Aim. This study aims to compare the results of the distal femoral access with the classic approach in patients undergoing pulmonary vein cryoballoon ablation and left atrial appendage occluder implantation.

Methods. The primary results of the 1:1 randomized single-center study are presented. The study group recruited 47 patients who underwent the catheter-based procedure using ultrasound-assisted distal femoral access. 38 patients with traditional ultrasound-guided proximal femoral access were involved in the control group.

Results. Total 85 patients were included: 47 in the study group and 38 in the control group. The median age was 61 years, and pulmonary vein cryo-ablation was performed in 84%. 95% of patients were taking direct oral anticoagulants. In the study group, the most frequent topographic and anatomical variant was the location of the superficial femoral vein on the lateral side from the artery (81%), whereas in the control group it was on the medial side (81%). The median access time was 30 s in the study group for the right leg and 35 s for the left leg. In the control group, access time was 33 s and 39 s for the right and left leg respectively. Unintentional arterial puncture occurred more frequently in both groups when the vein was fully overlapped by the artery for both right and left legs, but the differences were statistical unsignificant (p>0.05 and p=0.09 in the main group, p=0.24 and p=0.72 in the control group). In a correlation analysis, neither body mass index (p=0.19) nor femoral circumference (p=0.19 for right and p=0.06 for left legs) influenced the access time and did not increase the number of unintended arterial punctures. Two patients in the control group required additional manual hemostasis. There was no postprocedural venous thrombosis in both groups. Back pain was observed only in patients in the control group.

Conclusion. The efficacy and safety of the distal femoral access approach are comparable to the traditional proximal approach. Earlier postprocedural activation of patients can help improve quality of life.

Aim. Cardiac contractility modulation (CCM) is a device therapy for patients with heart failure with reduced ejection fraction (HFrEF), most of the data on its programming are concerned patients with narrow QRS and of limited follow up. Our aim was to propose programming approach for Optimizer device in setting of wide QRS complex and fragmented ventricular local activation.

Methods. We enrolled 11 patients with HFrEF (median age, 8 males, median NYHA class 3) and LBBB-related wide QRS complex, who underwent Optimizer™ device implantation. Three patients got Optimizer™ IV system and eight patients were implanted Optimizer™ Smart. Ten patients were previously implanted with CRT-D due to HFrEF and LBBB; one patient received CRT-D after Optimizer™ implantation.

Results. During the implantation procedure ventricular local sense (LS) channel signal fragmentation was detected in all patients. In five patients signal detection was optimized by lead relocation. In six patients LS signal sensitivity limitations were resolved by programming. At two-year follow-up survival 4 patients died of noncardiac causes (1 intracranial hemorrhage, 1 gastrointestinal bleeding and 2 - terminal kidney failure). At 12-month follow-up we observed a non-significant improvement in 6-minute walking distance (300 vs 305, p=0.093), NYHA class (2.75 vs 2, p=0.085), MLHF score (53 vs 42, p=0.109) and left ventricular ejection fraction (LVEF) (30 vs 33.5, p=0.212).

Conclusion. CCM system implantation is feasible and safe in patients with HFrEF and LBBB-related wide QRS complex. Device programming maneuvers can resolve the challenges of ventricular local signal detection in these patients.

Aim. To evaluate the efficacy of thoracoscopic ablation (TSA) of persistent and long-standing atrial fibrillation (AF) in the long-term follow-up period.

Methods. TSA of AF with unilateral left atrial appendage exclusion was performed in 50 patients with persistent (group I) and 50 patients with long-onset AF (group II). Efficacy was defined as the absence of any atrial tachyarrhythmia (atrial fibrillation, atrial flutter, or supraventricular tachycardia) lasting more than 30 seconds recorded on Holter ECG monitoring at study controls.

Results. TSA was 78% effective in group I and 63% effective in group II over the three-year follow-up period (p=0,037). Catheter ablations 3 months after TSA were required in 8 (16%) patients in group I and 9 (18%) in group II (p>0,05), of which two patients had typical atrial flutter on ECG, which required radiofrequency ablation of the cavotricuspid isthmus. The efficacy of staged treatment of AF at 3 months after additional catheter ablation was 100% and 88,2% after 6 months.

Conclusion. Video-assisted thoracoscopic ablation of atrial fibrillation should be considered a promising approach for the management of persistent and long-standing atrial fibrillation.

Aim. To develop a method for predicting the area of low-voltage area (LVA) in the left atrium (LA), associated with the minimum and maximum expected effectiveness of primary radiofrequency ablation (RFA) in patients with non-valvular atrial fibrillation (AF) using non-invasive predictors.

