Natural History of Asymptomatic Mitral Valve Prolapse in the Community

Abstract

Background-The outcome of mitral valve prolapse (MVP) is controversial, with marked discrepancies in reported complication rates. Methods and Results-We conducted a community study of all Olmsted County, Minn, residents first diagnosed with asymptomatic MVP between 1989 and 1998 (Nϭ833). Diagnosis, motivated by auscultatory findings (nϭ557) or incidental (nϭ276), was always confirmed by echocardiography with the use of current criteria. End points analyzed during 4581 person-years of follow-up were mortality (nϭ96, 19Ϯ2% at 10 years), cardiovascular morbidity (nϭ171), and MVP-related events (nϭ109, 20Ϯ2% at 10 years). The most frequent primary risk factors for cardiovascular mortality were mitral regurgitation from moderate to severe (Pϭ0.002, nϭ131) and, less frequently, ejection fraction Ͻ50% (Pϭ0.003, nϭ31). Secondary risk factors independently predictive of cardiovascular morbidity were slight mitral regurgitation, left atrium Ն40 mm, flail leaflet, atrial fibrillation, and age Ն50 years (all PϽ0.01). Patients with only 0 or 1 secondary risk factor (nϭ430) had excellent outcome, with 10-year mortality of 5Ϯ2% (Pϭ0.17 versus expected), cardiovascular morbidity of 0.5%/y, and MVP-related events of 0.2%/y. Patients with Ն2 secondary risk factors (nϭ250) had mortality similar to expected (Pϭ0.20) but high cardiovascular morbidity (6.2%/y, PϽ0.01) and notable MVP-related events (1.7%/y, PϽ0.01). Patients with primary risk factors (nϭ153) showed excess 10-year mortality (45Ϯ9%, Pϭ0.01 versus expected), high morbidity (18.5%/y, PϽ0.01), and high MVP-related events (15%/y, PϽ0.01). Conclusions-Natural history of asymptomatic MVP in the community is widely heterogeneous and may be severe.Clinical and echocardiographic characteristics allow separation of the majority of patients with excellent prognosis from subsets of patients displaying, during follow-up, high morbidity or even excess mortality as direct a consequence of MVP.

Mitral Valve Prolapse: Current Views and Challenges (Review)

“…[4, 6,15,16]. Physical examination supplemented by two-dimensional echocardiography remains a golden standard of MVP diagnosis [17][18][19].…”

“…Large-scale investigations in Mayo clinic demonstrated clinical heterogenicity of MVP and various prognoses for this pathology [15]. Asymptomatic patients under 50 years of age with a normal left ventricular function have a favorable prognosis even in the presence of heavy mitral regurgitation [15, 64].…”

“…Asymptomatic patients under 50 years of age with a normal left ventricular function have a favorable prognosis even in the presence of heavy mitral regurgitation [15, 64]. Advantages of early surgical correction of the valvular defect compared to a watchful waiting tactics in such patients remain unproved [64][65][66][67].…”

“…Reconsideration of diagnostic criteria for mitral prolapse aggravated the difference in the views on the prevalence of complications in this pathology [30]. In the Framingham study, none of the patients with MVP had a registered heart failure; the rate of atrial fibrillation, cerebral stroke, and syncope appeared to be comparable with the similar sequelae in the individuals without prolapse (1.2, 1.2, 3.6% vs. 1.7, 1.5, 3.0%) [1].Large-scale investigations in Mayo clinic demonstrated clinical heterogenicity of MVP and various prognoses for this pathology [15]. Asymptomatic patients under 50 years of age with a normal left ventricular function have a favorable prognosis even in the presence of heavy mitral regurgitation [15, 64].…”

“…Indications for surgery on the valves in these patients are progression of atrial fibrillation (4% per year) and heart failure (5.7% per year). Elderly age, clinical symptoms or decrease of ejection fraction by less than 60% at the time of establishing the diagnosis are markers of elevated mortality and speak in favor of performing operations on the heart valves [75,76].The Framingham study has demonstrated equal prevalence of MVP in men and women [1], though a community study in Olmsted County (USA) using current echocardiographic criteria showed that this pathology occurs more often in women and at a younger age than in men [15], with complications being revealed less commonly [76]. Investigation in Mayo clinic detected morphofunctional differences of heart structures in men and women with prolapse.…”