MITRAL-VALVE STRANDS AND THE RISK OF ISCHEMIC STROKE IN ELDERLY PATIENTS

Background and Purpose Strands are thin and filamentous attachments on the cardiac valves shown by transesophageal echocardiography. Their n ature and their potential for embolization are largely unknown. The ob jective was to estimate the risk of brain infarction in patients with mitral valve strands. Methods Using transesophageal echocardiography, we compared the frequency of strands on native mitral valves in 284 co nsecutive patients admitted with brain infarction and 276 control pati ents, all older than 60 years. In a second part, case subjects were fo llowed up over a 2- to 4-year period, and the risk of recurrence of br ain infarction was estimated in patients with and without strands. Res ults In the case-control study, mitral valve strands were found in 22. 5% of the case patients and in 12.1% of the control subjects. In case subjects, mitral valve strands were more frequent in those with mitral valve dystrophy (52.4% versus 37.4%: P=.03). Strands were not associa ted with mitral valve prolapse, annular calcifications, or left atrial spontaneous echocardiographic contrast. After adjustment for age, ses , and mitral valve dystrophy, the odds ratio for ischemic stroke among patients with mitral strands was 2.2 (95% confidence interval, 1.4 to 3.6; P=.005). The frequency of strands was not different in patients with a known cause of brain infarction (24.4%) from that in patients w ith no other apparent cause (20.9%). During 646 per 100 person-years o f follow-up, the incidence of recurrent brain infarction was 6.0 perso n-years in patients with strands and 4.2 in those without. In the Cox analysis, including potential confounders and poststroke treatment, mi tral valve strands did not appear as independent predictors of recurre nt brain infarction (relative risk, 1.3; 95% confidence interval, 0.5 to 3.0; P=.54). Conclusions The present study shows an independent ass ociation between mitral valve strands and the risk of brain infarction . However, the lock of an increased relative risk of recurrence raises doubts about the potential causal relation with brain infarction in p atients aged 60 years or older.