Effect and safety of morphine use in acute anterior ST-segment elevation myocardial infarction

Objectives The aim of this study was to examine the effect and safety of morphine in patients with acute anterior ST-segment elevation myocardial infarction (STEMI) followed up for one year. Background Morphine is commonly used to treat chest pain during myocardial infarction but its effect on cardiovascular outcome has never been directly evaluated. Methods and results We used the database of the CIRCUS trial, which included 969 patients with anterior STEMI, admitted for primary percutaneous coronary intervention (PPCI). Two groups were defined according to use of morphine prior to coronary angiography. The composite primary outcome was the combined incidence of major adverse cardiovascular events (MACE), including cardiovascular death, heart failure, cardiogenic shock, myocardial infarction, unstable angina and stroke during one year. 554 (57.1%) patients received morphine at first medical contact. Both groups, with and without morphine treatment, were comparable with respect to demographic and periprocedural characteristics. There was a non-significant trend toward increased MACE ( Fig. 1 ) in patients who received morphine compared to those who did not (26.2% versus 22.0%, respectively; P  = 0.15). The all-cause mortality was 5.3% in the morphine group versus 5.8% in the no-morphine group ( P  = 0.89). There was no difference between groups in infarct size as assessed by the creatine kinase peak after PPCI (4023 ± 118 IU/L versus 3903 ± 149 IU/L; P  = 0.52). Conclusion In anterior STEMI patients treated by PPCI, the use of morphine during initial management was not associated with a significant increase in MACE or mortality at one year.