Feasibility of concomitant left atrial appendage closure and percutaneous coronary intervention in patients with acute coronary syndrome and atrial fibrillation: a randomized pilot study.

The optimal approach for prevention of cardiovascular events and reduction of bleeding in patients with acute coronary syndrome (ACS) and atrial fibrillation (AF) is still controversial. The aim of our study is to asses our single-center experience with concomitant left atrial appendage occlusion (LAAO) and percutaneous coronary intervention (PCI). 50 patients with ACS without ST elevation and history of AF were randomized after successful PCI to LAAO or conventional medical therapy. The primary endpoints were safety and length of hospitalization. The follow-up period was 30 days. The mean procedural times were 113 ± 23 min PCI + LAAO implantation and 39 ± 19 min of PCI only (p < 0.001), while mean fluoroscopy times were 18 ± 8 min and 12 ± 8 min (p < 0.001), respectively. No procedure-related complications were observed. There was no difference observed for length of hospitalization between two groups. LAAO in patients with ACS and AF undergoing PCI appears safe.

Remote magnetic navigation ablation via the right jugular vein approach in patient with interruption of the inferior vena cava and incessant left atrial flutter.

Remote magnetic navigation (RMN) can be safely and effectively utilized in patients with difficult cardiac arrhythmias and complex anatomy. Interruption of the inferior vena cava (IVC) is a rare congenital abnormality that results in the inability to use conventional femoral access in patients that require interventional procedures. The present case demonstrates the feasibility of left atrial flutter ablation using RMN via jugular approach in a patient with interruption of IVC.

Effect of Renal Denervation and Catheter Ablation vs Catheter Ablation Alone on Atrial Fibrillation Recurrence Among Patients With Paroxysmal Atrial Fibrillation and Hypertension: The ERADICATE-AF Randomized Clinical Trial.

Importance: Renal denervation can reduce cardiac sympathetic activity that may result in an antiarrhythmic effect on atrial fibrillation. Objective: To determine whether renal denervation when added to pulmonary vein isolation enhances long-term antiarrhythmic efficacy. Design, Setting, and Participants: The Evaluate Renal Denervation in Addition to Catheter Ablation to Eliminate Atrial Fibrillation (ERADICATE-AF) trial was an investigator-initiated, multicenter, single-blind, randomized clinical trial conducted at 5 referral centers for catheter ablation of atrial fibrillation in the Russian Federation, Poland, and Germany. A total of 302 patients with hypertension despite taking at least 1 antihypertensive medication, paroxysmal atrial fibrillation, and plans for ablation were enrolled from April 2013 to March 2018. Follow-up concluded in March 2019. Interventions: Patients were randomized to either pulmonary vein isolation alone (n = 148) or pulmonary vein isolation plus renal denervation (n = 154). Complete pulmonary vein isolation to v an end point of elimination of all pulmonary vein potentials; renal denervation using an irrigated-tip ablation catheter delivering radiofrequency energy to discrete sites in a spiral pattern from distal to proximal in both renal arteries. Main Outcomes and Measures: The primary end point was freedom from atrial fibrillation, atrial flutter, or atrial tachycardia at 12 months. Secondary end points included procedural complications within 30 days and blood pressure control at 6 and 12 months. Results: Of the 302 randomized patients (median age, 60 years [interquartile range, 55-65 years]; 182 men [60.3%]), 283 (93.7%) completed the trial. All successfully underwent their assigned procedures. Freedom from atrial fibrillation, flutter, or tachycardia at 12 months was observed in 84 of 148 (56.5%) of those undergoing pulmonary vein isolation alone and in 111 of 154 (72.1%) of those undergoing pulmonary vein isolation plus renal denervation (hazard ratio, 0.57; 95% CI, 0.38 to 0.85; P = .006). Of 5 prespecified secondary end points, 4 are reported and 3 differed between groups. Mean systolic blood pressure from baseline to 12 months decreased from 151 mm Hg to 147 mm Hg in the isolation-only group and from 150 mm Hg to 135 mm Hg in the renal denervation group (between-group difference, -13 mm Hg; 95% CI, -15 to -11 mm Hg; P < .001). Procedural complications occurred in 7 patients (4.7%) in the isolation-only group and 7 (4.5%) of the renal denervation group. Conclusions and Relevance: Among patients with paroxysmal atrial fibrillation and hypertension, renal denervation added to catheter ablation, compared with catheter ablation alone, significantly increased the likelihood of freedom from atrial fibrillation at 12 months. The lack of a formal sham-control renal denervation procedure should be considered in interpreting the results of this trial. Trial Registration: ClinicalTrials.gov Identifier: NCT01873352.

