Histopathologic effects of radiofrequency catheter ablation in previously infarcted human myocardium

Colchicine Prevents Post-Ablation Atrial Fibrillation Recurrence: A Systematic Review and Meta-Analysis

Catheter ablation for atrial fibrillation (AF) is a commonly performed procedure, however, post-ablation AF recurrence is often observed due to inflammation and oxidative stress. Colchicine is a potent anti-inflammatory agent with conflicting efficacy in preventing post-ablation AF recurrence. A comprehensive literature search of the major bibliographic databases was conducted to retrieve studies comparing colchicine use versus placebo in AF patients post-ablation. Odds ratios (ORs) with 95% confidence intervals (CIs) were pooled using the DerSimonian-Laird random-effects model. Statistical significance was set at P < 0.05. Six studies were included with 1791 patients (721 in the colchicine group and 1070 in the placebo group). Patients who received colchicine had significantly lower odds of AF recurrence on follow-up (OR, 0.62; 95% CI, 0.48-0.79; P = 0.0001) but had higher gastrointestinal side effects (OR, 2.67; 95% CI, 1.00-7.12; P = 0.05). There were no statistically significant differences in acute pericarditis (OR, 0.54; 95% CI, 0.27-1.05; P = 0.07) or hospitalization (OR, 1.03; 95% CI, 0.73-1.45; P = 0.87). Prophylactic use of colchicine after catheter ablation in patients with AF leads to a reduction in AF recurrence, albeit with increased gastrointestinal side effects. Colchicine use did not lead to a reduction in the rates of pericarditis and hospitalization after ablation. Large randomized controlled trials are necessary to evaluate the efficacy of colchicine in preventing AF recurrence, particularly focusing on the dose and duration of treatment to optimize the side effect profile.

Comparison of Radiofrequency and Cryoballoon Pulmonary Vein Ablation for the Early and Late Recurrence of Atrial Fibrillation

Objective Early recurrence (ER) after pulmonary vein isolation (PVI) for atrial fibrillation (AF) is expected to resolve within the recommended 3-month blanking period, irrespective of the ablation device used. To compare the occurrence and relationship of AF within the blanking period and subsequent late recurrence (LR) with radiofrequency (RF) and cryoballoon (CB) ablation. Methods A retrospective analysis of 294 patients (mean age=62±9, 70.0% male) undergoing PVI for drug-refractory paroxysmal AF was done. After categorizing the patients into the RF group (n=152) and the CB group (n=142), a group-wise comparison was done to investigate the impact of ER on LR throughout a 2-year follow-up. Results The groups were similar regarding the occurrence of ER (RF=22.4%, CB=24.6%, p=0.62), while LR was significantly higher in the RF group (p=0.003). ER was associated with LR in the RF group (p<0.01) but not in the CB group (p=0.08), while a significant independent association with an increased LR risk was observed [hazard ratio (HR) 6.12; 95% confidence interval (CI) 3.56-10.51, p<0.01]. RF ablation also significantly increased the risk of LR (HR=2.93; 95% CI=1.64-5.23, p<0.01). Conclusion A recurrence of atrial arrhythmia is more frequent with RF-PVI than with CB-PVI for patients with paroxysmal AF. ER and RF-ablation are strong predictors for LR after the 3-month blanking period.

Differential effect of high-frequency electroporation on myocardium vs. non-myocardial tissues

AIMS

Pulsed-field ablation (PFA) is an emerging non-thermal ablation method based on the biophysical phenomenon of electroporation. Data on PFA cardiac selectivity nature and tissue-specific thresholds are lacking. We aim to compare the in vivo differential effect of high-frequency irreversible electroporation (HF-IRE) protocols on various tissues.

METHODS AND RESULTS

Twenty-three Sprague-Dawle rodents were allocated into three different protocols of 300, 600, and 900 V, respectively, while delivering twenty 100 µs bursts of a 150 kHz biphasic square wave to five tissues; cardiac muscle, skeletal muscle, liver, carotid artery and sciatic nerve. Lesions were evaluated quantitatively by histologic analysis and by morphometric evaluation. There were eight, seven and eight animals in the 300, 600, and 900 V protocols, respectively. High-frequency electroporation protocols showed a graded effect on myocardial tissue with larger lesions in the 900 V protocol compared with the other two protocols as demonstrated by width (P = 0.02), length (P = 0.01) and fibrosis ratio (P = 0.001). This effect was not observed for other tissues with attenuated degree of damage. No damage to the carotid artery was observed in all protocols. Partial damage to the sciatic nerve was observed in only two samples (25%) in the 600 V group and in one sample (14.3%) in the 900 V group.

CONCLUSION

Electroporation effect is tissue-specific such that myocardium is more prone to electroporation damage compared with neural and vascular tissues. Our results suggest no neural or vascular damage with using a low-amplitude HF-IRE protocol. Further investigation is warranted to better identify other tissue-specific thresholds.

Computer simulations of consecutive radiofrequency pulses applied at the same point during cardiac catheter ablation: Implications for lesion size and risk of overheating

BACKGROUND AND OBJECTIVES

To study temperature distribution and lesion size during two repeated radiofrequency (RF) pulses applied at the same point in the context of RF cardiac ablation (RFCA).

METHODS

An in-silico RFCA model accounting for reversible and irreversible changes in myocardium electrical properties due to RF-induced heating. Arrhenius damage model to estimate lesion size during the application of two 20 W pulses at intervals (INT) of from 5 to 70 s. We considered two pulse durations: 20 s and 30 s.

RESULTS

INT has a significant effect on lesion size and maximum tissue temperature (TMAX). The shorter the INT the greater the increase in lesion size after the second pulse but also the greater the TMAX. If the second pulse is applied almost immediately (INT=5 s), depth increases 1.4 mm and 1.5 mm for pulses of 20 s and 30 s, respectively. If INT is longer than 30 s it increases 1.1 mm and 1.3 mm for pulses of 20 s and 30 s, respectively. While a single 20 s pulse causes T_MAX=79 ºC, a second pulse produces values of from 92 to 96 ºC (the higher the temperature the shorter the INT). For 30 s pulses, T_MAX=93 ºC for a single pulse, and varied from 98 to 104 ºC for a second pulse.

CONCLUSIONS

Applying a second RF pulse at the same ablation site increases lesion depth by 1 - 1.5 mm more than a single pulse and could lead to higher temperatures (up to 17 ºC). Both lesion depth and maximum tissue temperature increased at shorter inter-pulse intervals, which could cause clinical complications from overheating such as steam pops.

