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Objectives STOP AF PAS (Sustained Treatment of Paroxysmal Atrial Fibrillation Post-Approval Study) is the first prospective, multicenter, 3-year study in North America to assess long-term safety and effectiveness of the cryoballoon for treatment of patients with drug-refractory symptomatic pAF. Background The STOP AF PAS was required by the U.S. Food and Drug Administration at the time of approval of the first-generation cryoballoon for the treatment of paroxysmal atrial fibrillation (pAF). The second-generation cryoballoon (CB2) was commercially released shortly after this trial was initiated. Methods The study was nonrandomized. Enrollment was completed with 344 eligible patients undergoing pulmonary vein isolation (PVI) using the CB2. Procedure-related safety and freedom from AF and symptomatic atrial flutter/atrial tachycardia through 3 years were determined. Documented atrial arrhythmias ≥30 s were considered treatment failures. Results Acute PVI was achieved in 99.3% (1,341 of 1,350) of veins. Mean follow-up was 34 ± 7 months. The rate of major complications was 5.8%, including a 3.2% rate of phrenic nerve injury, which resolved in all but 1 patient by 36 months. At 36 months, 11.7% of patients were prescribed antiarrhythmic agents, inclusive of “pill-in-the-pocket” administration. Freedom from AF was 81.6% at 12 months, 73.8% at 24 months, and 68.1% at 36 months. Freedom from AF and symptomatic atrial flutter/atrial tachycardia was 79.0% at 12 months, 70.8% at 24 months, and 64.1% at 36 months. Freedom from a repeat ablation procedure was 80.9% at 36 months. Conclusions PVI using the CB2 was an effective treatment for patients with pAF, with freedom from all atrial arrhythmias of 64% at 36 months. (Sustained Treatment of Paroxysmal Atrial Fibrillation Post-Approval Study [STOP AF PAS]; NCT01456949)

Flex Tip Comparative AblationIntroduction Next-generation catheters have been developed to reduce irrigation volume and preserve power delivery. A novel design uses a flexible tip (FlexAbility™ catheter) that directs flow to the contact surface. Because of recent safety issues with new catheters, we undertook a study in a canine heart with 3 irrigated catheters to compare efficacy and safety. Methods Endocardial ablation was performed by 2 independent operators in 12 anesthetized canines with the FlexAbility (St. Jude Medical), ThermoCool™ (Biosense Webster), and ThermoCool™ SF (Biosense Webster) catheters. Endocardial RF lesions were delivered with each catheter in all 4 chambers of each animal for 52 ± 16 seconds. Each chamber was randomized to receive ablation from one catheter with recording of safety events. Cardiac pathology was performed with triphenyl tetrazolium chloride stain. Results Average lesion dimensions were not significantly different between the 3 catheters. FlexAbility™ demonstrated a lower risk of steam pops relative to ThermoCool SF (P-value = 0.013) despite equal mean power and radiofrequency time. High-temperature generator shutdowns were observed with FlexAbility™ but not with either ThermoCool catheter. High-temperature shutdowns were associated with larger average impedance drops (28.5 ohms vs. 19 ohms) without compromising lesion size. Conclusions The FlexAbility™ tip is safe and effective with no significant difference in lesion sizes compared to both standard ThermoCool and ThermoCool SF. FlexAbility™ has a significantly lower risk of steam pops compared to ThermoCool SF in a beating heart as defined predominantly by an abrupt rise of impedance.

Next-generation catheters have been developed to reduce irrigation volume and preserve power delivery. A novel design uses a flexible tip (FlexAbility™ catheter) that directs flow to the contact surface. Because of recent safety issues with new catheters, we undertook a study in a canine heart with 3 irrigated catheters to compare efficacy and safety.Endocardial ablation was performed by 2 independent operators in 12 anesthetized canines with the FlexAbility (St. Jude Medical), ThermoCool™ (Biosense Webster), and ThermoCool™ SF (Biosense Webster) catheters. Endocardial RF lesions were delivered with each catheter in all 4 chambers of each animal for 52 ± 16 seconds. Each chamber was randomized to receive ablation from one catheter with recording of safety events. Cardiac pathology was performed with triphenyl tetrazolium chloride stain.Average lesion dimensions were not significantly different between the 3 catheters. FlexAbility™ demonstrated a lower risk of steam pops relative to ThermoCool SF (P-value = 0.013) despite equal mean power and radiofrequency time. High-temperature generator shutdowns were observed with FlexAbility™ but not with either ThermoCool catheter. High-temperature shutdowns were associated with larger average impedance drops (28.5 ohms vs. 19 ohms) without compromising lesion size.The FlexAbility™ tip is safe and effective with no significant difference in lesion sizes compared to both standard ThermoCool and ThermoCool SF. FlexAbility™ has a significantly lower risk of steam pops compared to ThermoCool SF in a beating heart as defined predominantly by an abrupt rise of impedance.

Background— The purpose of this study was to conduct a worldwide survey investigating the methods, efficacy, and safety of catheter ablation (CA) of atrial fibrillation (AF). Methods and Results— A detailed questionnaire was sent to 777 centers worldwide. Data relevant to the study purpose were collected from 181 centers, of which 100 had ongoing programs on CA of AF between 1995 and 2002. The number of patients undergoing this procedure increased from 18 in 1995 to 5050 in 2002. The median number of procedures per center was 37.5 (range, 1 to 600). Paroxysmal AF, persistent AF, and permanent AF were the indicated arrhythmias in 100.0%, 53.0%, and 20.0% of responding centers, respectively. The most commonly used techniques were right atrial compartmentalization between 1995 and 1997, ablation of the triggering focus in 1998 and 1999, and electrical disconnection of multiple pulmonary veins between 2000 and 2002. Of 8745 patients completing the CA protocol in 90 centers, of whom 2389 (27.3%) required >1 procedure, 4550 (52.0%; range among centers, 14.5% to 76.5%) became asymptomatic without drugs and another 2094 (23.9%; range among centers, 8.8% to 50.3%) became asymptomatic in the presence of formerly ineffective antiarrhythmic drugs over an 11.6±7.7-month follow-up period. At least 1 major complication was reported in 524 patients (6.0%). Conclusions— The findings of this survey provide a picture of the variable and evolving methods, efficacy, and safety of CA for AF as practiced in a large number of centers worldwide and may serve as a guide to clinicians considering therapeutic options in patients suffering from this arrhythmia.

This trial will significantly advance our understanding of the prognostic and therapeutic usefulness of electrophysiologic studies in patients with coronary artery disease. Several features of this trial are worth emphasizing. First, the protocol for performing programmed stimulation and serial drug testing is designed to mirror those currently in use by many practicing electrophysiologists. While practice patterns vary, the procedures used in the trial reflect what is considered "usual and standard" practice. Second, because half of the patients with inducible sustained ventricular tachycardia will be given no antiarrhythmic therapy, we will be able to ascertain the true risk of sudden death in this patient population without the influence of these agents. Third, this trial will assess the usefulness of a method of guiding antiarrhythmic therapy (electrophysiologic testing) to reduce mortality in this high-risk population. It will not evaluate the efficacy of a specific type of antiarrhythmic therapy.

AF Treatment Strategies. Introduction: The Atrial Fibrillation (AF) Exchange Group, an international multidisciplinary group concerned with the management of AF, was convened to review recent advances in the field and the potential impact on treatment strategies. Methods: Issues discussed included epidemiology and the impact of the rising incidence of AF on health care systems, developments in pharmacological and surgical interventions in the management of arrhythmias and thromboprophylaxis, the potential to affect treatment strategies, and barriers to implementing them. Results: The incidence of AF and the associated burden on health care systems are increasing with aging populations, prevalence of comorbidities and more effective treatment of cardiovascular diseases. Advances in available medical treatments, in particular dronedarone and dabigatran, with other products in development, offer the possibility of changes in treatment paradigms and a greater emphasis on reducing hospitalizations and improvement in long-term outcomes instead of a symptom/safety-driven approach in which the priority is symptom suppression without provoking drug toxicity. Developments in catheter ablation techniques may mean that, in experienced centers, ablation may be offered as first-line treatment in selected patient populations. Barriers to optimal treatment include underdiagnosis, lack of recognition as a serious condition and as a risk factor for stroke, limited access to care, inadequate implementation of guidelines, and poor adherence to treatment. Conclusions: The focus of the management of AF may be changing as a consequence of new treatments based on the outcome improvements they offer. However, the benefits will not be fully realized if guidelines and guidance are not observed in routine clinical practice. (J Cardiovasc Electrophysiol, Vol. 21, pp. 946-958, August 2010)

Ablation procedures for atrial fibrillation are being performed with increasing frequency. One of the most serious complications is the development of pulmonary vein stenosis, which occurs in 1% to 3% of current series. The presentation of pulmonary vein stenosis varies widely. The majority of patients are symptomatic although specific referral bias patterns can affect this. Symptoms may include dyspnea or hemoptysis or may be consistent with bronchitis. These symptoms are affected by the number of stenotic veins as well as the severity of the stenosis. The more severe the stenosis and the greater number of stenosed veins result in more symptoms. Because of the variability in symptoms, clinicians must have heightened sensitivity to the presence of the condition. Diagnostic tests of value include magnetic resonance angiography and computed tomography. Although echocardiography has been used, it does not usually provide adequate assessment. Progression of stenosis is unpredictable and may be rapid. The specific anatomy of the stenosis varies widely and affects management. Because of the presence of antral fusion of the origin of the left superior and left inferior pulmonary vein, a stenosis involving 1 or the other can impinge and affect outcome. In this setting, bifurcation techniques familiar to interventional cardiology are very helpful. Controversy currently exists about the optimal treatment approach. The use of balloons and larger stents (approximately 10 mm) results in more optimal results than just balloon angioplasty alone; however, even with stent implantation, recurrent restenosis may occur in 30% to 50% of patients. Follow-up of these patients typically involves computed tomography imaging to document restenosis. If significant restenosis is identified, it should be treated promptly because of the potential for progression to total occlusion.

The outcome of congestive heart failure (CHF) patients with syncope is understood incompletely.We analyzed data from patients enrolled in the SCD-HeFT (Sudden Cardiac Death Heart Failure Trial) to determine whether syncope predicted outcomes in patients with CHF.We compared outcomes (and associated clinical characteristics) in patients with and without syncope enrolled in SCD-HeFT.In SCD-HeFT, 162 (6%) patients had syncope before randomization, 356 (14%) had syncope after randomization (similar incidence in each randomized arm), and 46 (2%) had syncope before and after randomization. A QRS durationor=120 ms and absence of beta-blocker use predicted syncope during follow-up (hazard ratio [HR] 1.30 and 95% confidence interval [CI] 1.06 to 1.61, p = 0.014 and HR 1.25, 95% CI 1.01 to 1.56, p = 0.048, respectively). Syncope recurrence did not differ by randomization arm. However, in the implantable cardioverter-defibrillator (ICD) arm, syncope, before and after randomization, was associated with appropriate ICD discharges (HR 1.75, 95% CI 1.10 to 2.80, p = 0.019 and HR 2.91, 95% CI 1.89 to 4.47, p = 0.001, respectively). Post-randomization syncope predicted total and cardiovascular death (HR 1.41, 95% CI 1.13 to 1.76, p = 0.002 and HR 1.55, 95% CI 1.19 to 2.02, p = 0.001, respectively). The elevated relative risk of mortality for syncope versus non-syncope patients did not vary significantly across treatment arms (ICD, HR 1.54, 95% CI 1.04 to 2.27; amiodarone, HR 1.33, 95% CI 0.91 to 1.93; and placebo, HR 1.39, 95% CI 0.96 to 2.02, test for difference p = 0.86).For CHF patients with ICDs, syncope was associated with appropriate ICD activations. Syncope was associated with increased mortality risk in SCD-HeFT regardless of treatment arm (placebo, amiodarone, or ICD).

Venice Chart International Consensus Document on Atrial Fibrillation Ablation ANDREA NATALE, M.D.,∗ ANTONIO RAVIELE, M.D.,† THOMAS ARENTZ, M.D.,‡ HUGH CALKINS, M.D.,¶ SHIH-ANN CHEN, M.D.,∗∗ MICHEL HAISSAGUERRE, M.D.,†† GERHARD HINDRICKS, M.D.,‡‡ YEN HO, M.D.,¶¶ KARL HEINZ KUCK, M.D.,∗∗∗ FRANCIS MARCHLINSKI, M.D.,††† CARLO NAPOLITANO, M.D.,‡‡‡ DOUGLAS PACKER, M.D.,¶¶¶ CARLO PAPPONE, M.D.,∗∗∗∗ ERIC N. PRYSTOWSKY, M.D.,†††† RICHARD SCHILLING, M.D.,‡‡‡‡ DIPEN SHAH, M.D.,¶¶¶¶ SAKIS THEMISTOCLAKIS, M.D.,† and ATUL VERMA, M.D.,∗∗∗∗∗ for the Venice Chart members From the ∗Department of Cardiovascular Medicine, Cleveland Clinic Foundation, Cleveland, USA; †Department of Cardiology, Arrhythmologic Section, Umberto I Hospital, Venice-Mestre, Italy; ‡Arrhythmia Service, Herz-Zentrum, Bad Krozingen, Germany; ¶Department of Cardiology, The Johns Hopkins Hospital, Baltimore, USA; ∗∗Division of Cardiology, Department of Medicine, National Yang-Ming University School of Medicine and Taipei Veterans General Hospital, Taipei, Taiwan; ††Hospital du Haut Leveque, CHU Bordeaux, Bordeaux, France; ‡‡University Leipzig, Heart Center, Department of Cardiology, Leipzig, Germany; ¶¶National Heart and Lung Institute, Imperial College and Royal Brompton & Harefield Hospitals, London, UK; ∗∗∗Second Medical Department, St Georg General Hospital, Hamburg, Germany; †††Cardiovascular Division, Department of Medicine, Hospital of the University of Pennsylvania, Philadelphia, USA; ‡‡‡Molecular Cardiology Laboratory, University of Pavia, Salvatore Maugeri Foundation, Pavia, Italy; ¶¶¶Department of Clinical Cardiac Electrophysiology and Internal Medicine, Mayo Clinic, Rochester, USA; ∗∗∗∗Department of Cardiology, Electrophysiology and Cardiac Pacing Unit, San Raffaele University Hospital, Milan, Italy; ††††St. Vincent Hospital and Health Care Center Program, Indianapolis, USA; ‡‡‡‡St. Bartholomew’s Hospital, London, UK; ¶¶¶¶Cardiology Cantonal Hospital of Geneva, Geneva, Switzerland; ∗∗∗∗∗University of Toronto, Toronto, Canada.

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