Prophylactic pulmonary vein isolation during isthmus ablation for atrial flutter: Three-year outcomes of the PREVENT AF I study.

INTRODUCTION: The PREVENT AF I study demonstrated that prophylactic pulmonary vein isolation (PVI) in patients with pure typical atrial flutter (AFL) resulted in substantial reduction of new-onset atrial fibrillation (AF) during 1-year follow-up as assessed by continuous implantable cardiac monitor (ICM). The objective of this study was to assess 3-year outcomes. METHODS AND RESULTS: Fifty patients with documented AFL were randomized to either cavotricuspid isthmus (CTI) ablation alone (n = 25) or CTI with concomitant PVI (n = 25). The primary endpoint of the study was the occurrence of any atrial tachyarrhythmia with the monthly burden exceeding 0.5% on the ICM. At the end of 3 years, freedom from any atrial tachyarrhythmia was 48% (95% confidence interval [CI]: 32-72%) in the CTI plus PVI group as compared to 20% (95% CI: 9-44%) in the CTI-only group (P = 0.01). Freedom from redo procedures was also higher: 92% (95% CI: 82-100%) versus 68% (95% CI: 52-89%), respectively (P = 0.027). The 3-year AF burden favored the combined ablation group: 6.2% versus 16.8% (P = 0.03). In the CTI-only group, 12 (48%) patients were hospitalized compared to 4 (16%) in the PVI + CTI group (P = 0.03). Two patients in the CTI-only group developed stroke with no serious adverse events in the PVI + CTI group. CONCLUSION: Prophylactic PVI in patients with only typical AFL resulted in a significant reduction of new-onset AF and burden during long-term follow-up as assessed by ICM, with consequent reduction in hospitalizations and need to perform repeat ablation for AF.

Incidence of atrial fibrillation detected by continuous rhythm monitoring after acute myocardial infarction in patients with preserved left ventricular ejection fraction: results of the ARREST study.

Aims: Cardiac arrhythmias following acute myocardial infarction (AMI) can be associated with major adverse cardiovascular events. Data on the "real incidence" of post-MI arrhythmias are limited. We aimed to determine the rate and burden of cardiac arrhythmias by the use of insertable cardiac monitors (ICM) in patients with preserved left ventricular ejection fraction (LVEF) after AMI. Methods and results: In this prospective observational study, patients with LVEF ≥40% who underwent PCI within 7 days following AMI were enrolled to receive an ICM. Primary outcome was the incidence of new-onset atrial fibrillation (AF) measured by the ICM during a follow-up of 2 years; results: Of 165 consecutive patients with AMI, 50 (30.3%) eligible patients were recruited (mean age 57.8 ± 8.3, 88% male). During follow-up, AF was the most frequently detected arrhythmia. Twenty-nine (58%, 95% CI: 42-70%) patients developed new-onset AF, with a cumulative rate of all detected arrhythmias of 65%. Median time to the first detected AF episode was 4.8 months and the peak cumulative AF burden was detected between 3 and 6 months. Twenty-seven (93%) out of 29 patients with AF were asymptomatic. Cox regression analysis found that baseline troponin level (hazard ratio [HR] for 1 ng/mL increment: 1.03, 95% CI: 1.01-1.06, P = 0.01) and CHA2DS2-VASc score of 4 (HR: 11.42, 95% CI: 1.01-129.06, P = 0.04) were independent risk factors of new-onset AF post-AMI. Conclusion: AF is a frequent but largely underestimated cardiac arrhythmia after AMI. More rigorous monitoring strategies resulting in crucial medical interventions (e.g. implementation of oral anti-coagulation) are needed. Clinical Trial Registration: http://www.clinicaltrials.gov. Unique identifier: NCT02492243.

