Mitral Valve Prolapse: Current Views and Challenges (Review)

Abstract

City Clinical Hospital No.30, 85а Beryozovskaya St., Nizhny Novgorod, 603157, Russian Federation Mitral valve prolapse (MVP) is the most common valve abnormality. Many issues relating its diagnosis, epidemiology, prognosis, and genetics have lately been defined more precisely or revised.The most principal changes in MVP diagnosis are connected with establishing a three-dimensional saddle-like shape of the mitral valve annulus, which made mandatory the assessment of the valve condition from the parasternal longitudinal position during ultrasound examination. Implementation of standard diagnostic criteria based on two-dimensional echocardiography, and making the results of the Framingham Heart Study public made it possible to overcome the contradictions relative to the prevalence of this pathology, which appeared to be lower than it had been considered earlier. Age, gender, and ethnic characteristics of MVP occurrence have been established. Notions not only about the incidence of mitral prolapse development but the severity of its sequelae were subjected to reassessment. If previously MVP was thought to be a disease with serious complications, findings of conducted epidemiological studies gave reasons to consider it as a benign pathology with a low probability of unfavorable consequences. Concurrently, factors of unfavorable prognosis were identified, and mitral regurgitation was recognized to be the main of them.The results of molecular genetic investigations enriched essentially notion about MVP and improved its diagnosing. At present, this pathology is believed to be a result of multiple genetic disorders caused by identification of several genes linked with the onset of syndromic prolapse, and three loci for nonsyndromic one. Creation of large-scale registers of MVP patients and conduction of genome-wide studies will enable cardiologists to identify new genes related to the emergence of mitral prolapse and provide screening of asymptomatic patients. The leading role in various mechanisms of MVP pathogenesis is played by the impairment of regulation of transforming growth factor beta (TGF-β), understanding of pathogenetic role of which opens new perspectives of conservative treatment of this pathology with the application of antibodies neutralizing TGF-β, and angiotensin II receptor blockers. Such medical approaches may be rather promising at the early stage of undiagnosed MVP phenotypes, and also serve as an alternative to surgical treatment of clinical complications in patients with a verified diagnosis.Key words: mitral valve prolapse; mitral prolapse diagnosing; MVP epidemiology; prognosis in prolapses; molecular and genetic basics in MVP; mitral regurgitation; transforming growth factor beta.For contacts: Aleksey V. Klemenov, e-mail: klemenov_av@list.ru А.V. KlemenovMitral valve prolapse (MVP) is the most common valve abnormality, which occurs in 2-3% of population [1][2][3][4][5]. This pathology is thought to be the leading cause of isolated mitral insufficiency demanding surgical intervention [3,[6][7...