Use of Nitroglycerin by Bolus Prevents ICU Admission in Patients with Acute Hypertensive Heart Failure

Objectives: The purpose of this study was to compare healthcare resource utilization among patients who were given intravenous (IV) nitroglycerin for acute heart failure (AHF) in the emergency department (ED) by intermittent bolus, continuous infusion, or a combination of both. Methods: We retrospectively identified 395 patients that received nitroglycerin therapy in the ED for the treatment of AHF over a 5-year period. Patients that received intermittent bolus (n=124) were compared to continuous infusion therapy(n=182) and combination therapy of bolus and infusion(n=89). The primary outcomes were the frequency of intensive care unit (ICU) admission and hospital length of stay (LOS). Results: On unadjusted analysis, rates of ICU admission were significantly lower in the bolus versus infusion and combination groups (48.4% vs. 68.7% vs. 83%, respectively; p<0.0001) and median LOS (IQR) was shorter (3.7 (2.5 to 6.2 days)) compared to infusion (4.7 (2.9 to 7.1 days)) and combination ( 5.0 (2.9, 6.7 days)) groups; p = 0.02. On adjusted regression models, the strong association between bolus nitroglycerin and reduced ICU admission rate remained, and hospital LOS was 1.9 days shorter compared to infusion therapy alone. Use of intubation (bolus 8.9% vs. infusion 8.8% vs. combination 16.9%; p = 0.096) and BiPAP (bolus 26.6% vs. 20.3% infusion vs. combination 29.2%; p=0.21) were similar as was the incidence of hypotension, myocardial injury, and worsening renal function. AC C EP TE D M AN U SC R IP T ACCEPTED MANUSCRIPT 3 Conclusions: In ED patients with AHF, IV nitroglycerin by intermittent bolus was associated with a lower ICU admission rate and a shorter hospital LOS compared to continuous infusion.