Prevalence, Predictors, and Clinical Presentation of Acute Pericardial Effusion Following Percutaneous Coronary Intervention

Background: Iatrogenic pericardial effusion (PE) has been demonstrated to lead to cardiac injury as a sign of systemic inflammatory response. Objectives: This study sought to determine the anatomical characteristics and clinical presentation associated with PE after percutaneous coronary intervention (PCI) by using echocardiography. Methods: The clinical outcomes of all patients with coronary artery disease who underwent PCI from July 2014 to December 2018 were evaluated. The quantitative and qualitative analyses of PE were performed. The associations between the presence of PE and procedural factors were also evaluated. Results: A total of 882 patients were enrolled. PE was found in 144 patients (16.3%) and was mostly located in the anterior pericardium at low amounts. The serum levels of high-sensitive C-reaction protein before PCI and troponin T in the group with PE after PCI were significantly higher than those in the group without PE (p < 0.0001). The presence of PE was associated with the procedural time (OR = 1.02, p = 0.035) and the degree of interventional complexity (multiple vessels OR = 1.89, p = 0.014; chronic total occlusion OR = 2.04, p = 0.005; and PCI with rotational atherectomy OR = 1.15, p = 0.011) independent of the number of culprit vessels and stents. During 1-year follow-up, a significantly higher number of cardiac deaths (3) and myocardial infarctions (8) occurred in patients with PE than in patients without PE (P < 0.05). Conclusion: Post-PCI acute PE was frequent, generally mild, mainly asymptomatic, and independently associated with procedural time and complexity. This effusion, which is considered as a cardiac damage marker, could be a predominant clinical sign for long-term prognosis.

Early arrhythmia recurrence after catheter ablation for persistent atrial fibrillation: is it predictive for late recurrence?

BACKGROUND

Early recurrence of atrial tachyarrhythmia (ERAT) is common after radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF), but its clinical significance in patients with persistent AF remains unclear. We sought to determine the predictive value of ERAT for rhythm outcome after RFCA for persistent AF.

METHODS

The study included 207 consecutive patients (mean age 66.4 ± 10.7 years, male 66.2%) with persistent and long-standing persistent AF undergoing de novo pulmonary vein isolation (± atrial substrate ablation). All patients remained off antiarrhythmic drugs. ERAT was defined as any atrial arrhythmia ≥ 30 s occurring within the first 30 days. Late recurrence (LR) was determined during follow-up visits scheduled 1, 3, 6 and 12 months post-ablation using 7-day Holter ECGs.

RESULTS

ERAT occurred in 143/207 (69.1%) patients as AF (60%) or atrial tachycardia (40%) and was persistent in 82% of cases. During a median follow-up of 22.2 months, LR occurred significantly more often in patients with ERAT than in patients without ERAT (92.3 vs. 43.8%, P < 0.001). The only independent predictors for LR were ERAT (OR 16.8, 95% CI 6.184-45.797, P < 0.001) and intraprocedural termination to sinus rhythm (OR 0.052, 95% CI 0.003-0.851, P = 0.038). Extending the blanking period from 30 to 90 days did not impact LR rates.

CONCLUSION

ERAT following ablation of persistent AF is strongly associated with late arrhythmia recurrence, which challenges the assumption that ERAT represents merely a transient phenomenon. While limiting the blanking period to 30 days seems justified, the benefit of early re-ablations remains to be addressed in future studies.

The Blinding Period Following Ablation Therapy for Atrial Fibrillation: Proarrhythmic and Antiarrhythmic Pathophysiological Mechanisms

Atrial fibrillation (AF) causes heart failure, ischemic strokes, and poor quality of life. The number of patients with AF is estimated to increase to 18 million in Europe in 2050. Pharmacological therapy does not cure AF in all patients. Ablative pulmonary vein isolation is recommended for patients with drug-resistant symptomatic paroxysmal AF but is successful in only about 60%. In patients in whom ablative therapy is successful on the long term, recurrence of AF may occur in the first weeks to months after pulmonary vein ablation. The early recurrence (or delayed cure) of AF is not understood but forms the basis for the generally accepted 3-month blinding (or blanking) period after ablation therapy, which is not included in the evaluation of the eventual success rate of the procedures. The underlying pathophysiological processes responsible for early recurrence and the delayed cure are unknown. The implicit assumption of the blinding period is that the AF mechanism in this period is different from the ablation-targeted AF mechanism (ectopy from the pulmonary veins). In this review, we evaluate the temporary and long-lasting pro- and antiarrhythmic effects of each of the pathophysiological processes and interventions (necrosis, ischemia, oxidative stress, edema, inflammation, autonomic nervous activity, tissue repair, mechanical remodeling, and use of antiarrhythmic drugs) occurring in the blinding period that can modulate AF mechanisms. We propose that stretch-reducing ablation scar is a permanent antiarrhythmic mechanism that develops during the blinding period and is the reason for delayed cure.

Prevalence and outcome of early recurrence of atrial tachyarrhythmias in the Cryoballoon vs Irrigated Radiofrequency Catheter Ablation (CIRCA-DOSE) study

BACKGROUND

Early recurrence of atrial tachyarrhythmia (ERAT) is common after pulmonary vein isolation (PVI) and has been associated with an increased risk of late atrial fibrillation (AF) recurrence.

OBJECTIVE

The purpose of this study was to determine the incidence and outcomes of patients experiencing ERAT after PVI using advanced-generation ablation technologies.

METHODS

This is a prespecified substudy of the CIRCA-DOSE (Cryoballoon vs Irrigated Radiofrequency Catheter Ablation: Double-Short vs Standard Exposure Duration) trial, a prospective, randomized, multicenter study comparing PVI with contact force-guided radiofrequency ablation to secondary-generation cryoballoon ablation for paroxysmal AF. All study patients received an implantable cardiac monitor to allow continuous rhythm monitoring. ERAT was defined as any recurrent atrial tachyarrhythmia within the first 90 days after AF ablation.

RESULTS

ERAT occurred in 61% of the 346 patients at a median of 12 days (range 1-90 days) after ablation. ERAF was a significant predictor of late recurrence (60.1% with ER vs 25.9% without ER; P <.001) and symptomatic atrial tachyarrhythmia (31.6% with ERAF vs 6.7% without ERAF; P <.001). Receiver operating curve analyses revealed a strong correlation between ERAT timing and burden and late recurrence. Multivariate analysis identified ER timing (hazard ratio [HR] 2.90; 95% confidence interval [CI] 1.41-5.95; P = .004) and burden (HR 1.05 per 1% ER burden; 95% CI 1.04-1.07; P <.001) as strong independent predictors of late recurrence. Incidence rate, timing, burden, and prognostic significance of ER did not differ between the study groups.

