Frequency and Predictors for the Risk of Stroke Recurrence up to 10 years after stroke: The South London Stroke Register

Keerthi Michelle Mohan ^1*, Siobhan Laura Crichton ¹, Andrew Peter Grieve ¹, Anthony George Rudd ², Charles David Alexander Wolfe ¹ and Peter Ulrich Heuschmann ¹

¹ King's College London, United Kingdom
² Guy's and St. Thomas' NHS Foundation Trust, United Kingdom

^* To whom correspondence should be addressed. E-mail: kitty.mohan{at}kcl.ac.uk.

Accepted 24 March 2009

Abstract

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 cumulative risk of and predictors for first stroke recurrence. Variables analysed included socio-demographic 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. 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 1.08-2.78) and atrial fibrillation (HR 1.61; 95% CI 1.04-4.27); at 5 years, hypertension (HR 1.47; 95% CI 1.08-1.99) and atrial fibrillation (HR 1.79; 95% CI 1.29-2.49); and at 10 years, older age (p=0.04), and hypertension (HR 1.38, 95% CI 1.04-1.82), myocardial infarction (HR 1.50, 95% CI 1.06-2.11), and atrial fibrillation (HR 1.51, 95% CI 1.09-2.09).

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.