Intravenous Morphine Is Not Associated with Adverse Outcomes in Acute Coronary Syndrome: a Retrospective Review

Abstract

Traditional teaching has advocated for morphine in the treatment of acute coronary syndrome (ACS); however, recent data has called this into question. Previous data, though, has been riddled with bias. We sought to compare exposure to morphine versus other opioids and its effect on mortality and adverse outcomes in patients with ACS. We conducted a retrospective chart review of patients who presents to our emergency department for ACS and received a cardiac stent. Exposure of interest was receipt of narcotics and type, route, and dose of narcotics received prior to cardiac catheterization. Primary outcome was in-hospital mortality. Secondary outcome was a composite of in-hospital heart failure, hypotension, or dysrhythmia. We included 118 visits from 64 unique patients, of which 19 received morphine, 5 received fentanyl, 7 received oral opioids, and 88 received no opioids. There was no difference in mortality or adverse outcomes between patients receiving IV morphine (4.2%) or IV fentanyl (0%) but there was an increased mortality in patients receiving oral opioids (28.6%) compared to no opioids (4.5%) and an increase adverse outcome in patients receiving IV morphine (68.4%) versus no opioids (36.4%). Our limited-size study demonstrated that receipt of IV morphine is associated with an increased risk of adverse outcomes compared to not receiving opioids; however, there is no significant difference in adverse outcomes comparing morphine to other opioids. Our data adds evidence to the theory that prior reports of morphine-associated adverse outcomes are likely biased and not necessarily related to intrinsic properties of morphine.