Correlates of pre-hospital morphine use in ST-elevation myocardial infarction patients and its association with in-hospital outcomes and long-term mortality: the FAST-MI (French Registry of Acute ST-elevation and non-ST-elevation Myocardial Infarction) programme.

Aims: The use of opioids is recommended for pain relief in patients with myocardial infarction (MI) but may delay antiplatelet agent absorption, potentially leading to decreased treatment efficacy.

Methods And Results: In-hospital complications (death, non-fatal re-MI, stroke, stent thrombosis, and bleeding) and 1-year survival according to pre-hospital morphine use were assessed in 2438 ST-elevation MI (STEMI) patients from the French Registry of Acute ST-elevation and non-ST-elevation Myocardial Infarction (FAST-MI) 2010. The analyses were replicated in the 1726 STEMI patients of the FAST-MI 2005 cohort, in which polymorphisms of CYP2C19 and ABCB1 had been assessed. Specific subgroup analyses taking into account these genetic polymorphisms were performed in patients pre-treated with thienopyridines. The 453 patients (19%) receiving morphine pre-hospital were younger, more often male, with a lower GRACE score and higher chest pain levels. After adjustment for baseline differences, in-hospital complications and 1-year survival (hazard ratio = 0.69; 95% confidence interval: 0.35-1.37) were not increased according to pre-hospital morphine use. After propensity score matching, 1-year survival according to pre-hospital morphine was also similar. Consistent results were found in the replication cohort, including in those receiving pre-hospital thienopyridines and whatever the genetic polymorphisms of CYP2C19 and ABCB1.

Conclusion: In two independent everyday-life cohorts, pre-hospital morphine use in STEMI patients was not associated with worse in-hospital complications and 1-year mortality.

Clinical Trial Registration: Clinicaltrials.gov identifier: NCT00673036 (FAST-MI 2005); NCT01237418 (FAST-MI 2010).