Cryoballoon versus radiofrequency for pulmonary vein re-isolation after a failed initial ablation procedure in patients with paroxysmal atrial fibrillation.

AIM: Catheter ablation of paroxysmal atrial fibrillation (PAF) is associated with an important risk of early and late recurrence, necessitating repeat ablation procedures. The aim of this prospective randomized patient-blind study was to compare the efficacy and safety of cryoballoon (Cryo) versus radiofrequency (RF) ablation of PAF after failed initial RF ablation procedure. METHODS: Patients with a history of symptomatic PAF after a previous failed first RF ablation procedure were eligible for this study. Patients were randomized to Cryo or RF redo ablation. The primary endpoint of the study was recurrence of atrial tachyarrhythmia, including AF and left atrial flutter/tachycardia, after a second ablation procedure at 1 year of follow-up. All patients were implanted with a cardiac monitor (Reveal XT, Medtronic) to continuously track the cardiac rhythm. Patients with an AF burden (AF%) ≤ 0.5% were considered AF-free (Responders), while those with an AF% > 0.5% were classified as patients with AF recurrences (non-Responders). RESULTS: Eighty patients with AF recurrences after a first RF pulmonary vein isolation (PVI) were randomized to Cryo (N = 40) or to RF (N = 40). Electrical potentials were recorded in 77 mapped PVs (1.9 ± 0.8 per patient) in Cryo Group and 72 PVs (1.7 ± 0.8 per patient) in RF Group (P = 0.62), all of which were targeted. In Cryo group, 68 (88%) of the 77 PVs were re-isolated using only Cryo technique; the remaining 9 PVs were re-isolated using RF. In RF group, all 72 PVs were successfully re-isolated (P = 0.003 vs Cryo). By intention-to-treat, 23 (58%) RF patients were AF-free vs 17 (43%) Cryo patients on no antiarrhythmic drugs at 1 year (P = 0.06). Three patients had temporary phrenic nerve paralysis in the Cryo group; the RF group had no complications. Of the 29 patients who had only Cryo PVI without any RF ablation, 11 (38%) were AF-free vs 20 (59%) of the 34 patients who had RF only (P = 0.021). CONCLUSION: When patients require a redo pulmonary vein isolation ablation procedure for recurrent PAF, RF appears to be the preferred energy source relative to Cryo.

Catheter versus surgical ablation of atrial fibrillation after a failed initial pulmonary vein isolation procedure: a randomized controlled trial.

INTRODUCTION: The aim of this prospective randomized study was to compare the efficacy and safety of catheter ablation (CA) versus surgical ablation (SA) in the treatment of paroxysmal and persistent AF after failed initial pulmonary vein isolation procedure. METHODS AND RESULTS: Patients with a history of symptomatic AF after a previous failed first ablation procedure were eligible for this study. Patients were randomized to CA (n = 32) or SA (n = 32) redo ablation. The primary endpoint was recurrence of atrial tachyarrhythmia at 1 year of follow-up. At the 12-month follow-up, 26 (81%) of the 32 SA group patients and 15 (47%) of the 32 CA group were AF/AT-free on no antiarrhythmic drugs (P = 0.004, log-rank test). In patients with PAF, 17 (85%) patients of the 20 in SA group and 10 (56%) patients of the 18 in CA group were AF-free (P = 0.04, log-rank test). In patients with PersAF, 9 (75%) patients of the 12 in SA group and 5 (36%) patients of the 14 in CA group were AF-free (P = 0.04, log-rank test). The number of the serious adverse event in the SA group was significantly higher (1 CA group vs 7 SA group; P = 0.02). CONCLUSION: In patients with PAF and PersAF after failed initial CA, SA is superior to CA for maintenance of sinus rhythm, although serious adverse event rate is significantly higher for SA.

