Recurrence and survival after first-ever stroke in the area of Bajo Aragon, Spain. A prospective cohort study

Abstract

Objective: There have been no prospective studies in Spain focused on stroke recurrence. The purpose of this work is to estimate the risk of stroke recurrence and mortality in the community of Bajo Aragón, Spain and to compare it with previous studies conducted in other countries.

Methods: A cohort of 425 patients with first ever stroke was followed-up for a mean period of 4 years (range: 20-78 months). The mean age was 75.4 years. The survival function for recurrence and mortality was analysed by means of the actuarial method. Survival comparisons were made for the different vascular risk factors with the Kaplan-Meier method. The risk of recurrence and death was adjusted for relevant variables with the Cox proportional hazards model. We also made a separate analysis by stroke subtypes.

Results: At the end of the follow-up we found an overall mortality of 38% (163/425) with 69 patients dying in hospital, and an overall recurrence rate of 17.6% (63/356). The cumulative risk of recurrence was 2.1% at 30 days, 9.5% at 1 year and 26% at 5 years. The cumulative risk of mortality was 16% at 30 days, 30% at 1 year and 48% at 5 years. Only age (Hazard Ratio: 1.05, 95% CI: 1.02-1.08) and the addition of risk factors (Hazard Ratio: 1.32, 95% CI: 1.12-1.57) were significant predictors of recurrence. In general, none of the risk factors individually predicted stroke recurrence. The highest risk of recurrence was observed in large-vessel atherothrombotic infarction followed by cardioembolic infarction. In cardioembolic stroke, the association of atrial fibrillation plus either valvular disease or congestive heart failure significantly predicted recurrence of the same type (Relative Risk: 3.1; 95% CI: 2.2-4.4).

Conclusion: The risk of early stroke recurrence in our area was lower than those observed in most studies, so was the risk of long-term mortality. However, the risk of long-term recurrence was similar. Age was the main predictor of death and recurrence. The patients with atrial fibrillation plus another heart disease are at increased risk of recurrent cardioembolic stroke.