Aims: Catheter ablation (CA) for atrial fibrillation (AF) has a considerable risk of procedural complications. Major vascular complications (MVCs) appear to be the most frequent. This study investigated gender differences in MVCs in patients undergoing CA for AF. Methods: A total of 4734 CAs for AF (65% paroxysmal, 26% repeated procedures) were performed at our center between January 2006 and August 2018. Patients (71% males) aged 60 ± 10 years and had body mass index of 29 ± 4 kg/m2. Radiofrequency point-by-point ablation was employed in 96.3% procedures with the use of 3D navigation systems and facilitated by intracardiac echocardiography. Pulmonary vein isolation was mandatory; cavotricuspid isthmus and left atrial substrate ablation were performed in 22% and 38% procedures, respectively. MVCs were defined as those that resulted in permanent injury, required intervention, or prolonged hospitalization. Their rates and risk factors were compared between genders. Results: A total of 112 (2.4%) MVCs were detected: 54/1512 (3.5%) in females and 58/3222 (1.8%) in males (P < 0.0001). On multivariate analysis, lower body height was the only risk factor for MVCs in females (P = 0.0005). On the contrary, advanced age was associated with MVCs in males (P = 0.006). Conclusion: Females have a higher risk of MVCs following CA for AF compared to males. This difference is driven by lower body size in females. Low body height in females and advanced age in males are independent predictors of MVCs. US-guided venipuncture lowered the MVC rate in males.

Aims: Saline-irrigated radiofrequency ablation (RFA) for atrial fibrillation (AF) is limited by the absence of reliable thermal feedback limiting the utility of temperature monitoring for power titration. The DiamondTemp (DT) ablation catheter allow efficient temperature-controlled irrigated ablation. We sought to assess the 1-year clinical safety and efficacy of the DT catheter in treating drug-refractory paroxysmal AF. Methods and results: The TRAC-AF trial (NCT02821351) is a prospective, multi-center (n=4), single-arm study that enrolled patients with symptomatic, drug-refractory paroxysmal AF. Using the DT catheter, point-by-point ablation was performed around all pulmonary veins (PVs) to achieve PV isolation (PVI). Ablation was performed in a temperature-control mode (60oC, max 50 W) until the split-tip EGM amplitude decreased by ≤75%. The primary efficacy endpoints included acute procedural success and freedom from AF at 12 months. A total of 62 patients (age 60.3 ± 11.4 years; 60% male) were evaluated after AF ablation using the DT catheter. The mean fluoroscopy and RF ablation times were 9.4±6.4 min and 19.8±8.6 min, respectively. Acute isolation of all PVs was achieved in 100% of patients. There were no steam pops and there were not seen any char or caugulum on the catheter tip after ablation. There were very few serious procedure/device-related adverse events including a single case of cardiac tamponade (1.6%). At 1 year, the freedom from AF was 74.2%. Conclusion: This first in man series demonstrates that temperature-controlled irrigated RFA with the DT catheter is efficient, safe, and effective in the treatment of paroxysmal AF.