Background: Hypertension is a recognized risk factor for ischemic stroke. Recent studies have suggested that patients with acute hypertension on admission for acute ischemic stroke (AIS) have worse outcomes compared to patients who present with blood pressure values within normal range. We sought to determine whether patients who are medicated for chronic hypertension prior to admission have better outcomes following ischemic stroke compared to unmedicated patients.
Methods: Patients who presented to our center with AIS between 07/2008-07/2014 were included if pertinent past medical history and medication status were available at admission. Logistic regression was used to assess differences in baseline, in-hospital, and outcome variables in patients with medicated hypertension (HTN+/M+) and unmedicated hypertension (HTN+/M-) as compared to those with no hypertension (HTN-). The primary outcome measure was poor functional outcome (modified Rankin Scale > 2) on discharge.
Results: A total of 1,401 cases were analyzed; 305 patients (21.8%) in the HTN- group, 200 patients (14.3%) in the HTN+/M- group, and 896 patients (63.9%) in the HTN+/M+ group. After adjustment for age, NIHSS score at baseline, and tPA administration, patients in the HTN- group were significantly less likely to experience poor functional outcome than patients in the HTN+/M+ group (OR=0.63, 95% CI 0.45-0.88, p=0.0031). There was no significant difference in likelihood of poor functional outcome between HTN+/M- and HTN+/M+ patients (OR=0.87, 95% CI 0.64-1.19, p=0.2870).
Conclusions: The absence of hypertension in the setting of AIS is associated with lower odds of poor functional outcome. However, patients who were medicated for hypertension compared to those who had untreated hypertension did not differ in functional outcome following ischemic stroke, suggesting that the presence of hypertension contributes to outcome and this exposure is not completely ameliorated by antihypertensive therapy.