Russian Federation President Grant Research Articles

Ongoing antiarrhythmic drug therapy type does not affect the rate of first-pass pulmonary vein isolation: data from a multicenter registry

Abstract Background It is well-known that antiarrhythmic drugs (AAD) change the electrophysiological properties of the atrium mostly by increasing the atrial refractory period and wavelength for reentry. Frequently, atrial fibrillation (AF) catheter ablation is being performed with AAD interruption. However, the information on the impact of AAD on AF ablation performance is lacking, and AAD interruption is not desirable in highly symptomatic patients with persistent arrhythmia. Purpose We sought to study potential differences in achieving first-pass pulmonary vein isolation (FPI) during AF ablation in patients receiving different classes of ongoing AADs. Methods This was a prospective observational multicenter registry. All centers were invited to participate in the registry voluntarily. Data on demographic, clinical, and procedure characteristics were derived from a web-based system. All catheter ablation procedures were performed according to local practices. A total of 450 patients were enrolled, 408 of them underwent first-time AF ablation. Data on AAD characteristics were available in 350 patients (mean age 61±9 years, 195 (56%) males, 270 (77%) had paroxysmal AF). All patients were divided into three groups: ongoing I class AAD treatment (propafenone, ethacyzin, allapinin, n=76), ongoing II class AAD (beta-blockers, n=60), and ongoing III class AAD (amiodarone, sotalol, n=214). Results Baseline clinical and procedural characteristics between AAD groups are summarized in Table. Patients in the I class AAD group were younger, likely had paroxysmal AF, and a smaller mean left atrial diameter. Procedures in the III class AAD group were performed with a higher median target ablation index on the posterior left atrial wall. But the percentage of first-pass isolation was distributed equally between groups (60%, 68%, 61%, p=0.56). The correlation matrix revealed no significant associations between FPI and clinical and procedural variables (r=0.02–0.09; p>0.05 for all). Conclusion(s) Our real-life multicenter data demonstrate no difference in FPI achievement between patients receiving different AADs. We suggest that highly symptomatic patients may continue pharmacological treatment during AF ablation without compromising acute ablation success. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Ministry of Science and Higher Education grant (Russian Federation President Grant) Table 1. Clinical and procedural parameter

Features of remote rehabilitation using the developed mobile app in patients after cardiac bypass surgery

Abstract Aim of the study The aim of the study is to evaluate the features and availability of the developed remote rehabilitation program with the use of a mobile application in patients who have undergone coronary artery bypass surgery (CABG) and surgical correction of valvular heart disease (VHD). Material and methods of research In the current epidemiological situation, to increase the availability of cardiorehabilitation for patients after open heart surgery, a mobile application with the program “Remote rehabilitation of patients who have undergone heart surgery” was developed. The remote rehabilitation program included 46 patients (median age 60.0 [53.0; 64.0]) who underwent cardiac surgery. Of these, 22 patients after CABG (median age 61.0 [53.0; 63.5]) and 24 patients after surgical correction of VHD (median age 59.5 [54.0; 63.75]). On the 5th day after the surgery, the developed application for remote rehabilitation was installed on the smartphone. It consisted of 5 sections: Dosed Walking, Therapeutic gymnastics, Diet, Psychology and Chat. After application installing and until the moment of discharge from the hospital, 3 classes with a total duration of 6 academic hours were conducted with each patient. After being discharged from the hospital the patients were recommended to use the mobile app for rehabilitation at home for 4 months. 4 months after the surgery the app usage statistics were evaluated and a telephone survey of the reasons for non-complience was conducted. Results A total of 34 (74%) patients used the mobile app for remote rehabilitation. Of these, 24 (52.0%) used the app section “Dosed Walking” and “Therapeutic Gymnastics” at least 5 times a week for 4 months, 10 (22%) used the app no more than 10 times during the entire follow-up period, and 12 (26%) did not engage in remote rehabilitation using the app. 22% of patients received consultations with a cardiologist via chat in mobile app. The telephone survey revealed the main reasons for the irregular participation of patients in the remote rehabilitation program using the mobile app: lack of interest/desire to engage in physical rehabilitation – 16 (35%), problems with the Internet – 6 (13%), lack of time – 4 (8.5%), incorrect function of the app – 4 (8.5%). Conclusions Insufficient adherence of patients after cardiac surgery to a remote rehabilitation program using a mobile application, associated with a lack of motivation in patients, was demonstrated. This implies the importance of developing and implementing further measures to increase the motivation and adherence of patients to participate in long-term remote cardiac rehabilitation programs. Funding Acknowledgement Type of funding sources: Public Institution(s). Main funding source(s): Russian Federation President grant

