Randomized trial of intracardiac echocardiography during cavotricuspid isthmus ablation

Abstract

Introduction: Despite a high success rate, radiofrequency ablation (RFA) of the cavotricuspid isthmus (CTI) can be unusually challenging in some cases. We postulated that visualization of the CTI with intracardiac echocardiography (ICE) could maximize the succes rate, decrease the procedure and ablation time, and minimize the radiation exposure. Methods and Results: In our prospective, randomized study, we included 102 patients scheduled for CTI ablation. We randomized patients in 2 groups: guided only by fluoroscopy (n=52) or ICE-guided (n=50) group. Procedure time, fluoroscopy time, and the time spent for RFA were significantly shorter, radiation exposure (dose-area product-DAP) and the sum of delivered radio frequency energy were significantly lower in the ICE-group (68.06±15.09 minutes vs 105.94±36.51 minutes, P<0.001, 5.54±3.77 minutes vs 18.63±10.60 minutes, P<0.001, 482.80±534.12 seconds vs 779.76±620.82 seconds, P=0.001 and 397.62±380.81 cGycm2 vs 1,312.92±1,129.28 cGycm 2, P<0.001, 10,866.84±6,930.84 Ws vs 16,393.56±13, 995.78 Ws, P=0.048, respectively). Seven patients (13%) fromthe fluoroscopy-only group crossed over to ICE-guidance because of prolonged unsuccessful RFA and were all treated successfully. Four vascular complications and 2 recurrences were equally distributed between the 2 groups. Conclusions: ICE-guided ablation of the CTI significantly shortens the procedure and fluoroscopy time, markedly decreases radiation exposure, and time spent for ablation in comparison with fluoroscopy-only procedures. At the same time, visualization with ICE allowed successful ablation in challenging cases.