Mitral valve prolapse - morphology and clinical phenotype in the wide-age spectrum of mitral valve prolapse population

Introduction Mitral valve prolapse (MVP) is a structural valve defect and a ventricular arrhythmia substrate, its clinical significance my differ in the wide-age spectrum population. Purpose To obtain data on the morphology, clinical phenotype of MVP in the wide-age spectrum MVP population and compare pediatric and adult age-divided subgroups. Methods 544 patients with MVP (mean age 42.5 years, females: 326/59.7%) were enrolled into the prospective observational registry MITPROL AR-PL of the Polish Cardiac Society. There were 90/16.5% pediatric (≤18 yrs. mean age 13.5 yrs., females 59/65.0%) patients and 454/83.5% adults (>18 yrs. mean age 53.7 yrs., females 267/58.8%) including young adults (19-45 yrs., 170/31.3%), middle-aged (46-59 yrs., 84/15.4%), and elderly (60+ yrs., 200/36.8%). The analysis included demographics, clinical symptoms, 12-lead ECG, 24-hour Holter ECG, transthoracic and transesophageal echocardiography. The MVP morphology was defined as Barlow’s disease (BD), Forme Fruste (FF), and Fibroelastic deficiency (FED). Clinical phenotypes of MVP were based on the occurrence of ventricular arrhythmia, comorbidities, and significant mitral regurgitation (MR): arrhythmic MVP (aMVP), non-aMVP and MVP + comorbidities ± significant MR (MVP C±MR). Results In the general population BD was present in 169 (31.1%), FF in 326 (59.9%), and FED in 49 (9.0%) patients; bileaflet prolapse occurred in 273 (50.2%), anterior leaflet in 87 (16.0%), and posterior leaflet prolapse in 184 (33.8%). Distribution of MVP morphology differed regarding the age with BD diagnosed more and FF diagnosed less in young adults (40.0%, 52.3%) and middle-aged population (33.3%, 52.4%) vs. the pediatric patients (27.8%, p<0.001; 67.8%, p<0.001). Bileaflet prolapse was observed more in the pediatric group (80%) vs. the young adults (58.2%), middle-aged (53.6%) and elderly (28.5%, p<0.001 for all). Curling, Pickelhaube sign and MAD were found in most pediatric subjects (73.3%, 54.4%, 92.2%) and were less frequent in the adult groups (young adults: 47.7%, 31.8%, 64.7%; middle-aged: 44.1%, 27.4%, 48.8%; elderly: 23%, 11.6%, 29.5 %). The aMVP was diagnosed in 7.8% of pediatric and in 20% of young-adults population (p<0.05); in 14.3% in middle-age and 7.5% in elderly subjects. Percentage of non-aMVP was 92.2% of pediatric patients and lower in young-adults (65.3%, p<0.001) and middle-aged (45.2%, p<0.001). Percentage of MVP C±MR was increasing with age: 0% in pediatric, 14.7% in young-adult, 40.4% in middle-age and 59.5% in elderly patients (p<0.001). Conclusion The MVP is a primary, heterogenous disease affecting the general population with predominance of FF morphology, bileaflet prolapse and age-dependent MVP clinical phenotype. Potent proarrhythmic markers: bileaflet prolapse, curling, Pickelhaube sign and MAD are observed more frequently in pediatric population with the highest percentage of aMVP in young adults. Long-term follow-up is required.