Catheter ablation of atrial fibrillation in patients with hypertrophic cardiomyopathy: a European observational multicentre study.

AIMS: Atrial fibrillation (AF) is common in hypertrophic cardiomyopathy (HCM). Data on the efficacy of catheter ablation of AF in HCM patients are sparse. METHODS AND RESULTS: Observational multicentre study in 137 HCM patients (mean age 55.0 ± 13.4, 29.1% female; 225 ablation procedures). We investigated (i) the efficacy of catheter ablation for AF beyond the initial 12 months; (ii) the available risk scores, stratification schemes and genotype as potential predictors of arrhythmia relapse, and (iii) the impact of cryoballoon vs. radiofrequency in procedural outcomes. Mean follow-up was 43.8 ± 37.0 months. Recurrences after the initial 12-month period post-ablation were frequent, and 24 months after the index procedure, nearly all patients with persistent AF had relapsed, and only 40% of those with paroxysmal AF remained free from arrhythmia recurrence. The APPLE score demonstrated a modest discriminative capacity for AF relapse post-ablation (c-statistic 0.63, 95% CI 0.52-0.75; P = 0.022), while the risk stratification schemes for sudden death did not. On multivariable analysis, left atrium diameter and LV apical aneurysm were independent predictors of recurrence. Fifty-eight patients were genotyped; arrhythmia-free survival was similar among subjects with different gene mutations. Rate of procedural complications was high (9.3%), although reducing over time. Outcome for cryoballoon and radiofrequency ablation was comparable. CONCLUSION: Very late AF relapses post-ablation is common in HCM patients, especially in those with persistent AF. Left atrium size, LV apical aneurysm, and the APPLE score might contribute to identify subjects at higher risk of arrhythmia recurrence. First-time cryoballoon is comparable with radiofrequency ablation.

A Primary Prevention Clinical Risk Score Model for Patients With Brugada Syndrome (BRUGADA-RISK).

OBJECTIVES: The goal of this study was to develop a risk score model for patients with Brugada syndrome (BrS). BACKGROUND: Risk stratification in BrS is a significant challenge due to the low event rates and conflicting evidence. METHODS: A multicenter international cohort of patients with BrS and no previous cardiac arrest was used to evaluate the role of 16 proposed clinical or electrocardiogram (ECG) markers in predicting ventricular arrhythmias (VAs)/sudden cardiac death (SCD) during follow-up. Predictive markers were incorporated into a risk score model, and this model was validated by using out-of-sample cross-validation. RESULTS: A total of 1,110 patients with BrS from 16 centers in 8 countries were included (mean age 51.8 ± 13.6 years; 71.8% male). Median follow-up was 5.33 years; 114 patients had VA/SCD (10.3%) with an annual event rate of 1.5%. Of the 16 proposed risk factors, probable arrhythmia-related syncope (hazard ratio [HR]: 3.71; p < 0.001), spontaneous type 1 ECG (HR: 3.80; p < 0.001), early repolarization (HR: 3.42; p < 0.001), and a type 1 Brugada ECG pattern in peripheral leads (HR: 2.33; p < 0.001) were associated with a higher risk of VA/SCD. A risk score model incorporating these factors revealed a sensitivity of 71.2% (95% confidence interval: 61.5% to 84.6%) and a specificity of 80.2% (95% confidence interval: 75.7% to 82.3%) in predicting VA/SCD at 5 years. Calibration plots showed a mean prediction error of 1.2%. The model was effectively validated by using out-of-sample cross-validation according to country. CONCLUSIONS: This multicenter study identified 4 risk factors for VA/SCD in a primary prevention BrS population. A risk score model was generated to quantify risk of VA/SCD in BrS and inform implantable cardioverter-defibrillator prescription.

Non-vitamin K oral anticoagulants in hypertrophic cardiomyopathy patients undergoing catheter ablation of atrial fibrillation.

INTRODUCTION: Patients with hypertrophic cardiomyopathy (HCM) and atrial fibrillation (AF) require chronic anticoagulation due to high thromboembolic risk. Evidence supporting the use of non-vitamin K oral anticoagulants (NOACs) in patients with HCM remains sparse, and there are no data regarding the use of NOACs in patients with HCM undergoing catheter ablation of AF. METHODS: Observational nonrandomized study in four European centers. We aimed to investigate the safety and efficacy of NOACs compared with vitamin K antagonists (VKAs) in patients with HCM undergoing catheter ablation for AF. RESULTS: A total of 137 patients with HCM (mean age: 55.0 ± 13.4, 29.1% female) underwent 230 catheter ablations for AF (1.7 ± 1.0 per patient). A total of 55 patients (39.4%) underwent 70 procedures (30.4%) on NOAC, while the remaining were on VKA. Warfarin (97.6%) and rivaroxaban (56.4%) were the most frequently used agents in the respective groups. No procedure-related deaths were reported. We observed no significant difference in the rate of thromboembolism (VKA: 0.6%; NOAC: 0%; p = 1.0) or minor bleeding (VKA: 0.6%; NOAC: 1.4%; p = .54). There was a nonsignificant trend towards a lower incidence of major bleeding (VKA: 6.9%; NOAC: 1.4%; p = .09). CONCLUSION: These preliminary data suggest that NOACs are at least as safe and effective as VKAs in patients with HCM undergoing catheter ablation for AF.

Impact of Body Mass Index on the Outcomes of Catheter Ablation of Atrial Fibrillation: A European Observational Multicenter Study.

