Frequency and predictors for the risk of stroke recurrence up to 10 years after stroke: the South London Stroke Register

Background: Data estimating the risk of, and predictors for, long-term stroke recurrence are lacking. Methods: Data were collected from the population-based South London Stroke Register. Patients were followed up for a maximum of 10 years. Kaplan-Meier estimates and Cox proportional hazards models were used to assess the cumulative risk of and predictors for first stroke recurrence. Variables analysed included sociodemographic factors, stroke subtype (defined as cerebral infarction, intracerebral haemorrhage and subarachnoid haemorrhage), stroke severity markers and prior-to-stroke risk factors. Results: Between 1995 and 2004, 2874 patients with first-ever stroke were included. The mean follow-up period was 2.9 years. During 8311 person-years of follow-up, 303 recurrent events occurred. The cumulative risk of stroke recurrence at 1 year, 5 years and 10 years was 7.1%, 16.2% and 24.5% respectively. No differences in stroke recurrence were noted between the stroke subtypes. Factors increasing the risk of recurrence at 1 year were previous myocardial infarction (HR 1.73; 95% CI 1.08 to 2.78) and atrial fibrillation (HR 1.61; 95% CI 1.04 to 4.27); at 5 years, hypertension (HR 1.47; 95% CI 1.08 to 1.99) and atrial fibrillation (HR 1.79; 95% CI 1.29 to 2.49); and at 10 years, older age (p = 0.04), and hypertension (HR 1.38, 95% CI 1.04 to 1.82), myocardial infarction (HR 1.50, 95% CI 1.06 to 2.11) and atrial fibrillation (HR 1.51, 95% CI 1.09 to 2.09). Conclusions: Very-long-term risk of stroke recurrence is substantial. Different predictors for stroke recurrence were identified throughout the follow-up period. Risk factors prior to initial stroke have a significant role in predicting stroke recurrence up to 10 years.