Lack of evidence of an association between mitral-valve prolapse and stroke in young patients

Background Previous studies have reported a high prevalence of mitral-valve prolapse among patients with embolic stroke (28 to 40 percent), especially among young patients (those less than or equal to 45 years old); this find ing has practical implications for prophylaxis. However, diagnostic criteri a for prolapse have changed and are now based on three-dimensional analysis of the shape of the valve; use of the current criteria reduces markedly th e frequency of such a diagnosis and increases its specificity. Previously d escribed complications must therefore be reconsidered. Methods In a case-control study, we reviewed data on 213 consecutive patien ts 45 years of age or younger with documented ischemic stroke or transient ischemic attack between 1985 and 1995; they underwent complete neurologic a nd echocardiographic evaluations. The prevalence of prolapse in these patie nts was compared with that in 263 control subjects without known heart dise ase, who were referred to our institution for assessment of ventricular fun ction before receiving chemotherapy. Results Mitral-valve prolapse was present in 4 of the 213 young patients wi th stroke (1.9 percent), as compared with 7 of the 263 controls (2.7 percen t); prolapse was present in 2 of 71 patients (2.8 percent) with otherwise u nexplained stroke. The crude odds ratio for mitral-valve prolapse among the patients who had strokes, as compared with those who did not have strokes, was 0.70 (95 percent confidence interval, 0.15 to 2.80; P = 0.80); after a djustment for age and sex, the odds ratio was 0.59 (95 percent confidence i nterval, 0.12 to 2.50; P = 0.62). Conclusions Mitral-valve prolapse is considerably less common than previous ly reported among young patients with stroke or transient ischemic attack, including unexplained stroke, and no more common than among controls. Using more specific and currently accepted echocardiographic criteria, therefore , we could not demonstrate an association between the presence of mitral-va lve prolapse and acute ischemic neurologic events in young people. (N Engl J Med 1999;341:8-13.) (C)1999, Massachusetts Medical Society.