Joanna Wieczorek

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Background: MicroRNA (miRNA) have the potential to be non-invasive and attractive biomarkers for a vast number of diseases and clinical conditions; however, a reliable analysis of miRNA expression in blood samples meets a number of methodological challenges. In this report, we presented and discussed, specifically, the principles and limitations of miRNA purification and analysis in blood plasma samples collected from the left atrium during an ablation procedure on patients with atrial fibrillation (AF). Materials and Methods: Consecutive patients hospitalized in the First Department of Cardiology for pulmonary vein ablation were included in this study (11 with diagnosed paroxysmal AF, 14 with persistent AF, and 5 without AF hospitalized for left-sided WPW ablation—control group). Whole blood samples were collected from the left atrium after transseptal puncture during the ablation procedure of AF patients. Analysis of the set of miRNA molecules was performed in blood plasma samples using the MIHS-113ZF-12 kit and miScript microRNA PCR Array Human Cardiovascular Disease. Results: The miRNS concentrations were in the following ranges: paroxysmal AF: 7–23.1 ng/µL; persistent AF: 4.9–66.8 ng/µL; controls: 6.3–10.6 ng/µL. The low A260/280 ratio indicated the protein contamination and the low A260/A230 absorbance ratio suggested the contamination by hydrocarbons. Spectrophotometric measurements also indicated low concentration of nucleic acids (<10 ng/µL). Further steps of analysis revealed that the concentration of cDNA after the Real-Time PCR (using the PAXgene RNA Blood kit) reaction was higher (148.8 ng/µL vs. 68.4 ng/µL) and the obtained absorbance ratios (A260/A280 = 2.24 and A260/A230 = 2.23) indicated adequate RNA purity. Conclusions: Although developments in miRNA sequencing and isolation technology have improved, detection of plasma-based miRNA, low RNA content, and sequencing bias introduced during library preparation remain challenging in patients with AF. The measurement of the quantity and quality of the RNA obtained is crucial for the interpretation of an efficient RNA isolation.

A potential relationship between the initial left atrial (LA) echocardiographic parameters and LA remodeling after pulmonary vein isolation using (PVI) radiofrequency energy energy with effectiveness of this treatment was discussed. We aimed to determine the relationship between initial and post-follow-up transthoracic echocardiography- derived predictors of successful PVI in patients with paroxysmal atrial fibrillation (AF). Eighty patients with paroxysmal AF (aged 58 [interquartile range, IQR, 50-63] years; male, 50 [62.5%]), hospitalized for the first PVI procedure were included. Before and after a minimum of 6 months of follow-up, clinical and echocardiographic evaluations were performed. LA morphological parameters (diameter, volumes, and other detailed LA parameters), as well as LA peak segmental and global longitudinal strains (PLS) and LA wall strain synchrony were assessed. In the whole group after the follow-up period, patients presented higher mean LA Volconduit. Patients with no AF recurrences had lower post-PVI LA volumes, higher LA ejection fraction, and LA expansion index when compared to the patients after ineffective PVI. Patients who maintained sinus rhythm after the PVI procedure were characterized by higher initial segmental strains: LA PLSbasal-inferior and PLSapical-septal, as well as higher LA wall strain dispersion over time. Some echocardiographic parameters related to LA morphology improve after successful PVI treatment. LA strains and wall strain dispersion over time are not related to LA remodeling after a successful PVI procedure. However, the baseline LA standard and novel echocardiographic parameters cannot be used for remote evaluation of the effectiveness of the PVI procedure.

