Trans-esophageal Echocardiography Trends in Atrial Fibrillation Ablation

Trans-esophageal echocardiography (TEE) may be avoided prior to ablation for atrial fibrillation (AF) in patients without high-risk characteristics, according to research published in JACC: Clinical Electrophysiology.

David Spragg, MD, of Johns Hopkins Heart and Vascular Institute in Baltimore, and colleagues conducted a retrospective analysis of TEE and ablation outcomes in 1224 cases between January 2010 and September 2015. They documented presence of left atrial appendage (LAA) thrombus, dense spontaneous echo contrast, and patent foramen ovale. 

As the researchers noted, LAA thrombus is an “absolute contraindication” to AF catheter ablation and can be screened prior to the procedure, with TEE being the “gold standard” imaging method. However, more recently, some study findings have suggested that “uninterrupted peri-procedural anticoagulation” (eg, warfarin or novel oral anticoagulants [NOACs]) may be effective in reducing risk of a cerebrovascular accident.

In this study cohort, anticoagulation was started at least 3.5 weeks prior to ablation in nearly all of the patients (94.3%); those taking warfarin continued without interruption throughout the ablation period. The average age was 60.8 years and 26.7% were female. Approximately 34% of the ablations in 38% of patients were repeat procedures; 8% of patients had a history of previous cerebrovascular accident.

Nearly half (47.8%) of patients continued uninterrupted warfarin therapy. The remaining patients underwent “minimally interrupted” therapy with one of the following NOACs: dabigatran (23.2%), rivaroxaban (21.9%), or apixaban (6.4%).

TEE was requested more often among patients with a history of persistent AF (P <.001), patients presenting in AF (P <.001), and patients with history of hypertension (P =.024) and congestive heart failure (P =.005). Pre-ablation TEE rates dropped from 86% to 42% from 2010 to 2015 (P <.001). Meanwhile, cerebrovascular accidents occurred in 0.40% of patients (or 0.33% of cases), including 2 transient ischemic attacks and 2 strokes. There was no “appreciable change” in the rate of cerebrovascular accidents over time.

The researchers found LAA thrombus in 1.04% of patients, which led to cancelation of those ablation procedures. More than 80% of these patients had history of persistent AF, 50% presented in AF, had average CHA₂DS₂VASc scores of 2.5 ± 1.6, and a reduced ejection fraction (48.3% ± 13.3%). As a result of the TEEs positive for LAA thrombus, 2 patients were switched from warfarin to a NOAC and 1 patient switched from dabigatran to warfarin.

As routine TEE use has fallen, so too have rates for TEE positive for thrombus. “We attribute these declines in part to the strategy of minimally interrupted anticoagulation, and (in the case of CVA [cerebrovascular accident] reduction, despite fewer screening TEEs performed) to improvements in equipment and institutional experience,” the researchers wrote.

“Avoiding TEE use in low-risk patients for CVA, including those with low CHA₂DS₂VASc scores, presenting in sinus rhythm, and systemically anticoagulated, is not associated with increased risk of peri-procedural CVA,” they concluded. “Whether this strategy can be safely extended to higher-risk patients requires further investigation.”

Study Limitations

This study has several limitations: its retrospective nature; anticoagulation protocol varying from other facilities; and the possibility of subclinical cases of thromboembolic events.

Reference

Balouch M, Ipeak EG, Chrispin J, et al. Trends in trans-esophageal echocardiography use, findings, and clinical outcomes in the era of minimally interrupted anticoagulation for atrial fibrillation ablation. JACC Clin Electrophysiol. 2016 Nov 23. doi:10.1016/j.jacep.2016.09.011 [Epub ahead of print].