Features of atherosclerosis in patients with angina and no obstructive coronary artery disease

An association between atherosclerosis and coronary vasospasm has previously been suggested. However, to date, no conclusive data on the whole spectrum of these disorders have been published.This study aimed to define specific morphological features of atherosclerosis in patients with angina and no obstructive coronary artery disease (ANOCA) due to coronary vasospasm.From February 2019 to January 2020, we enrolled 75 patients referred to our laboratory for a coronary function test (CFT) due to ANOCA and suspected coronary vasomotor dysfunction. The CFT consisted of an acetylcholine test and a physiology assessment with hyperaemic indexes using adenosine. Patients were divided into two groups according to the presence or absence of coronary vasospasm triggered by acetylcholine (ACH+ and ACH-, respectively). In addition, optical coherence tomography (OCT) was performed to assess the lipid index (LI), a surrogate for lipid area, and the prevalence of markers of plaque vulnerability.ACH+ patients had a higher LI than ACH- patients (LI: 819.85 [460.95-2489.03] vs 269.95 [243.50-878.05], respectively, p=0.03), and a higher prevalence of vulnerable plaques (66% vs 38%, p=0.04). Moreover, ACH+ patients showed a higher prevalence of neovascularisation compared to ACH- subjects (37% vs 6%, p=0.02) and a trend towards a higher prevalence of all individual markers, in particular thin-cap fibroatheroma (20% vs 0%, p=0.06). No differences were detected between patterns of coronary vasospasm.The presence of coronary vasospasm, regardless of its phenotype, is associated with higher lipid burden, plaque vulnerability and neovascularisation.