Atrioesophageal Fistula Rates Before and After Adoption of Active Esophageal Cooling During Atrial Fibrillation Ablation.

BACKGROUND: Active esophageal cooling reduces the incidence of endoscopically identified severe esophageal lesions during radiofrequency (RF) catheter ablation of the left atrium for the treatment of atrial fibrillation. A formal analysis of the atrioesophageal fistula (AEF) rate with active esophageal cooling has not previously been performed. OBJECTIVES: The authors aimed to compare AEF rates before and after the adoption of active esophageal cooling. METHODS: This institutional review board (IRB)-approved study was a prospective analysis of retrospective data, designed before collecting and analyzing the real-world data. The number of AEFs occurring in equivalent time frames before and after adoption of cooling using a dedicated esophageal cooling device (ensoETM, Attune Medical) were quantified across 25 prespecified hospital systems. AEF rates were then compared using generalized estimating equations robust to cluster correlation. RESULTS: A total of 14,224 patients received active esophageal cooling during RF ablation across the 25 hospital systems, which included a total of 30 separate hospitals. In the time frames before adoption of active cooling, a total of 10,962 patients received primarily luminal esophageal temperature (LET) monitoring during their RF ablations. In the preadoption cohort, a total of 16 AEFs occurred, for an AEF rate of 0.146%, in line with other published estimates for procedures using LET monitoring. In the postadoption cohort, no AEFs were found in the prespecified sites, yielding an AEF rate of 0% (P < 0.0001). CONCLUSIONS: Adoption of active esophageal cooling during RF ablation of the left atrium for the treatment of atrial fibrillation was associated with a significant reduction in AEF rate.

Acute Lesion Imaging in Predicting Chronic Tissue Injury in the Ventricles.

BACKGROUND: Chronic lesion formation after cardiac tissue ablation is an important indicator for procedural outcome. Moreover, there is a lack of knowledge regarding the features that predict chronic lesion formation. OBJECTIVE: The aim of this study is to determine whether acute lesion visualization using late gadolinium enhanced magnetic resonance imaging (LGE-MRI) can reliably predict chronic lesion size. METHODS: Focal lesions were created in left and right ventricles of canine models using either radiofrequency (RF) ablation or cryofocal ablation. Multiple ablation parameters were used. The first LGE-MRI was acquired within 1-5 h post-ablation and the second LGE-MRI was obtained 47-82 days later. Corview software was used to perform lesion segmentations and size calculations. RESULTS: Fifty-Five lesions were created in different locations in the ventricles. Chronic volume size decreased by a mean of 62.5 % (95% CI 58.83-67.97, p < 0.0005). Similar regression of lesion volume was observed regardless of ablation location (p = 0.32), ablation technique (p = 0.94), duration (p = 0.37), power (p = 0.55) and whether lesions were connected or not (p = 0.35). There was no significant difference in lesion volume reduction assessed at 47-54 days and 72-82 days after ablation (p = 0.31). Chronic lesion volume was equal to 0.32 of the acute lesion volumes (R2 = 0.75). CONCLUSION: Chronic tissue injury related to catheter ablation can be reliably modeled as a linear function of the acute lesion volume as assessed by LGE-MRI, regardless of the ablation parameters.

Smartphone ECG Monitoring System Helps Lower Emergency Room and Clinic Visits in Post-Atrial Fibrillation Ablation Patients.

AIM: To evaluate the effectiveness of using a smartphone-based electrocardiography (ECG) monitoring device (ECG Check) on the frequency of clinic or emergency room visits in patients who underwent ablation of atrial fibrillation (AF). METHODS: Two groups of patients were identified and compared: The conventional monitoring group (CM group) included patients who were prescribed conventional event monitoring or Holter monitoring systems. The ECG Check group (EC group) included patients who were prescribed the ECG Check device for continuous monitoring in addition to conventional event monitoring. The primary outcome was the number of patient visits to clinic or emergency room. The feasibility, accuracy, and detection rate of mobile ECG Check were also evaluated. RESULTS: Ninety patients were studied (mean age: 66.2 ± 11 years, 64 males, mean CHA2DS2-VASc score: 2.6 ± 2). In the EC group, forty-five patients sent an average of 52.8 ± 6 ECG records for either routine monitoring or symptoms of potential AF during the follow-up period. The rhythm strips identified sinus rhythm (84.7%), sinus tachycardia (8.4%), AF (4.2%), and atrial flutter (0.9%). Forty-two EC transmissions (1.8%) were uninterpretable. Six patients (13%) in the EC group were seen in the clinic or emergency room over a 100-day study period versus 16 (33%) in the standard care arm (P value < 0.001). CONCLUSIONS: Use of smartphone-based ECG monitoring led to a significant reduction in AF-related visits to clinic or emergency department in the postablation period.

Improvement in estimated glomerular filtration rate in patients with chronic kidney disease undergoing catheter ablation for atrial fibrillation.

INTRODUCTION: Chronic kidney disease (CKD) and atrial fibrillation (AF) often coexist. We studied the association of CKD with atrial fibrosis and the effect of AF ablation on kidney function. METHODS: AF patients who had a pre- and postablation serum creatinine and who completed a late gadolinium enhancement cardiac magnetic resonance imaging (MRI; LGE-MRI) prior to ablation were included. Estimated glomerular filtration rate (eGFR) was calculated and CKD was staged using the National Kidney Foundation guidelines. Patients with eGFR <30 mL/min/1.73 m(2) were excluded. LGE-MRI was used to quantify atrial fibrosis. Patients were followed for recurrence and change in eGFR. RESULTS: A total of 392 patients were included in the study. A total of 118 (30.2%) had CKD stage 1, 198 (50.4%) CKD stage 2, 56 (14.3%) CKD stage 3A, and 20 (5.1%) CKD stage 3B. Patients with advanced CKD were more likely to be male and to have cardiovascular disease. Atrial fibrosis was not significant different between included CKD stages: 15.8 ± 8.8%, 16.6 ± 12.1%, 17.1 ± 10.4%, and 16.5 ± 8.4% for CKD stage 1, 2, 3A, and 3B, respectively (P = 0.476). At a median of 115 days following ablation, eGFR increased significantly in CKD stage 2 (74 ± 9 to 80 ± 23; P = 0.04), 3A (53 ± 5 to 69 ± 24; P < 0.001), and 3B (40 ± 4 to 71 ± 28; P < 0.01) and decreased in CKD stage 1 (109 ± 18 to 82 ± 28; P < 0.001). Arrhythmia recurrence was associated with atrial fibrosis (hazard ratio [HR] = 1.04, P < 0.01) and persistent AF (HR = 1.5; P = 0.04) but not with CKD stage (HR = 0.98; P = 0.89). CONCLUSIONS: Restoring sinus rhythm with ablation leads to significant improvement of renal function in patients with chronic kidney disease.