Christopher Piorkowski

Perception of atrial fibrillation before and after radiofrequency catheter ablation: relevance of asymptomatic arrhythmia recurrence.

Background—The objective of this study was to assess the incidence and impact of asymptomatic arrhythmia in patients with highly symptomatic atrial fibrillation (AF) who qualified for radiofrequency (RF) catheter ablation. Methods and Results—In this prospective study, 114 patients with at least 3 documented AF episodes together with corresponding symptoms and an ineffective trial of at least 1 antiarrhythmic drug were selected for RF ablation. With the use of CARTO, circumferential lesions around the pulmonary veins and linear lesions at the roof of the left atrium and along the left atrial isthmus were placed. A continuous, 7-day, Holter session was recorded before ablation, right after ablation, and after 3, 6, and 12 months of follow-up. During each 7-day Holter monitoring, the patients recorded quality and duration of any complaints by using a detailed symptom log. More than 70 000 hours of ECG recording were analyzed. In the 7-day Holter records before ablation, 92 of 114 patients (81%) had documented AF episodes. All episodes were symptomatic in 35 patients (38%). In 52 patients (57%), both symptomatic and asymptomatic episodes were recorded, whereas in 5 patients (5%), all documented AF episodes were asymptomatic. After ablation, the percentage of patients with only asymptomatic AF recurrences increased to 37% (P<0.05) at the 6-month follow-up. An analysis of patient characteristics and arrhythmia patterns failed to identify a specific subset who were at high risk for the development of asymptomatic AF. Conclusions—Even in patients presenting with highly symptomatic AF, asymptomatic episodes may occur and significantly increase after catheter ablation. A symptom-only–based follow-up would substantially overestimate the success rate. Objective measures such as long-term Holter monitoring are needed to identify asymptomatic AF recurrences after ablation.

Implant-based multiparameter telemonitoring of patients with heart failure (IN-TIME): a randomised controlled trial

BACKGROUND An increasing number of patients with heart failure receive implantable cardioverter-defibrillators (ICDs) or cardiac resynchronisation defibrillators (CRT-Ds) with telemonitoring function. Early detection of worsening heart failure, or upstream factors predisposing to worsening heart failure, by implant-based telemonitoring might enable pre-emptive intervention and improve outcomes, but the evidence is weak. We investigated this possibility in IN-TIME, a clinical trial. METHODS We did this randomised, controlled trial at 36 tertiary clinical centres and hospitals in Australia, Europe, and Israel. We enrolled patients with chronic heart failure, NYHA class II-III symptoms, ejection fraction of no more than 35%, optimal drug treatment, no permanent atrial fibrillation, and a recent dual-chamber ICD or CRT-D implantation. After a 1 month run-in phase, patients were randomly assigned (1:1) to either automatic, daily, implant-based, multiparameter telemonitoring in addition to standard care or standard care without telemonitoring. Investigators were not masked to treatment allocation. Patients were masked to allocation unless they were contacted because of telemonitoring findings. Follow-up was 1 year. The primary outcome measure was a composite clinical score combining all-cause death, overnight hospital admission for heart failure, change in NYHA class, and change in patient global self-assessment, for the intention-to-treat population. The trial is registered with ClinicalTrials.gov, number NCT00538356. FINDINGS We enrolled 716 patients, of whom 664 were randomly assigned (333 to telemonitoring, 331 to control). Mean age was 65·5 years and mean ejection fraction was 26%. 285 (43%) of patients had NYHA functional class II and 378 (57%) had NYHA class III. Most patients received CRT-Ds (390; 58·7%). At 1 year, 63 (18·9%) of 333 patients in the telemonitoring group versus 90 (27·2%) of 331 in the control group (p=0·013) had worsened composite score (odds ratio 0·63, 95% CI 0·43-0·90). Ten versus 27 patients died during follow-up. INTERPRETATION Automatic, daily, implant-based, multiparameter telemonitoring can significantly improve clinical outcomes for patients with heart failure. Such telemonitoring is feasible and should be used in clinical practice. FUNDING Biotronik SE & Co. KG.

Tailored Atrial Substrate Modification Based On Low-Voltage Areas in Catheter Ablation of Atrial Fibrillation

