Angina: contemporary diagnosis and management

Six decades have passed since the first reported invasive coronary angiogram; however, many physicians still consider detecting obstructive epicardial CAD on coronary angiography a ‘sine qua non’ for the diagnosis of angina. The detection of obstructive CAD allows evidence-based medical treatment and consideration of myocardial revascularisation. However, underlying pathophysiology is more nuanced with contributions from anatomical atherosclerotic and/or functional alterations of epicardial vessels and/or microcirculation (figure 1). ESC guidelines have revised nomenclature (‘Chronic Coronary Syndromes’) in part reflecting the importance of patients with signs and symptoms of ischaemia without obstructive coronary artery disease—INOCA. Around half of all patients with angina undergoing elective coronary angiography have no obstructive epicardial CAD. This large, heterogeneous chronic coronary syndrome is comprised of distinct vasomotor disorders including microvascular angina (MVA) and/or vasospastic angina (VSA)—the two most common underlying disorders of coronary vascular function in the INOCA population. Crucially, we stress that there are often multiple mechanisms of myocardial ischaemia occurring in various coronary compartments via different mechanisms. These frequently coexist in combination; however, an appreciation of this fact can help stratify treatment and help us understand patients with poor treatment response (eg, angina after revascularisation).