Myocardial infarction in the population of some Russian regions and its prognostic value

Abstract

Aim. To study the prevalence of myocardial infarction (MI) in the population of Russian regions and its contribution to cardiovascular events.Material and methods. The analysis material was representative samples of the population aged 35-64 years from 11 Russian regions,  examined within the multicenter study “Epidemiology of Cardiovascular Diseases and their Risk Factors in Regions  of Russian Federation”. The response rate was about 80%. The study used a community-based  systematic stratified multiply random sample. During the study, information on prior MI was obtained using a standard questionnaire. Anthropometry and measurement of blood pressure (BP) and heart rate (HR) with an automatic BP monitor were performed. Resting electrocardiography (ECG) was performed, followed by Minnesota coding. Major and minor QQS waves and STT segments were considered as ischemic  ECG abnormalities. Biochemical parameters were determined using an Arkhitect 000 Clinical Chemistry Analyzer. The median prospective  follow-up was 6,21 [5,25; 6,75] years. A composite endpoint (CE) was analyzed, including cardiovascular death and non-fatal MI. During the follow-up period, 363 all-cause deaths were detected,  of which 134 were from cardiovascular diseases, while 196 — CEs. Statistical analysis was carried out in R 3.6.1 environment.Results. The MI prevalence among the Russian population was 2,9%; 5,2% for men and 1,5% for women,  increasing  with age. Men with prior MI were  more likely to take statins and beta-blockers  than women as follows: 39,0% vs 25,6% and 29,3% vs 27,1%, respectively. MI newly diagnosed within the follow-up  period was associated with the following risk factors (RFs): smoking, increased BP, HR, triglycerides and glucose.  For individuals with prior MI, a significant relationship was found only with smoking.  Multiple comparison  of the contribution of RFs, ECG abnormalities,  and prior MI showed  that the inclusion of ischemic ECG abnormalities in the analysis significantly increases  the risk of cardiovascular events in individuals without prior MI compared with individuals without both MI and ECG changes.  A high CE risk was noted in patients with prior MI: relative risk (RR), 4,73 (2,92-7,65); the addition of ischemic ECG abnormalities increased the RR to 5,75 (3,76-8,8).Conclusion. The RR of CEs in patients  with prior MI without or with ischemic ECG changes  is 4,73 and 5,75 times higher than in patients without MI and ECG abnormalities. The risk factors  identified  in this case cannot explain such an increase  in CEs. It is obvious  that people  with prior MI need  rehabilitation. The presence of RFs in patients with newly diagnosed  MI indicates insufficient primary prevention, which suggests  that strengthening preventive measures to eliminate conventional risk factors in patients with newly diagnosed  MI will help reduce the risk of recurrent MI or cardiovascular  mortality.