Ischemic stroke on awakening: patients' characteristics, outcomes and potential for reperfusion therapy

Abstract

Background: Reports on differences between patients with and without wake-up stroke are inconsistent. We studied the proportion, characteristics, and outcomes of wake-up ischemic stroke (IS) and estimated the number of potential candidates for reperfusion therapy in a national registry of hospitalized patients.

Methods: IS patients in all three National Acute Stroke ISraeli (NASIS) registry periods (2004, 2007, and 2010; 2 months each) were included. In-hospital neurological complications, poor functional outcome (death, modified Rankin scale ≥ 2, or discharge to a nursing home), and in-hospital mortality were the study outcomes. Risks of poor outcomes were estimated with logistic regression analysis.

Results: Wake-up IS was reported for 820/4,408 (18.6%) patients. Baseline characteristics were similar for patients with and without wake-up IS. ORs (95% CIs) for wake-up compared to non-wake-up IS were 1.2 (0.9-1.6) for neurological complications, 0.8 (0.7-0.98) for poor functional outcome, and 0.8 (0.5-1.2) for death. According to an estimated 20-40% prevalence of penumbra, wake-up stroke patients could add 3.7-7.4% to the number of patients potentially eligible for reperfusion therapy.

Conclusions: Stroke on awakening is present in almost one fifth of IS patients. Characteristics and stroke outcomes are similar for patients with and without wake-up IS. Confirmation of a valid approach for the detection of wake-up stroke patients who can potentially benefit from reperfusion therapy is essential.