Background. January 2021 marked one year since the start of COVID-19 pandemic: it is the time of intermediate conclusions. Objective. To evaluate CFR and IFR due to COVID-19 in various countries and territories, and to study if parameters of a population age affect CFR and IFR. Material and Methods. The databases of 219 countries were collected on the Worldometers, Index Mundi, Country Meters and World Bank websites. The processing of data was divided into two parts: the first part dealt with the calculation and analysis of CFR while the second, the calculation and analysis of IFR. Results. The calculations revealed that in 74 out of 219 countries, CFR was less than 1.00 %, in 69 countries it varied between 1.00 % and 2.00 %, and in 76 countries it was more than 2.00 %. The calculation of IFR revealed that in 183 countries, IFR was less than 1.00 %, in 22 countries IFR was between 1.00 % and 2.00 %, and only in 14 out of 219 countries IFR was more than 2.00 %. A correlation between IFR and parameters of a population age was found: the less median age and the percentage of 'aged' people – the less value of IFR, although, there was no correlation between parameters of a population age and CFR. Conclusion. The global health care system has gone through a year of serious trial caused by COVID-19 and appeared to have emerged victorious. In the majority of countries analyzed, the parameters of mortality due to COVID-19 were at a low level. So, there seems to be an objective basis for optimism and hope for an early end to the pandemic.

Haemodynamic indices are widely used in clinical practice for deciding on a particular type of treatment. Low quality of the CT data and tachycardia complicate interpretation of the measured or simulated values. In this work, we present a novel approach for evaluating resistances in terminal coronary arteries. Using 14 measurements from 10 patients, we show that this algorithm retains the accuracy of 1D haemodynamic simulations in less detailed (truncated) geometric models of coronary networks. We also apply the variable systole fraction model to study the effect of elevated heart rate on the values of FFR, CFR and iFR. We conclude that tachycardia may produce both overestimation or underestimation of coronary stenosis significance.