Long-Term Renal Function after Catheter Ablation of Atrial Fibrillation.

Background: Atrial fibrillation (AF) is associated with the development and progression of chronic kidney disease (CKD). This study evaluated the impact of long-term rhythm outcome after catheter ablation (CA) of AF on renal function. Methods and results: The study group included 169 consecutive patients (the mean age was 59.6 ± 10.1 years, 61.5% were males) who underwent their first CA of AF. Renal function was assessed by eGFR (using the CKD-EPI and MDRD formulas), and by creatinine clearance (using the Cockcroft-Gault formula) in each patient before and 5 years after index CA procedure. During the 5-year follow-up after CA, the late recurrence of atrial arrhythmia (LRAA) was documented in 62 patients (36.7%). The mean eGFR, regardless of which formula was used, significantly decreased at 5 years following CA in patients with LRAA (all p < 0.05). In the arrhythmia-free patients, the mean eGFR at 5 years post-CA remained stable (for the CKD-EPI formula: 78.7 ± 17.3 vs. 79.4 ± 17.4, p = 0.555) or even significantly improved (for the MDRD formula: 74.1 ± 17.0 vs. 77.4 ± 19.6, p = 0.029) compared with the baseline. In the multivariable analysis, the independent risk factors for rapid CKD progression (decline in eGFR > 5 mL/min/1.73 m2 per year) were the post-ablation LRAA occurrence (hazard ratio 3.36 [95% CI: 1.25-9.06], p = 0.016), female sex (3.05 [1.13-8.20], p = 0.027), vitamin K antagonists (3.32 [1.28-8.58], p = 0.013), or mineralocorticoid receptor antagonists' use (3.28 [1.13-9.54], p = 0.029) after CA. Conclusions: LRAA after CA is associated with a significant decrease in eGFR, and it is an independent risk factor for rapid CKD progression. Conversely, eGFR in arrhythmia-free patients after CA remained stable or even improved significantly.

Risk factors for late reconnections after circumferential pulmonary vein isolation guided by lesion size index - Data from repeat invasive electrophysiology procedure.

Background: Late reconnections (LR) of pulmonary veins (PVs) after wide antral circumferential ablation (WACA) using point-to-point radiofrequency (RF) ablation are common. Lesion size index (LSI) is a novel marker of lesion quality proposed by Ensite Precision mapping system, expected to improve PV isolation durability. This study aimed to assess the durability of LSI-guided PVI and the risk factors for LR of PVs. Methods: The prospective study included 33 patients with paroxysmal atrial fibrillation (PAF) who underwent (1) the index LSI-guided WACA procedure (with target LSI of 5.5-6.0 for anterior and 5.0-5.5 for posterior WACA segments) and (2) the 3-month protocol-mandated re-mapping procedure in all patients, irrespective of AF recurrence after the index procedure. Ablation parameters reported by Ensite mapping system were collected retrospectively. The inter-lesion distance (ILD) between all adjacent WACA lesions was calculated off-line. Association between index ablation parameters and the LRs of PVs at 3 months was analyzed. Results: The median patient age was 61 (IQR: 53-64) years and 55% of them were males. At index procedure, the first-pass WACA isolation rate was higher for the left PVs than the right PVs (64 vs. 33%, p = 0.014). In addition, a low acute reconnection rates were observed, as follows: in 12.1% of patients, in 6.1% of WACA circles, in 3.8% of WACA segments and in 4.5% of PVs. However, the 3-month remapping study revealed LR of PV in 63.6% of patients, 37.9% of WACA circles, 20.5% of WACA segments and 26.5% of PVs. The LRs were identified mostly along the left anterior WACA segment. Independent risk factors for the LR of WACA were left-sided WACA location (OR 3.216 [95%CI: 1.065-9.716], p = 0.038) and longer ILD (OR 1.256 [95%CI: 1.035-1.523] for each 1-mm increase, p = 0.021). The ILD of > 8.0 mm showed a predictive value for the LR of WACA, with the sensitivity of 84% and specificity of 46%. A single case of cardiac tamponade occurred following the re-mapping invasive procedure. No other complications were encountered. Conclusion: Although the LSI-guided PVI ensures a consistent PVI during the index procedure, LRs of PVs are still common. Besides the LSI, the PVI durability requires an optimal ILD between adjacent lesions, especially along the anterior lateral ridge.