The relationship between global cardiac and regional left atrial sympathetic innervation and epicardial fat in patients with atrial fibrillation.

AIM: To investigate the relationship between epicardial adipose tissue (EAT) volume and distribution and the parameters of global cardiac and regional left atrial (LA) sympathetic activity in patients with atrial fibrillation (AF). METHODS AND RESULTS: The data of the 45 consecutive patients scheduled for an index catheter ablation (CA) for AF were analyzed. Total and peri-atrial EAT volumes were measured by cardiac CT. Parameters of global cardiac sympathetic activity and discrete sympathetic regions around LA were assessed by 123I-mIBG SPECT/CT. The patients were followed up for AF recurrences assessment during 12 months after CA. A total of 133 (mean per patient 2.96 ± 1.07) discrete 123I-mIBG uptake areas (DUAs), corresponding to typical anatomical locations of LA ganglionated plexi (GP), were identified. Peri-atrial EAT volume was associated with the number of DUAs (regression estimate, 5.1 [95% CI, 0.3-9.9], p = 0.03). There was no statistically significant association between either total or peri-atrial EAT volumes and risks of AF recurrence. The washout rate (WR) was associated with reduced risk of AF recurrence (HR = 0.95; 95% CI 0.92-0.99; p = 0.01), while left ventricular (LV) myocardium 123I-mIBG summed defect score (SDS) was linked to increased hazards of AF recurrence (HR = 1.04; 95% CI 1.01-1.08; p = 0.03). CONCLUSION: Peri-atrial EAT volume is associated with regions of sympathetic activity corresponding to typical anatomical locations of LA GP. The WR was associated with reduced risk of AF recurrence while LV myocardial SDS was linked to increased hazards of AF recurrence.

Pulmonary Artery Denervation for Patients With Residual Pulmonary Hypertension After Pulmonary Endarterectomy.

BACKGROUND: Pulmonary artery denervation (PADN) procedure has not been applied to patients with residual chronic thromboembolic pulmonary hypertension (CTEPH) after pulmonary endarterectomy (PEA). OBJECTIVES: This study sought to assess the safety and efficacy of PADN using remote magnetic navigation in patients with residual CTEPH after PEA. METHODS: Fifty patients with residual CTEPH despite medical therapy at least 6 months after PEA, who had mean pulmonary artery pressure ≥25 mm Hg or pulmonary vascular resistance (PVR) > 400 dyn‧s‧cm-5 based on right heart catheterization were randomized to treatment with PADN (PADN group; n = 25) using remote magnetic navigation for ablation or medical therapy with riociguat (MED group; n = 25). In the MED group, a sham procedure with mapping but no ablation was performed. The primary endpoint was PVR at 12 months after randomization. Key secondary endpoint included 6-min walk test. RESULTS: After PADN procedure, 2 patients (1 in each group) developed groin hematoma that resolved without any consequences. At 12 months, mean PVR reduction was 258 ± 135 dyn‧s‧cm-5 in the PADN group versus 149 ± 73 dyn‧s‧cm-5 in the MED group, mean between-group difference was 109 dyn‧s‧cm-5 (95% confidence interval: 45 to 171; p = 0.001). The 6-min walk test distance was significantly increased in the PADN group as compared to distance in the MED group (470 ± 84 m vs. 399 ± 116 m, respectively; p = 0.03). CONCLUSIONS: PADN in patients with residual CTEPH resulted in substantial reduction of PVR at 12 months of follow-up, accompanied by improved 6-min walk test.

Long-term suppression of atrial fibrillation by botulinum toxin injection into epicardial fat pads in patients undergoing cardiac surgery: Three-year follow-up of a randomized study.

