Progression of the atherosclerotic lesions of the coronary arteries in patients after myocardial infarction at 3-year follow-up

Abstract

The aim – to study and analyze the clinical and functional characteristics and parameters of lipid metabolism in patients after acute myocardial infarction (MI), depending on the progression of atherosclerosis according to the data of repeated coronary angiography (CAG) during a three-year follow-up.
Materials and methods. The study prospectively included 91 patients with primary Q-MI, 47 of whom underwent a full cardiac rehabilitation (CR) program with physical training (FT), 44 patients – had only complexes of physical exercises and distance walking in accordance with the terms of MI. For three years, CAG was performed in 38 patients, in 18 (group 1) of whom the progression of the atherosclerotic process was established, in 20 (group 2) progression was not visualized in CAG. 53 patients (group 3) had a stable satisfactory condition and refused to repeat CAG. Treatment was performed in accordance with modern guidelines with urgent stenting of the infarct-dependent coronary artery. All patients underwent dosed testing on a bicycle ergometer, echocardiography and an evaluation of lipid metabolism indicators. Control examinations were carried out at discharge on the 10-15th day of myocardial infarction and in dynamics after 1 and 3 years.
Results and discussion. Undesirable cardiovascular events (recurrent MI, coronary artery bypass grafting, restenosis, and hemodynamic significant stenoses) occurred only in the 1st group: 7 events – during the first year, also 7 – during the second year, and the last 14 – during the third year. In the second group, in the first week of myocardial infarction stent thrombosis occurred in 2 patients, coronary bypass grafting was performed according to the data of urgent coronary angiography also in 2 patients. During the 3-years follow up in the group with the progression of atherosclerosis the number of patients with diabetes mellitus tripled, and there was also a tendency to an increase in body mass index. According to the results of the exercise test on a bicycle ergometer and echocardiography, significant differences in the groups were not established, however, a positive trend in the dynamics of observation was noted in patients of the 2nd group without progression of atherosclerosis. Low-density lipoprotein cholesterol values ​​were obtained on the 5–7th day of myocardial infarction at the background of high-intensity statin therapy and were considered as basic. Further results showed the best performance in the first 6–12 months after myocardial infarction with better adherence to medical recommendations in the period as close as possible to acute MI. In the group of patients with progression of atherosclerosis, the maximum decrease in the level of low-density lipoprotein cholesterol (up to 2.10 (1.79–2.38) mmol/L) was observed after 6 months, followed by an increase in 1 and 3 years to a level exceeding the baseline. Variations in this indicator in patients without progression were 1.85–2.02–1.83 mmol/L, which was close to the recommended target values ​​(up to 2019).
Conclusions. In the group with the progression of the atherosclerotic process, the number of patients with diabetes mellitus increased over 3 years and a tendency towards an increase in body mass index was observed. Most of the patients returned to smoking by the end of the first year after myocardial infarction, but then 3 years later, some of the patients in group 2 stopped smoking again, which may indicate the effectiveness of training and the psychological component of cardiac rehabilitation in the group without progression of the atherosclerotic process. The results of echocardio­­graphy and the level of exercise tolerance at the time of examination did not differ in patients with and without progression of the atherosclerotic process. Maintaining the target levels of LDL cholesterol is possible only under the condition of long-term high-intensity statin therapy under the supervision of a physician, adherence to the comprehensive recommendations of stage III CR at each contact with the patient.