Optimization of PVI Strategy Using QDOT Catheter. What is the Proper Energy Level for Anterior Wall of Pulmonary Veins- Intraprocedural Efficacy Comparison Between HSPD and vHPSD (The A-Q-RATE POWER Trial)

This study is a dual-center, prospective, randomized controlled study to evaluate intraprocedural efficacy of anterior aspects of pulmonary veins isolation between very High Power Short Duration (vHPSD) and High Power Short Duration (HPSD) in patient with paroxysmal or persistent atrial fibrillation (AF).

Catheter ablation of atrial fibrillation with circumferential pulmonary vein isolation is an well-established method of treatment, particularly in symptomatic patients with atrial fibrillation (AF) who are ineffective or refractory to pharmacological treatment. Recurrence of pulmonary veins conduction is considered as a risk factor for future recurrence of AF. This may be partly related to the incomplete scar formation during the index ablation procedure. Constant technological progress (i.e. ablation catheters with contact force) has led to greater efficiency in obtaining complete isolation of pulmonary veins, achieving nearly 90% success rate in 12-month follow-up paroxysmal AF (CLOSE protocol). The duration of the RF application depends on the ablation index (AI), which proves that the energy has been effectively delivered to the myocardium. Currently, AI values are considered representative of RF power up to 50W. When energy above 50 W was used, the scar size was shown to be smaller than when the same AI value was used but with higher power. The safety and efficacy of novel ablation catheter QDOT (Biosense Webster, Irvine, CA, USA), that allows to deliver very high and high-power short-duration ablation, was already proven in clinical trials (QDOT FAST, Q-FFICIENCY). The benefits from using very high power short-duration ablation include: 1) shortening the duration of the procedure, 2) reducing the volume of fluids administered through the ablation electrode during RF application, which may be important in patients with heart and kidney failure, 3) reducing the frequency of collateral damages to surrounding structures of the heart (e.g. oesophagus). One of the differences related to the biophysics of RF applications between high and low energy is the range of penetration into the muscle tissue, which could impact on effectiveness of ablation. It was shown that lesions performed with vHPSD were smaller (up to 2,9 mm deep) compared to HPSD or conventional power with target AI. It is attractive for posterior wall of left atrium and can reduce peri-procedural complications. However vHPSD could be insufficient in some regions of anterior wall of the left atrium, which thickness may vary from 1 to 4 mm. Our research hypothesis is that integrated approach with different energies depending on the left atrium location is safe and lead to better efficacy than use of only vHPSD ablation in terms of first pass isolation.