CONCLUSION

ERAT remains common after PVI despite use of advanced-generation ablation technologies. Early AF recurrence beyond 3 weeks after ablation is associated with increased risk of late recurrence.

Early recurrence after pulmonary vein isolation is associated with inferior long-term outcomes: Insights from a retrospective cohort study

AIMS

The aim of this retrospective cohort study was to assess the influence of early recurrence (ER) after pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (AF) on long-term outcomes and to identify clinical variables associated with ER.

METHODS

We retrospectively collected clinical and procedural data from 1285 patients with paroxysmal AF who underwent PVI from 2011 to 2016. Kaplan-Meier, receiver operating characteristic (ROC) curve, logistic and Cox regression analyses were performed to analyze the influence of ER on long-term outcomes.

RESULTS

ER was observed in 13% of patients. Kaplan-Meier analyses showed significantly different outcomes in 1285 patients with and without ER (49% vs 74%, log rank P < .01) and in 286 patients in the subgroup that underwent reablation (44% vs 79%, log rank P < .01). The hazard ratio (HR) of ER was 1.7 within 48 hours (5% of patients), 2.7 within 1 month (5%), 3.0 within 2 months (2%), and 6.4 within 3 months (1%) for late recurrence (LR), P < .01. ROC analysis (area under the curve [AUC] = 0.79) resulted in 70.3% sensitivity and 74.2% specificity for a 14-day blanking period, and 53.1% sensitivity and 85.5% specificity for a 30-day blanking period. Female patients (odds ratio [OR] 1.69, P < .01) and those with diabetes (OR 1.95, P = .01) were at higher risk for ER.

CONCLUSIONS

ER is observed in a substantial number of patients with paroxysmal AF after PVI and has a continuous direct effect on LR according to the timing of ER. Randomized trials are required to assess the safety and effects of reablations in a shortened blanking period on long-term outcomes.

Re-definition of blanking period in radiofrequency catheter ablation of atrial fibrillation in the contact force era

INTRODUCTION

Early recurrence (ER) of atrial fibrillation (AF) is defined as the recurrence of atrial tachyarrhythmias within 3 months after AF ablation, however, this definition is based on data from the era of radiofrequency catheter ablation (RFCA), without contact force (CF) technology. We investigated the significance of ER as a risk factor for late recurrence (LR) in paroxysmal AF (PAF) patients treated with CF and non-CF-guided ablation.

METHODS AND RESULTS

We studied 395 patients with PAF who underwent RFCA. Of these, 97 patients underwent RFCA without-CF technology (non-CF group) and 298 underwent with CF technology (CF group). Over a 2-year postablation follow-up period, LR occurred in 54 (55.7%) patients in the non-CF group, and in 105 (35.2%) patients in the CF group. ER had a more significant relationship with LR in the CF group, and all patients in the CF group with ER in the third month developed LR.

CONCLUSION

PAF patients with ER who have undergone CF-guided ablation have a greater risk of LR than those who have undergone non-CF-guided ablation. ER in the third month after CF-guided ablation may indicate an absolute risk of LR. Blanking period could be defined as 2 months in the CF era.

Predictors of Recurrence of AF in Patients After Radiofrequency Ablation

Catheter ablation is a well-known treatment for patients with AF. Despite the growing knowledge in the field, the identification of predictors of recurrence of AF after catheter ablation is one of the primary goals and is of major importance to improve long-term results of the procedure. The aim of this article is to provide an overview of what has been published in recent years and to summarise the major predictors, helping cardiac electrophysiologists in the selection of the right candidates for catheter ablation.

Catheter ablation for atrial fibrillation is associated with lower incidence of heart failure and death

Aims

Catheter ablation for atrial fibrillation (CAF) improves symptoms, but whether CAF improves outcome is less clear. The purpose of this study was to investigate whether CAF is associated with improved outcome in atrial fibrillation (AF) patients with previous direct current (DC) cardioversion.

Methods and results

We performed a nationwide cohort study including all patients who underwent their 1st direct current cardioversion for AF in the period 2003–15 (N = 25 439). End points were all-cause death, cardiovascular death, stroke/thromboembolism, and incident heart failure (HF). Catheter ablation for AF was treated as a time-varying covariate and the association with outcome was assessed using Cox regression. We also constructed a propensity-matched cohort and assessed the association between CAF and outcome. Median follow-up was 5.3 years (inter-quartile range 3.0–8.7 years). A total of 3509 patients (13.8%) underwent CAF during the study period. Following adjustment for age, gender, comorbidities, medications, educational level, household income, and CHA2DS2VASc score, CAF was associated with reduced risks of all-cause death, cardiovascular death, and incident HF [all-cause death: hazard ratio (HR) 0.69, P &lt; 0.001; cardiovascular death: HR 0.68, P = 0.003; incident HF: HR 0.76, P = 0.011]. Catheter ablation for AF was not associated with a reduced risk of stroke/thromboembolism. These results were replicated in a propensity-matched cohort.

Conclusion

In AF patients with a prior DC cardioversion, CAF was associated with a reduced risk of all-cause and cardiovascular death. This may be due to a reduced risk of HF.

Evaluation of myocardial injury induced by different ablation approaches (radiofrequency ablation versus cryoablation) in atrial flutter patients: a meta-analysis

Background: To evaluate myocardial injury in Atrial flutter (AFL) patients undergoing Radiofrequency ablation (RF) and cryoablation (CRYO) treatments.

Methods: We conducted a systematic search on PubMed, Embase, Cochrane Library, and CBM databases. All relevant clinical trials (up to October 2018) on myocardial injury in AFL patients were retrieved and subsequent results analyzed with a random-effects model or a fixed-effects model.

Results: A total of eight clinical trials with a sample size of 644 patients, were identified and incorporated in the present study. The results indicated no significant differences in creatine kinase (CK) levels (mean difference (MD) = 62.74, P=0.46; 4–6 h and MD = 30.73, P=0.49; 12–24 h after ablation), creatine kinase MB(CK-MB) levels (MD = 17.32, P=0.25; 12–24 h post-ablation), troponinI (TnI) levels (MD = 0.12, P=0.08; 6 h after ablation), and troponin T (TnT) levels (MD = 0.30, P=0.08; 4–6 h post-ablation) between the two treatment approaches. However, patients receiving CRYO xhibited higher levels of CK (MD = 179.54, P=0.04; tested immediately after the procedure), CK-MB (MD = 10.08, P=0.004) 4–6 h after ablation, and TnT (MD = 0.19, P=0.002) tested the next morning. Moreover, those patients had a significantly reduced pain perception (odds ratio (OR) = 0.05, P=0.04) compared with those in the RF group.

