The effect of intensive therapy of atorvastatin on vascular rigidity and lipid profile in patients with ST-segment elevation myocardial infarction

Abstract

Objective. To evaluate the effect of 24-week atorvastatin therapy on the lipid profile, structure and functions of the large arteries in patients with ST-elevation myocardial infarction (STEMI) with single-vessel hemodynamically significant stenosis of the coronary arteries.Design and methods. We enrolled 85 patients with STEMI aged 33 to 66 years (51,9 ± 9,3 years), 75 men (88 %), and 10 women (12 %). Inclusion criteria were: age from 30 years to 70 years, STEMI confirmed by electrocardiogram and increased troponin I and creatine kinase-MB, the presence of a significant stenosis of the infarct-related artery, stenosis of other arteries less than 50 %, and the stenosis of the trunk of the left coronary artery less than 30 %. Patients underwent laboratory (lipids) and instrumental examination at baseline (7–9 days from the symptoms onset) and 24 weeks after the therapy was started. We assessed carotid atherosclerosis by the ultrasound scanner MyLab 90 (“Esaote”, Italy). Central pressure parameters and arterial stiffness were evaluated using the applanation tonometry (SphygmoCor, “AtCorMedical”, Australia).Results. After 24 weeks of treatment patients from the control group demonstrated a decrease in total cholesterol by 26 %, low density lipoproteins — by 40,5 % and high density lipoproteins — by 3 %. Patients receiving atorvastatin 80 mg/day showed similar reduction of the parameters: by 45 %, 55 % and 14 %, respectively. Patients who took lower dose of atorvastatin showed no change in intima-media thickness (IMT), but there was a positive change of the coefficient of transverse extensibility — DC, which increased by 25 % (p < 0,05). In the same cohort of patients, locPsys and locPdia increased by 5,4 and 3,6 mm Hg, respectively, and there was a 3,5-fold increase in the augmentation index (p < 0,05). In the group of high-dose atorvastatin therapy carotid IMT decreased by 11 % after 24 weeks (p < 0,05). The coefficient of transverse compliance (CC) increased by 11 % (p < 0,05), the stiffness indices α and β significantly decreased by 11 % and 13 %, respectively (p < 0,05). There was also a decrease in pulse wave velocity (PWV) measured locally in the carotid arteries by 6 % (p < 0,05). We found a 3-fold increase in augmentation pressure (AP) and augmentation index (Aix) after 6 months of therapy (p < 0,05).Conclusions. Patients who receive the maximum daily dose of atorvastatin develop a more significant improvement of lipid profile compared to the control group. Our results are consistent with the statement of the American Association of Cardiologists proving that high-dose statin therapy can reduce the level of low density lipids by more than 50 % compared to the baseline values. Using the radiofrequency analysis of the ultrasound signal (echotracking), we analyzed the stiffness parameters α and β, the compliance and distensibility coefficients, which reflect the vascular wall rigidity, regardless of the arterial pressure level. When comparing two schemes of atorvastatin therapy, intensive therapy showed a more evident favourable effect on carotid stiffness.