ICU · Cardiovascular / ACS

Acute Coronary Syndromes (STEMI/NSTEMI) in the ICU

Also known as Acute coronary syndrome · ACS · STEMI · NSTEMI · Unstable angina · Primary PCI · Dual antiplatelet therapy · DAPT · Ticagrelor · PLATO trial · SHOCK trial · GRACE score

Acute coronary syndromes (ACS) span the spectrum of acute myocardial ischaemia — unstable angina (UA), NSTEMI and STEMI — now unified under the Fourth Universal Definition of Myocardial Infarction (Thygesen 2018, Circulation), which classifies MI into five pathophysiological types (spontaneous, supply-demand, sudden death, PCI-related and CABG-related). STEMI (complete coronary occlusion) is treated with primary PCI within 90 minutes or thrombolysis within 30 minutes; NSTEMI is risk-stratified by the GRACE score for early invasive PCI within 24 hours. All ACS receives aspirin plus a P2Y12 inhibitor (ticagrelor preferred per PLATO, NEJM 2009) plus parenteral anticoagulation (heparin or bivalirudin per HORIZONS-AMI). In MI complicated by cardiogenic shock, early revascularisation is the standard (SHOCK, NEJM 1999); routine IABP confers no mortality benefit (IABP-SHOCK II, NEJM 2012), culprit-only PCI beats multivessel PCI in shock (CULPRIT-SHOCK, NEJM 2017), and early routine VA-ECMO did not improve outcomes (ECLS-SHOCK, NEJM 2023). The mechanical complications of MI — VSD, papillary muscle rupture and free wall rupture — classically occur at days 2 to 7 and present with sudden haemodynamic collapse.