Conclusion: These results indicate that CRYO in comparison with RF significantly increases myocardial injury in AFL patients. Additionally, it decreases pain perception during the procedure. Further large-sampled studies are needed to support these findings.

Usefulness of Failed Electrical Cardioversion for Early Recurrence After Catheter Ablation for Atrial Fibrillation as a Predictor of Future Recurrence

Early recurrence of atrial arrhythmia (ERAA) during a blanking period after catheter ablation (CA) for atrial fibrillation (AF) does not always result in subsequent AF recurrence. We investigated whether failed electrical cardioversion (ECV) during the blanking period was associated with recurrence. A total of 1,240 consecutive patients who underwent first-time CA for AF at our institution between March 2012 and March 2016 were investigated. Among the 517 patients (42%) who experienced ERAA, 262 underwent ECV. Failure or success of ECV was defined according to the current expert consensus statement. Failed ECV was defined as failure to terminate AF and/or relapse into AF within 30 seconds after transient sinus rhythm conversion by ECV with a shock energy of 270 J in this study. Of the patients, 254 (97%) with restored sinus rhythm were included, and 8 who experienced sustained AF afterward and discontinued the rhythm-control strategy were excluded. We divided the 254 patients into the following 2 groups on the basis of failed or successful ECV: failed-ECV (n = 105; at least 1 failed ECV but experienced successful ECV at a later date nevertheless) and successful-ECV (n = 149, no failed ECV) groups. At the median follow-up period of 610 days after CA, the recurrence rate was higher in the failed-ECV group than in the successful-ECV group (76.2% vs 45.6%, log-rank p < 0.001). After adjustment for baseline differences, failed ECV was found to be a significant predictor of recurrence in the multivariate model (p < 0.001). In conclusion, failed ECV for ERAA was an independent predictor of future recurrence.

Biomarkers Determining Prognosis of Atrial Fibrillation Ablation

Catheter ablation for rhythm control is recommended in specific patient populations with paroxysmal, persistent, or long-standing persistent atrial fibrillation. Pulmonary vein isolation is the cornerstone of the ablative therapy for atrial fibrillation. However, relapse is still common since the single procedure efficacy of atrial fibrillation ablation was estimated to be 60-80% in paroxysmal and 50-70% in persistent atrial fibrillation. It is important to identify predictors of successful atrial fibrillation patients ablation. In the present review, we will assess the role of available biomarkers to predict responders of an initial atrial fibrillation catheter ablation. Emphasis has been given on the role of myocardial injury biomarkers, natriuretic peptides and traditional inflammatory markers. Novel inflammatory markers, oxidative stress biomarkers and microRNAs have also been examined as predictors of a successful atrial fibrillation procedure. Notably, the impact of procedural and short-term administration of steroids, as well as the role of colchicine on preventing atrial fibrillation recurrence after ablation is thoroughly presented.

[Biomarkers and atrial fibrillation : Prediction of recurrences and thromboembolic events after rhythm control management]

Atrial fibrillation (AF) is the most common arrhythmia in clinical praxis and is associated with an increased risk for cardio- and cerebrovascular complications leading to an increased mortality. Catheter ablation represents one of the most important and efficient therapy strategies in AF patients. Nevertheless, the high incidence of arrhythmia recurrences after catheter ablation leads to repeated procedures and higher treatment costs. Recently, several scores had been developed to predict rhythm outcomes after catheter ablation. Biomarker research is also of enormous interest. There are many clinical and blood biomarkers pathophysiologically associated with AF occurrence, progression and recurrences. These biomarkers-including different markers in blood (e. g. von Willebrand factor, D‑dimer, natriuretic peptides) or urine (proteins, epidermal grown factor receptor) but also cardiac imaging (echocardiography, computed tomography, magnetic resonance imaging)-could help to improve clinical scores and be useful for individualized AF management and optimized patients' selection for different AF treatment strategies. In this review, the role of diverse biomarkers and their predictive value related to AF-associated complications are discussed.

Prognostic implications and procoagulant activity of phosphatidylserine exposure of blood cells and microparticles in patients with atrial fibrillation treated with pulmonary vein isolation

The present study aimed to evaluate the procoagulant effects of phosphatidylserine (PS) exposure on blood cells and microparticles (MPs), and examine its role in predicting early recurrence atrial fibrillation (ERAF) in patients with atrial fibrillation (AF) treated with pulmonary vein isolation (PVI). Blood samples were obtained from 40 healthy controls and 56 patients with AF at baseline (prior to PVI), and 0, 1 h, 1 day, 3 days and 7 days following PVI. The exposure of PS (PS⁺) to blood cells (platelets, erythrocytes and leukocytes) and MPs was detected using flow cytometry. The procoagulant activity was evaluated by coagulation time, and the formation of factor Xa (FXa) and thrombin. In addition, independent factors associated with PS⁺ blood cells and MPs, and significant predictors of ERAF following PVI were investigated by statistical analyses. The numbers of PS⁺ blood cells and MPs were significantly increased by PVI (P<0.01). A significant decrease in coagulation time, and increases in FXa and thrombin were exhibited in the PS⁺ blood cells and MPs from patients with AF treated with PVI, whereas these alterations were inhibited by either lactadherin or anti-tissue factor (P<0.01). The maximum power of the PVI was significantly associated with platelet-derived MPs, and high-sensitivity C-reactive protein (hs-CRP) was closely associated with leukocyte-derived MPs and endothelial-derived MPs (EMPs) (P<0.01). In addition, hs-CRP and EMPs >355/µl were identified as independent predictors of ERAF (P<0.05). The increased numbers of PS⁺ platelets, erythrocytes, leukocytes and MPs contributed to the procoagulant state of AF, and hs-CRP and EMPs were able to predict ERAF following PVI.

Very early recurrence predicts long-term outcome in patients after atrial fibrillation catheter ablation: a prospective study

Background

Long-term recurrence (LR) is a tendency that re-occurs within 3 months after catheter ablation for atrial fibrillation (AF). Whether very early recurrence (VER) within 7 days of post ablation is a prognostic factor of LR or not is unclear. For this reason, present study sought to examine the relationship between VER and LR.