Background Outcomes of catheter ablation of atrial fibrillation (AF) are variable and the predictors of success require further elucidation since the identification of correctable risk factors could help to optimize therapy. We aimed to assess the impact of body mass index (BMI) in the overall safety and efficacy of catheter ablation of AF, with emphasis on the use of cryoballoon ablation and novel oral anticoagulants. Methods and Results There were 2497 consecutive patients undergoing catheter ablation of AF in 7 European high volume centers were stratified according to BMI (normal weight <25 kg/m2, pre-obese 25-30 kg/m2, obesity 30-35 kg/m2, and morbid obesity ≥35 kg/m2) and comparisons of procedural outcomes evaluated. Pre-obese and obese patients presented more comorbidities (hypertension, diabetes mellitus, and sleep apnea), and had higher rates of non-paroxysmal AF ablation procedures. The rate of atrial 12-month arrhythmia relapse increased alongside with BMI (35.2%, 35.7%, 43.6%, and 48.0% P<0.001). During a median follow-up of 18.8 months (interquartile range 11-28), after adjusting for all baseline differences, BMI was an independent predictor of relapse (hazard ratio=1.01 per kg/m2; 95% CI 1.01-1.02; P=0.002), adding incremental predictive value to obstructive sleep apnea. BMI was not a predictor for any of the reported complications. Using novel oral anticoagulants and cryoballoon ablation was safe and efficacy was comparable with vitamin-K antagonists and radiofrequency ablation. Conclusions Obese patients present with a more adverse comorbidity profile, more advanced forms of AF, and have lower chances of being free from AF relapse after ablation. Use of novel oral anticoagulants and cryoballoon ablation may be an option in this patient group.

Catheter ablation of atrial fibrillation in patients with heart failure with reduced ejection fraction: Real world experience from six European centers.

INTRODUCTION: Catheter ablation of atrial fibrillation (AF) has been recently shown to have an impact on the outcome of patients with heart failure and reduced LV ejection fraction (LVEF). We aimed to assess patients with reduced LVEF referred to catheter ablation of AF, and the efficacy and safety of this procedure compared with healthier patients. METHODS: 2083 consecutive procedures of catheter ablation of AF in six centers were divided into two groups on the basis of LVEF (≤ vs >35%) and comparisons were performed regarding procedural safety and efficacy. RESULTS: Only 51 (2.4%) of patients had low LVEF. Complication rate was comparable: 8.0% vs 6.9% (P = .760). Low LVEF patients are more frequently in persistent AF at the time of the procedure, have a higher degree of left atrial dilation, and higher CHA2 DS2 VASc score. The rate of atrial arrhythmia relapse post-blanking period in the first 12 months was higher in the low LVEF group: 58.0% vs 37.6% (P < .001). During a median follow-up of 14 months (IQR 5-24), after adjusting for all baseline differences, AF duration, paroxysmal AF, CHA2 DS2 VASc score, BMI, and indexed LA volume were independent predictors of relapse. LVEF and LVEF ≤ 35% were not identified as predictors of relapse. CONCLUSIONS: Patients with reduced LVEF account for only a minority of patients undergoing catheter ablation of AF. However, ablation appears to be as safe as for the general population, and albeit the efficacy seems lower, this appears to be driven by other comorbidities or features, which are more frequent in this population.

Polymorphic Wide QRS Complex Tachycardia: Differential Diagnosis.

Polymorphic wide QRS complex tachycardia is defined as a tachyarrhythmia showing variable and frequently alternating morphologies of the QRS complex with irregular R-R intervals. It may present with a specific and reproducible pattern including torsade de pointes and bidirectional ventricular tachycardia or with a nonspecific and very irregular pattern, different from ventricular fibrillation. Polymorphic ventricular tachycardia is a challenging diagnosis and is associated with a high risk for sudden cardiac death. Although rare, preexcited atrial fibrillation over multiple accessory pathways can also generate a polymorphic wide QRS complex tachycardia mimicking polymorphic ventricular tachycardia.

Duration of hospital admission, need of on-demand analgesia and other peri-procedural and short-term outcomes in sub-cutaneous vs. transvenous implantable cardioverter-defibrillators.

BACKGROUND: Post-procedural recovery following sub-cutaneous ICD (S-ICD) implantation is feared to be more painful and to require more prolonged hospital admission. The purpose of this study was to compare peri-procedural and short clinical outcomes of the S-ICD vs. the Transvenous ICD (TV-ICD). METHODS: We conducted a single-center cross-sectional study including all consecutive patients who underwent S-ICD implantation by the same operator since January 2016 and a gender and age-matched control group with all single chamber TV-ICD implanted patients over a contemporary time period. RESULTS: Thirty-one patients (sex ratio 1/5; mean age 58.7±13.2years) with S-ICD were compared to 31 matched TV-ICD patients. Duration of the implant procedure was significantly longer for the S-ICD (58.0±24.4min vs 41.7±20.8min TV-ICD, p<0.01). Mean fluoroscopy time for the TV-ICD was 3.5±3.6min vs 0.1±0.01min for all S-ICD patients (p<0.01). Requirement of on-demand analgesia administration, and duration of hospitalization (1.5days for both groups; p=NS) were similar in the two groups. No peri-procedural events were reported, and after a mean follow-up of 6months, the only complication was a pocket infection requiring reintervention in the TV-ICD group. CONCLUSIONS: The S-ICD appears to be as effective and safe as the conventional single chamber TV-ICD. Duration of hospital admission and need of on-demand analgesia are also comparable for S-ICD patients.