Aspirin for acute stroke of unknown etiology in resource-limited settings: a decision analysis

To analyze the potential impact of aspirin on outcome at hospital discharge after acute stroke in resource-limited settings without access to neuroimaging to distinguish ischemic stroke from intracerebral hemorrhage (ICH).

A decision analysis was conducted to evaluate aspirin use in all patients with acute stroke of unknown type for the duration of initial hospitalization. Data were obtained from the International Stroke Trial and Chinese Acute Stroke Trial. Predicted in-hospital mortality and stroke recurrence risk were determined across the worldwide reported range of the proportion of strokes caused by ICH. Sensitivity analyses were performed on aspirin-associated relative risks in patients with ICH.

At the highest reported proportion of strokes due to ICH from a large epidemiologic study (34% in sub-Saharan Africa), aspirin initiation after acute stroke of undetermined etiology is predicted to reduce in-hospital mortality (from 85/1,000 without treatment to 81/1,000 with treatment), in-hospital stroke recurrence (58/1,000 to 50/1,000), and combined risk of in-hospital mortality or stroke recurrence (127/1,000 to 114/1,000). Benefits of aspirin therapy remained in sensitivity analyses across a range of plausible parameter estimates for relative risks associated with aspirin initiation after ICH.

Aspirin treatment for the period of initial hospitalization after acute stroke of undetermined etiology is predicted to decrease acute stroke-related mortality and in-hospital stroke recurrence even at the highest reported proportion of acute strokes due to ICH. In the absence of clinical trials to test this approach empirically, clinical decisions require patient-specific evaluation of risks and benefits of aspirin in this context.