Methods

In this prospective analysis 378 consecutive patients underwent an initial catheter ablation for paroxysmal or persistent AF. The association between VER and LR was analyzed by univariate and multivariate Cox regression, as well as time-dependent receiver operator characteristic (ROC) analysis.

Results

After a mean follow-up of 14.71 ± 8.58 months, 81 (65.90%) patients with VER experienced LR and were associated with lower event of free survival from LR (Log rank test, P < 0.001). Multivariate Cox regression analysis revealed that VER (HR = 7.02, 95% CI = 4.78–10.31; P < 0.001), left atrial enlargement (HR = 2.92, 95% CI = 1.88–4.54; P < 0.001), tendency in advanced age (HR = 1.50, 95% CI = 0.99–2.28; P = 0.054), and tendency in male (HR = 0.71, 95% CI = 0.50–1.01; P = 0.060) were independent predictors of LR. According to time-dependent ROC analysis, it was found that VER was more sensitive than common risk factors in predicting LR (0.74 vs 0.66, P < 0.001) and combination model further improved the C statistic for predicting LR (0.82 vs 0.66, P < 0.001).

Conclusions

After a single procedure of catheter ablation, patients with VER were strongly associated with LR and combination of VER and common risk factors could further improve prediction of patients who were at high risk for LR.

Effect of remote ischemic preconditioning on myocardial injury and inflammatory response induced by ablation for atrial fibrillation: A randomized controlled trial

BACKGROUND

Remote ischemic preconditioning (RIPC) has been suggested to reduce postoperative release of cardiac and inflammatory markers in patients undergoing cardiac surgery. This study aimed to evaluate the effect of RIPC on nonischemic myocardial damage and inflammatory response in patients undergoing radiofrequency catheter ablation for paroxysmal atrial fibrillation (AF).

METHODS

Seventy-two patients with drug-refractory paroxysmal AF undergoing radiofrequency catheter ablation were randomized into RIPC or control groups. RIPC (intermittent arm ischemia through four cycles of 5-min inflation and 5-min deflation of a blood-pressure cuff) was performed once daily on 2 consecutive days before the ablation and immediately before ablation. Cardiac troponin-I (cTnI), high-sensitive C-reactive protein (hs-CRP), and interleukin (IL)-6 levels were measured before RIPC/sham RIPC, after the ablation, and 24 and 72h later. The early recurrence of atrial fibrillation (ERAF) in the two groups was observed over the subsequent 3months.

RESULTS

Radiofrequency ablation resulted in a significant rise in cTnI, hs-CRP, and IL-6 in both groups, which persisted for 72h. The RIPC group showed a lower increase in cTnI (P<0.001), hs-CRP (P=0.003), and IL-6 (P=0.008) than the control and tended to have a lower risk of ERAF (hazard ratio [HR]=0.77, 95% confidence interval [CI]: 0.32-1.88).

CONCLUSIONS

These results show that RIPC before ablation for paroxysmal AF significantly reduces the increase in cTnI, hs-CRP, and IL-6 associated with the procedure and results in a lower risk of ERAF. These findings suggest that RIPC could provide cardioprotection against nonischemic myocardial damage.

Early Recurrence After Pulmonary Vein Isolation of Paroxysmal Atrial Fibrillation With Different Ablation Technologies - Prospective Comparison of Radiofrequency vs. Second-Generation Cryoballoon Ablation

BACKGROUND

Inflammation plays a prominent role in the etiology of the early recurrence of atrial fibrillation (ERAF). We prospectively compared the proportion of ERAF and time-course patterns of biomarkers between radiofrequency (RF) and cryoballoon (CB) ablation.

METHODS AND RESULTS

We enrolled 82 consecutive paroxysmal AF patients undergoing pulmonary vein (PV) isolation, performed with either a 28-mm 2nd-generation CB and 3-min freeze technique or point-by-point RF ablation. Each group had 41 patients. In the RF group, all PVs were successfully isolated with 28.9 ± 6.5 min of RF delivery. In the CB group, a mean of 5.3 ± 1.4 applications/patient was delivered. The proportion of ERAF was similar between the groups. The time-course patterns significantly differed between the groups for high-sensitivity C-reactive protein (hs-CRP) value (P=0.006) and myocardial injury markers (P<0.0001). Greater myocardial injury was observed in the CB than in the RF group (P<0.0001), whereas the peak hs-CRP value was comparable between the groups. The 2-day post-procedure hs-CRP value was the sole factor correlating with ERAF as identified by the multivariable analysis (hazard ratio 1.697; 95% confidence interval, 1.005-2.865; P=0.048) in the RF, but not the CB group.

CONCLUSIONS

The proportion of ERAF was comparable after RF and 2nd-generation CB ablation. Despite CB ablation exhibiting greater myocardial injury than RF ablation, the inflammatory responses were comparable between the groups. The inflammatory response extent predicted ERAF post-RF ablation but not post-CB ablation.

eNOS3 Genetic Polymorphism Is Related to Post-Ablation Early Recurrence of Atrial Fibrillation

PURPOSE

Previous studies have demonstrated an association between eNOS polymorphisms and atrial fibrillation (AF). We sought to determine whether eNOS polymorphisms are associated with AF recurrence after a radiofrequency catheter ablation (RFCA).

MATERIALS AND METHODS

A total of 500 consecutive patients (56±11 years, 77% male) with paroxysmal (68%) or persistent (32%) AF who underwent RFCA and 500 age, gender-matched controls were genotyped for the eNOS3 single nucleotide polymorphism (rs1799983). AF recurrence was monitored according to 2012 ACC/AHA/ESC guidelines.

RESULTS

The frequencies of the rs1799983 variant alleles (T) in the case and control group were not significantly different (OR 1.05, 95% CI 0.75-1.46, p=0.798). AF patients with rs1799983 variants were more likely to have coronary artery disease or stroke than those without genetic variant at this gene (31.0% vs. 17.3%, p=0.004). During mean 17 months follow-up, early recurrence of AF (ERAF; within 3 months) and clinical recurrence (CR) of AF were 31.8% and 24.8%, respectively. The rs1799983 variant was associated with higher risk of ERAF (OR 1.71, 95% CI 1.06-2.79, p=0.028), but not with CR. ERAF occurred earlier (11±16 days) in variant group than those without variant allele (20±25 days, p=0.016). A multiple logistic regression analysis showed that presence of the rs1799983 variant (OR 1.75, 95% CI 1.07-2.86, p=0.026) and persistent AF were independent predictors for ERAF after AF ablation.

CONCLUSION

The rs1799983 variant of the eNOS3 gene was associated with ERAF, but not with CR, after RFCA. eNOS3 gene variants may have a potential role for stratification of post-ablation management.