The role of a difference between target and actual ablation index values for first-pass point-by-point pulmonary vein isolation: results from a multicenter prospective registry

Abstract Funding Acknowledgements Type of funding sources: Other. Main funding source(s): Ministry of Science and Higher Education grant (Russian Federation President Grant) Background/Introduction. Pulmonary vein electrical isolation (PVI) is a cornerstone of atrial fibrillation (AF) ablation. The Ablation Index (AI) aims to improve the efficacy and safety of radiofrequency (RF) PVI. First-pass isolation (FPI) is an indicator of PVI acute success. Target AI is being calculated for every operator as a mean value (usually, differently for anterior and posterior left atrial (LA) segments) following several "ideal" first-pass PVI procedures. However, adherence to target values, as well as its clinical importance, are unknown. Purpose. The aim of the present study was to evaluate the difference between the target and actual AI in the real practice. Methods. This work represents data from the Prospective Multicenter AF Ablation Registry. Data were collected using a web-based system. PVI procedures were performed according to the local practice, and RF ablation settings depended on operators’ preferences. Between January 2019 and December 2020, a total of 446 patients were enrolled from 7 centers, 407 of them underwent first-time AF ablation and were included into the analysis (mean age 61 ± 9 years old; 226 (55%) males; 313 (76%) with paroxysmal AF). FPI was determined as PVI achieved after circular ablation around PVs without additional applications plus persistence of bidirectional block over a 20-minute waiting period. Therefore, patients were divided in two groups: Group 1 (FPI, n = 242) and Group 2 (non-FPI, n = 165). Results. There was a significant difference between target (the mean target AI for the anterior LA segments was 438 ± 58 and 390 ± 27 for the posterior segments) and actually achieved mean AI (406 ± 33 for anterior segments and 389 ± 34 for posterior segments) with a greater difference for anterior segments (Δ 26 (95% CI [19; 32], p = 0,0001) than for posterior (Δ 4 (95% CI [0,2; 8], p = 0,042). The number of patients with a mean actual AI lower than a target value on the anterior and posterior LA walls was 219 (54%) and 171 (42%), respectively. In the FPI group higher mean values of target AI were present (FPI 444 ± 52 for anterior and 393 ± 27 for posterior LA segments vs non-FPI 432 ± 51 (p = 0,04) and 387 ± 23 (p = 0,01), respectively). The FPI group was characterized by higher mean actual AIs on anterior segments (FPI 410 ± 36 vs non-FPI 399 ± 25, p = 0,0001). There was no difference between groups in actual AI on the posterior wall (391 ± 27 vs 386 ± 41, p = 0,1). The non-FPI group was characterized by a higher proportion of subjects with hypertension (87% vs 69%, p = 0,0001) and a lower number of subjects with central obesity (body mass index≥30 in 48% vs 57%, p = 0,04). Conclusion(s). According to our prospective multicenter data, target AI is not achieved in a significant proportion of patients during PVI. This is associated with acute PV electrical reconduction and the necessity in additional ablations. FPI can be achieved more frequently when a higher mean AI value is achieved.

Shorter interlesion distance is associated with a longer procedure time but not with poorer acute results of pulmonary vein isolation: results from a prospective ablation index registry

