OBJECTIVES: Antihypertensive agents (AH) have been shown to reduce the risk of major cardiovascular (CVD) events. However, there is no large scale effectiveness studies which have assessed the relationship between adherence to AH medications and major CVD outcomes in high risk individuals that have suffered an ischemic stroke. The aim of the study was to evaluate the relationship between AH drug adherence and vascular outcomes in a cohort of older patients hospitalized for an ischemic stroke and discharged in the community. METHODS: A cohort of 14,227patients with ischemic stroke was reconstructed from RAMQ and Med-Echo databases. Eligible subjects were 65 years and older and treated with AH agents between 1999 and 2007. A nested case-control design was used to study major CVD outcomes. Every case was matched for age and duration of follow-up. The adherence to AH drugs was measured as the proportion of days’ supply of medication dispensed over a defined period. Conditional logistic regression models were used to estimate the rate ratio of vascular events adjusting for covariables. RESULTS: Mean patient age was 75 years, 54% were male, 23% had diabetes, and 47% had dyslipidemia, 38% had CAD, 6% MI and 14% had atrial fibrillation. Adherence to AH agents ≥80% reduced the risk of vascular events (RR: 0.70; 0.64-0.77) compared to the one of <80%. Male gender, prior CVD, and non adherence to therapies for diabetes and dyslipidemia were risk factors. CONCLUSIONS: Higher adherence to AH therapy is linked with a risk reduction of vascular events among patients with ischemic stroke.