Characteristics of Patients That Do Not Initially Respond to Intravenous Antihypertensives in the Emergency Department: Subanalysis of the CLUE Trial
Abstract
Introduction: Hypertensive emergency has a high mortality risk and the treatment goal is to quicklylower blood pressure with intravenous (IV) medications. Characteristics that are associated withnon-response to IV antihypertensives have not been identified. The objective is to identify patientcharacteristics associated with resistance to IV antihypertensives.
Methods: This was a subanalysis of patients enrolled in the previously described comparativeeffectiveness trial of IV nicardipine vs. labetalol use in the emergency department (CLUE) study, arandomized trial of nicardipine vs. labetalol. Non-responders were defined as those patients whodid not achieve target systolic blood pressure (SBP), as set by the treating physician, within thirtyminutes of IV antihypertensive medication, +/- 20mmHg. Stepwise logistic regression was used toidentify covariates associated with the measurement outcomes.
Results: CLUE enrolled 226 patients, 52.7% female, 76.4% black, mean age of 52.6±14.6 years,of whom 110 were treated with nicardipine and 116 with labetalol. The median (IQR) initial systolicblood pressure was 211mmHg (198, 226), 210 (200, 230), and 211mmHg (198,226), for the total,non-responder, and responder cohorts, respectively (p-value=0.65, 95% CI [-5.8-11.3]). Twentyninewere non-responders, 9 in the nicardipine and 20 in the labetalol group. In univariate analysis,several symptoms suggestive of end organ damage were associated with non-response. Aftermultiple variable logistic regression (AUC = 0.72), treatment with labetalol (OR 2.7, 95% CI [1.1-6.7]), history of stroke (OR 5.4, 95% CI [1.6-18.5]), and being male (OR 3.3, 95% CI [1.4-8.1]) wereassociated with failure to achieve target blood pressure.
Conclusion: Male gender and history of previous stroke are associated with difficult to controlblood pressure. [West J Emerg Med. 2015;16(2):276–283.]