Impact of polypharmacy on stroke severity and functional outcome in acute ischemic stroke

Polypharmacy is considered an important and growing challenge for clinical practice, causing negative health outcomes in patients. Our aim was to investigate whether pre-stroke polypharmacy is associated with stroke severity and functional outcomes in acute ischemic stroke (AIS).

We retrospectively reviewed consecutive AIS patients hospitalized within 7 days after onset from October 2012 through May 2020. All patients were divided into two groups based on pre-stroke polypharmacy: 1) polypharmacy (≥5 medications/day); and 2) non-polypharmacy. Stroke severity was defined using the National Institutes of Health Stroke Scale (NIHSS), dichotomized into mild stroke (NIHSS score 0-5) and moderate to severe stroke (NIHSS score 6-42). Poor outcome was defined as a modified Rankin scale (mRS) score of 3-6 at 90 days after onset. Clinical backgrounds were compared between polypharmacy and non-polypharmacy groups. Multivariable regression analysis was then conducted to identify independent factors including polypharmacy and known factors concerning stroke severity and poor outcome.

We consecutively enrolled 1,060 AIS patients (285 women; median age, 67 years). Of these, 407 patients (38 %) showed polypharmacy. Median NIHSS score was 2 (interquartile range, 1-5). Poor functional outcome was seen in 175 patients (16 %). Multivariable regression analysis revealed polypharmacy (odds ratio [OR] 1.57, 95 % confidence interval [CI] 1.02-2.42; P = 0.04), atrial fibrillation (OR 1.95, 95 %CI 1.20-3.18; P < 0.01) and Diffusion-Weighted Imaging-Alberta Stroke Program Early Computed Tomography Score > 7 (OR 0.07, 95 %CI 0.05-0.11; P < 0.01) as factors independent associated with moderate to severe stroke. However, polypharmacy was not associated with poor outcomes.

In AIS patients, pre-stroke polypharmacy is associated with stroke severity but not post-stroke recovery.