Atherosclerotic plaque structure according to optical coherence tomography in patients with coronary artery disease living in extreme weather conditions

Abstract

Aim. To evaluate the plaque structural features in patients with coronary artery disease (CAD) permanently residing in the Far North of the Tyumen region in com­parison with patients in the South of the Tyumen region.Material and methods. This pilot case-control study included 32 patients with stable CAD (mean age 62,7±8,9 years, 24 (75%) men). The main group consisted of 16 patients permanently residing in the Far North of Tyumen region (non-indi­ge­nous population), while the comparison group consisted of 16 patients permanently residing in the South of the Tyumen region. In all patients, CAD was verified using paraclinical diagnostic methods. All patients underwent optical coherence tomography (OCT), according to which the plaque type was analyzed. The following plaque types were distinguished: fibrous, fibroatheroma, calcified fibroatheroma, thin-cap fibroatheroma (TCFA). TCFA was defined as the presence of a fibrous cap ≤65 μm thick and an arc of the necrotic core of at least 90о. In addition, a lipid-rich plaque was isolated, which was determined by a lipid arc of more than 180о.Results. According to clinical and angiographic characteristics, patients in the compared groups were statistically comparable. A total of 134 plaques were analyzed from 32 patients (main group — 65 plaques; control group — 69 plaques (p>0,05)). The most common plaque type in both groups was calcified fibroatheroma (46,2% in the Far North group and 50,7% in the South group, p=0,609). TCFA was significantly more often detected in patients living in far north (33,8% vs 17,4%, p=0,031). In this group of patients, thin (<65 µm) fibrous plaque cap was also more often determined (35,4% vs 18,8%, p=0,034). Lipid-rich plaques in both groups was determined with the same frequency (56,9% vs 62,3%, p=0,598).Conclusion. In patients with verified CAD living in extreme weather conditions, according to OCT, TCFA was more often determined, which could potentially be associated with a higher risk of adverse cardiovascular events.