Contemporary pharmacological treatment strategies for patients with angina and unobstructed coronary arteries (ANOCA) due to coronary microvascular dysfunction

Abstract

In recent years, there has been important progress in the evolving field of coronary vasomotor disorders regarding diagnostic assessments and therapeutic strategies. It is now commonly accepted that patients with angina and unobstructed coronary arteries (ANOCA) frequently suffer from coronary vasomotor disorders. The latter can be reliably diagnosed using invasive diagnostic procedures. They comprise the detection of epicardial and/or microvascular spasm, impaired coronary vasodilatation, and enhanced microvascular resistance. As these mechanisms may overlap in one given patient, various endotypes of disease can be distinguished. Although evidence from randomized clinical trials in this setting is still sparse, it has been suggested that - in addition to strict risk factor control-targeted pharmacological therapies/treatments based on the identified mechanism of disease can improve symptoms and prognosis. In patients with coronary spasm as the predominant mechanism, first-line treatment consists of high-dose calcium channel blockers and nitrates. In patients with impaired vasodilatation or enhanced microvascular resistance, beta-blockers, angiotensin-converting enzyme inhibitors, and statins represent first-line treatment. In the group of patients with symptoms refractory to first-line medication, second-line drugs such as nicorandil, molsidomine, ranolazine, ivabradine, and others for microvascular dysfunction are available. Moreover, ongoing studies in this area are evaluating the usefulness of newer pharmacological agents such as endothelin-receptor antagonists or soluble guanylate cyclase stimulators. This article summarizes the currently available evidence for pharmacological treatment strategies in patients with ANOCA due to coronary microvascular dysfunction.