Acute coronary syndrome is a term used to describe a range of conditions associated with sudden, reduced blood flow to the heart. One such condition is a heart attack (myocardial infarction). Acute coronary syndrome is a medical term used to describe problems that occur when there isn't enough blood flow to the heart. eath results in damaged or destroyed heart tissue. Acute coronary syndrome (ACS) refers to a spectrum of clinical presentations ranging from those for ST-segment elevation myocardial infarction (STEMI) to presentations found in non–ST-segment elevation myocardial infarction (NSTEMI) or in unstable angina. It is almost always associated with rupture of an atherosclerotic plaque and partial or complete thrombosis of the infarct-related artery. It refers to a range of conditions in which too little blood can reach the heart, for example, because of a blockage. Acute coronary syndrome is a term for a group of conditions that suddenly stop or severely reduce blood from flowing to the heart. The management of acute coronary syndromes (ACS) has made enormous progress over the last five decades due to the introduction of defibrillation, beta blockers, thrombolytics, aspirin, primary percutaneous transluminal intervention (PCI), P2Y12 inhibitors, statins, radial access, and eventually PCSK9 inhibitors, among others.