Clinical significance of early atrial arrhythmia type and timing after single ring isolation of the pulmonary veins

AIMS

Early atrial arrhythmia following atrial fibrillation (AF) ablation is associated with higher recurrence rates. Few studies explore the impact of early AF (EAF) and atrial tachycardia (EAT) on long-term outcomes. Furthermore, EAF/EAT have not been characterized after wide pulmonary vein isolation. We aimed to characterize EAF and EAT and its impact on late AF (LAF) and AT (LAT) after single ring isolation (SRI).

METHODS AND RESULTS

We recruited 119 (females 21, age 58 ± 10 years) consecutive patients with AF (paroxysmal 76, persistent 43) undergoing SRI. Early atrial fibrillation/ early atrial tachycardia was defined as AF/AT within 3 months post-procedure (blanking period). Patients were followed for median 2.8[2.2-4] years. Early atrial fibrillation occurred in 28% (n = 33) and EAT in 25% (n = 30). At follow-up, 25% (n = 30) had LAF and 28% (n = 33) had LAT. Patients with EAF and EAT had higher rates of LAF (48 vs. 16%, P<0.0001) and LAT (60 vs. 16%, P < 0.0001), respectively. Independent predictors of LAF were EAF (3.53(1.72-7.29) P = 0.001); and of LAT were EAT (5.62(2.88-10.95) P < 0.0001) and procedure time (1.38/ h(1.07-1.78) P = 0.04). Importantly, EAF did not predict LAT and EAT did not predict LAF. Early atrial fibrillation late in the blanking period was associated with higher rates of LAF (73% for month 3 vs. 25% for Months 1-2, P = 0.004). However, EAT timing did not predict LAT.

CONCLUSION

Early atrial fibrillation and EAT are predictive of LAF and LAT, respectively. Early atrial fibrillation late in the blanking period has greater predictive significance for LAF. This timing is not relevant for LAT. Early arrhythmia type and timing have important prognostic significance following SRI.

CLINICAL TRIAL REGISTRATION

http://www.anzctr.org.au;ACTRN12606000467538.

Inflammation and the pathogenesis of atrial fibrillation

Atrial fibrillation (AF) is the most common cardiac arrhythmia. However, the development of preventative therapies for AF has been disappointing. The infiltration of immune cells and proteins that mediate the inflammatory response in cardiac tissue and circulatory processes is associated with AF. Furthermore, the presence of inflammation in the heart or systemic circulation can predict the onset of AF and recurrence in the general population, as well as in patients after cardiac surgery, cardioversion, and catheter ablation. Mediators of the inflammatory response can alter atrial electrophysiology and structural substrates, thereby leading to increased vulnerability to AF. Inflammation also modulates calcium homeostasis and connexins, which are associated with triggers of AF and heterogeneous atrial conduction. Myolysis, cardiomyocyte apoptosis, and the activation of fibrotic pathways via fibroblasts, transforming growth factor-β and matrix metalloproteases are also mediated by inflammatory pathways, which can all contribute to structural remodelling of the atria. The development of thromboembolism, a detrimental complication of AF, is also associated with inflammatory activity. Understanding the complex pathophysiological processes and dynamic changes of AF-associated inflammation might help to identify specific anti-inflammatory strategies for the prevention of AF.

Predictors of Atrial Fibrillation Recurrence after Catheter Ablation

Atrial fibrillation (AF) catheter ablation is a well-known treatment option for patients with drug refractory AF. The increasing number of electrophysiology laboratories able to perform this procedure will create in the next years an economic issue, which each cardiac electrophysiologist will have to face with. Identification of predictors of recurrence of AF after catheter ablation is therefore of primary importance to reduce health costs and improve long-term results of this intervention. The aim of this review is to give a brief overview on what have been published already in the literature on the topic and henceforth to increase the awareness of cardiac electrophysiophysiologists on the importance of selection of the right candidates to this intervention.

Rhythm outcomes after catheter ablation of atrial fibrillation. Clinical implication of biomarkers

Atrial fibrillation (AF) occurs as the result of numerous complex physiological processes in the atria leading to AF promotion and maintenance. Improved diagnostic techniques have identified various biomarkers which may play an important role in the prediction of AF related outcomes (cardio- and cerebrovascular events, as well as mortality and rhythm outcomes). Biomarkers refer to 'biological markers' and biomarkers in blood, urine as well as imaging marker (eg, dimensions (left atrial diameter and volume), anatomical features (left appendage and pulmonary vein anatomy), and physiological pattern (LAA flow velocity)) may play important role(s) as clinically important indices in relation to outcomes after different therapeutic strategies. However, the main domain in the biomarker field has focused on blood-based biomarkers, which are widely used to predict therapeutic success regarding underlying pathophysiological mechanism, such as inflammation, fibrosis, endothelial damage. This review provides an update of the role of clinically relevant biomarkers in AF, with particular focus on AF rhythm outcomes.

2012 HRS/EHRA/ECAS expert consensus statement on catheter and surgical ablation of atrial fibrillation: recommendations for patient selection, procedural techniques, patient management and follow-up, definitions, endpoints, and research trial design

This is a report of the Heart Rhythm Society (HRS) Task Force on Catheter and Surgical Ablation of Atrial Fibrillation, developed in partnership with the European Heart Rhythm Association (EHRA), a registered branch of the European Society of Cardiology and the European Cardiac Arrhythmia Society (ECAS), and in collaboration with the American College of Cardiology (ACC), American Heart Association (AHA), the Asia Pacific Heart Rhythm Society (APHRS), and the Society of Thoracic Surgeons (STS). This is endorsed by the governing bodies of the ACC Foundation, the AHA, the ECAS, the EHRA, the STS, the APHRS, and the HRS.

Clinical significance of early recurrences of atrial tachycardia after atrial fibrillation ablation

BACKGROUND

atrial tachycardia (AT) commonly recurs within 3 months after radiofrequency catheter ablation for atrial fibrillation (AF). However, it remains unclear whether early recurrence of atrial tachycardia (ERAT) predicts late recurrence of AF or AT.

METHODS

of 352 consecutive patients who underwent circumferential pulmonary vein isolation with or without linear ablation(s) for AF, 56 patients (15.9%) with ERAT were identified by retrospective analysis. ERAT was defined as early relapse of AT within a 3-month blanking period after ablation.