Methods. A longitudinal single-center study included 150 symptomatic non-valvular AF pts aged 20-72 years (median 59.0 [51.0; 64.0]), including 63 women (42%) hospitalized for primary RFA; 119 pts (79.3%) had paroxysmal and 31 (20.7%) - persistent AF. All pts initially underwent general clinical examination, transesophageal and advanced transthoracic echocardiography, estimation of NT-proBNP (pg/ml) and growth differentiation factor 15 (GDF-15, pg/ml) in the blood. Electroanatomical mapping was performed in sinus rhythm before RFA. The area of LVA (<0.5 mV) was calculated as percentage of total LA area. Left ventricular (LV) ejection fraction (LVEF) was >50% in all pts.

Results. LVA area varied from 0 to 95.3%, median was 13.7% [5.1; 30.9]. Depending on LVA area, pts were divided into 3 groups: 36 pts (<5%) in gr. 1; 74 pts (5-30%) in gr. 2; 40 pts (>30%) in gr. 3. Increase of LVA area was associated with age, presence, and severity of congestive heart failure (CHF), persistent AF, CHA₂DS₂ -VASc score ≥3 points, increase of LA volume, LV hypertrophy and increase of NT-proBNP and GDF-15 levels. In univariate analysis, LVA area <5% was associated with NT-proBNP level <125 pg/ml, absence of obesity and CHF, lower LA volume index (<28 ml/ m²). Independent predictors of LVA <5% were: NT-proBNP <125 pg/ml, absence of obesity and LA volume index ≤28 ml/ m². The model was of good quality, C-statistics was 0.775 (p<0.001). In univariate analysis, LVA area >30 % was associated with age >60 years, NT-proBNP >125 pg/ml, GDF-15 >840 pg/ml, persistent AF, presence of LV hypertrophy, LVEF ≤60%, LA volume index ≥ 32 ml/m². Independent predictors of LVA >30% were: LA volume index ≥32 ml/m², GDF-15 >840 pg/ml, and LVEF ≤60%. The model was of good quality, C-statistics was 0.752 (p<0.001).

Conclusion. Evaluation of noninvasive parameters, including clinical characteristics, echocardiographic parameters, and blood levels of NT-proBNP and GDF-15, allows prediction of electroanatomical substrate in left atrium in pts with non-valvular AF referred to primary RFA.

Aim. To study the effectiveness of “extended” cryoballon ablation in patients with a persistent form of atrial fibrillation (AF) and to determine the risk factors for AF recurrence after cryoablation.

Methods. The study included 89 patients (62±10 years, 24 [27%] men) with a persistent form of AF. The patients were randomized into two groups: in the 1st, the pulmonary veins (PV) cryoablation was performed (n=48 [53.9%]); in the 2nd, the PV cryoablation was performed in combination with cryoablation of the posterior wall of the left atrium (n=41 [46.1%]). The number of patients at high risk of thromboembolic events predominated in Group 2 (p=0,03). There is a high frequency of taking antiarrhythmic drugs of class III in this group (p=0.018). The follow-up period was 12 months. Clinical efficacy was assessed during a survey and daily ECG monitoring at face-to-face visits after 3, 6 and 12 months.

Results. Antral isolation of PV was achieved in all 89 (100%) patients in both groups. In group 2, the average number of applications in the posterior wall of the PV was 10 [9; 13]. The effectiveness of cryoablation in group 1 by the end of the 12-month follow-up period was 54.2%, in group 2 - 56.1%. The complication rate (6.7%) in both groups did not differ statistically (p=0.683). The risk of arrhythmia recurrence didn’t depend on the strategy of cryoablation in postablation period (p=0.834). When conducting a single-factor analysis, a statistically significant effect on the probability of AF recurrence in the period of 3-12 months in group 1 was caused by AF recurrence in the blind period (95% confidence interval (CI): 1.5-27.7, p=0.013), in group 2 belonging to the female sex (95% CI: 1.2-24.6, p=0.032) and AF relapse in the blind period (95% CI: 1.5-128.5, p=0.020). During multivariate analysis in group 2, a statistically significant influence on the risk of AF recurrence in the period of 3-12 months was exerted by belonging to the female sex (hazard ratio (HR) 7.84; 95% CI 1478-42,23; p=0.016) and the presence of early AF recurrence (HR 20.36; 95% CI 1.99-208.23; p=0.011).

Conclusion. Extended cryoablation in terms of efficiency and safety was comparable with the standard cryoablation. Early recurrence of AF (in the first 3 months after the intervention) turned out to be an independent risk factor for AF recurrence in the long-term period up to 12 months after cryoablation in both groups.

Aim. To develop a multifactorial model for predicting the development of polymorphic ventricular tachycardia (VT) in patients with drug-induced long QT syndrome (LQTS) induced by class III antiarrhythmic drugs (AADs) by identifying electrocardiographic, laboratory and molecular genetic predictors.