BACKGROUND: Botulinum toxin (BTX) injections into epicardial fat pads in patients undergoing coronary artery bypass grafting (CABG) has resulted in suppression of atrial fibrillation (AF) during the early postoperative period through 1-year of follow-up in a pilot program. OBJECTIVE: The purpose of this study was to report 3-year AF patterns by the use of implantable cardiac monitors (ICMs). METHODS: Sixty patients with a history of paroxysmal AF and indications for CABG were randomized 1:1 to either BTX or placebo injections into 4 posterior epicardial fat pads. All patients received an ICM with regular follow-up for 3 years after surgery. The primary end point of the extended follow-up period was incidence of any atrial tachyarrhythmia after 30 days of procedure until 36 months on no antiarrhythmic drugs. The secondary end points included clinical events and AF burden. RESULTS: At the end of 36 months, the incidence of any atrial tachyarrhythmia was 23.3% in the BTX group vs 50% in the placebo group (hazard ratio 0.36; 95% confidence interval 0.14-0.88; P = .02). AF burden at 12, 24, and 36 months was significantly lower in the BTX group than in the placebo group: 0.22% vs 1.88% (P = .003), 1.6% vs 9.5% (P < .001), and 1.3% vs 6.9% (P = .007), respectively. In the BTX group, 2 patients (7%) were hospitalized during follow-up compared with 10 (33%) in the placebo group (P = .02). CONCLUSION: Injection of BTX into epicardial fat pads in patients undergoing CABG resulted in a sustained and substantial reduction in atrial tachyarrhythmia incidence and burden during 3-year follow-up, accompanied by reduction in hospitalizations.

Pulmonary vein isolation with concomitant renal artery denervation is associated with reduction in both arterial blood pressure and atrial fibrillation burden: Data from implantable cardiac monitor.

BACKGROUND: Renal artery denervation (RDN) has provided incremental atrial fibrillation (AF) suppression after pulmonary vein isolation (PVI) in patients with AF in the setting of drug-resistant hypertension. OBJECTIVE: To assess the relationship between changes of mean blood pressure (BP) and AF recurrences/AF burden after PVI combined with RDN. METHODS: All patients from two randomized studies with symptomatic paroxysmal AF and/or persistent AF and resistant hypertension who underwent PVI-only (n=37) or PVI with RDN (n=39), and implantable cardiac monitor (ICM) implantation were eligible for this study. Mixed-effects linear models were used to investigate the effect of RDN on mean BP and mean AF burden and associations between the two during the 12-month follow-up. RESULTS: Concomitant RDN was associated with a significant reduction in both mean AF burden (2.43 [95% CI: 1.76-3.09] % vs 6.95 [95% CI: 5.44-8.45] %) and mean BP (104 [95% CI: 103-106] mm Hg vs 112 [95% CI: 110-113] mm Hg). Decrease in mean BP was positively correlated with decline in mean AF burden: reduction of 5-10 mm Hg was accompanied by a 7.0% decreased mean AF burden, with greater reduction (up to 20 mm Hg) associated with on average 17.7% lower mean AF burden. CONCLUSIONS: Renal artery denervation when added to PVI decreases AF recurrences, AF burden, and mean BP. Reduction in mean BP is associated with both AF burden and recurrences. Further large-scale studies are needed to define the mechanistic pathway(s) of the antiarrhythmic effects of RDN.

Effect of left atrial appendage excision on procedure outcome in patients with persistent atrial fibrillation undergoing surgical ablation.

