SYSTEMATIC CHARACTERIZATION OF CAUSES OF RESTENOSIS IN PATIENTS WITH CORONARY ANGIOPLASTY

Abstract

Treatment of patients with various manifestations of ischemic heart disease (IHD) has changed much during the last decade due to introduction of endovascular technologies. However, invasive therapy methods can be followed by some dangerous complications, restenosis/thrombosis in stent placement site being one of them. According to literature data, such type of complications is registered in 1-8% of patients within the first year of coronary angioplasty. In spite of low complication rate, they have adverse impact on the end points, as mortality rate can rise to 26% in that category of patients. The aim of the study was to analyze the incidence and causes of late (after 6 months) restenosis/thrombosis development in patients with IHD and coronary angioplasty. 1350 case histories during the period of 28 months (between January, 2015 and April, 2017) were analyzed. They included coronary angiography findings and some common indices of clotting and fibrinolytic blood system (prothrombin time, blood plasma recalcification time, fibrinogen A, fibrinogen B, fibrinolytic activity). 32 patients (26 males and 6 females) were found to have the history of restenosis, comprising 2.4% of the whole study group. The average age of the patients was 59.91.6 years. Restenosis in the left coronary artery system was registered in14 patients (43.8%), that in the right one - in 11 patients (35.3%) and in circumflex artery - in 7 (21.9%). 12 patients had stent subocclusion followed by development of progressive angina pectoris. Urgent stent implantation was performed in 13 patients (39.4%). In general, 22 metal stents (66.7%) and 11 drug-eluting stents (33.3%) were inserted in the study group. It should be noted that restenosis of both drug-eluting stents occurred in one patient. There were 2/3 of patients with angiographic B type of coronary artery disease. Chronic heart failure CH I and CH IIA were diagnosed in 8 (25%) and 24 patients (75%), respectively; stage III of arterial hypertension - in 27 patients (84%). In addition, 27 patients had the history of myocardial infarction, and 11 patients (34.4%) - type II diabetes mellitus. All patients were observed to have rather low compliance to protocol treatment. Only 56.25% of patients (18 individuals), irrespective of the stent type implanted, followed complete double antiplatelet therapy with brand drugs not less than for a year. Assessment of hemostasis indices did not prove the coagulogram to be the marker of probable restenosis threat. Fibrinogen appeared to be the only parameter with the tendency to increase at that stage of study, its concentration averaged 4.160.22 mg/ml. This fact indicates that prediction of restenosis development can be improved by comprehensive study of fibrinolytic, pro- and anticoagulant links of hemostasis. Thus, characterization of restenosis causes in patients with coronary angioplasty demonstrated it to be multifactorial process (stent types, type of vascular lesions, compliance of patients to protocol treatment). At the same time, the factors which have led to that complication remain unknown in the majority of cases. Hence, introduction of more informative markers-indicators of hemostasis for diagnosis of probable thrombotic events is an urgent necessity today.

Keywords

• coronary angioplasty
• restenosis
• antiplatelet therapy
• coagulogram