Embolic brain infarction in nonrheumatic atrial fibrillation: a clinicopathologic study in the elderly

Although CT studies have addressed symptomatic and asymptomatic cerebral 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 asymptomatic brain infarction in autopsy specimens from elderly patients with NRAF. We examined autopsy specimens from 136 consecutive NRAF patients 70 years of age or older who received no anticoagulant therapy during their lifetime and compared them with 231 age-matched control subjects with similar health histories except for the absence of NRAF. Symptomatic cerebral infarctions were present in 82 (60.3%) NRAF patients and in 55 (23.8%) control subjects (p < 0.0001). Of symptomatic cerebral infarctions, cardioembolic infarction was present in 53 (64.6%) NRAF patients and in two (3.6%) of the control subjects (p < 0.0001), atherothrombotic 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-related death occurred in 34 (25.0%) NRAF patients and in 18 (7.8%) control subjects (p < 0.0002). Symptomatic cerebral infarction was generally accompanied by asymptomatic infarctions in both NRAF patients and control subjects. Asymptomatic cortical infarctions were more common in NRAF patients, but asymptomatic infarctions in the white matter or deep structures were more common in control subjects. In this autopsy series of individuals over 70 years of age, symptomatic brain infarction 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.