Effectiveness of statins on outcomes of patients with Embolic Stroke of Undetermined Source (ESUS).

Background: Statins are highly recommended as a secondary prevention strategy after a stroke. Embolic Stroke of Undetermined Source (ESUS) accounts for up to one fifth of cases of ischemic stroke. There is a lack of studies investigating the effectiveness of statins in this subgroup of patients.

Methods: We designed a longitudinal cohort study involving patients properly diagnosed with ESUS. Data about statin therapy included information about the time of initiation of the treatment, pre-stroke statin use, statin withdrawal, and the type and dosage of the statin prescribed. Patients were followed for 48 months after the index stroke. The primary endpoints included stroke recurrence, major cardiovascular events, and death from all causes. The secondary endpoint was the functional outcome, assessed in a standardized and systematic way using the modified Rankin Scale (mRS).

Results: Patients who were not taking any statin after ESUS have significantly increased odds of stroke recurrence (OR = 3.29, 95% CI 1.27 - 8.55) or presenting the composite outcome of stroke recurrence, major cardiovascular events, and death (OR = 3.70, 95% CI 1.44 - 9.50) in the multivariate analysis. No statin therapy was directly associated with the functional outcome as well (OR = 3.32, 95% CI = 1.58 - 6.96). The early initiation of the statin therapy was estimated to reduce the risk of a second stroke and the composite outcome by 89% and 87%.

Conclusions: Our pioneering study provides evidence that patients with ESUS may benefit from statin therapy, especially if prescribed early and at higher dosages.