Morphine Does Not Affect Myocardial Salvage in ST-Segment Elevation Myocardial Infarction

Area of Science:

• Cardiology
• Interventional Cardiology
• Cardiovascular Imaging

Background:

• Intravenous (IV) morphine use in acute myocardial infarction (AMI) is debated due to potential delays in antiplatelet agent action.
• The impact of IV morphine on myocardial damage in ST-segment elevation myocardial infarction (STEMI) patients undergoing primary percutaneous coronary intervention (PCI) remains unclear.

Purpose of the Study:

• To investigate whether IV morphine administration adversely affects myocardial injury in STEMI patients undergoing primary PCI.
• To assess the impact of IV morphine on myocardial salvage index (MSI) in this patient population.

Main Methods:

• A study of 299 STEMI patients who underwent contrast-enhanced magnetic resonance imaging (CE-MRI) post-primary PCI.
• Quantification of infarct size and area at risk using delayed-enhancement and T2-weighted imaging, respectively.
• Calculation of MSI and comparison between patients who received IV morphine and those who did not, including propensity score matching.

Main Results:

• Patients receiving IV morphine had shorter symptom-to-balloon times and higher initial Thrombolysis in Myocardial Infarction (TIMI) flow grades.
• Unmatched analysis showed a trend towards larger MSI and infarct size in the morphine group.
• After propensity score matching, MSI, infarct size, and area at risk were similar between the morphine and non-morphine groups.

Conclusions:

• In propensity score-matched analysis, IV morphine administration prior to primary PCI in STEMI patients did not result in adverse impacts on myocardial salvage.
• These findings suggest that IV morphine can be safely administered to STEMI patients undergoing primary PCI without compromising myocardial reperfusion or salvage.