Background: The aim was to determine the occurrence, consequences and risk factors for brain white matter hyperintensities (WMH) assessed in magnetic resonance imaging (MRI) in low-risk patients with paroxysmal atrial fibrillation (AF) undergoing radiofrequency pulmonary vein isolation (PVI-RF). Methods: 74 patients with AF (median 58.5 years (IQR 50–63), 45 male) were included. Before and after a minimum of 6 months after PVI-RF, a brain MRI and a mini-mental state examination (MMSE) were performed. Results: Baseline WMH lesions were found in 55 (74.3%) patients and in 48 from 62 (77.4%) patients after PVI-RF. The WMH lesions were more frequent among older patients, with a higher CHA2DS2-Vasc (C—Congestive heart failure/LV dysfunction, H—Hypertension, A—Age, D—Diabetes mellitus, S—Stroke, V—Vascular Disease, Sc—Sex category). Factors affecting the severity of the WMH were: older age, the co-existence of the PFO and coronary artery disease (CAD). After a follow-up period, the factors predisposing to brain WMH lesions occurrence (age, higher BMI and CHA2DS2-Vasc score) and to the more advanced changes (age, higher CHA2DS2-Vasc score, CAD, PFO) were obtained. Conclusions: The presence and severity of cerebral microembolism are associated with age, higher CHA2DS2-Vasc score and the coexistence of PFO and CAD. PVI-RF procedure and its efficacy does not influence on MRI lesions. In this population, cerebral microembolism is not related to cognitive impairment.

DOI: 10.33963/KP.15076, Published online: November 29, 2019, Authors: Anna Bednarek, Joanna Wieczorek, Marek Elżbieciak, Katarzyna Mizia-Stec

Introduction Atrial fibrillation ablation can be associated with microembolism detected in the intracranial arteries and risk of neurological incidents. The aims of this study were to evaluate microembolic signals (MES) during pulmonary vein isolation (PVI) and establish the potential...

Obesity constitutes a risk factor for atrial fibrillation (AF) and modifies the efficacy of invasive AF treatment. Left atrial (LA) global longitudinal strain (GLS), which is measured using speckle-tracking echocardiography (STE), is one of the new methods that are helpful in evaluating the function of LA. The aim of the study was to evaluate LA function in obese and non-obese patients that were undergoing percutaneous pulmonary vein isolation (PVI) before and 6 months after the procedure. 89 patients (F/M: 31/58; mean age: 55.8 ± 9.8 years) with paroxysmal or persistent symptomatic AF that had been qualified for percutaneous PVI were prospectively enrolled in the study. Body mass index (BMI) constituted as a discriminating factor for the study groups: obese group: BMI ≥ 30 kg/m² (29 patients, F/M: 13/16, mean age: 55.13 ± 10.1 years) and non-obese group BMI < 30 kg/m² (60 patients, F/M: 18/42, mean age: 57.17 ± 9.0 years). Transthoracic echocardiography (TTE) with LA GLS and segmental longitudinal strain were analysed 1 day before and 6 months after PVI. PVI efficacy was evaluated 6 months after PVI via a seven-day Holter monitoring. Baseline analysis revealed significantly lower two-chamber (2-Ch) LA GLS in the obese patients compared to the non-obese subjects (− 10.55 ± 3.7 vs − 13.11 ± 5.1, p = 0.004). Segmental strain analysis showed no significant differences between the groups. The data that was obtained 6 months after PVI showed a significantly lower 4-Ch LA GLS in the obese patients compared to the non-obese subjects (− 11.04 ± 5.0 vs − 13.91 ± 4.2, p = 0.02), which was accompanied by a significantly lower segmental 4-Ch LA function in the obese patients (med-sept: − 11.66 ± 11.2 vs − 15.97 ± 5.3, p = 0.04; api-sept: − 9.04 ± 6.3 vs − 13.62 ± 6.5, p < 0.001; api-lat: − 7.62 ± 4.0 vs − 13.62 ± 6.5, p < 0.001; med-lat: −9.31 + − 7.9 vs − 15.04 + − 6.3, p = 0.003, global: − 11.04 + − 5.0 vs − 13.91 + − 4.2, p = 0.02). PVI efficacy was confirmed in 52 (58.4%) patients and was similar in both groups. Comparison of the baseline and 6-month strain revealed no differences in LA GLS in either group. Differences in LA GLS before and after the procedure (delta LA GLS) were not obesity dependent. Apical-septal and apical-lateral strain in the obese group, which were measured in 4-Ch view, were significantly lower after the procedure compared to the baseline (p < 0.001). Obese patients with paroxysmal AF were characterised by impaired LA GLS, which is persistent and was accompanied by segmental dysfunction after PVI at the 6-month follow-up. PVI efficacy was comparable between the obese and non-obese patients.

