of the DMVD (prolapse vs. flail) were determined. We used stratification methods in order to control for confounders.
Results: The study included1912 patients (60.8% male, mean age 63.8±17.4 years), of whom 1627 (85.5%) had no MAC, 94 (4.9%) had severe MAC and 183 (9.6%) had MAC, lesser than severe. The prevalence of flail mitral leaflet in these groups was 27.1%, 29.5% and 45.7%, respectively (p<0.001). When stratifying the population according to age and gender, the association between MAC and flail mitral leaflet persisted in women aged 60-75years (p=0.002) and in men older than 75 years (p=0.016).
Conclusion: In our cohort of patients with DMDV, severe MAC was significantly associated with flail valve and particularly in women aged 60-75years and men older than 75 years. The pathogenesis of this association merits further study.