Background—Reduced electrogram amplitude has been shown to correlate with diseased myocardium. We describe a novel individualized approach for catheter ablation of atrial fibrillation (AF) based on low-voltage areas (LVAs) in the left atrium (LA). We sought to assess (1) the incidence of LVAs in patients undergoing AF catheter ablation, (2) the distribution of LVAs within the LA, and (3) the effect of an individualized ablation strategy on long-term rhythm outcomes. Methods and Results—In 178 patients with paroxysmal or persistent AF, LA voltage maps were created during sinus rhythm after circumferential pulmonary vein isolation. Subsequent substrate modification was confined to the presence of LVA (<0.5 mV) and inducible regular atrial tachycardias. LVAs were identified in 35% and 10% of patients with persistent and paroxysmal AF, respectively. The LA roof and the anterior, septal, and posterior wall LA were most often affected. The 12-month atrial tachycardias/AF-free survival was 62% for patients without LVAs and 70% for patients with LVAs and tailored substrate modification (P=0.3). Success rate in a comparison group of 26 LVA patients without further substrate modification was 27%. Conclusions—LVAs can be found at preferred sites in 10% of patients with paroxysmal AF and in 35% of patients with persistent AF. This is the first clinical report describing a consistent voltage-based approach for substrate modification in addition to circumferential pulmonary vein isolation irrespective of AF type. Application of this limited individualized approach may have the potential to compensate for the impaired 12-month outcome of patients with endocardial structural defects.

Chromosome 4q25 Variants and Atrial Fibrillation Recurrence After Catheter Ablation

OBJECTIVES This study tested the hypothesis that chromosome 4q25 single-nucleotide polymorphisms (SNPs) associate with atrial fibrillation (AF) recurrence after catheter ablation. BACKGROUND Recent genome-wide association studies identified 2 SNPs on chromosome 4q25 associated with AF. Although the mechanisms underlying this increased risk are unknown, the closest gene, PITX2, is critical for myocardium development in the pulmonary veins. METHODS A total of 195 consecutive patients (mean age 56 +/- 12 years, 73% male) with drug-refractory paroxysmal (78%) or persistent (22%) AF who underwent AF catheter ablation were included. Two SNPs, rs2200733 and rs10033464, were genotyped using real-time polymerase chain reaction and fluorescence resonance energy transfer. Serial 7-day Holter electrocardiographic recordings were acquired to detect AF recurrences. RESULTS Early recurrence of atrial fibrillation (ERAF) (within the first 7 days) was observed in 37%, whereas late recurrence of atrial fibrillation (LRAF) (between 3 and 6 months) occurred in 21% of the patients. None of the clinical or echocardiographic baseline characteristics were associated with ERAF or LRAF. In contrast, the presence of any variant allele increased the risk for both ERAF (odds ratio [OR]: 1.994, 95% confidence interval [CI]: 1.036 to 3.837, p = 0.039) and LRAF (OR: 4.182, 95% CI: 1.318 to 12.664, p = 0.011). In patients with ERAF, 45% had LRAF, as opposed to 8% in patients without ERAF (OR: 9.274, 95% CI: 3.793 to 22.678, p < 0.001). CONCLUSIONS Polymorphisms on chromosome 4q25 modulate the risk for AF recurrence after catheter ablation. This finding points to a potential role for stratification of AF ablation therapy or peri-interventional management by genotype.

Outcomes in Catheter Ablation of Ventricular Tachycardia in Dilated Nonischemic Cardiomyopathy Compared With Ischemic Cardiomyopathy Results From the Prospective Heart Centre of Leipzig VT (HELP-VT) Study

Background— Data on the outcomes of ventricular tachycardia (VT) ablation in nonischemic dilated cardiomyopathy (NIDCM) are insufficient. The Heart Center of Leipzig VT (HELP-VT) study was conducted prospectively to compare outcomes after radiofrequency catheter ablation of VT in patients with NIDCM compared with ischemic cardiomyopathy (ICM). Methods and Results— Two hundred twenty-seven patients, 63 with NIDCM and 164 with ICM, presenting with sustained VT were ablated with radiofrequency catheter ablation. Noninducibility of any clinical and nonclinical VT was achieved in 66.7% of NIDCM and in 77.4% of ICM patients. Ablation of the clinical VT only was achieved in 18.3% of ICM and in 22.2% of NIDCM patients. There was no statistically significant difference in short-term outcomes between the 2 groups. At the 1-year follow-up, VT-free survival in NIDCM was 40.5% compared with 57% in ICM. In univariate analysis, the hazard ratio for VT recurrence was significantly higher for NIDCM (1.62; 95% confidence interval, 1.12– 2.34; P=0.01). In both the ICM and NIDCM subgroups, procedure failure and incomplete procedural success were independent predictors of VT recurrence. Conclusions— Although the short-term success rates after VT ablation in NIDCM and ICM patients were similar, the long-term outcomes in NIDCM patients were significantly worse. Complete VT noninducibility at the end of the ablation is associated with beneficial long-term outcome in NIDCM. Pursuing compete elimination of all inducible VTs is desirable and may improve the long-term success in NIDCM.

