Background: Cardiovascular morbidity and mortality rates are high in Russia and it is likely that this reflects a similar impact on the general cardiac health of the population. The current study seeks to compare standard echocardiography and strain-based measurements between Russian and Norwegian populations, while also exploring their links to hemodynamic and risk factors.
Methods: This study included echocardiographic measurements of 1,192 participants from Arkhangelsk and Novosibirsk, Russia, and 917 from the Tromsø Study population, Norway. The sample included men and women aged 40–69 years. Normalcy, defined as the absence of hypertension or indicators of CVD, was observed in 840 individuals. We performed conventional echocardiography and analysed two-dimensional speckle-tracking longitudinal strains, including systolic, early-, and late-diastolic SR values. The study population was divided into four groups: normal, controlled hypertension, hypertensive blood pressure, and cardiac disease. Echocardiographic parameters were compared between the Russian and Norwegian populations,adjusted for age, sex, height, body mass index, blood pressure, heart rate (HR), atrial fibrillation (AF), smoking, pulmonary hypertension, and serum values for total, LDL (low density lipoprotein), and HDL (high density lipoprotein) cholesterol; triglycerides; creatinine; high-sensitivity C-reactive protein; and HbA1C.
Results: Russians showed a tendency towards lower longitudinal systolic functional parameters, which were most prominent in the normotensive group. However, these differences became insignificant after adjusting for parameters that influence pre- and after-loads. Russians also had a lower stroke volume, higher HR, higher left atrial volume, lower A, and higher E/A ratio, indicating a higher incidence of diastolic dysfunction in the Russian population that persisted after adjustments.
Conclusion: After adjusting for factors that influence cardiac function, there were no differences in systolic functional parameters betweenthe Norwegian and Russian populations. However, differences in diastolic parameters, which persisted after adjusting for conventionally influential factors, indicated unexplained underlying causes of diastolic dysfunction in the Russian population.