Non-ST-Elevation Myocardial Infarction: A Heterogeneous Syndrome with Evolving Management—A Narrative Review

Non-ST-segment elevation myocardial infarction (NSTEMI) has become the predominant form of acute coronary syndrome (ACS) and is frequently associated with multivessel coronary artery disease (MVD). Patients presenting with NSTEMI and MVD represent a particularly high-risk population characterized by advanced age, comorbidities, and an increased atherosclerotic burden. Although advances in pharmacological therapy and early invasive management have improved prognosis, the optimal revascularization strategy in this setting remains uncertain. In contrast to ST-segment elevation myocardial infarction (STEMI), where randomized controlled trials consistently support complete revascularization, evidence in NSTEMI with MVD is limited and is largely derived from observational studies and registry data. This has generated ongoing debate regarding whether complete revascularization offers superior outcomes compared with culprit-only percutaneous coronary intervention (PCI), and whether non-culprit lesions should be treated during the index procedure (immediate strategy) or in a staged manner. Current data suggest that complete PCI is generally associated with reduced recurrent ischemia, reinfarction, and repeat revascularization, with potential long-term survival benefits. However, patient comorbidities, lesion complexity, and procedural risk continue to influence outcomes, highlighting the importance of individualized decision-making. This narrative review synthesizes contemporary evidence on PCI-based revascularization strategies in NSTEMI with MVD, focusing on two central aspects: the extent of revascularization (complete versus incomplete) and the timing of intervention (single-stage versus staged). By integrating findings from registries, randomized trials and guideline recommendations, the review identifies areas of consensus, persisting uncertainties, and key evidence gaps. Ultimately, it underscores the need for large, dedicated trials to guide practice and optimize outcomes for NSTEMI patients with multivessel coronary disease.