Underutilization of IV Nitrates in the Treatment of Acute Heart Failure

Abstract

SUMMARYAcute heart failure (AHF) is a growing public health concern with high inhospital mortality and costs. Clinical practice guidelines, underpinned by positive randomized controlled trials, recommend the early use of intravenous (IV) nitrates in the treatment of AHF. However, the "real-world" usage of IV nitrates has not been clearly defined. The objective of this study was to examine the use of IV nitrates in the treatment of AHF as recommended by clinical practice guidelines. A case-record analysis was conducted of all admissions with AHF at a large teaching hospital. Of the 81 AHF patients (mean age 77 AE 11, mean SBP 130 AE 27 mmHg) enrolled for this analysis, only 5 (6%) received IV nitrates at the time of AHF admission. Forty (49%, mean age 77 AE 11, mean SBP 131 AE 27 mmHg) of these 81 patients met the guideline criteria for suitability for IV nitrates and only 5 (12%) of these received them during this admission. Patients who received IV nitrates were more likely to have higher blood pressure and all had myocardial ischemia as a precipitant. Seventy-five (93%) of the total population received loop diuretics on admission. Overall, this study shows that loop diuretics remain the first-line therapy in AHF with little use of IV nitrates, despite recommendations from clinical practice guidelines.

Temporal trends in nitrate utilization for acute heart failure in elderly emergency patients: A single-centre observational study

“…In the ESC Heart Failure Long-Term Registry [12], Maggioni et al reported that only 20% of patients received intravenous nitrates in accordance with European guidelines. Similarly, a single-centre study carried out by Mohan et al in Scotland [17] showed that among the 49% of patients with AHF and eligible for treatment with nitrates, only 12% actually received them. Finally, in a Canadian study carried out in six EDs, only 29% of AHF patients received nitrates [18].…”

Revisiting nitrates use in pre-shock state of contemporary cardiogenic shock classification

“…Organic nitrates at low doses cause venous dilatation, whereas arteries and coronary arteries dilate at higher doses. By provoking venous and arterial dilation, intravenous nitrates can reduce the increased left ventricular filling pressures and systemic vascular resistance without affecting tissue perfusion ( 23 ), and improve stroke volume and cardiac output ( 24 ). As a result, nitrates provide marked improvement in acute pulmonary edema in which there is rapid deterioration especially in patients who have an acute rise in systemic vascular resistance and left ventricular filling pressures due to decreased baseline diastolic and systolic reserve ( 23 ).…”

“…It has been reported that only 12% of patients who were suitable for intravenous nitrate therapy received it. Those patients were more likely to have hypertension or myocardial ischemia ( 24 ). Another study reported 42% of patients with acute heart failure received nitrates who often had pulmonary edema or hypertension ( 36 ).…”

“…In acute heart failure, there is no consensus on the optimal dosing regimen for nitrate therapy and the published studies have based nitrate dose up-titration on pre-specified blood pressure limits and physician's clinical judgement ( 23 ). Hence, there is inconsistency between the international guidelines recommendations with regards the routine use of nitrates in acute heart failure, which was attributed to the absence of robust evidence ( 24 ). The general approach is to use nitrate therapy when blood pressure is 110 mmHg or above, and to be avoided in symptomatic hypotensive patients ( 23 ).…”

“…Evidence from randomised controlled trials suggested that early administration of intravenous nitrates when combined with loop diuretics may provide improved outcomes. Patients who were not managed effectively in the early phase, i.e., first 6–12 h within presentation, have experienced poor outcomes ( 24 ). However, administration of continuous intravenous nitrate for more than 48 h led to greater attenuation of response compared with two intermittent 12-h infusions.…”