Thermal Esophageal Lesions After Radiofrequency Catheter Ablation of Left Atrial Arrhythmias

OBJECTIVES:Radiofrequency catheter ablation in patients with left atrial arrhythmias may cause esophageal damage because of the close proximity between the posterior wall of the left atrium and the esophagus. The aim of this prospective study was to determine the incidence, endoscopic characterization, and endoluminal temperature dependency of esophageal thermal lesions after catheter ablation.METHODS:In all, 185 consecutive patients with symptomatic atrial fibrillation or left atrial macro-re-entrant tachycardia who underwent left atrial radiofrequency catheter ablation were scheduled for upper gastrointestinal endoscopy. During the ablation procedure, a non-fluoroscopic three-dimensional system for catheter orientation, computed tomography (CT) image integration, and activation mapping was used. The esophagus was intubated with a temperature probe for visualization within the three-dimensional image and for real-time intraluminal temperature monitoring.RESULTS:A total of 27 (14.6%) asymptomatic ulcer-like or hemorrhagic esophageal thermal lesions with a diameter of 2–16 mm were observed. Esophageal lesions did not occur below an intraluminal esophageal temperature of 41 °C. The maximal temperature in the esophagus was significantly higher in patients with thermal lesions than in patients without lesions (42.6±1.7 °C vs. 41.4±1.7 °C, P=0.003). For every 1 °C increase in endoluminal temperature, the odds of an esophageal lesion increased by a factor of 1.36 (95% confidence interval (CI) 1.07–1.74, P=0.012). No progression of the lesions was observed during follow-up endoscopies.CONCLUSIONS:Localized esophageal ulcer-like lesion is a frequent event after left atrial catheter ablation and can be found in patients whose intraluminal temperature has reached at least 41 °C.

Topographic variability of the esophageal left atrial relation influencing ablation lines in patients with atrial fibrillation.

Introduction: The close anatomic relationship of the posterior wall of the left atrium (LA) and the thermosensitive esophagus creates a potential hazard in catheter ablation procedures.

Influence of the duration of Holter monitoring on the detection of arrhythmia recurrences after catheter ablation of atrial fibrillation: Implications for patient follow-up

We investigated the influence of Holter duration on the detection of recurrences after ablation for atrial fibrillation (AF). Two-hundred-and-fifteen patients underwent a 7-day Holter ECG at 6 months after catheter ablation. We analyzed the number of patients who had a recurrence within the first 24, 48, 72 h etc. up to the total of 7 days. During the complete 7-day recording, 30% had a recurrence. All Holter durations ≤5 days would have detected significantly less patients with recurrence than the complete 7-day recording. A 24-hour Holter would have detected 59%, a 48-hour Holter 67% and a 72-hour Holter 80% of patients with recurrences, whereas a 4-day recording would have detected 91% of the recurrences that were detected with the complete 7-day recording. In conclusion, a Holter duration of less than 4 days misses a great portion of recurrences, whereas a 4-day recording might offer a reasonable compromise.

Steerable Versus Nonsteerable Sheath Technology in Atrial Fibrillation Ablation A Prospective, Randomized Study

Background— Steerable sheath technology is designed to facilitate catheter access, stability, and tissue contact in target sites of atrial fibrillation (AF) catheter ablation. We hypothesized that rhythm control after interventional AF treatment is more successful using a steerable as compared with a nonsteerable sheath access. Methods and Results— One hundred thirty patients with paroxysmal or persistent drug-refractory AF undergoing their first ablation procedure were prospectively included in a randomized fashion in 2 centers. Ablation was performed by 10 operators with different levels of clinical experience. Treatment outcome was measured with serial 7-day Holter ECGs and additional symptom-based arrhythmia documentation. Single procedure success (freedom from AF and/or atrial macroreentrant tachycardia) was significantly higher in patients ablated with a steerable sheath (78% versus 55% after 3 months, P=0.005; 76% versus 53% after 6 months, P=0.008). Rate of pulmonary vein isolation, procedure duration, and radiofrequency application time did not differ significantly, whereas fluoroscopy time was lower in the steerable sheath group (33±14 minutes versus 45±17 minutes, P<0.001). Complication rates showed no significant difference (3.2% versus 5%, P=0.608). On multivariable analysis, steerable sheath usage remained the only powerful predictor for rhythm outcome after 6 months of follow-up (hazard ratio, 2.837 [1.197 to 6.723]). Conclusions— AF catheter ablation using a manually controlled, steerable sheath for catheter navigation resulted in a significantly higher clinical success rate, with comparable complication rates and with a reduction in periprocedural fluoroscopy time. Clinical Trial Registration— URL: http://clinicaltrials.gov. Unique identifier: NCT00469638.

Effect of Electroanatomically Guided Versus Conventional Catheter Ablation of Typical Atrial Flutter on the Fluoroscopy Time and Resource Use: A Prospective Randomized Multicenter Study

Aims: Radiofrequency catheter ablation of typical atrial flutter is one of the most frequent indications for catheter ablation in electrophysiology laboratories today. Clinical utility of electroanatomic mapping systems on treatment results and resource utilization compared with conventional ablation has not been systematically investigated in a prospective multicenter study.