Methods. The study included 64 patients (37 (57.9%) women and 27 (42.1%) men, mean age 57.2±9.4 years) with ischemic heart disease and/or arterial hypertension. and cardiac arrhythmias, in which drug-induced prolongation of the QTc interval (Bazett) (over 450 ms in men and over 470 ms in women) was noted with the use of class III AADs (amiodarone or sotalol) in a cardiac hospital. Depending on the presence or absence of non-sustained polymorphic VT according to 24-hour ECG Holter monitoring, patients were further divided into two groups: 17 patients with episodes of non-sustained polymorphic VT and 47 patients without such episodes. All patients underwent clinical and laboratory, instrumental and molecular genetic studies, which included taking an anamnesis, recording ECG in 12 leads, biochemical blood test, determining the levels of neuronal NO-synthase (NOS1) and the adapter protein of neuronal NO-synthase (NOS1AP) in blood serum by enzyme immunoassay, determination of nitric oxide synthase gene polymorphisms by polymerase chain reaction. To assess the relationship of the studied parameters with the achievement of the end point, the method of logistic regression with a binary response and the logit function of the connection was used.

Results. To assess the risk of developing non-sustained polymorphic VT in patients with drug-induced LQTS while taking class III AADs, a complex binary logistic regression model was developed, including the following indicators: patient gender (p=0.019), relative variance of the QT interval (p=0.002), duration of the T_peak-T_end interval, (p=0.034), serum magnesium (p=0.004) and NOS1 (p=0.004) levels, as well as the AA genotype of the G84A polymorphism of the NOS1 gene (p=0.049). With the calculated value of the threshold probability p≥0.48, the developed model makes it possible to identify patients at high risk of developing polymorphic VT in patients with drug-induced LQTS with a sensitivity of 94.12%, a specificity of 89.36%, and an area under the ROC curve of 0.977 (0.95-1.0, p<0.001).

Conclusion. The developed complex model will allow predicting the risk of proarrhythmic effects in patients with drug-induced LQTS, which will lead to a decrease in the number of cardiovascular events in this category of patients.

Aim. To investigate the relationship between left ventricular (LV) mechanical dyssynchrony with cardiac resynchronization therapy (CRT) response in chronic heart failure (CHF) pts with left bundle branch block.

Methods. Forty-nine pts (male - 34 [69.4%], average age 58.3±11.4 years) with sinus rhythm, permanent left bundle branch block with QRS duration ≥150 ms and New York Heart Association (NYHA) II-III functional class of CHF were included in the study. In addition to full examination, myocardial perfusion scintigraphy (MPS) and gated blood pool single-photon emission computed tomography (gBPS) were performed before and 6 months after CRT devices with cardioverter-defibrillator function implantation. Pts were considered as responders to CRT if they fulfilled after 6-month follow-up the following combined criteria: NYHA FC improvement ≥1 class + LV end systolic volume decrease >15% or NYHA FC improvement ≥1 class + LV ejection fraction improvement >5%.

Results. The 1st and 2nd groups included 35 (71.4%) and 14 (28.6%) pts with and without response to CRT respectively. Groups were comparable in terms of pre-CRT implantation clinical and instrumental parameters, except for MPS and gBPS parameters. The multivariate logistic regression had shown that only ∆interventricular dyssynchrony (adjusted odds ratio [OR] 1,0349; 95% confidence interval [CI] 1.0075-1,0631; р=0.01) and phase standard deviation of the anterior LV wall (OR 1.0669; 95% CI 1.0118-1.1251; p=0.01) were independently related with CRT response. An increase in the prognostic coefficient, calculated using the ∆interventricular dyssynchrony and phase standard deviation of the anterior LV wall, more than 0.67 was a predictor of CRT response (area under the curve 0.918; sensitivity 85.71; specificity 85.71; p <0.001).

Conclusion. The mechanical dyssynchrony assessed by MPS and gBPS is associated with CRT response. According to our predictive model, an increase in prognostic coefficient more than 0.67 is a predictor of CRT response.

The prevalence of familial atrial fibrillation (AF) in the general population and in the structure of AF is considered, and genetic predictors of AF and pathogenetic mechanisms of atrial remodeling are analyzed. The assessment of the genetic risk of AF occurrence, the prediction of its outcomes and the effectiveness of AF therapy, as well as the prospects for AF gene therapy are discussed.

The increasing use of air transport by people with cardiovascular diseases, prone to problems associated with air travel, and require more attention during the entire journey. Considerations for preventing the worsening of the condition of patients during air travel based on the available data are summarised, algorithms for preliminary risk assessment and preparation of patients with cardiac arrhythmias are given.