Formation of denser plasma fibrin clots is associated with coronary artery ectasias and aneurysms - preliminary results from the CARE-ANEURYSM study
Authors: Chmiel J , Zabczyk M , Natorska J 
Published: November 2023

Abstract

Background
Coronary artery ectasias and aneurysms (CAEAs) are defined as diffused or localized coronary artery dilations, that exceed diameter of the adjacent segment by at least 50%. In the Caucasian population, CAEAs are present in 2-5% of all-comer patients undergoing coronary angiography and are associated with increased risk of myocardial infarction and death.

Purpose
To determine whether CAEAs are associated with increased thrombin generation potential and unfavorably modified plasma fibrin clot properties.

Methods
In this prospective study 19 patients with CAEAs, 19 sex-, age-, fibrinogen- and diabetes mellitus-matched patients with coronary artery disease (CAD) but without CAEAs, and 20 healthy control subjects were assessed. Plasma fibrin clot permeability (Ks) reflecting an average pore size within fibrin network, plasma fibrinolytic potential expressed as clot lysis time (CLT), and thrombin generation capacity defined as endogenous thrombin potential (ETP) were assessed. The CARE-ANEURYSM study, founded by the Polish National Science Centre (no. UMO-2020/39/O/NZ5/02863), was approved by the Ethical Committee and conducted in accordance with the Declaration of Helsinki. Patients provided written informed consent.

Results
As many as 84.2% of CAEA patients were men, mean age was 69.6 years, and 73.7% individuals had CAD. On average, CAEA affected 3 coronary segments and exceeded vessels referral diameter by 2.15-fold. Patients with CAEA had 46.5% reduced Ks (median, 3.98 [3.30-4.63] vs 7.43 [6.15-8.88] x10-9cm2, p&lt;0.001), a tendency to prolonged CLT (112 [103-116.5] vs 99 [89-114] min, p=0.07), and 51% higher ETP (1685 [1502-1786] vs 1119 [1025-1189] nM×min, p&lt;0.001) compared to healthy control (Fig. 1A-C). Moreover, individuals with CAEA compared to CAD patients had 19.5% lower Ks (median 3.98 [3.30-4.63] vs 5.33 [4.86-6.78] x10-9cm2, p=0.016) and 21% longer CLT (112 [103-116.50] vs 92.52 [81.50-97.50] min, p=0.015) and (1685 [1502-1786] vs 1119 [1693-1966] nM×min, p&lt;0.001) (Fig. 1A-C). In the CAEA group, Ks was associated with the CAEA maximal diameter (R=-0.595, p=0.007) and the ratio of CAEA maximal diameter to referral vessel diameter (R=0.743, p&lt;0.001; Figu.1D). There were no associations between the number of coronary artery segments affected by the lesion and fibrin clot properties or ETP. However, CAEA patients in whom the ratio of the CAEA maximal diameter to the referral vessel diameter exceed 2 (n=9) had 24.5% lower Ks (3.45 [1.88-3.68] vs 4.57 [4.08-5.35] x10-9cm2, p=0.004) and 14.7% higher ETP (1779 [1685-1812] vs 1515 [1431-1674] nM×min, p=0.028) with no difference in CLT (p&gt;0.05).

Conclusion
CAEAs are associated with denser fibrin clot structure and enhanced thrombin generation, which indicate that CAEA patients are characterized by prothrombotic state. Further studies are needed to elucidate whether prothrombotic clot phenotype may be associated with increased risk of thromboembolic events in CAEA patients.Figure 1.