22 Nitroglycerin for Treatment of Acute, Hypertensive Heart Failure: Bolus, Drip or Both?

Abstract

Study Objectives: Small studies suggest benefit when nitroglycerin is administered as an intravenous bolus using higher doses in patients with hypertensive heart failure but clinical experience is limited. We sought to compare outcomes with differing methods of intravenous nitroglycerin administration in patients with acute hypertensive heart failure. Methods: We performed a retrospective cohort study of patients who presented to the emergency department (ED) of an urban, teaching hospital with severe, acute hypertensive heart failure between Jan 2007 and July 2011 and received intravenous nitroglycerin. 3 subgroups were defined: 1) those given nitroglycerin by higher dose (≥ 0.5 mg) bolus alone (higher dose nitroglycerin); 2) those given nitroglycerin by continuous intravenous infusion alone (intravenous nitroglycerin); and 3) those given nitroglycerin by concurrent higher dose bolus and continuous IV infusion (higher dose intravenous nitroglycerin). Baseline and acute treatment data were compiled along with the following outcome measures: use of bilevel positive airway pressure or endotracheal intubation; intensive care unit [ICU] admission rate; ED, ICU and total hospital length of stay; rate of delayed-onset cardiac injury (ie, 2nd but not 1st troponin positive); inhospital mortality; 30-day heart failure readmission rate; and days out-of-hospital and alive through 30-days post-discharge. Descriptive statistics were applied and comparisons using chi-square, ANOVA or Kruskall-Wallis were performed. Results: Three hundred ninety-five patients (mean [SD] age 58 [15] yrs; 51% male, 88% black) were included: 124 (31%) higher dose nitroglycerin, 182 (46%) intravenous nitroglycerin, and 89 (22%) higher dose/intravenous nitroglycerin. While demographics were generally similar between groups, higher dose nitroglycerin patients were more likely to have a history of heart failure (72% versus 53% for intravenous nitroglycerin and 45% for higher dose intravenous nitroglycerin; p<0.001). At baseline, mean systolic blood pressure was significantly greater (p<0.001) in the higher dose/intravenous nitroglycerin group (Figure) while mean [SD] respiratory rate was lower in the intravenous nitroglycerin group (24[7] bpm versus 27 [11] in the higher dose nitroglycerin and 28 [8] higher dose/IV nitroglycerin groups; p<0.001). Most patients (∼75%) received similar mean [SD] intravenous furosemide dosing (64 [32] mg, 69 [53] mg, and 67 [35] mg in the higher dose nitroglycerin, intravenous nitroglycerin and higher dose/intravenous nitroglycerin groups, respectively; p=NS). Mean [SD] total dose of bolus higher dose nitroglycerin was greater in the higher dose/intravenous nitroglycerin group (3.9 [3.7] versus 2.4 [2.6] mg; p=0.001). No difference was found (Table) among the groups in use of bilevel positive airway pressure or endotracheal intubation, ED or ICU length of stay, rate of delayed cardiac injury, inhospital mortality, or out of hospital and alive. The ICU admission rate and total hospital length of stay however, were significantly lower among higher dose nitroglycerin patients and the 30-day heart failure readmission rate was substantial higher for the intravenous nitroglycerin group.Tabled 1 Conclusion: In this single-center, retrospective, unadjusted analysis of primarily African-American patients with acute hypertensive heart failure, nitroglycerin administered by higher dose bolus without concurrent intravenous infusion was associated with a significant decrease in ICU admissions and hospital length of stay. Based on our findings, bolus higher dose nitroglycerin appears to be a viable option for the management of such patients.