Outcomes of cavotricuspid isthmus-dependent flutter ablation: randomized study comparing single vs. multiple catheter procedures-the SIMPLE study.

BACKGROUND: Catheter ablation is recommended as first-line therapy for patients with symptomatic typical AFl. Although the conventional multi-catheter approach is the standard of care for cavotricuspid isthmus (CTI) ablation, a single-catheter approach was recently described as a feasible alternative. The present study sought to compare safety, efficacy, and efficiency of single vs. multi-catheter approach for atrial flutter (AFl) ablation. METHODS: In this randomized multi-center study, consecutive patients referred for AFl ablation (n = 253) were enrolled and randomized to multiple vs. single-catheter approach for CTI ablation. In the single-catheter arm, PR interval (PRI) on the surface ECG was used to prove CTI block. Procedural and follow-up data were collected and compared between the two arms. RESULTS: 128 and 125 patients were assigned to the single-catheter and to the multi-catheter arms, respectively. In the single-catheter arm, procedure time was significantly shorter (37 ± 25 vs. 48 ± 27 minutes, p = 0.002) and required less fluoroscopy time (430 ± 461 vs. 712 ± 628 seconds, p < 0.001) and less radiofrequency time (428 ± 316 vs. 643 ± 519 seconds, p < 0.001), achieving a higher first-pass CTI block rate (55 (45%) vs. 37 (31%), p = 0.044), compared with the multi-catheter arm. After a median follow-up of 12 months, 11 (4%) patients experienced AFl recurrences (5 (4%) in the single-catheter arm and 6 (5%) in the multi-catheter arm, p = 0.99). No differences were found in arrhythmia-free survival between arms (log-rank = 0.71). CONCLUSIONS: The single-catheter approach for typical AFl ablation is not inferior to the conventional multiple-catheter approach, reducing procedure, fluoroscopy, and radiofrequency time.

A hybrid clinical and electrocardiographic score to predict the origin of outflow tract ventricular arrhythmias.

BACKGROUND: To predict the outflow tract ventricular arrhythmias (OTVA) site of origin (SOO) before the ablation procedure has important practical implications. The present study sought to prospectively evaluate the accuracy of a clinical and electrocardiographic hybrid algorithm (HA) for the prediction of OTVAs-SOO, and at the same time to develop and to prospectively validate a new score with improved discriminatory capacity. METHODS: In this multicenter study, we prospectively enrolled consecutive patients referred for OTVA ablation (N = 202), and we divided them in a derivation sample and a validation cohort. Surface ECGs during OTVA were analyzed to compare previous published ECG-only criteria and to develop a new score. RESULTS: In the derivation sample (N = 105), the correct prediction rate of HA and ECG-only criteria ranged from 74 to 89%. R-wave amplitude in V3 was the best ECG parameter for discriminating LVOT origin in V3 precordial transition (V3PT) patients, and was incorporated to the novel weighted hybrid score (WHS). WHS correctly classified 99 (94.2%) patients, presenting 90% sensitivity and 96% specificity (AUC 0.97) in the entire population; WHS mantained a 87% sensitivity and 91% specificity (AUC 0.95) in patients with V3PT subgroup. The high discriminatory capacity was confirmed in the validation sample (N = 97): the WHS exhibited an AUC (0.93), and a WHS ≥ 2 allowed a correct prediction of LVOT origin in 87 (90.0%) cases, yielding a sensitivity of 87% and specificity of 90%; moreover, the V3PT subgroup showed an AUC of 0.92, and a punctuation ≥ 2 predicted an LVOT origin with a sensitivity of 94% and specificity of 78%. CONCLUSIONS: The novel hybrid score has proved to accurately anticipate the OTVA's origin, even in those with a V3 precordial transition. A Weighted hybrid score. B Typical examples of the use of the weighted hybrid score. C ROC analysis of WHS and previous ECG criteria for prediction of LVOT origin in the derivation cohort. D ROC analysis of WHS and previous ECG criteria for prediction of LVOT origin in the V3 precordial transition OTVA subgroup.

Relationship between the posterior atrial wall and the esophagus: Esophageal position during atrial fibrillation ablation.

