Associations of ECG Signs of Ischemic and Non-Specific Signs of Metabolic Changes in the Myocardium With Unfavorable Cardiovascular Prognosis in a 7-Year Prospective Follow-Up of Young People Under 45 Years

Abstract

Aim. To study ischemic and/or nonspecific ECG signs of metabolic changes in the myocardium and to determine their relationship with unfavorable cardiovascular prognosis in a 7-year prospective observation of young people under 45 years of age.Material and methods. A cross-sectional population survey of a random sample aged 25-44 years (n=1363) was conducted in Novosibirsk. The survey program used the standardized epidemiological Rose questionnaire. Biochemical tests were used to measure blood concentrations of total cholesterol (C), triglycerides (TG), low- and high-density lipoprotein cholesterol (LDL-C, HDL-C), and fasting blood plasma glucose. Systolic and diastolic BP (SBP, DBP), the presence of arterial hypertension (AH), body mass index (BMI), waist circumference (WC), and smoking status were assessed. ECG was recorded at rest in 12 standard leads followed by interpretation according to the Minnesota Code. The presence of ischemic and/or nonspecific ECG signs of metabolic changes in the myocardium was determined. Subjects with ECG signs of ischemic changes in the myocardium were selected for long-term follow-up and additional examination by cardiologists. Then the whole cohort was monitored for 7 years, and cardiovascular events were recorded, including using data from the WHO Myocardial Infarction Registry in Novosibirsk. For statistical analysis of the results, cardiovascular events were combined into a composite endpoint.Results. During 7 years, 40 people (27 men and 13 women) had an unfavorable cardiovascular prognosis. Multivariate regression analysis showed that a 7-year unfavorable cardiovascular prognosis in people younger than 45 years was associated with signs of ischemic myocardial alterations identified on the background ECG (OR 5.319, 95% CI: 1.543-18.342, p=0.008) and nonspecific ECG signs of metabolic changes in the myocardium (OR 2.978, 95% CI: 1.216-7.216, p=0.017) regardless of age, gender, the presence of arterial hypertension (AH) and type 2 diabetes mellitus (DM2).Conclusion. In young people under 45 years of age, not only ECG signs of ischemic changes in the myocardium, but also nonspecific ECG signs of metabolic changes in the myocardium are associated with an unfavorable cardiovascular prognosis, directly and independently on age and gender, in a long-term, 7-year period.