Background: Renalase is a catecholamine-metabolising enzyme, but its possible association with atrial fibrillation (AF) remains unknown. Aim: We sought to evaluate plasma renalase concentration in patients with AF undergoing pulmonary vein isolation (PVI) with respect to AF clinical characteristics, left atrial (LA) remodelling, and PVI efficacy. Methods: This case-control study included 69 patients (median age 58 years) with either paroxysmal (89%) or persistent (11%) AF, referred for PVI, and a control group consisting of 15 patients without AF, matched for age, sex, and comorbidi­ties. An evaluation of transthoracic echocardiography with LA speckle tracking and plasma renalase concentration using an enzyme-linked immunosorbent assay was performed. AF recurrence was defined as any AF episode on seven-day electro­cardiographic monitoring at six-month follow-up. Results: Renalase level was higher in the study group than in the control group (mean 27.99 vs. 21.48 μg/mL, p = 0.004), but it was lower in patients with persistent AF (19.05 vs. 28.77 μg/mL; p = 0.023) and among patients with AF episodes di­rectly preceding PVI (24.50 vs. 29.66 μg/mL; p = 0.04). Renalase concentration within the first quartile was associated with higher mean heart rate (70 vs. 61 bpm, p = 0.029), greater AF burden (36.9% vs. 9.3%, p = 0.027), greater LA diameter (41.1 vs. 37.9 mm, p = 0.011), and a trend towards less negative global LA strain (–9.4 vs. –13.5, p = 0.082). Logistic regres­sion revealed that global four-chamber LA strain was the only independent predictor of renalase variability (p = 0.0045). Renalase concentration did not predict AF recurrence at six-month follow-up (area under curve [AUC] = 0.614, p = 0.216). Conclusions: Low renalase level may be associated with impaired rate control, higher AF burden, and advanced LA remodel­ling in AF patients undergoing PVI, but it does not predict sinus rhythm maintenance. Background: Renalase is a catecholamine-metabolising enzyme, but its possible association with atrial fibrillation (AF) remains unknown. Aim: We sought to evaluate plasma renalase concentration in patients with AF undergoing pulmonary vein isolation (PVI) with respect to AF clinical characteristics, left atrial (LA) remodelling, and PVI efficacy. Methods: This case-control study included 69 patients (median age 58 years) with either paroxysmal (89%) or persistent (11%) AF, referred for PVI, and a control group consisting of 15 patients without AF, matched for age, sex, and comorbidi­ties. An evaluation of transthoracic echocardiography with LA speckle tracking and plasma renalase concentration using an enzyme-linked immunosorbent assay was performed. AF recurrence was defined as any AF episode on seven-day electro­cardiographic monitoring at six-month follow-up. Results: Renalase level was higher in the study group than in the control group (mean 27.99 vs. 21.48 μg/mL, p = 0.004), but it was lower in patients with persistent AF (19.05 vs. 28.77 μg/mL; p = 0.023) and among patients with AF episodes di­rectly preceding PVI (24.50 vs. 29.66 μg/mL; p = 0.04). Renalase concentration within the first quartile was associated with higher mean heart rate (70 vs. 61 bpm, p = 0.029), greater AF burden (36.9% vs. 9.3%, p = 0.027), greater LA diameter (41.1 vs. 37.9 mm, p = 0.011), and a trend towards less negative global LA strain (–9.4 vs. –13.5, p = 0.082). Logistic regres­sion revealed that global four-chamber LA strain was the only independent predictor of renalase variability (p = 0.0045). Renalase concentration did not predict AF recurrence at six-month follow-up (area under curve [AUC] = 0.614, p = 0.216). Conclusions: Low renalase level may be associated with impaired rate control, higher AF burden, and advanced LA remodel­ling in AF patients undergoing PVI, but it does not predict sinus rhythm maintenance.