EMBOLIC BRAIN INFARCTION IN NONRHEUMATIC ATRIAL-FIBRILLATION - A CLINICOPATHOLOGICAL STUDY IN THE ELDERLY

Although CT studies have addressed symptomatic and asymptomatic cerebr al infarctions in nonrheumatic atrial fibrillation (NRAF), pathologic verification of the results is lacking. The purpose of this study was to assess the frequency, location, and extent of symptomatic and asymp tomatic brain infarction in autopsy specimens from elderly patients wi th NRAF. We examined autopsy specimens from 136 consecutive NRAF patie nts 70 years of age or older who received no anticoagulant therapy dur ing their lifetime and compared them with 231 age-matched control subj ects with similar health histories except for the absence of NRAF. Sym ptomatic cerebral infarctions were present in 82 (60.3%) NRAF patients and in 55 (23.8%) control subjects (p < 0.0001). Of symptomatic cereb ral infarctions, cardioembolic infarction was present in 53 (64.6%) NR AF patients and in two (3.6%) of the control subjects (p < 0.0001), at herothrombotic infarction in 13 (15.9%) NRAF patients versus 36 (65.5% ) control subjects (p < 0.0001), and lacunar infarction in four (4.9%) NRAF patients versus 12 (21.8%) control subjects (p < 0.01). Stroke-r elated death occurred in 34 (25.0%) NRAF patients and in 18 (7.8%) con trol subjects (p < 0.0002). Symptomatic cerebral infarction was genera lly accompanied by asymptomatic infarctions in both NRAF patients and control subjects. Asymptomatic cortical infarctions were more common i n NRAF patients, but asymptomatic infarctions in the white matter or d eep structures were more common in control subjects. In this autopsy s eries of individuals over 70 years of age, symptomatic brain infarctio n was 2.5 times more common in NRAF patients than in NRAF-free control subjects; two-thirds of the infarctions in the NRAF cases were judged to be cardioembolic in origin. Most asymptomatic cerebral infarctions in the NRAF patients were located in the cortices.