Impact of nitrate use on survival in acute heart failure: A propensity-matched analysis

Abstract

Background-There is limited evidence that the use of nitrates in acute decompensated heart failure early after presentation to a hospital can improve clinical outcomes. We aimed to determine whether early nitrate exposure is associated with improved survival in a large retrospective cohort study. Methods and Results-We examined 11 078 acute decompensated heart failure patients who presented to emergency departments in Ontario, Canada, between 2004 and 2007, in the Enhanced Feedback For Effective Cardiac Treatment and the Emergency Heart failure Mortality Risk Grade studies. In propensity-matched analyses, we examined the effect of nitrate administration in the acute emergency department setting for its impact on death at 7, 30, and 365 days. In propensity-matched analyses, we found no difference in survival between those who received nitrates in the emergency department and the non-nitrate comparator group. Hazard ratios for mortality were 0.76 (95% CI; 0.51, 1.12) over 7 days, 0.97 (95% CI; 0.77, 1.21) over 30 days, and 0.91 (95% CI; 0.82, 1.02) over 1 year of follow-up. There was no significant difference in survival or hospital length of stay between nitrate and non-nitrate controls in extended follow-up. There was also no significant effect of nitrates in subgroups stratified by presence of chest pain, troponin elevation, chronic nitrate use, and known coronary artery disease. Conclusions-In acute decompensated heart failure, use of nitrates acutely in the emergency department setting was not associated with improvement in short-term or near-term survival. Our study does not support generalized use of nitrates when the primary goal of therapy is to reduce mortality.