Ablation of Paroxysmal Atrial Fibrillation Using the Appropriate Contact Force in a Chinese Population: A Prospective Randomized Single-center Trial

Background： Atrial fibrillation (AF) is a major cause of substantial mortality and morbidity from thromboembolism, heart failure (HF), and cognitive dysfunction. With the aging of the population and improved survival after myocardial infarction and HF, AF is emerging as a major public health concern.

Recently, significant progress has been made in treatment of AF with catheter ablation, emerging as an increasingly important technique. According to the current guidelines, catheter ablation can be considered as the first-line treatment of choice for patients with drug refractory paroxysmal AF (PAF). Circumferential PV isolation (CPVI) is a widely accepted cornerstone of this procedure, but limited by an unacceptable recurrence rate, mainly due to recovery of pulmonary vein (PV) conduction.

Durable, continuous, transmural isolation of PV is one of the most important goals of radiofrequency catheter ablation (RFCA) for PAF. The contact force (CF) between the ablation catheter and target tissue was considered closely related to the ablation effectiveness. Appropriate CF should be able to generate enough tissue lesions, and avoid the complications, such as cardiac perforation, atrial-esophageal fistula. Nowadays, irrigated ablation catheters are widely used, but the CF is mostly dependent on operators' experience and feeling, unable to be precisely measured. The tissue lesion produced would be variable in different operators, and the learning curve would be time consuming.

The newly approved CF catheter enables measurement of catheter tip contact force and force vector, providing the real-time CF during ablation. It would be helpful, not only for effective lesions formation, but also for the prevention from complications.

Studies from Western-population indicated that higher long-term successful rate could be achieved by using CF catheter, and CF between 10 to 20g was adopted in most centers. It would be important to find the appropriate range of CF for Chinese populations, because of various factors including for instance thinner and smaller atrial chambers among Chinese.