Vasospastic angina: a review on diagnostic approach and management

Abstract

Vasospastic angina (VSA) refers to chest pain experienced as a consequence of myocardial ischaemia caused by epicardial coronary spasm, a sudden narrowing of the vessels responsible for an inadequate supply of blood and oxygen. Coronary artery spasm is a heterogeneous phenomenon that can occur in patients with non-obstructive coronary arteries and obstructive coronary artery disease, with transient spasm causing chest pain and persistent spasm potentially leading to acute myocardial infarction (MI). VSA was originally described as Prinzmetal angina or variant angina, classically presenting at rest, unlike most cases of angina (though in some patients, vasospasm may be triggered by exertion, emotional, mental or physical stress), and associated with transient electrocardiographic changes (transient ST-segment elevation, depression and/or T-wave changes). Ischaemia with non-obstructive coronary arteries (INOCA) is not a benign condition, as patients are at elevated risk of cardiovascular events including acute coronary syndrome, hospitalization due to heart failure, stroke and repeat cardiovascular procedures. INOCA patients also experience impaired quality of life and associated increased healthcare costs. VSA, an endotype of INOCA, is associated with major adverse events, including sudden cardiac death, acute MI and syncope, necessitating the study of the most effective treatment options currently available. The present literature review aims to summarize current data relating to the diagnosis and management of VSA and provide details on the sequence that treatment should follow.

Keywords: acetylcholine; coronary artery spasm; ischaemia with non-obstructive coronary arteries; vasospastic angina.

Figure 1.

Risk factors and pathophysiology of vasospasm. Ca²⁺, calcium; NO, nitric oxide; OS, oxidative stress; VSMCs, vascular smooth muscle cells.

Figure 2.

Validated original provocative ACh testing for VSA assessment (high-dose ACh boluses) and endothelial function assessment test (low-dose ACh boluses). Several alternatives to the original ACh test have been adopted in recent years, although not validated as the standard protocol. ACh, acetylcholine; AF, atrial fibrillation; AV, atrioventricular; IC, intracoronary; LCA, left coronary arteries; RCA, right coronary artery; RV, right ventricle; VSA: vasospastic angina; µg, micrograms.

Figure 3.

Summary of diagnostic and therapeutic recommendations for vasospastic angina. ACEi, angiotensin-converting enzyme inhibitor; ACh, acetylcholine; ARB, Angiotensin II receptor blocker; CAD, coronary artery disease; CCBs, calcium-channel blockers; CCTA, coronary computed tomography angiography; CMD, coronary microvascular dysfunction; IC, intracoronary; IOCA, ischaemia with obstructive coronary arteries; LANs, long-acting nitrates; LVEDP, left ventricle end diastolic pressures; RF, risk factor; VSA, vasospastic angina.