Cryoablation of atrial fibrillation in “very severe” obese patients (BMI ≥ 40): Indications, feasibility, procedural safety and efficacy, and clinical outcome (the ICE‐Obese Extreme)

Abstract

BackgroundManagement of atrial fibrillation (AF) in very severe obese patients is challenging. Cryoballoon ablation (CBA) represents an effective rhythm control strategy. However, data in this patient group were limited.MethodsHighly symptomatic AF patients with body mass index (BMI) ≥ 40 kg/m2 who had failed antiarrhythmic drug therapy and electrocardioversion and failure to achieve targeted body‐weight‐reduction underwent CBA.ResultsData of 72 very severe obese AF patients (Group A) and 129 AF patients with normal BMI (Group B, BMI < 25 kg/m2) were consecutively collected. Group A had significantly younger age (60.6 ± 10.4 vs. 69.2 ± 11.2 years), higher BMI (44.3 ± 4.3 vs. 22.5 ± 1.6 kg/m2). Procedural pulmonary vein isolation (PVI) was successful in all patients (2 touch‐up ablation in Group A). Compared to Group B, Group A had similar procedural (61.3 ± 22.6 vs. 57.5 ± 19 min), similar fluoroscopy time (10.1 ± 5.5 vs. 9.2 ± 4.8 min) but significantly higher radiation dose (2852 ± 2095 vs. 884 ± 732 µGym2). We observed similar rates of real‐time‐isolation (78.6% vs. 78.5%), single‐shot‐isolation (86.5% vs. 88.8%), but significantly longer time‐to‐sustained‐isolation (53.5 ± 33 vs. 43.2 ± 25 s). There was significantly higher rate of puncture‐site‐complication (6.9% vs. 1.6%) in Group A. One‐year clinical success in paroxysmal AF was (Group A: 69.4% vs. Group B: 80.2%; p < .001), in persistent AF was (Group A: 58.1% vs. Group B: 62.8%; p = .889). In Re‐Do procedures Group A had a numerically lower PVI durability (75.0% vs. 83.6%, p = .089).ConclusionFor very severe obese AF patients, CBA appears feasible, leads to relatively good clinical outcome.

Detailed mechanism of difficulty in cryoablation for atrial fibrillation in patients with very severe obesity

“…It is reasonable that the higher rates of puncture site complications and radiation doses were observed in obese patients, 1 given their anatomical features. However, the detailed association between obesity and the difficulty of CBA, as indicated by the longer mean time to sustained pulmonary vein isolation, remains uncertain.…”

“…The ablation of lower pulmonary veins required more procedural time than other veins in obese patients. 1 The elevation of the diaphragm due to obesity may inhibit appropriate atrial septum puncture and make CBA to lower pulmonary veins challenging.…”

Catheter ablation of atrial fibrillation in “very severe” obese patients (BMI ≥ 40): Insights from “the ICE‐Obese Extreme” study

“…In our recent "ICE-Obese Extreme" study, highly symptomatic AF patients with BMI ≥ 40 kg/m 2 who had failed AADs and ECV therapy and failed to achieve target body weight reduction underwent cryoablation, and the data showed the procedural feasibility and efficacy of cryoablation in very severe obese patients, and we concluded that in such selected patient group, catheter ablation may still serve as an effective rhythm-control option although increased technical difficulty can be expected. 5 The limitations of the study were also clearly discussed, including the single center fashion instead of multicenter trial, and the high proficiency of the primary operators (>6000 ablation experience: Chen, Chun, Schmidt, and Bordignon), which may make it difficult to generate our results to low-volume centers.…”