Intracardiac Echocardiography Outperforms Transesophageal Echocardiography in Atrial Fibrillation

Intracardiac echocardiography (ICE) has demonstrated noninferiority to transesophageal echocardiography (TEE) in preventing thromboembolic complications during atrial fibrillation (AF) ablation, offering advantages in terms of safety, efficiency, and patient comfort.1

Catheter ablation is a first-line therapy for symptomatic AF, with increasing evidence supporting its role as a central component of early rhythm control strategies. These have been associated with improved cardiovascular outcomes in patients with AF based on recent research. Although TEE is a semi-invasive procedure and has been associated with complications, including oropharyngeal, esophageal, and laryngeal injury, it is currently the standard imaging modality recommended to accurately detect left atrial thrombus before ablation.2

ICE, typically used during AF ablation to guide catheter positioning and detect procedural complications, has been suggested as an alternative in preprocedural thrombus assessment. Prior research has suggested that ICE can detect left atrial appendage thrombus with high accuracy. However, clinical evidence supporting its role as a replacement for TEE is lacking.3

“To address this gap, we conducted a multicenter randomized clinical trial to evaluate the noninferiority of ICE compared to TEE not in terms of image-based thrombus detection alone, but more importantly, in terms of clinical safety as measured by the incidence of periprocedural thromboembolic events,” wrote Xiaofeng Hu, MD, Shanghai Chest Hospital, Shanghai Jiao Tong University School of Medicine, and colleagues.1

Investigators included adults aged 18-80 years undergoing AF ablation from August 2022 to July 2023 while receiving uninterrupted oral anticoagulation for ≥3 weeks, either with a direct oral anticoagulant or a vitamin K antagonist. Patients were excluded if they had contraindications to TEE, including esophageal strictures, active esophageal or gastric ulcers, bleeding risks, obstructive conditions, or pharyngeal malignancies.1

The primary study endpoint was the incidence of periprocedural thromboembolic events, which were defined as stroke, transient ischemic attack (TIA), or systemic embolism within 30 days post-ablation. Secondary endpoints included thrombus detection rate, all-cause mortality, major bleeding complications, procedural characteristics such as fluoroscopy time and ablation time, and preprocedural waiting time.1

A total of 1832 patients were screened, with 1810 randomly assigned in a 1:1 ratio to either TEE (n = 904) or ICE (n = 906). The mean age among patients was 64.3 years (standard deviation [SD] 9.4). A total of 923 patients had persistent or long-standing persistent AF, and baseline characteristics were well-balanced between groups.1

Periprocedural thromboembolic events occurred in 4 patients in the ICE group and 5 in the TEE group, with no statistically significant difference between groups. The absolute risk difference (ICE – TEE) was -0.11% (95% CI, -0.65% to 0.43%). Thrombus was detected in 18 patients in the ICE group and 14 in the TEE group (risk ratio [RR], 1.29; 95% CI, 0.64 to 2.61; P = .48).1

Among procedure-related complications, major bleeding occurred in 7 patients in the ICE group and 16 in the TEE group (RR, 0.43; 95% CI, 0.18 to 1.06; P = .07). Minor bleeding occurred in 12 patients in the ICE group and 10 patients in the TEE group (RR, 1; 95% CI, 0.42 to 2.42; P = .99). No deaths were reported from either group.1

“While ICE is increasingly used for procedural guidance during AF ablation, its role in thrombus screening remains underrecognized in clinical practice,” Hu and colleagues wrote. “Addressing this evidence gap, our study provides the first outcome-driven, randomized clinical trial evidence demonstrating that ICE is a clinically feasible and safe alternative to TEE for preprocedural thrombus exclusion in patients undergoing AF ablation.”1

References

1. Hu X, Jiang W, Wang X, et al. Intracardiac vs transesophageal echocardiography in atrial fibrillation ablation. JAMA Cardiology. Published online October 8, 2025. doi:10.1001/jamacardio.2025.3687

2. Lurie A, Wang J, Hinnegan KJ, et al. Prevalence of left atrial thrombus in anticoagulated patients with atrial fibrillation. Journal of the American College of Cardiology. 2021;77(23):2875-2886. doi:10.1016/j.jacc.2021.04.036

3. Tzeis S, Gerstenfeld EP, Kalman J, et al. 2024 European heart rhythm association/heart rhythm society/asia pacific heart rhythm society/latin american heart rhythm society expert consensus statement on Catheter and surgical ablation of atrial fibrillation. Heart Rhythm. 2024;21(9). doi:10.1016/j.hrthm.2024.03.017