A randomised comparison of Cartomerge vs. NavX fusion in the catheter ablation of atrial fibrillation: The CAVERN Trial

PURPOSE: Integration of a 3D reconstruction of the left atrium into cardiac mapping systems can aid catheter ablation of atrial fibrillation (AF). The two most widely used systems are NavX Fusion and Cartomerge. We aimed to compare the clinical efficacy of these systems in a randomised trial. METHODS: Patients undergoing their first ablation were randomised to mapping using either NavX fusion or CartoMerge. Pulmonary vein isolation by wide area circumferential ablation was performed for paroxysmal AF with additional linear and fractionated potential ablation for persistent AF. Seven-day Holter monitoring was used for confirmation of sinus rhythm maintenance at 6 months. RESULTS: Ninety-seven patients were randomised and underwent a procedure. There was no difference in the primary endpoint of freedom from arrhythmia at 6 months (51% in the Cartomerge group vs. 48% in the NavX Fusion group, p = 0.76). 3D image registration was faster with Cartomerge (24 vs. 33 min, p = 0.0001), used less fluoroscopic screening (11 vs. 15 min, p = 0.039) with a lower fluoroscopic dose (840 vs. 1,415 mGyCm(2), p = 0.043). There was a strong trend to lower ablation times in the Cartomerge group, overall RF time (3,292 s vs. 4,041, p = 0.07). Distance from 3D lesion to 3D image shell was smaller in the Cartomerge group (2.7 ± 1.9 vs. 3.3 ± 3.7 mm, p < 0.001). CONCLUSIONS: Cartomerge appears to be faster and uses less fluoroscopy to achieve registration than NavX Fusion, but overall procedural times and clinical outcomes are similar.