RESULTS

during 21.7 ± 12.5 months, the rate of late recurrence was higher in patients with ERAT (41.1%) compared with those without ERAT (11.8%, P < 0.001). In a multivariable model, positive inducibility of AF or AT immediately after ablation (65.2% vs 36.4%, P = 0.046; odd ratio, 3.9; 95% confidence interval, 1.0-14.6) and the number of patients who underwent cavotricuspid isthmus (CTI) ablation (73.9% vs 42.4%, P = 0.042; odd ratio, 4.5; 95% confidence interval, 1.1-19.5) were significantly related to late recurrence in the ERAT group. The duration of ablation (174.3 ± 62.3 vs 114.7 ± 39.5 minutes, P = 0.046) and the procedure time (329.3 ± 83.4 vs 279.2 ± 79.7 minutes, P = 0.027) were significantly longer in patients with late recurrence than in those without late recurrence following ERAT.

CONCLUSIONS

the late recurrence rate is higher in the patients with ERAT compared with those without ERAT following AF ablation, and is more often noted in the patients who underwent CTI ablation and had a prolonged procedure time. Furthermore, inducibility of AF or AT immediately after ablation independently predicts late recurrence in patients with ERAT.

Early recurrence of atrial tachyarrhythmias following radiofrequency catheter ablation of atrial fibrillation

The use of blanking periods, the immediate period postablation during which transient tachyarrhythmia episodes are not considered recurrences, has been predicated on the assumption that not all early recurrences of atrial tachyarrhythmias (ERAT) will lead to later recurrences and, as such, does not necessarily represent treatment failure. While ERAT can be expected to occur in approximately 38% of patients within the first 3 months of atrial fibrillation (AF) ablation, only half of these patients will manifest later recurrences. Clinical features related to the patient's history of AF, the index ablation procedure, and particularities of the ERAT can help identify patients at higher risk of later recurrence in whom aggressive attempts to control rhythm, including early cardioversion and reintervention, may be justified.

IntravenousCorticosteroid Use Is Associated With Reduced Early Recurrence of Atrial Fibrillation Immediately Following Radiofrequency Catheter Ablation

Background: Early recurrence of atrial fibrillation (ERAF) occurs in up to 40% of patients after radiofrequency catheter ablation for atrial fibrillation (RFCA), increasing hospital stay, need for anti-arrhythmic medications (AADs) and cardioversion, and, possibly, the risk of future AF. It has been postulated that inflammation plays a key role in developing ERAF. Short term postoperative use of corticosteroids to reduce ERAF post-RFCA has not been vigorously studied. Methods: This was a case-control study of consecutive patients undergoing RFCA for the management of AF at a single-institution. RFCA was performed by a single operator from October 2005 through July 2009. Patients receiving intravenous corticosteroids immediately following the ablation and for 48 hours (6 doses) constituted the treatment group. Controls received no intravenous corticosteroids during their hospitalization. All other management strategies were similar between the 2 groups, including the administration of AADs post- operatively. All patients had continuous electrocardiographic monitoring throughout their hospitalization. Multivariable logistic regression analysis was used to determine the impact of intravenous corticosteroids on ERAF defined as any AF>10 minutes during hospitalization. Results: A total of 68 patients undergoing RFCA for the management of AF were included in this analysis. The overall ERAF rate, irrespective of intravenous corticosteroid use, was 23.5%. The administration of intravenous corticosteroids (n=37; mean±SD dexamethasone mean dose 11.9±4.6 mg/day; range 4-16 mg/day) was associated with an 82% reduction in patients' odds of ERAF (adjusted odds ratio; 0.18, 95% confidence interval [CI] 0.04 to 0.78) compared with those who did not receive corticosteroids (n=31). A dose-response effect was also observed, with a 17% reduction in ERAF odds for each dexamethasone mg-equivalent administered (adjusted odds ratio; 0.83, 95%CI 0.73 to 0.96). Conclusions: The use of intravenous corticosteroids was associated with a dose-dependent reduction in the odds of developing ERAF after RFCA for the management of AF.

Acute pericardial effusion following atrial fibrillation ablation: characteristics and relationship with arrhythmia recurrences

BACKGROUND

Pericardial effusion (PE) can occur during or after atrial fibrillation (AF) ablation, and may induce atrial arrhythmia.

AIM

To characterize the impact of PE on arrhythmia recurrences following AF ablation.

METHODS

Patients referred for a first radiofrequency AF ablation were studied prospectively. Transthoracic echocardiography was performed before and 24h after the procedure. If PE was present, transthoracic echocardiography was repeated at 1 month to evaluate PE evolution. Early arrhythmia recurrences (EARs) were defined as any arrhythmia documented within 1 month of the procedure.

RESULTS

PE was diagnosed in 18/81 patients (22%); and was present in significantly more patients with persistent versus paroxysmal AF (14/40 [35%] vs 4/41 [10%]; P=0.008). PEs were mild (mean 6 ± 3mm), mainly asymptomatic (89%), and none required pericardiocentesis. Early and late arrhythmia recurrences were present in 25/81 (31%) and 29/81 (36%), respectively. The incidence of PE was significantly higher among patients with EARs versus those without (12/25 [48%] vs 6/56 [11%]; P=0.0004). By multivariable analysis, PE and duration in AF were the two independent predictors of EARs. PE incidence was similar in patients with and without late arrhythmia recurrences. At 1 month, no patients had PE on transthoracic echocardiography.

CONCLUSION

PE following radiofrequency AF ablation is frequent, particularly following persistent AF ablation. This effusion is generally mild, mainly asymptomatic, and independently associated with EARs.

Prevention of atrial fibrillation recurrence with corticosteroids after radiofrequency catheter ablation: a randomized controlled trial

OBJECTIVES

We sought to clarify the efficacy of corticosteroid therapy for preventing atrial fibrillation (AF) recurrence after pulmonary vein isolation (PVI).

BACKGROUND

The inflammatory process may cause acute AF recurrence after PVI. However, no studies have examined the relationship between corticosteroid administration and AF recurrence after PVI.

METHODS

A total of 125 patients with paroxysmal AF were randomized to receive either corticosteroids (corticosteroid group) or a placebo (placebo group). In the corticosteroid group, intravenous hydrocortisone (2 mg/kg) was given the day of the procedure, and oral prednisolone (0.5 mg/kg/day) was administered for 3 days after the PVI. The body temperature and high-sensitivity C-reactive protein level were measured before and on each of the first 3 days after ablation.

