Abstract 232: Parenteral Antihypertensive Use on the First Day of Hospitalization after Acute Ischemic Stroke: A US Population Study

Abstract

Introduction: Elevated blood pressure (BP) is associated with increased risk of neurologic decline and poor outcome in acute ischemic stroke (AIS). The American Stroke Association (ASA) recommends antihypertensive (AH) therapy if BP is >220/120 mmHg, with a goal of 15-25% reduction in the first 24 hours. In thrombolytic candidates, BP should be maintained ≤185/110 mmHg for 24 hours after rt-PA. Labetalol and nicardipine are the recommended parenteral (IV) agents. We sought to characterize the use of IV AHs in the first 24 hours after AIS admission, stratified by treatment with rt-PA. Methods: This analysis utilized the Premier database, a representative sampling of US hospitals that includes approximately 20% of hospital discharges with pharmacy data, years 2006-2011. Patients with primary or admitting diagnosis of AIS (ICD-9 codes 433.x1, 434.x1, and 436) were included. Patients with age<18 or unknown gender were excluded. Pharmacy records were queried for IV AH and thrombolytic medication use (alteplase, 50 or 100mg vials). Results: There were 413,110 AIS patient discharges included in the analysis, with 64.3% white, 53.0% female, median age of 73 (range 18-89), and 2.8% receiving rt-PA. Of these, 62,438 (16.3%) received IV AH medications on Day 1. The most common AHs used were labetalol (47.1%), metoprolol (17.5%), hydralazine (16.1%), enalapril (12.9%), and diltiazem (11.7%). Nicardipine was used less frequently (11.8%). Patients treated with rt-PA were more likely to receive AHs than patients not treated (40.9 vs 15.6%, p<0.001). The rate of AH use increased from 14.5% in 2006 to 17.1% in 2011 (p<0.001); this rate increase was seen in non-rt-PA patients (14.1 to 16.2%, p<0.001), but not in rt-PA patients (figure). Conclusion: Approximately 16% of AIS patients receive IV AH medication in the first 24 hours of admission in the US. The rate of early AH treatment has increased over time both overall and among those who did not receive rt-PA. Whether this is due to increasingly aggressive BP treatment by physicians or higher BP on admission among AIS patients is unclear. Contrary to recommendations, nicardipine was used infrequently. More evidence is required to justify specific AH agents for BP treatment in AIS.