Lattice-tip Versus Irrigated-tip Catheter for Linear Ablation of the Cavotricuspid Isthmus. A Multicenter, Randomized Study. (The LINEAR Study)

This is a prospective, multicenter, randomized controlled trial designed to compare the efficacy, efficiency and safety of CTI catheter ablation using two different catheter technologies: the lattice-tip, dual-energy catheter (Sphere-9, Medtronic) and the irrigated radiofrequency (RF) catheter (ThermoCool® SmartTouch™, Biosense Webster, USA). The primary focus of the acute procedural data analysis will be:

Procedural efficacy: This will be evaluated based on the rate of bidirectional CTI block persistence after 60 min waiting period documented by high resolution activation mapping. Furthermore, provocative test with intravenous adenosine infusion will be conducted to exclude dormant CTI conduction.

Procedural efficiency: This will be evaluated based on the number of RF lesions delivered, ablation time, the rate of first-pass CTI block, and fluoroscopy exposure and time.

Procedural safety: The incidence of procedural complications will be recorded.

Patient Population Based on previously published data, the proportion of patients with documented CTI bidirectional block at 60 minutes as assessed by high density electroanatomical mapping is estimated at 60% for the control group. Based on preliminary studies conducted by our group, we expected a respective percentage of bidirectional block of 85% in the intervention group. Hence, for a superiority design with two-sided α of 0.05, equal (1:1) allocation between groups and 80% power, 48 patients per group (96 in total) were estimated as the target sample size. As the outcome is assessed intraprocedurally, no dropouts are expected, and therefore no further adjustments were made to the sample size estimations.