RESULTS

The prevalence of immediate AF recurrence (≤3 days after the PVI) was significantly lower in the corticosteroid group (7%) than in the placebo group (31%). The maximum body temperature and C-reactive protein during the initial 3 days after ablation and the increase in the body temperature and C-reactive protein level from baseline were significantly lower in the corticosteroid group than in the placebo group. Corticosteroid treatment did not decrease AF recurrences between 4 and 30 days after ablation. The AF-free rate at 14 months post-ablation was greater in the corticosteroid group (85%) than in the placebo group (71%, p=0.032 by the log-rank test).

CONCLUSIONS

Transient use of small amounts of corticosteroids shortly after AF ablation may be effective and safe for preventing not only immediate AF recurrences but also AF recurrences during the mid-term follow-up period after PVI.

The modified anterior line: an alternative linear lesion in perimitral flutter

INTRODUCTION

Ablation of left atrial flutter (LAF) is often limited by the need for technically demanding linear lesions. We evaluated the safety and efficacy of a new modified anterior line (MAL), connecting the anterior/anterolateral mitral annulus with the left superior pulmonary vein for ablation of perimitral flutter.

METHODS AND RESULTS

MAL was performed in 65 patients (15 females, age 63.6 +/- 9.8 years) with perimitral flutter using 3D mapping systems (70.8% Carto, 29.2% NavX). Perimitral flutter was either the presenting arrhythmia (73.8%) or an intermediate organized rhythm during atrial fibrillation ablation. Follow-up included repetitive 7-day Holter with 93.8% of patients off antiarrhythmics. MAL was acutely effective in 63/65 patients (96.9%). Termination to sinus rhythm occurred in 36 of 65 patients (55.4%), and in 27 of 65 patients (41.5%) there was a change to another LAF type. Bidirectional block across the MAL was achieved in 56 of 65 patients (86.1%). After 6 months of follow-up, 20 of 41 patients (48.8%) had a LAF recurrence, with 6 patients undergoing a reablation. In all redo patients the MAL was still complete and LAF mechanism was different to the initially targeted. No major complication occurred during the ablation procedures or in the postablation period.

CONCLUSION

The MAL is a safe and effective linear lesion for the treatment of perimitral LAF. Its value compared to more established linear lesions as the mitral isthmus line has to be evaluated in larger studies.

Protracted CRP elevation after atrial fibrillation ablation

BACKGROUND

Atrial fibrillation (AF) has been linked to an inflammatory process detected through various biomarkers, including C-Reactive Protein (CRP). Early recurrence of AF within the first 3 months after curative AF ablation is not felt to reflect success or failure of the procedure. We hypothesized that this early recurrence is due to an inflammatory response to the ablation itself. We therefore sought to evaluate levels of CRP after AF ablation.

METHODS

We prospectively enrolled subjects undergoing AF ablation. A control group of patients undergoing ablation for supraventricular tachycardia (SVT) was also enrolled. Each patient had CRP drawn on the day of the procedure (prior to ablation) and during their first follow-up (median 49 days, interquartile range [IQR] 37-93) and second follow-up (median 147 days, IQR 141-257) clinic visits. Patient interviews were performed and medical histories reviewed for evidence of recurrent AF prior to the first follow-up.

RESULTS

CRP levels significantly increased from baseline to first follow-up in the AF ablation group (P = 0.0017). CRP did not significantly change after SVT ablation (P = 0.92). Seventeen (45%) of the AF subjects exhibited recurrence of AF prior to first follow-up. After adjusting for multiple potential confounders, AF ablation patients with recurrent AF prior to their first follow-up had a statistically significant greater odds of having an increase in CRP (OR 21, 95% CI 1.1-417, P = 0.045).

CONCLUSIONS

AF ablation generates an inflammatory response that persists for several weeks. This inflammation may explain early recurrence of AF after curative ablation.

Predictive value of early recurrence and delayed cure after catheter ablation for patients with chronic atrial fibrillation

BACKGROUND

Radiofrequency catheter ablation (RFCA) for curing atrial fibrillation (AF) is often followed by early recurrence and delayed cure, so the present study investigate the predictive factors this in patients with chronic AF.

METHODS AND RESULTS

Ninety-two consecutive patients (70 males; mean age, 58.7+/-6.4 years) with chronic AF who underwent RFCA for treatment of symptomatic AF were enrolled. Early recurrence of AF (ERAF) occurred in 45 patients after ablation. Not achieving AF termination could predict ERAF (odds ratio (OR) 0.95; 95% confidence interval (CI) 0.84-1.13; p=0.02) in multivariate analysis. During a follow-up of 12+/-11 (range, 5-25) months, delayed cure occurred in 35.6% (16/45) of the patients with ERAF. Left atrial size and AF termination during ablation were related to delayed cure. AF termination was the only independent predictive factor for delayed cure (OR 1.47; 95% CI 1.05-1.87; p=0.02).

CONCLUSION

Not achieving AF termination is the only independent predictor of ERAF. Among patients with ERAF, those with a smaller left atrium and AF termination have a higher probability of delayed cure. AF termination can independently predict delayed cure. These results emphasize the importance of AF termination during ablation for patients with chronic AF.

Early recurrences after atrial fibrillation ablation: prognostic value and effect of early reablation

INTRODUCTION

Early arrhythmia recurrences are common within the first month after atrial fibrillation (AF) ablation. The long-term consequences of these early recurrences (ER) are controversial. We investigated whether ER were predictive of late recurrences and the impact of early reablation on clinical outcome.

METHODS

Three hundred two consecutive patients with paroxysmal or persistent AF were studied. Arrhythmia recurrence was defined as documented episode of AF or atrial tachycardia. Of 151 patients with ER, a subset of 61 patients had reablation within the first month following the index ablation (early reablation). In the remaining 90 patients, a repeat procedure was only performed for later arrhythmia recurrences occurring beyond 1 month. Patients were followed with clinical interview and ambulatory 24 hours monitoring.

RESULTS

Patients with and without early reablation had similar baseline characteristics including echocardiographic parameters and type of AF. During a mean follow-up of 11 +/- 11 months, 82 patients (91%) without early reablation experienced late clinical recurrences. In contrast, patients with early reablation had lower rate of clinical recurrences (51% vs 91%, P < 0.0001) and fewer additional procedures (36% vs 91%, P < 0.0001). However, the total number of procedures over the entire follow-up was greater in those patients with early reablation (2.5 +/- 0.7 vs 2.2 +/- 0.6, P = 0.02).

CONCLUSION

An overwhelming majority of patients with recurrences within the first month after ablation have late recurrences. An early reablation reduces the incidence of further recurrences. However, the overall number of procedures is higher in the medium-term follow-up. The optimal timing for the second procedure remains to be defined.