Very high-power short-duration temperature-controlled ablation for cavotricuspid isthmus block: The Fast-and-Furious CTI study

Abstract Background Catheter ablation of atrial flatter is well-known to exert an effective treatment option with encouraging clinical outcome. The novel micro-electrode ablation catheter allows very high power-short duration (vHP-SD) procedures and hence, might offer a safe, effective and faster innovation in CTI ablation. Purpose Within this trial, we investigated the safety, feasibility and efficacy of a very high-power short-duration, temperature-controlled radiofrequency (RF) ablation of the cavotricuspid isthmus (CTI) in the treatment of typical right atrial flutter (AFL) by using a novel vHP-SD contact force (CF) sensing ablation catheter with micro-electrodes. Methods 40 consecutive patients (median age of 73 years [interquartile range, IQR: 62, 78], 58 % male) with documented typical atrial flatter were prospectively enrolled undergoing vHP-SD based cavotricuspid isthmus ablation with 90 Watt/4 sec. Durability of CTI block was proven by pacing maneuvers from both sides of the ablation line. Results Complete CTI block using vHP-SD ablation was achieved in all patients. A continuous ablation line (tricuspid valve to inferior vena cava) with proven CTI block after the first ablation line (first-line isthmus block, FLIB) was accomplished in 12/40 (30 %). A median of 33 vHP-SD RF applications (IQR 22; 42) over a median RF ablation time of 132 (IQR 88, 228) seconds were applied. The switch to a standard temperature-controlled approach to achieve durable CTI block was not necessary for any patient. No peri-procedural complications including steam pops and tamponades were observed. After 12 months of follow-up, 3/40 patients (7.5%) suffered from recurrent symptomatic atrial flutter requiring re-intervention. Conclusions Very high-power short-duration CTI ablation for the treatment of typical AFL is safe, feasible and efficient showing good long-term results. An effective CTI block can be achieved in about 2 minutes of RF time.vHP-SD ablation of CTI depending flatter