BACKGROUND: Catheter ablation is less successful for treatment of persistent atrial fibrillation (PersAF) than for paroxysmal atrial fibrillation. Some studies suggest that left atrial appendage (LAA) isolation in addition to pulmonary vein isolation (PVI) is required to maximize the benefits for PersAF after ablation. OBJECTIVE: The purpose of this study was to compare the efficacy and safety of 2 surgical ablation approaches for PersAF via video-assisted thoracoscopy: PVI + box lesion and PVI + box lesion + LAA excision. METHODS: We randomly assigned 176 patients with PersAF to video-assisted thoracoscopic surgical ablation with PVI + box lesion (88 patients) or PVI + box lesion + LAA excision (88 patients). The primary endpoint was freedom from any documented atrial arrhythmia lasting >30 seconds after a single ablation procedure without antiarrhythmic drug (AAD). RESULTS: After 18 months of follow-up, 61 of 86 patients (70.9%) assigned to PVI + box lesion were free from recurrent atrial fibrillation compared to 64 of 87 patients (73.6%) assigned to PVI + box lesion + LAA excision after a single ablation procedure without AAD (P = .73). Freedom from any atrial arrhythmia after a single procedure with or without AAD was also nonsignificant (70.9% vs 74.7%, respectively). There were no significant differences between groups with regard to adverse events, including death, transient ischemic attack, stroke, pneumothorax, and hydrothorax. CONCLUSION: Among patients with PersAF, no reduction in the rate of recurrent atrial fibrillation was found when LAA excision was performed in addition to PVI and box lesion during surgical ablation.

Prophylactic pulmonary vein isolation during isthmus ablation for atrial flutter: the PReVENT AF Study I.

BACKGROUND: Although catheter ablation of isthmus-dependent atrial flutter (AFL) is successful at eliminating the target arrhythmia, many patients subsequently experience new-onset atrial fibrillation (AF). OBJECTIVE: The aim of this study was to determine whether AF can be prevented by prophylactic pulmonary vein ablation in patients with AFL. METHODS: A prospective, single-blind, randomized clinical trial in patients whose sole arrhythmia was AFL without AF was conducted. Patients were randomized to cavotricuspid isthmus ablation alone or with concomitant pulmonary vein isolation. All patients received an implantable cardiac monitor. RESULTS: Fifty patients completed the trial, and patients were well matched. Isthmus ablation was successful in all patients; pulmonary vein isolation was successful in 25 (100%) randomized patients. Procedure (P < .0001) and fluoroscopy (P < .0001) times were longer in the combined ablation group. More patients in the isthmus ablation-only group experienced new-onset AF during follow-up (52% vs. 12%; P = .003). The 1-year AF burden also favored the combined ablation group compared with the isthmus ablation-only group (8.3% vs. 4.0%; P = .034). In the isthmus ablation-only group, 8 (32%) patients subsequently underwent another ablation for AF. The performance of pulmonary vein isolation and male sex were independent predictors of freedom from AF. CONCLUSION: In the PREVENT-AF Study I randomized clinical trial of patients in whom only typical AFL had been observed clinically, the addition of pulmonary vein isolation to cavotricuspid isthmus ablation resulted in a marked reduction of new-onset AF during clinical follow-up as assessed with a continuous implantable cardiac monitor.

Renal denervation for improving outcomes of catheter ablation in patients with atrial fibrillation and hypertension: early experience.

BACKGROUND: The potential role of renal denervation (RD) in patients with AF and less severe hypertension is unknown. OBJECTIVE: The purpose of this study was to assess the potential role of RD as an adjunct to pulmonary vein isolation (PVI) in patients with atrial fibrillation (AF) and moderate resistant or severe resistant hypertension. METHODS: The data for this study were obtained from 2 different prospective randomized studies, analyzed by meta-analysis. Patients with paroxysmal AF or persistent AF and moderate resistant hypertension (office blood pressure BP ≥140/90 mm Hg and <160/100 mm Hg; first study; n = 48) or severe resistant hypertension (≥160/100 mm Hg; second study; n = 38) were randomized to PVI or PVI with RD. RESULTS: At 12 months, 26 of the 41 PVI with RD patients (63%) were AF-free vs 16 of the 39 patients (41%) in the PVI-only group (P = .014). In patients with severe hypertension, 11 of the 18 PVI with RD patients (61%) vs 5 of the 18 PVI-only patients (28%) were AF-free (P = .03). For moderate hypertension, the differences were less dramatic: 11 of 21 (52%) vs 15 of 23 (65%) when RD added (P = .19). The superior efficacy of adding RD was most apparent in persistent AF and severe hypertension (hazard ratio 0.25, confidence interval 0.09-0.72, P = .01). Duration of the procedure and fluoroscopy were nonsignificantly longer in the RD group. CONCLUSION: RD may improve the results of PVI in patients with persistent AF and/or severe resistant hypertension.

