The role of collateral circulation in the results of invasive treatment In patients with acute coronary syndrome

Abstract

The aim of the work: to investigate the clinical portrait of patients with developed collaterals on the background of acute coronary syndrome and their influence on the results of invasive treatment.

Materials and Methods. 135 patients were involved in the study, of whom 105 were men (77.78 %) and 30 were women (22.22 %). The average age of the examined was (61.81±1.13) years, including men – (60.15±0.91) years, women –(66.43±1.27) years, p<0.0009. 113 (83.70 %) patients were diagnosed with acute coronary syndrome (ACS) with ST-segment elevation (STEMI), 22 (16.30 %) – ACS without ST-segment elevation (NSTEMI). In the subjects, collateral blood flow was assessed using the Rentrop technique during coronary angiography followed by angioplasty and stenting of the infarct-related artery. Depending on the development of coronary collaterals (CC), all patients were divided into two groups: 1 – with well-developed collaterals (2-3 points according to Rentrop), 2 – with poorly developed CC (0-1 points according to Rentrop). In these groups, the features of the clinical course of ACS, the influence of comorbidity, the estimated mass of necrosis according to the ECG, echocardioscopy indicators, coronary angiographic parallels between the damage of different departments of the coronary bed and the development of CC, and the immediate and remote consequences of invasive treatment were compared. The risks of an unfavorable prognosis were assessed according to the GRACE-2 scale.

Results and Discussion. According to coronary angiography, developed CC (Rentrop 2–3) was established in 43 patients, and in 92 – insufficient CC or absence of collaterals. A direct relationship was established between the degree of coronary artery obstruction and the presence of well-developed collaterals (r=0.316, p<0.001). According to partial correlation analysis (with removal of age), there was a certain relationship between the presence of CC and the six-month risk of an unfavorable prognosis according to the GRACE-2 scale (r=0.205, p=0.018). The assessment of total mortality during the entire observation period revealed a slightly higher mortality in the group of patients who had developed collaterals compared to patients in whom the latter were not detected, respectively, 25.58 % vs. 17.39 %, but the difference was statistically unreliable. When analyzing mortality within 6 months after MI, the actual mortality in the presence of developed collaterals was 9.3 %, and the estimated mortality according to the GRACE scale was 15.24 %. At the same time, the same indicators in the group of patients in whom no collaterals were detected during coronary angiography were, respectively, 3.26 % and 3.00 %, i.e., the actual and estimated mortality in the latter were identical.

Collaterals are better developed in patients with more severe coronary artery stenosis. In the choice of tactics for the treatment of acute coronary syndrome, the features of the collateral blood circulation should be taken into account. In a relatively short period of time, the presence of collateral blood flow has a positive effect in acute coronary syndrome.