P199 Mitral Valve Annular Disjunction Prevalence and Significance Amongst Patients with Mitral Valve Prolapse

Mitral valve prolapse (MVP) is a common and usually benign entity. Occasionally, patients with MVP present with mitral annular disjunction (MAD), whose prevalence and clinical significance are still not clearly established. This study aimed to define the prevalence of MAD in a population of patients with MVP and study its echocardiographic and clinical implication. A total of 31 patients with MVP who underwent echocardiographic evaluation in our laboratory were retrospectively evaluated. Echocardiographic, demographic and clinical variables were assessed. Disjunction amplitude (DA) was measured in parasternal long axis view (PLAX) and MAD was considered present if a separation of ≥ 5mm was verified. Annular diameter was measured in PLAX and apical four chamber view (A4C) both in systole and diastole. MAD was identified in 9 patients (29%), having a mean DA of 12.3 ± 3.2 mm. The group of patients with MAD was significantly younger than the group without MAD (mean age of 54 ± 18 vs 67 ± 15 years; p = 0.001), but there were no significant differences regarding gender, height, weight or cardiovascular risk factors. DA was inversely correlated with body surface area (r=-0.8, p = 0.009). Systolic annular diameters in PLAX and A4C views were increased in patients with MAD (4.2 ± 0.6 vs 3.6 ± 0.7 mm, p= 0.04 and 4.8 ± 0.7 vs 4.1 ± 0.7 mm, p = 0.025, respectively). The difference between systolic and diastolic diameters in PLAX was also greater in MAD (0.5 ± 0.2 vs 0.1 ± 0.3 mm, p = 0.007). Posterior wall thickness (8.5 ± 1.1 vs 9.7 ± 1.4 mm, p = 0.035), indexed left ventricular mass (89.0 ± 15.8 vs 110.6 ± 40,2 g/m2, p = 0.04) and ascending aortic dimensions (28.7 ± 6.7 vs 37.4 ± 3.6 mm, p = 0.018) were notably inferior in MAD patients, as was left ventricle ejection fraction (LVEF) (57.5 ± 5.8 vs 62.6 ± 4.9 %, p = 0.0023). No differences were found in chamber volumes. Similarly, eletrocardiographic parameters were identical in both groups. Five patients (56%) in the group with MAD had documentation of events (palpitations, dizziness, syncope or sudden cardiac death), in contrast with just 3 (21%) in the group without MAD, although statistical significance was not achieved (p = 0.078). This study revealed that MAD is common among patients with MVP and is associated with altered annulus dynamics during the cardiac cycle. Its association with younger individuals, lower LVEF and, apparently, more clinical events highlight the importance of this entity.