RT Journal Article
SR Electronic
T1 Prehospital opioid dose and myocardial injury in patients with ST elevation myocardial infarction
JF Open Heart
JO Open Heart
FD British Cardiovascular Society
SP e001307
DO 10.1136/openhrt-2020-001307
VO 7
IS 2
A1 Himawan Fernando
A1 Ziad Nehme
A1 Karlheinz Peter
A1 Stephen Bernard
A1 Michael Stephenson
A1 Janet Bray
A1 Peter Cameron
A1 Andris Ellims
A1 Andrew Taylor
A1 David M Kaye
A1 Karen Smith
A1 Dion Stub
A1 ,
YR 2020
UL http://openheart.bmj.com/content/7/2/e001307.abstract
AB Objective To characterise the relationship between opioid dose and myocardial infarct size in patients with ST elevation myocardial infarction (STEMI).Methods Patients given opioid treatment by emergency medical services with confirmed STEMI were included in this secondary, retrospective cohort analysis of the Air versus Oxygen in Myocardial Infarction (AVOID) study. Patients with cardiogenic shock were excluded. The primary endpoint was comparison of cardiac biomarkers as a measure of infarct size based on opioid dose (low ≤8.75 mg, intermediate 8.76–15 mg and high >15 mg of intravenous morphine equivalent dose).Results 422 patients were included in the analysis. There was a significantly higher proportion of patients with Thrombolysis in Myocardial Infarction (TIMI) 0 or 1 flow pre-percutaneous coronary intervention (PCI) (94% vs 81%, p=0.005) and greater use of thrombus aspiration catheters (59% vs 30%, p<0.001) in the high compared with low-dose opioid group. After adjustment for potential confounders, every 1 mg of intravenous morphine equivalent dose was associated with a 1.4% (95% CI 0.2%, 2.7%, p=0.028) increase in peak creatine kinase; however, this was no longer significant after adjustment for TIMI flow pre-PCI.Conclusions Our study suggests no benefit of higher opioid dose and a dose-dependent signal between opioid dose and increased myocardial infarct size. Prospective randomised controlled trials are required to establish causality given that this may also be explained by patients with a greater ischaemic burden requiring higher opioid doses due to more severe pain. Future research also needs to focus on strategies to mitigate the opioid–P2Y12 inhibitor interaction and non-opioid analgesia to treat ischaemic chest pain.