Clinical Perspectives
Mitral valve prolapse (MVP) is a common condition in the community and is often encountered by clinicians in
Mitral valve prolapse (MVP) has been reported as a relatively common finding in the general population.1, 2 A recent analysis from the Framingham cohort showed a prevalence of 1% with almost equal sex distribution and familial clustering.1 Patients with relatively nonspecific symptoms such as palpitations and atypical chest pain who are found to have MVP continue to represent a major clinical conundrum for the practicing cardiologist.3
The existing literature continues to generate significant controversy about this condition. Several studies indicate that a subset of patients may suffer adverse outcomes, with sudden cardiac arrest (SCA) potentially the most devastating of these. SCA has been described as one of the possible outcomes on follow-up in MVP,4, 5 and several instances of SCA in young patients with MVP have been reported.6, 7 In addition, the occurrence of ventricular arrhythmias on resting or ambulatory electrocardiograms is reported to be higher in patients with MVP,8, 9 though some studies have challenged this finding.10 Conversely, other natural history studies2, 4 indicate that MVP may have a benign prognosis. Considering the fact that MVP is a common, often incidental diagnosis in the community, the extent to which MVP contributes to excess SCA risk therefore continues to remain unclear. It is conceivable that a rare complication of a relatively common condition may account for a sizable number of events. Thus, it is worthwhile to examine the relevance of MVP vis-à-vis SCA in the general population. Population-based studies looking at the prevalence of MVP among SCA patients are scarce. In the ongoing Oregon Sudden Unexpected Death Study (Oregon-SUDS), we have systematically collected data on SCA in the community over a period of 13 years. We sought to ascertain the frequency of MVP in SCA patients in the general population and characterize the clinical profile of SCA cases with MVP.
Details of case and control ascertainment in the Oregon-SUDS have been published earlier.11, 12 The Oregon-SUDS is an ongoing prospective study of SCA in the Portland, Oregon metropolitan area (population ~1 million) presently in its 14th year. Briefly, multiple source surveillance, which includes first responders (Portland fire department and ambulance service), local hospital emergency departments, and the county medical examiner’s office, is used to track cases of out-of-hospital cardiac
Of 3040 SCA subjects, 729 patients with relevant echocardiograms were analyzed over a 12-year period. The differences between patients with and without echocardiograms are listed in Online Supplemental Table 1. Patients with echocardiograms were more likely to be older and have known cardiovascular risk factors. The mean time between the performance of echocardiography and the SCA event was 654 ± 788 days; 80% of echocardiograms were performed within 3 years before the event. The clinical,
In this community-based study, MVP was observed in 2.3% of SCA patients. SCA patients with MVP were distinguished by younger age and lesser prevalence of cardiovascular risk factors as well as known coronary artery disease. Most MVP patients had associated MR, and the presence of moderate or severe MR was much more likely in patients with MVP.
The prevalence of MVP in our SCA population is similar to the prevalence of 2.4% reported by Freed et al2 in the general population in the Framingham
MVP was present in 2.3% of SCA patients in this population-based study. SCA patients with MVP were younger and less likely to have cardiac or noncardiac disease conditions. Future prospective studies that focus on imaging for valve structure/insufficiency as well as genetic propensity are likely to have the most yield for SCA risk stratification in the MVP patient. Mitral valve prolapse (MVP) is a common condition in the community and is often encountered by clinicians inClinical Perspectives
We acknowledge the significant contribution of American Medical Response, Portland/Gresham fire departments, and the Oregon State Medical Examiner’s office.
An additional study from the same region in Italy utilized a cardiac pathology registry of 650 young adults (≤ 40 years age) with SCD and determined that MVP was the cause of SCD in 43 subjects (26 female from 19 to 40 years of age) representing 7% of the total number of SCDs.38,41 In a population-based Oregon Sudden Death Study (population approximately 1 million), the frequency of cardiac arrest in patients with MVP was determined over a 12-year period; a total of 729 subjects who had an echocardiogram performed prior to cardiac arrest were evaluated.42 MVP was diagnosed by echocardiography in 17 (2.3%) subjects prior to cardiac arrest.
This work was supported in part by the National Heart, Lung, and Blood Institute (grant nos. R01HL105170 and R01HL122492, to Dr Chugh). Dr Chugh holds the Pauline and Harold Price Chair in Cardiac Electrophysiology at the Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA.