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Introduction: Electrical isolation of pulmonary veins (PVI) is a cornerstone for atrial fibrillation (AF) ablation. The overall effect of AF ablation, and especially lesions beyond PVI, on left atrial (LA) function is currently poorly understood. Our aim was to determine if LA function is different in patients after extensive LA ablation compared to PVI only. We performed non‐inferiority analysis of LA function after PVI with additional nonpulmonary vein ablation lesions in LA (PVI+) and PVI alone. Methods: We studied 68 patients consecutive patients who underwent AF ablation and who had complete transthoracic echocardiogram (TTE) within 12 months before AF ablation and 1−12 months after the procedure. Patients were stratified into two groups: PVI only and PVI+. Primary outcome was change in LA reservoir strain (LASr). Noninferiority margin was defined at 6%. Results: The PVI only group had a higher proportion of patients with paroxysmal AF (70% vs. 30%). The PVI+ group was observed to have a slightly higher increase in LASr compared to PVI alone (5.0% vs. 4.3%, p <.01 for noninferiority). LASr noninferiority was confirmed when adjusted for age, sex, coronary artery disease, hyperlipidemia, and AF type, rhythm at preprocedure TTE in a multivariable linear regression model, 90% CI (−5.46 to 2.04), p <.01. Conclusion: LA functional improvement evaluated by LASr was noninferior after PVI with additional LA ablation lesions compared to PVI alone. These findings were confirmed when adjusted for confounding clinical variables, suggesting that more extensive ablation does not negatively affect LA function. [ABSTRACT FROM AUTHOR]

Impact of Age After Atrial Fibrillation Catheter Ablation Background Catheter ablation of atrial fibrillation (AF) is an established therapeutic rhythm approach in symptomatic patients. Many studies have shown that age has little to no impact on outcomes during the first year after ablation. However, AF is a disease of aging and age-based substrate for arrhythmia is likely to progress. To this regard, we examined patients with 5-year outcome data following an index AF ablation procedure to define the impact of age on long-term outcomes. Methods A total of 923 patients that underwent their index AF ablation and had 5 years of follow-up were studied. Patients were followed up for atrial flutter/AF recurrence, heart failure, stroke, death, and cardiac function. Patients were separated and compared in 5 age-based groups (<50, 51-60, 61-70, 71-80, >80). Results The average age of the population was 66 ± 11 years and 59% were male. The AF was paroxysmal in 55%, persistent in 27%, and longstanding persistent in 18%. Older patients were more likely female and had higher rates of cardiovascular diseases. For every 10-year increase in age there was a higher multivariate-adjusted risk of atrial flutter/AF recurrence (HR: 1.13, P = 0.01), death (HR:1.91, P < 0.0001), and major adverse cardiac events (HR: 1.09, P = 0.07). Although atrial flutter/AF recurrence rates by age were similar at 1 year, at 5 years, younger patients had significantly lower rates of recurrences. Conclusion Age significantly impacts outcomes after AF ablation when analyzed with long-term follow-up. These data highlight the progressive nature of AF and the need to consider interventions early. [ABSTRACT FROM AUTHOR]

Cardiac Autoantibodies and AF Recurrence Introduction Recent evidence has suggested that autoantibodies may play an important role in the development of atrial fibrillation (AF). The predictive value of preprocedural autoantibodies against beta-1 adrenergic receptor (anti-β1-R) and M2-muscarinic acetylcholine receptor (anti-M2-R) for AF recurrence following cryoballoon-based pulmonary vein isolation (PVI) is still unclear. We aimed to determine the predictive value of preprocedural anti-β1-R and anti-M2-R levels for AF recurrence. Methods Eighty patients (mean age 54.25 ± 7.70 years; 40% female) with paroxysmal AF and preserved left ventricular function who underwent cryoballoon-based PVI were included in the study. Preprocedural anti-M2-R and anti-β1-R levels were measured with ELISA. Results At 1-year follow-up after ablation, late AF recurrence was observed in 17 (21.25%) patients. In the Cox regression model, including number of antiarrhythmic drugs, early AF recurrence, anti-β1-R levels >159.88 ng/mL, anti-M2-R levels >277.65 ng/mL, AF duration, and left atrial volume index, only anti-β1-R levels >159.88 ng/mL (HR: 4.281, P = 0.039) and anti-M2-R levels >277.65 ng/mL (HR: 4.313, P = 0.030) were found to be independent predictors of late AF recurrence. Anti-β1-R level >159.88 ng/mL was shown to predict late AF recurrence with a sensitivity of 70.59% and specificity of 90.48%. A cut-off value of 277.65 ng/mL for anti-M2-R level predicted AF recurrence with a sensitivity of 70.59% and specificity of 95.24%. Conclusion Preprocedural serum anti-β1-R and anti-M2-R levels are independent predictors of late AF recurrence following cryoballoon-based PVI in paroxysmal AF patients. Detection of preprocedural anti-β1-R and anti-M2-R levels may serve as a novel method for determination of paroxysmal AF patients who may not benefit from cryoballoon-based PVI. [ABSTRACT FROM AUTHOR]

Ablation Effectiveness Quotient Introduction Inability to predict clinical outcome despite acutely successful pulmonary vein isolation (PVI) remains the Achilles' heel of atrial fibrillation ablation (AFA). Arrhythmia recurrence is frequently due to recovery of radiofrequency (RF) ablation lesions believed to be complete at the original procedure. Objectives We hypothesized that a high ratio between post-AFA levels of serum high sensitivity cardiac troponin T (HScTnT), a highly specific marker of acute myocardial injury, and duration of RF application (the ablation effectiveness quotient, AEQ) would indicate effective ablation and correlate with early clinical success. Methods We prospectively measured HScTnT levels in 60 patients (42 [70%] male, 22 [37%] with paroxysmal AF [PAF], mean age 62.5 ± 10.6 years) 12-18 hours after AFA and calculated the AEQ for each. Patients were followed-up with ECGs and Holter monitors for recurrence of atrial tachyarrhythmia (AT). Results Early recurrence of AT within 6 months occurred in 22 (37%). AT recurrence was not significantly related to left atrial size or comorbidities, nor to RF time or HScTnT level. Mean AEQ was significantly lower in those with recurrence than those without (0.35 ± 0.14 ng/L/s vs. 0.45 ± 0.18 ng/L/s), P = 0.02. Subgroup analysis showed this finding was due to patients with PAF in whom early significance was maintained to one year, with an AEQ >0.4 ng/L/s having 75% sensitivity and 90% specificity in predicting freedom from AT. Conclusion A high AEQ correlates well with freedom from AT in patients with PAF in both the short and medium term. If confirmed in further studies, AEQ may become a useful marker of risk of AT post-AFA. [ABSTRACT FROM AUTHOR]

Mechanisms of Pulmonary Vein Reconnection After Radiofrequency Ablation of Atrial Fibrillation Introduction Pulmonary vein reconnection (PVR) is an important cause of AF recurrence after ablation. With the advent of force sensing catheters, catheter-tissue contact can be determined quantitatively. Since contact force (CF) plays a major role in determining the characteristics of RF lesion, we prospectively assessed the mechanisms of PVR with regard to catheter-contact and lesion distances in patients undergoing AF ablation. Methods and Results Forty symptomatic AF patients underwent wide circumferential PV isolation (PVI) with SmartTouch™ CF catheter. The exact locations of acute PVI and spontaneous or adenosine-provoked PVR were annotated on CARTO. One thousand nine hundred and twenty-six RF lesions isolated 153 PVs. PVR occurred in 35 (23%) PVs: 22 (63%) adenosine-provoked and 13 (37%) spontaneous. CF was significantly lower at PVR versus PVI sites for RF lesions within 6 mm from these sites: mean CF 5 versus 11 g (P < 0.0001) and force-time integral (FTI) 225 versus 415 gs (P < 0.0001); 86% of PVR occurred with a mean CF < 10 g (FTI < 400 gs); and the remaining 14% occurred at ablation sites with a long interlesion distance (≥5 mm) despite mean CF ≥ 10 g. Eighty percent of PVR sites were located anteriorly. There were no significant differences in regard to arrhythmia freedom between the patients without (69%) versus with PVR (67%; P = 1.0). Conclusions Acutely durable PVI can be achieved when RF lesions are delivered with a mean CF ≥ 10 g and an interlesion distance <5 mm. The majority of PVR occur anteriorly due to inadequate CF or long interlesion distances. [ABSTRACT FROM AUTHOR]

Catheter-Tissue Contact Force Determines Atrial Electrogram Characteristics Introduction Electrogram (EGM) characteristics are used to infer catheter-tissue contact. We examined if (a) atrial EGM characteristics predicted CF and (b) compared the value of CF versus other surrogates for predicting lesion efficacy. Methods and Results Twelve paroxysmal AF patients underwent pulmonary vein isolation using radiofrequency (RF) ablation facilitated by a novel CF-sensing catheter. Operators were blinded to CF. EGM amplitude, width, and morphology were measured pre- and post-RF. At each RF site, average CF, force-time integral (FTI), impedance fall, time to impedance plateau, maximum power, catheter tip temperature, and total energy delivered were recorded. An effective lesion was defined based on previously validated EGM criteria for transmural lesions. There was a moderate correlation between CF and EGM amplitude (r = 0.19) and EGM width (r = −0.22). Pre-RF, EGM amplitude, and width had modest to poor discriminative capacity for identifying preablation CF (e.g., EGM amplitude identified CF>20 g with sensitivity and specificity of 67% and 60%, respectively). Preablation CF, FTI, and total energy delivered during RF were the only independent predictors of effective lesion formation. Neither pre-RF EGM amplitude/width nor power, temperature, and impedance changes during RF predicted effective lesion formation. An average CF >16 g or FTI >404 g*s had excellent sensitivity and specificity (>80%) for identifying an effective lesion. Conclusions EGM characteristics do not reliably predict either CF before the onset of RF, nor do they predict the likelihood of an effective lesion. CF parameters were superior to power, temperature, and impedance changes during RF in predicting lesion efficacy. [ABSTRACT FROM AUTHOR]

Left Atrial Sphericity Predicts AF Ablation Outcome Background Atrial fibrillation (AF) ablation outcome is mainly determined by atrial remodeling that, nowadays, is only estimated through clinical presentation (persistent vs. paroxysmal) and left atrial (LA) dimension. The aim of the study was to stage the atrial remodeling process using the Left Atrial Sphericity (LASP) and determine whether this technique may help to predict AF ablation outcome. Methods Consecutive patients who underwent contrast-enhanced cardiac magnetic resonance angiography before AF ablation were included in the study. Three-dimensional reconstruction of LA excluding pulmonary veins and the LA appendage was used to define the LA cavity. The LASP was automatically obtained with self-customized software. Results 106 patients were included and categorized in 3 groups (Gs): discoid-LA (G1), intermediate-LA (G2), and spherical-LA (G3). The G3 patients had larger LA anteroposterior diameter than G1 and G2 patients (47 ± 7 vs 43 ± 6 and 39 ± 5mm; P < 0.001), greater LA volume (90 ± 39 vs 86 ± 24 and 73 ± 20 mm; P = 0.012), and higher prevalence of persistent AF (75% vs 48% and 29%; P = 0.034) structural heart disease (75% vs 19% and 19%; P < 0.001), and AF recurrence at 12 months follow-up (58% vs 29% and 5%, P < 0.001). The LASP had linear correlation to predicted probability of recurrence. Multivariate analysis identified LASP (OR 1.320 [1.096-1.591], P = 0.004) and hypertension (OR 3.694 [1.282-10.645]; P = 0.016) as independent risk factors for arrhythmia recurrence. Conclusion Left Atrial Sphericity is a new independent predictor of recurrence after AF ablation and may be useful in selecting the best candidates for AF ablation. [ABSTRACT FROM AUTHOR]

Prognostic Impact of Inappropriate Shocks. Introduction: Recent studies suggest a worse impact of inappropriate shock therapies on the outcome of patients with an implantable cardioverter-defibrillator (ICD). However, it is not known whether the worse impact is attributed to the ICD shock itself or due to the underlying heart disease. The aim of the study was to evaluate the impact of inappropriate ICD shocks on clinical outcome by comparing ICD shocks triggered by atrial fibrillation (AF) with shocks caused by lead failure. Methods and Results: A total of 1,411 consecutive patients of the prospective single-center ICD-registry Ludwigshafen who underwent an ICD implantation between 1992 and 2008 for primary or secondary prevention of sudden cardiac death were analyzed. During the median follow-up of 3 years, 297 (21%) patients experienced inappropriate ICD shocks. Sixty percent of patients had inappropriate shocks due to AF and 24% due to lead defect or T-wave oversensing. Multiple ICD shocks (≥2) triggered by AF were associated with a worse prognosis, whereas a single shock due to AF or 1 or multiple shocks resulting from lead failure were not. ICD shocks caused by AF occurred more often in tandem with a serious adverse event than in patients with a lead failure (15% vs 6%, P < 0.05). Conclusion: Multiple ICD shocks triggered by AF are associated with a worse prognosis in ICD patients, whereas a single shock due to AF or shocks resulting from lead failure are not. These data support that the ICD shock itself has no worse impact on the outcome of ICD patients. (J Cardiovasc Electrophysiol, Vol. 23, pp. 735-740, July 2012) [ABSTRACT FROM AUTHOR]