The narrative review on morphine in acute coronary syndrome: Recognizing opioidergic cardioprotection

Morphine and Ticagrelor Interaction in Primary Percutaneous Coronary Intervention in ST-Segment Elevation Myocardial Infarction: ATLANTIC-Morphine

BACKGROUND

Morphine adversely impacts the action of oral adenosine diphosphate (ADP)-receptor blockers in ST-segment elevation myocardial infarction (STEMI) patients, and is possibly associated with differing patient characteristics. This retrospective analysis investigated whether interaction between morphine use and pre-percutaneous coronary intervention (pre-PCI) ST-segment elevation resolution in STEMI patients in the ATLANTIC study was associated with differences in patient characteristics and management.

METHODS

ATLANTIC was an international, multicenter, randomized study of treatment in the acute ambulance/hospital setting where STEMI patients received ticagrelor 180 mg ± morphine. Patient characteristics, cardiovascular history, risk factors, management, and outcomes were recorded.

RESULTS

Opioids (97.6% morphine) were used in 921 out of 1862 patients (49.5%). There were no significant differences in age, sex or cardiovascular history, but more morphine-treated patients had anterior myocardial infarction and left-main disease. Time from chest pain to electrocardiogram and ticagrelor loading was shorter with morphine (both p = 0.01) but not total ischemic time. Morphine-treated patients more frequently received glycoprotein IIb/IIIa inhibitors (p = 0.002), thromboaspiration and stent implantation (both p < 0.001). No significant difference between the two groups was found regarding pre-PCI ≥ 70% ST-segment elevation resolution, death, myocardial infarction, stroke, urgent revascularization and definitive acute stent thrombosis. More morphine-treated patients had an absence of pre-PCI Thrombolysis in Myocardial Infarction (TIMI) 3 flow (85.8% vs. 79.7%; p = 0.001) and more had TIMI major bleeding (1.1% vs. 0.1%; p = 0.02).

CONCLUSIONS

Morphine-treatment was associated with increased GP IIb/IIIa inhibitor use, less pre-PCI TIMI 3 flow, and more bleeding. Judicious morphine use is advised with non-opioid analgesics preferred for non-severe acute pain.

TRIAL REGISTRATION

clinicaltrials.gov identifier: NCT01347580.

Post-infarct morphine treatment mitigates left ventricular remodeling and dysfunction in a rat model of ischemia-reperfusion

Following myocardial infarction, the heart undergoes a series of dramatic compensations which may later form a maladaptive picture characterized by ventricular dilation and pump failure. Among several opioid agents, morphine has been shown to confer protection against reperfusion injury and infarct size. Here, we sought to study the cardioprotective effect of post-infarct morphine treatment against left ventricular adverse remodeling. We induced myocardial infarction in male Sprague - Dawley rats by ligating left anterior descending artery and then, treated these animals with three different doses of morphine -0.3, 3 and 10 mg/kg (i.p.). The echocardiographic evaluation depicted improved cardiac performance and lesser chamber dilation in the animals that had received 3 mg/kg of morphine. Next, we studied the effect of 3 mg/kg morphine administration on left ventricular hemodynamics, infarct size, tissue architecture, changes in lung and heart weight, circulating TNF-α level and post-MI mRNA expression of collagen-1, collagen-3, TGF-β, TNF-α, MMP-2 and MMP-9. Five-day morphine administration markedly improved LV function, and also reduced infarct size, myocyte hypertrophy, fibrosis, index of infarct expansion, heart weight and serum TNF-α level. Moreover, morphine alleviated MI-induced increase in wet and dry lung weight. Morphine also altered the mRNA expression of fibrosis-related genes, TNF-α, MMP-2 and MMP-9. In conclusion, post-infarct morphine treatment can mitigate adverse remodeling and cardiac dysfunction after MI. Beside analgesic effect, we may be able to harvest benefits from the antifibrotic and anti-remodeling action of morphine in patients with the acute coronary syndrome.