Abstract Funding Acknowledgements Type of funding sources: Other. Main funding source(s): This work was supported by the Ministry of Science and Higher Education grant (Russian Federation President Grant) #MD-2314.2020.7. Background/Introduction. Radiofrequency ablation (RFA) is the mainstay of invasive management of atrial fibrillation (AF). Amongst a variety of performance indicators, interlesion distance (ILD) has a potential to become a guiding one. Uptodate clinical AF RFA protocols suggest that ILD has to be less than 6 mm, however the research is still lacking in regard to its actual targeted value. Purpose. The aim of the research is to study a relationship between ILD and first-pass isolation (FPI) in ablation-index guided AF ablation procedures. Methods. This was a prospective observational multicenter study. Data were derived from the web-based system. Pulmonary veins (PV) isolation procedures were performed according to the local practice, and RFA settings depended on operators’ preferences. A total of 446 patients were enrolled, 407 of them underwent first-time AF ablation, data on ILD available in 322 subjects (177 (55%) males, mean age 62 ± 9 years old, 259 (80%) with paroxysmal AF). A mean ILD was calculated manually in each case as a sum of all ILDs divided by number of ablation tag points. FPI was considered in cases when no additional applications were required for bidirectional PV block following creation of a one circle around ipsilateral PVs and after a 20-min waiting period. Patients were divided into two groups according to ILD (Group 1 ILD≤ 4 mm, 163 patients and Group 2 ILD > 4m, 159 patients) post-procedurally. Results. The mean procedure time was 102 ± 52 min, the median fluoro time was 9 min [IQR 6; 15]. The following VisiTag parameters were used: the median target ablation index 400 [IQR 400; 500] on the left atrial anterior wall and 380 [IQR 380; 400] on the posterior segments, the median minimal contact force 3g [IQR 3; 4], median minimal time per a point - 4 sec [IQR 3; 15], mean catheter stability 3 mm (ranged between 2.5 and 3 mm). In 261 (81%) cases operators used 3 mm ablation tag size, and in 19% - 2 mm. The mean ILD was 4,1 ± 1,0 mm (3,2 ± 0,5 mm in Group 1 vs 4,6 ± 0,5 mm Group 2). FPI was achieved in 189 (59%) cases. In the "ILD ≤ 4 mm" group FPI was achieved in 93 (49,2%) cases and there were 96 (50,8%) cases of durable FPI in the "ILD >4 mm" group (χ2 = 2,4, p = 0,124). The mean procedure time was 111 ± 46 min and 100 ± 35 min in Group 1 and 2 (p = 0,01), respectively. The mean fluoro time was 13 ± 4 min and 11 ± 4 min in Group 1 and 2 (p = 0,08), respectively Conclusion(s). The results of our multicenter study suggest that shortening of the distance ≤4 mm has no effect on the achievement of first-pass PV isolation, but required more procedure and relatively more X-ray exposure time.

P1.30 Intratumoral Heterogeneity in Expression of Chemotherapy Response Markers in Invasive Ductal Breast Carcinoma Nos

ABSTRACT Background Chemotherapy response is composed of drug resistance and sensitivity. Previously, we found that intratumoral heterogeneity of invasive ductal breast carcinoma not otherwise specified (IDBC NOS), presented by the different types of morphological structures (tubular, trabecular, solid, alveolar structures, and discrete groups of tumor cells) displaying architectural arrangements of tumor cells may influence on chemotherapy response (Zavyalova et al., 2008); however, the mechanism of this effect is unknown. Aim We aimed to analyze expression of the multidrug resistance (MDR) and chemosensitivity genes in the different types of morphological structures and their microenvironment of tumor in IDBC NOS. Materials and methods Tubular, trabecular, alveolar structures, and their microenvironment (local and distant) were isolated by laser microdissection PALM (Carl Zeiss, Gemany) from 10 um sections of FFPE breast tumor. The isolated and whole amplified cDNA (RNA) was used for analysis of the MDR (ABCB1, ABCC1, ABCC2, ABCC5, ABCG2, GSTP1, and MVP) and chemosensitivity (TOP1, TUBB3, and TYMS) genes by the real-time TaqMan PCR. Results As seen in Table 1, expression of the MDR and chemosensitivity genes was significantly different between both the studied types of morphological structures and their microenvironment. Moreover, we observed the interesting phenomenon consisting in the fact that different types of morphological structures and their local microenvironments are supplemented each other in expression of the MDR and chemosensitivity genes. Tubular structures had a significantly higher activity of the MDR and chemosensitivity genes in comparison with other types of morphological structures, whereas their microenvironment was fully inactive in respect of the expressing genes. In contrast, a low expression level of the MDR and chemosensitivity genes in alveolar structures was compensated by high activity of these genes in the surrounding microenvironment. Interestingly that trabecular structures displaying moderate expression of the analyzed genes had microenvironment with a similar level of activity of these genes. Conclusion Together, the data obtained demonstrates that within IDBC NOS tumor there are subclones of tumor cells and their specific microenvironment with different expression of chemotherapy response markers.The study was supported by the Russian Federation President Grant (MK-1259.2012.7) and grant of the OPTEK company.