Treatment of coronary microvascular dysfunction

Abstract

Contemporary data indicate that patients with signs and symptoms of ischaemia and non-obstructive coronary artery disease (INOCA) often have coronary microvascular dysfunction (CMD) with elevated risk for adverse outcomes. Coronary endothelial (constriction with acetylcholine) and/or microvascular (limited coronary flow reserve with adenosine) dysfunction are well-documented, and extensive non-obstructive atherosclerosis is often present. Despite these data, patients with INOCA currently remain under-treated, in part, because existing management guidelines do not address this large, mostly female population due to the absence of evidence-based data. Relatively small sample-sized, short-term pilot studies of symptomatic mostly women, with INOCA, using intense medical therapies targeting endothelial, microvascular, and/or atherosclerosis mechanisms suggest symptom, ischaemia, and coronary vascular functional improvement, however, randomized, controlled outcome trials testing treatment strategies have not been completed. We review evidence regarding CMD pharmacotherapy. Potent statins in combination with angiotensin-converting enzyme inhibitor (ACE-I) or receptor blockers if intolerant, at maximally tolerated doses appear to improve angina, stress testing, myocardial perfusion, coronary endothelial function, and microvascular function. The Coronary Microvascular Angina trial supports invasive diagnostic testing with stratified therapy as an approach to improve symptoms and quality of life. The WARRIOR trial is testing intense medical therapy of high-intensity statin, maximally tolerated ACE-I plus aspirin on longer-term outcomes to provide evidence for guidelines. Novel treatments and those under development appear promising as the basis for future trial planning.

Keywords: Angina; CMD; Ischaemia; Women; INOCA.

Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2020. For permissions, please email: journals.permissions@oup.com.

Figures

Graphical Abstract

Figure 1

CMD reactivity testing and prognosis. Women with no obstructive coronary artery disease and the potential role of coronary reactive testing to identify those at higher risk for adverse events. Permission granted to reproduce figure from AlBadri et al.

Figure 2

CorMicA. Stratified medical therpay guided by an interventional diagnostic procedure (IDP) improves health status of patients with symptoms and/or sings of angina but no ischaemia and non-obstructive coronary artery disease (INOCA). Permission granted to reproduce figure from Ford et al.

Figure 3

ACCF/AHA/ACP/AATS/PCNA/SCAI/STS stable ischaemic heart disease guidelines. Colours respond to the class of recommendations in the ACCF/AHA. The algorithms do not represent a comprehensive list of recommendations. The use of bile acid sequestrant is relatively contraindicated when triglycerides are ≥200 mg/dL and is contraindicated when triglycerides are ≥500 mg/dL. Dietary supplement niacin must not be used as a substitute for prescription niacin. ACCF, American College of Cardiology Foundation; ACE-I, angiotensin-converting enzyme inhibitor; AHA, American Heart Association; ARB, angiotensin-receptor blocker; ASA, aspirin; ATP III, Adult Treatment Panel 3; BP, blood pressure; CCB, calcium channel blocker; CKD, chronic kidney disease; HDL-C, high density lipoprotein cholesterol; JNC VII, Seventh report of the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure; LDL-C, low density lipoprotein cholesterol; LV, left ventricular; MI, myocardial infarction; NHLBI, National Heart, Lung and Blood Institute; NTG, nitroglycerine.

Figure 4

CMD and INOCA knowledge gaps.

Figure 5

WARRIOR trial.