The dissertation work was aimed at studying: features of clinical, instrumental and laboratory data in patients of young age, to determine the predictors of unfavorable course of the disease and to substantiate pathogenetic-conditioned methods of their prevention. The urgency of the problem is due to the primary and secondary prevention of cardiovascular events in patients of different age groups.
The main criteria for inclusion in the database were acute coronary syndrome with ST segment elevation (STEMI) on the ECG, patients aged 18 to 65 years. Clinical diagnosis of acute myocardial infarction (AMI) was confirmed on the basis of clinical, electrocardiographic and laboratory criteria according to the ESC guidelines and Association of Cardiologists of Ukraine.
All patients received standard therapy according to the guidelines at the time of study entry. Patients in the hospital were performed: electrocardiography (ECG), echocardiography (ECHO), coronary angiography (CAG), endothelium-dependent, flow-mediated vasodilation (FMD), laboratory examinations and long-term out-of-hospital follow-up 4.9±1.7 years.
The study included 835 STEMI patients. The patients were divided into the two groups depending on age: 1 group (n=189) – patients<45 years of age, 2 group (n=646) 45-65 years.
According to the clinical-anamnestic characteristics, among young patients (mean age 37.8±2.54), the predominant was men with family premature coronary heart disease (29.6%), who were smokers (63.5%) and had a higher body mass index (BMI), but were less likely to have a history of concomitant arterial hypertension (AH) (41.8%), DM (4.2%), stroke, and chronic heart failure (CHF). Patients under 45 years had a better hospital prognosis, with fewer hospital complications, despite the same treatment between the groups. The most common risk factors for the development of AMI at a young age were male (OR 6.581: 95% CI, 2.638-16.415), smoking (OR 2.018: 95% CI 1.445-2.819), premature CAD (OR 1.75 (95% CI 1.214-2.536).
Studying the features of coronary blood flow it was found that young adults had a more frequent single-vessel lesion of the coronary arteries (62.7% vs. 46.6%), more likely to have lesion of the infarction-dependent left anterior descending artery (LAD) and less often a lesion of right coronary artery (RCA) (20.3% versus 33.3%, p=0.037). The development of STEMI in the group of young patients was associated with non-arteriosclerotic causes.
The FMD test showed that young patients had worse endothelial function on admission, but faster improvement this function in dynamics by day 7 (104% versus 23%, p<0.05).
On day 7, there was a tendency to increase in the end-diastolic index more often in young patients, by more than 10% (39.7% versus 27.8%, p=0.053), and by more than 15% (27.6% versus 18.0%, p=0.087).
Probable familial hypercholesterolemia (FH) was more common in the patients <45 years (7.34 % and 1.32%, p=0.036).
For the 10 years of follow-up, on average (4.92±1.72) years, young patients had a more favorable prognosis, rarely reaching such endpoints as cardiovascular death (CV death), MI, stroke. Patients before 35 years of age, mean age 28.3±2.34 years, did not experience any complications during long-term follow-up, with the best prognosis. Young patients without AH had the greatest differences in the development of CV events (Log-Rank, p=0.005), compared with the older age group, while young patients with AH had a complication rate similar to the older age group (Log-Rank, p=0.692). LVEF less than 40% for the first day of AMI indicated a high probability of death from any cause not only during the hospital period, but also within 5 years of observation - RR 3.4: 95% CI 1.2 - 20.5; p=0.022.
It was found that the incidence of at least one of MACE events in young patients with level of LDL-C≥4.0 mmol/l, was 14.8% after 1 year, 25.9% after 3 years and after 5 years of follow-up (Log-rank test, p=0.026), compared to patients with LDL-C<4.0 mmol/l.
ROC analysis revealed that LDL-C=4.125 mmol/l has a high prognostic significance in patients <45 years for the development of complications after STEMI, sensitivity=58.3%, specificity=80.6%, area under the ROC curve 0.746 (95% CI 0.59-0.90).
Using the Cox Regression analysis AH and smoking were identified as independent predictors of the development of cardiovascular death in young people during 5 years of follow-up (HR 10.36 (95% CI 1.69-63.50) and HR 6.34 (95% CI 1.33-30.14), accordingly. Patients who underwent revascularization had a 67% lower risk of mortality, taking into account other clinical features (aHR: 0.33, 95% CI: 0.11-0.97). DM type 2 was the most influenced factors of the development of recurrent non-fatal CV events within 5 years after undergoing AMI (HR 6.63 (95% CI 1.76-25.05).
Young adults have a lower adherence to treatment compared to the older group (24.2% vs. 42%, p<0.001).
Patients of young age after AMI should give one of the antithrombotic drugs and statins for secondary prevention.
