Abstract Body (Do not enter title and authors here): Introduction
Acute myopericarditis can mimic acute myocardial infarction (AMI) on electrocardiogram (ECG), especially in patients with underlying cardiovascular disease. This diagnostic overlap can lead to inappropriate activation of invasive pathways. In people living with HIV (PLWH), particularly those with poor adherence to antiretroviral therapy (ART), myopericarditis is not uncommon and can progress to HIV-associated cardiomyopathy if missed.

Research Question
Can multimodal diagnostic evaluation accurately differentiate myopericarditis from AMI in HIV-positive patients presenting with ST-elevation on ECG?

Goals/Aims
To highlight the importance of integrating biomarkers, echocardiography, and cardiac magnetic resonance imaging (CMR) in evaluating PLWH presenting with chest pain and ST-segment elevation.

Case Presentation
We present a case of a 62-year-old man with untreated HIV, presenting with acute chest pain and ST elevations in inferolateral leads. He underwent emergent coronary angiography after STEMI activation. Subsequent testing included serial cardiac biomarkers, transthoracic echocardiography, and CMR to further characterize the cause of cardiac dysfunction and ECG changes.

Management/Outcome
Coronary angiography revealed multivessel coronary artery disease with TIMI 3 flow and no culprit lesion. Echocardiography showed severely reduced left ventricular ejection fraction (24%) with global hypokinesis and moderate pericardial effusion. High-sensitivity troponin was mildly elevated. CMR confirmed acute myopericarditis with elevated native T1 times, myocardial fibrosis, and absence of ischemic late gadolinium enhancement. The patient was managed with colchicine, NSAIDs, ART, and heart failure therapy. He was discharged in stable condition with outpatient follow-up.

Conclusion
This case underscores the critical role of multimodal diagnostics in evaluating chest pain with ST-segment elevation in PLWH. Relying solely on ECG and coronary angiography may lead to misdiagnosis. Advanced imaging modalities such as CMR and inflammatory biomarkers can distinguish inflammatory causes like myopericarditis from ischemic events, guiding appropriate and timely treatment while avoiding unnecessary interventions.