Improvement of Maximal Exercise Performance After Catheter-Ablation of Atrial Fibrillation and Its Prognostic Significance for Long-Term Rhythm Outcome.

Background Rhythm control may improve functional capacity in patients with atrial fibrillation (AF). Long-term exercise tolerance improvement and its prognostic implications following catheter-ablation (CA) of paroxysmal and nonparoxysmal AF are underreported. Methods and Results Consecutive patients underwent cardiopulmonary exercise testing just before and 12 months after their index CA of AF. Follow-up 24-hour Holter recordings were obtained at 6-month intervals post-CA, and any atrial arrhythmia >30 seconds detected after 3 months postprocedure was considered AF recurrence. Of 110 patients (mean age 57.5±10.6 years, 77.2% males) with paroxysmal AF (n=66) or nonparoxysmal AF (n=44), the 12-month exercise tolerance improved significantly in those who maintained sinus rhythm during the first 12 months post-CA (n=96), but not in patients with AF recurrence (n=14). After CA, the 12-month respiratory exchange ratio at maximal workload significantly increased in patients with paroxysmal AF, whereas those with nonparoxysmal AF significantly reduced their heart rate during the 12-month cardiopulmonary exercise testing (all P≤0.001). During the follow-up of 42.8±7.8 months, a total of 29 patients (26.3%) experienced recurrent AF. On multivariate analysis including patients without recurrent AF at 12 months after CA, the extent of work time improvement at follow-up cardiopulmonary exercise testing was independently associated with the rhythm outcome beyond 12 months postprocedure (hazard ratio of 0.936 [95% CI, 0.894-0.979] for each 10 seconds increase in the work time following ablation, P=0.004). Conclusions CA of AF was associated with recovery of exercise intolerance in patients with paroxysmal AF or nonparoxysmal AF. Inability to improve exercise capacity at 12 months post-CA was an independent risk factor for later AF recurrence.

Clinical approach to the patient with Brugada Syndrome: risk stratification and optimal management.

The Brugada Syndrome (BrS) is an inherited cardiac ion channel disorder associated with increased risk of ventricular arrhythmias and mortality. Diagnosis is based on a characteristic electrocardiographic (ECG) pattern of coved type ST-segment elevation >2 mm followed by a negative T-wave in ≥1 of the right precordial leads V1 to V3. Since the first description of BrS, the definition of disease and underlying pathophysiological mechanisms have been significantly improved in recent years. Also, significant progress has been made in the field of genetic testing in these patients. Still, there are several open questions regarding the management and outcome of these patients. There is more information about patients who would need an implantable cardiac defibrillator for the primary prevention of sudden cardiac death (that is, those with spontaneous Type I Brugada ECG pattern and arrhythmia-related syncope), but currently published data concerning asymptomatic patients with Brugada ECG pattern and other less-well defined presentations are conflicting. Whereas the role of cardiac defibrillator in patients with Brugada Syndrome is clear, optimal use of catheter ablation and antiarrhythmic drug therapy needs to be further investigated. In this review, we summarize current evidence and contemporary management of patients with BrS.

Catheter ablation of lone atrial fibrillation.

Atrial fibrillation is the most common sustained arrhythmia in clinical practice, associated with increased mortality, risk of stroke and heart failure, as well as the reduction of the quality of life. Atrial fibrillation may be encountered in young otherwise healthy individuals, due to the isolated electrophysiological disorder limited mostly to the pulmonary veins and posterior left atrial wall, or associated with the presence of advanced underlying heart disease and numerous cardiac and non-cardiac comorbidities with significant structural remodeling of the atrial myocardium. Due to limited efficacy and serious side effects of antiarrhythmic drugs, catheter ablation of atrial fibrillation, based on the pulmonary vein isolation for paroxysmal atrial fibrillation and adjunctive substrate modification for persistent atrial fibrillation, has emerged as an attractive and promissing alternative therapeutic option for selected patients with atrial fibrillation. In this review article, we discuss the electrophysiological left atrial abnormalities underlying lone atrial fibrillation and the role of pulmonary veins in pathophysiology of arrhythmia, and we summarize results of the studies on the long term outcome of catheter ablation of atrial fibrillation, as well as the studies on comparison of antiarrhythmic drugs with catheter ablation for treatment of atrial fibrillation. In addition, we present available data that provide better understanding of mechanisms, diagnosis, prevention and treatment of specific procedure-related complications and discuss current periprocedural anticoagulation strategies and their impact on the thromboembolic risk reduction.