Physiological Lesion Assessment in STEMI and Other Acute Coronary Syndromes

Abstract

Invasive coronary physiology is a key instrument in decision-making for the interventional cardiologist. Fractional flow reserve has been well validated in chronic stable coronary artery disease. Its practical applications have expanded into other clinical situations such as acute coronary syndrome (ACS) including ST-elevation myocardial infarction (STEMI). Recently, other invasive indices of coronary physiology including instantaneous wave-free ratio (iFR), index of microvascular resistance (IMR), hyperemic stenosis resistance (HSR), and coronary flow reserve (CFR) have been explored in the context of ACS. This review will focus on the fundamentals and role of physiologic lesion assessment in the ACS patient.