Abstract
BACKGROUND: Secondary prevention studies for cardioembolic strokes show a remarkable variability in stroke recurrence rates. Various reports have raised questions regarding differences in baseline clinical characteristics and in methodology to explain this wide variability. HYPOTHESIS: The purpose of the present study is to examine the 2-year outcome after first cardioembolic stroke of atrial origin and to correlate secondary prognosis with left atrial and left atrial appendage dysfunction. METHODS: Baseline evaluation included computed tomographic and/or magnetic resonance scanning, Doppler scanning, digital subtraction angiography, and transthoracic and transesophageal echocardiography to establish the diagnosis of atrial source of emboli. Twenty-six patients in nonrheumatic atrial fibrillation and 13 in sinus rhythm were followed for recurrent stroke and vascular death as endpoints (event +/-). RESULTS: Patients in sinus rhythm had a total of 23% (standard deviation +/- 12%) recurrence rate. All event (+) patients were on aspirin and died from this second cardioembolic stroke. Of patients in nonrheumatic atrial fibrillation, 50% were event (+) at the end of the first year (death rate 46%). Patients on warfarin therapy had 20% recurrence rate versus 70% on aspirin (relative risk 0, 18, 95% confidence interval, 0.05-0.48, p 0.041). Inward peak velocity of left atrial appendage was the only echocardiographic variable significantly reduced in event (+) patients (21 +/- 7 vs. 31 +/- 17 cm/s, p 0.048). CONCLUSIONS: Patients with nonrheumatic atrial fibrillation and first atrial origin cardioembolic stroke are at increased risk for recurrence if severe dysfunction of the left atrial appendage is present and if they do not receive warfarin treatment. Patients with sinus rhythm and first atrial origin cardioembolic stroke form a small stroke subgroup, in which recurrences are accompanied by a remarkably high death rate.