Background: Atrial fibrillation ablation implies a risk of esophageal thermal injury. Esophageal position can be analyzed with imaging techniques, but evidence for esophageal mobility is inconsistent. Objectives: The purpose of this study was to analyze esophageal position stability from one procedure to another and during a single procedure. Methods: Esophageal position was compared in 2 patient groups. First, preprocedural multidetector computerized tomography (MDCT) of first pulmonary vein isolation and redo intervention (redo group) was segmented with ADAS 3D™ to compare the stability of the atrioesophageal isodistance prints. Second, 3 imaging modalities were compared for the same procedure (multimodality group): (1) preprocedural MDCT; (2) intraprocedural fluoroscopy obtained with the transesophageal echocardiographic probe in place with CARTOUNIVU™; and (3) esophageal fast anatomic map (FAM) at the end of the procedure. Esophageal position correlation between different imaging techniques was computed in MATLAB using semiautomatic segmentation analysis. Results: Thirty-five redo patients were analyzed and showed a mean atrioesophageal distance of 1.2 ± 0.6 mm and a correlation between first and redo procedure esophageal fingerprint of 91% ± 5%. Only 3 patients (8%) had a clearly different position. The multi-imaging group was composed of 100 patients. Esophageal position correlation between MDCT and CARTOUNIVU was 82% ± 10%; between MDCT and esophageal FAM was 80% ± 12%; and between esophageal FAM and CARTOUNIVU was 83% ± 15%. Conclusion: There is high stability of esophageal position between procedures and from the beginning to the end of a procedure. Further research is undergoing to test the clinical utility of the esophageal fingerprinted isodistance map to the posterior atrial wall.

Personalized paroxysmal atrial fibrillation ablation by tailoring ablation index to the left atrial wall thickness: the 'Ablate by-LAW' single-centre study-a pilot study.

AIMS: To determine if adapting the ablation index (AI) to the left atrial wall thickness (LAWT), which is a determinant of lesion transmurality, is feasible, effective, and safe during paroxysmal atrial fibrillation (PAF) ablation. METHODS AND RESULTS: Consecutive patients referred for PAF first ablation. Left atrial wall thickness three-dimensional maps were obtained from multidetector computed tomography and integrated into the CARTO navigation system. Left atrial wall thickness was categorized into 1 mm layers and AI was titrated to the LAWT. The ablation line was personalized to avoid thicker regions. Primary endpoints were acute efficacy and safety, and freedom from atrial fibrillation (AF) recurrences. Follow-up (FU) was scheduled at 1, 3, 6, and every 6 months thereafter. Ninety patients [60 (67%) male, age 58 ± 13 years] were included. Mean LAWT was 1.25 ± 0.62 mm. Mean AI was 366 ± 26 on the right pulmonary veins with a first-pass isolation in 84 (93%) patients and 380 ± 42 on the left pulmonary veins with first-pass in 87 (97%). Procedure time was 59 min (49-66); radiofrequency (RF) time 14 min (12.5-16); and fluoroscopy time 0.7 min (0.5-1.4). No major complication occurred. Eighty-four out of 90 (93.3%) patients were free of recurrence after a mean FU of 16 ± 4 months. CONCLUSION: Personalized AF ablation, adapting the AI to LAWT allowed pulmonary vein isolation with low RF delivery, fluoroscopy, and procedure time while obtaining a high rate of first-pass isolation, in this patient population. Freedom from AF recurrences was as high as in more demanding ablation protocols. A multicentre trial is ongoing to evaluate reproducibility of these results.

A standardized stepwise zero-fluoroscopy approach with transesophageal echocardiography guidance for atrial fibrillation ablation.

PURPOSE: There is growing interest in performing fluoroless radiofrequency ablation (RFA) for atrial fibrillation (AF) due to the increasing awareness of risk associated with radiation exposure of patients and professional staff. The present study aimed to evaluate the feasibility, safety, and efficacy of a stepwise transesophageal echocardiography (TEE)-guided zero-fluoroscopy approach (ZFA) for RFA. METHODS: Consecutive patients (n = 111) referred for AF-ablation were prospectively enrolled with intention to RFA with ZFA. Procedural outcomes were compared with historical controls (HCs) after 1:1 propensity score matching. ZFA success was considered when no X-ray was utilized to perform the whole procedure. RESULTS: ZFA success was achieved in 80 (72%) procedures. BMI > 35 kg/m2 resulted in the only independent predictor of ZFA failure (OR = 6.10, 95% CI 1.15-46.49, p = 0.04). In comparison to HCs, a significant reduction in radiation exposure was observed in the ZFA group: fluoroscopy time (3 vs. 63 s, p < 0.001), total emitted fluoroscopy dose (0.2 vs. 6.0 mGy, p < 0.001), dose area product (0.04 vs. 1.4 Gy*cm2, p < 0.001), and effective dose (0.8 vs. 27.2 mSv*100, p < 0.001). Complete pulmonary vein isolation was achieved in all procedures. No difference was observed between the groups in in-hospital complication rate (0.9% vs. 1.8%, p = 0.99). CONCLUSIONS: This is the largest study proving procedural feasibility, safety, and efficacy of TEE-guided AF-ablation with a complete or near-complete avoidance of radiological exposure, without using intracardiac echocardiography.