Progression of atrial fibrillation after a failed initial ablation procedure in patients with paroxysmal atrial fibrillation: a randomized comparison of drug therapy versus reablation.

BACKGROUND: The aim of this prospective randomized study was to assess whether an early reablation was superior to antiarrhythmic drug (AAD) therapy in patients with previous failed pulmonary vein isolation. METHODS AND RESULTS: Patients with paroxysmal atrial fibrillation (AF) eligible for AAD therapy or reablation after a previously failed initial pulmonary vein isolation procedure were eligible for this study and were followed up for 3 years to assess rhythm by means of an implanted cardiac monitor. After the blanking period postablation, 154 patients had symptomatic AF recurrences and were randomized to AAD (n=77) or repulmonary vein isolation (n=77). At the end of follow-up, 61 (79%) patients in the AAD group and 19 (25%) patients in the reablation group demonstrated AF% progression (P<0.01). The AF% at 36 months was significantly greater in the AAD group compared with patients in the reablation group (18.8±11.4% versus 5.6±9.5%, respectively; P<0.01). In addition, 18 (23%) patients in the AAD group and 3 (4%) patients in the reablation group progressed to persistent AF (P<0.01). Furthermore, 45 (58%) of the 77 reablation group patients were free of AF/atrial tachycardia on no AADs; in contrast, in the AAD group, only 9 (12%) of the 77 patients were free of AF/atrial tachycardia (P<0.01) throughout follow-up. CONCLUSIONS: Redo AF ablation was substantially more effective than AAD in reducing the progression and prevalence of AF after the failure of an initial ablation. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01709682.

Does atrial fibrillation burden measured by continuous monitoring during the blanking period predict the response to ablation at 12-month follow-up?

BACKGROUND: Recurrences are common within the first months following atrial fibrillation (AF) ablation. However, prior studies using only intermittent ECG recording have not shown a powerful correlation with ultimate response. OBJECTIVE: The purpose of this study was to use continuous AF monitoring with an implanted monitor to assess the AF burden measured continuously during the first months postablation and the relationship to subsequent AF recurrences. METHODS: Six hundred thirteen patients with symptomatic drug-refractory AF (17% with persistent AF) were part of this retrospective analysis. All patients underwent circumferential pulmonary vein isolation and were implanted with a subcutaneous AF monitor (Reveal XT, Medtronic) for collecting data on AF burden (AF%) during a 12-month follow-up period. AF freedom (responders) was defined as AF% ≤0.5% during each monthly telemetric follow-up. A receiver operating characteristic curve analysis was performed to identify the value in AF% during the first months in the postablation blanking period that was predictive of later recurrence of AF. Sensitivity of 90% was selected as the target value. RESULTS: After the first ablation procedure, 396 of the 613 patients (65%) were responders (AF ≤0.5%) at 12 months: 346 of 508 (68%) in the paroxysmal AF group and 50 of 105 (47%) in the persistent AF group. Using the receiver operating characteristic curve, the specificity corresponding to 90% sensitivity was 85% for AF% at 2 months. The corresponding threshold in the AF burden during the blanking period able to identify patients at risk for late recurrences was 4.5%, corresponding to a cumulative 65.9 hours (2.75 days) spent in AF during the first 2 months. In a multivariate analysis, AF% <4.5% during the first 2 months was highly significant (P <.001), and the odds ratio of responders/nonresponders was 39.8 (95% CI, 19.1-82.9). CONCLUSION: The AF burden measured during the blanking period can predict the response to catheter ablation at 12 months. AF% ≥4.5% at 2 months assessed by continuous monitoring is a powerful predictor of subsequent AF recurrences after initial ablation, thus providing relevant clinical information to select patients for early reintervention.