Dissertation for scientific degree of Candidate of Medical Sciences (Doctor of Philosophy) in specialty 14.01.11 – Cardiology. – Lviv Danylo Halytsky National Medical University, Ministry of Health of Ukraine, Lviv, 2020.
Coronary artery disease (CAD) holds the leading position among cardiovascular diseases in Ukraine and worldwide. Surgical methods of myocardial revascularization play a crucial role in the complex therapeutic strategy in these patients. Many researches were directed toward the development of effective prophylactic strategy after revascularization procedures that require a detailed study of the postoperative period. Therefore, prolonged observation of patients after myocardial infarction (MI) treated with myocardial revascularization is extremely relevant in order to assess remote cardiac function, influence of cardiovascular risk factors and definition of risk predictors.
A comprehensive clinical examination with laboratory and imaging testing of 101 patients with CAD and acute MI were performed. The main group (MG) included 71 patients (59 men аnd 12 women) who underwent myocardial revascularization with. The control group (CG) included 30 patients (25 men and 5 women) who received standard pharmacotherapy according to unified clinical protocols.
The results of the study supplemented available scientific data about the effectiveness of myocardial revascularization contributed to less severe left ventricle (LV) remodeling, slower progression of CAD and less frequent occurrence of cardiovascular complications. The 5-year course of CAD after myocardial revascularization and standard pharmacotherapy without revascularization were compared with the assessment of echocardiographic structural and functional cardiac indices, lipid profiles, parameters of inflammatory activity and endogenous intoxication. In the main group myocardial hypertrophy developed later; in two years left ventricular myocardial mass index (LVMMi) was significantly lower. Besides, in five years the reduction of left ventricular ejection fraction (LVEF) was less severe. Positive influence of revascularization on cardiac function was the most prominent in 5 years after procedure. In both groups, mean levels of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and triglycerides (TG) significantly decreased three months after MI. The mean TC level did not exceed the baseline level even in 60 months after revascularization, whereas in the control group mean TC level was significantly higher and exceeded the baseline level already in 30 months after MI. In five years after event the mean TG level was significantly lower in the main group comparing with the baseline level and comparing to control group.
Using the Kaplan-Meier method, the following predictors of 5-year risk of cardiovascular events were identified: increased right ventricular dimension ≥ 2.5 cm (P = 0.03), left atrial dimension > 4.0 cm (P = 0.04), end-diastolic LV dimension ≥ 5.7 cm (P = 0.009), LVEF < 50% (P = 0.001), relative LV wall thickness <0.42 (P = 0.003), eccentric LV hypertrophy (P = 0.05); TC level > 5.0 mmol/l, LDL-C level > 2.5 mmol/l, non-HDL-C level > 4.0 mmol/l, β-lipoprotein level > 50 units, creatinine level ˃ 115 μmol/l, fibrinogen level > 4.0 mmol/l, HDL-C level <1.1 mmol/l, and total bilirubin level < 11.0 μmol/l (all P <0.05). Our study demonstrated that revascularization was associated with better event-free survival. This positive influence was observed not only among patients with better values of well-established risk factors, but also in patients with existing cardiovascular abnormalities and dyslipidemia (left atrial dimension > 4.0 cm, right ventricular dimension ≥ 2.6 cm, aortic root diameter ≥ 3.0 cm, and serum TC level > 5.0 mmol/l; all P <0.05).
