Cryptogenic mechanism in ischaemic stroke patients is a predictor of 5-year survival: A population-based study

The present study sought to identify factors affecting mortality beyond 28 days in ischaemic stroke patients with whatever ischaemic mechanism.

A prospective population-based registry was set up in Brest County, Brittany, France. Demographic data, clinical presentation, vascular risk factors and mortality were collected from January 2008 to December 2012. At "home without help" was used as a surrogate marker for low Rankin (0-1) at discharge from the hospital. IS was classified on the TOAST classification. Overall mortality was calculated using the Kaplan-Meier method. Multivariate analysis of mortality beyond 28 days was implemented, using a Cox model, on significant risk factors identified on univariate analysis.

About 3024 IS cases were followed up beyond 28 days. Overall mortality beyond 28 days was 38.49% at 60 months. On multivariate analysis, age (10 years: HR = 1.84; [1.66-2.02]), coronary artery disease (HR = 1.28; [1.05-1.56]), cardiac arrhythmia (HR = 1.36; [1.11-1.67]), peripheral artery disease (HR = 1.66 [1.29-2.13]) and incomplete assessment (HR = 1.39; [1.12-1.74]) were associated with higher mortality risk, whereas female gender (HR = 0.80; [0.68-0.94]), high Glasgow Coma Scale score (GCS > 12) (HR = 0.58; [0.45-0.76]), lacunar syndrome (HR = 0.82; [0.68-0.99], being 'at home without help' (HR = 0.50; [0.41-0.59]) and negative assessment (HR = 0.75; [0.58-0.97], compared to cardioembolism) were associated with better survival probability.

Initial clinical status, prior cardiovascular diseases and age was associated with more risk of death: an increment of 10 years almost doubled mortality. Women had more survival probability than men, controlling for age. Ischaemic stroke mechanisms were predictors of late 5-year mortality.

Patients with negative assessment, i.e. representing truly cryptogenic ischaemic stroke, had the best survival probability probably due to fewer atherosclerotic markers.