Aim.To evaluate the diagnostic accuracy of a noninvasive method of fractional flow reserve (FFR) assessment based on a one-dimensional hemodynamic model build on data obtained from the coronary computed tomography angiography (CCTA).Material and methods.The study enrolled 57 patients: 16 of them underwent 64-slice computed tomography — included retrospectively, 34 — prospectively, with a 640-slice CT scan. Specialists from the Laboratory of Mathematical Modeling processed CT images and evaluated noninvasive FFR. Ischemia was confirmed if FFR <0,80 and disproved if FFR ≥0,80. After that the prospective group of patients was hospitalized for invasive FFR assessment as a reference standard; if ischemia was proved, patients underwent stent implantation. In the retrospective group, patients already had invasive FFR values estimated. Statistical analysis was performed using R programming language packages (cran-r.project.com). Continuous variables are presented as mean values ± standard deviations, order variables are presented as medians with interquartile ranges in parentheses. We used the D’Agostino-Pearson omnibus test for the assessment of normality of distribution; a Q-Q Plot was also constructed. We performed the Bland-Altman analysis and ROC-analysis for comparison of these two methods, and the Pearson’s chi-squared to assess the degree of correlation.Results.During data processing, 3 patients of the retrospective and 34 patients of the prospective group were excluded from the study. The sensitivity of our method was 90,91% (95% CI; 58,72-99,77), specificity — 86,67% (95% CI; 59,54-98,34), P<0,05, accuracy — 88,46 (95% CI; 69,85-97,55) — in per-vessel analysis. In perpatient analysis, the sensitivity was 91,67% (95% CI; 61,52-99,79), specificity — 80% (95% CI; 28,36-99,49), (P<0,05); accuracy 88,24 (95% CI; 63,56-98,54).Conclusion.Our method has quite a high accuracy and can be successfully used in clinical practice in order to enhance the diagnostic efficiency of the CCTA.

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Атеросклероз сонных артерий является одной из наиболее частых причин развития ишемических инсультов и выступает этиологическим фактором в 20-30% случаев [1]. Учитывая достаточно высокий периоперационный риск (смерть, острые нарушения мозгового кровотока (ОНМК)), каротидная реваску-ляризация (эндартерэктомия и стентирование) пока-зана только пациентом с тяжелым атеросклеротиче-ским поражением брахиоцефальных артерий (стеноз более 70% при ультразвуковом исследовании или более 50% при ангиографии) [1,2]. Несмотря на тща-тельный отбор пациентов, частота ОНМК при каро-тидной реваскуляризации составляет от 1,5 до 9,0% [1,3] Aim. Hemodynamic shifts in the brain, developing due to carotid surgery (carotid endarterectomy or stenting) might be the cause of perioperation strokes. Assessment for hemodynamic shifts is important. The aim of current study was to develop methodics of cerebral hemodynamics assessment at pre-operation and post-operation periods of carotid endarterectomy. Material and methods. The authors propose a mathematical model for preoperation analysis of hemodynamics changes in extracranial regions of brachiocephalic arteries after carotid endarterctomy. The development of mathematical model was based upon the data from pre-and postsurgery duplex scan and CT-angiography. Results. The results showed good prediction capacity for the shifts in cerebral hemodynamics, using the developed mathematical model.

The aim. To evaluate the reliability of blood pressure (BP) measurement results using a cuffless blood pressure device (CardioQVARK®) in comparison with the values obtained using the Korotkov method.Materials and methods. An observational cross-sectional study of 50 patients (25 men, mean age 60 ± 14 years) with arterial hypertension was performed. Blood pressure was measured by the Korotkov method as a standard method, and a CardioQVARK® device, made in the form of a smartphone case, was used as a new method. The device records the electrocardiogram and the photoplethysmogram. Based on the parameters of the electrocardiogram and the photoplethysmogram the systolic and diastolic blood pressure (SBP and DBP) is calculated. Correlation analysis, Student’s t-test, Bland-Altman method were used for comparing the two methods, the standard deviation of the difference and a 95% confidence interval (95% CI) were calculated.Results. There were no statistically significant differences in the mean values of SBP and DBP for the two methods. There was a strong direct relationship between SBP (r = 0.976, p < 0.0001) and DBP (r = 0.817, p < 0.0001), measured by two methods. Bias for SBP and DBP measured by the new method was: –0.5 mm Hg (95% CI: –1.7; 0.7) and –0.3 mmHg (95% CI: –1.4; 0.7), respectively. The difference in DBP measurements depended on the blood pressure level (r = 0.302, p = 0.03). The underestimation of DBP values was more pronounced for low blood pressure from 55 to 75 mm Hg. At the time of the study, 13 (26%) patients had an increase in blood pressure. The sensitivity of the new method in detecting arterial hypertension was 77% (95% CI: 46; 95), specificity 100% (95% CI: 91; 100), accuracy 94% (95% CI: 83; 99).Conclusion. The blood pressure measurement method based on the analysis of the electrocardiogram and photoplethysmogram showed reliable blood pressure measurement results in comparison with the Korotkov method.

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Aim.To assess the efficacy of algorithms for minimization of the rightventricular stimulation (MVS) for prevention of atrial fibrillation (AF) progression in patients with sick sinus node syndrome (SSS) and documented AF in anamnesis, comparing to standard bi-chamber electrical stimulation (DDDR). Material and methods. The study was one-center, prospective, randomized trial with consequent 74 patients inclusion, who had indications to permanent DDDR due to SSS and AF in anamnesis. Patients were randomized to DDDR group (n=36) and active MVS (n=38) group. Procedure of electrocardiostimulator (ECS) maintenance was done at 6 months and 1 year. During follow-up visits, information was saved in the ECS memory, as the data on AF burden. Primary endpoints were AF burden and time to persistent AF onset. Results. During the study, there were no significant differences in AF burden between the groups. Median of AF burden was 6,0 min/day (25-75 percentiles: 0-42 min/day) in DDDR, and 6,0 min/day (25-75 perc.: 0-42 min/day; p=0,67) in MVS group. Persistent AF development was registered in 5 patients, of those 3 (8,6%) in DDDR and in 2 (5,3%) in MVS (HR 1,25; 95% CI 0,2-7,98; p=0,47). Medication or electrocardioversion was done for 9 (25,7%) patients from DDDR and 12 (31,6%) from MVS groups (HR 0,86, 95% CI 0,31-2,38, p=0,39). Conclusion.There was no benefit of MVS algorithms in short term period in decrease of AF burden and in its progression prevention towards persistent AF in SSS patients with the anamnesis of paroxysmal AF, comparing to standard DDDR regimen of ECS.

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