Achieving contrast-free ultra-low radiation exposure without compromising safety and acute efficacy through evolving AF cryoballoon ablation procedure techniques

Systematic Workflow and Electrogram guidance to reduce X-ray Exposure Time during cryoballoon ablation of atrial fibrillation: the SWEET-Cryo strategy

AIMS

Cryoballoon pulmonary vein isolation (CB-PVI) offers similar efficacy to point-by-point radiofrequency PVI for patients with atrial fibrillation (AF), but generally with higher X-ray exposure. Strategies aimed at reducing fluoroscopy mostly rely on other costly imaging techniques, limiting their applicability. We designed a Systematic Workflow and Electrogram guidance to reduce X-ray Exposure Time during CB-PVI (SWEET-Cryo) strategy and analysed its impact on fluoroscopy use and acute procedural and clinical outcomes.

METHODS AND RESULTS

We enrolled 100 patients with paroxysmal or persistent AF undergoing CB-PVI by two operators with different levels of expertise. Patients treated with the SWEET-Cryo strategy (prospective cohort; n = 50) or conventional fluoroscopy (retrospective control cohort; n = 50) were compared. When applied by the senior operator, the SWEET-Cryo strategy significantly reduced the mean fluoroscopy time (FT) (2.6 ± 1.25 vs. 20.3 ± 10.8 min) and mean dose area product (DAP) (5.1 ± 3.8 vs. 35.3 ± 22.3 Gy cm2) compared with those of the control group, respectively (P < 0.001). Significant reductions in FT (6.4 ± 2.5 min vs. 32.5 ± 10.05) and DAP (13.9 ± 7.7 vs. 92.3 ± 63.8) were also achieved by the less experienced operator (P < 0.001). No difference was observed in acute and long-term complications or freedom from AF between fluoroscopy strategies during a 33-month median follow-up. Mean FT was maintained below 3 min in randomly selected cases performed during the follow-up period.

CONCLUSION

In contrast to conventional protocols and regardless of the operator's experience, the optimized SWEET-Cryo strategy dramatically reduced fluoroscopy exposure during CB-PVI. The efficacy, safety, or added costs of the ablation procedure were not compromised.

Radiation dose reduction in the setting of cryoballoon ablation for atrial fibrillation: the value of optimized fluoroscopy settings and intracardiac echocardiography

Cryoballoon (CB) has proven to be very effective in the percutaneous treatment of atrial fibrillation (AF). CB ablation is still hampered by X-ray exposure and the doses applied are consistently higher if compared to radiofrequency ablation. All patients who underwent CB ablation between 2015 and 2020 were analysed. Intracardiac echography was consistently used for transeptal puncture. To demonstrate the differences in radiation exposure 3 groups of 50 consecutive patients were selected. In the first group (G1) 3D rotational angiography (3DRA) was used as an intraprocedural imaging method. In the second group (G2), traditional X-ray imaging was used and frame rates both for fluoro and cine modes of diascopy were lowered. In the third group (G3) only 2-3 frames per second were used, cine mode was abandoned and the grid was removed from the X-ray detector. A total of 150 patients were included (76% males, mean age 57.3 ± 11.5 years). A dramatic reduction of radiation dose was obtained from 9585 ± 5610 µGy/m² in G1 to 2469 ± 2002 µGy/m² in G2 and finally 227.1 ± 360 µGy/m² in G3 (p < 0.0001). There was also a significant decrease of procedural and fluoroscopy times. No difference in major complications and midterm outcomes was found between the groups. By following a few relatively simple steps (omitting the pre-procedural imaging, removing grid from the X-ray detector and using very low frame rates) CB ablation could be performed with ultralow radiation exposure without compromising the safety of efficacy of the procedure.

Safety and efficacy of zero fluoroscopy transseptal puncture with different approaches

INTRODUCTION

Atrial fibrillation (AF) ablation requires access to the left atrium (LA) via transseptal puncture (TP). TP is traditionally performed with fluoroscopic guidance. Use of intracardiac echocardiography (ICE) and three-dimensional mapping allows for zero fluoroscopy TP.

OBJECTIVE

To demonstrate safety and efficacy of zero fluoroscopy TP using multiple procedural approaches.

METHODS

Patients undergoing AF ablation between January 2015 and November 2017 at five institutions were included. ICE and three-dimensional mapping were used for sheath positioning and TP. Variable technical approaches were used across centers including placement of J wire in the superior vena cava with ICE guidance followed by dragging down the transseptal sheath into the interatrial septum, or guiding the transseptal sheath directly to the interatrial septum by localizing the ablation catheter with three-dimensional mapping and replacing it with the transseptal needle once in position. In patients with pacemaker/implantable cardiac defibrillator leads, pre-/poststudy device interrogation was performed.

RESULTS

A total of 747 TPs were performed (646 patients, age 63.1 ± 13.1, 67.5% male, LA volume index 34.5 ± 15.8 mL/m² , ejection fraction 57.7 ± 10.9%) with 100% success. No punctures required fluoroscopy. Two pericardial effusions, two pericardial tamponades requiring pericardiocentesis, and one transient ischemic attack were observed during the overall ablation procedure, with a total complication rate of 0.7%. There were no other periprocedural complications related to TP, including intrathoracic bleeding, stroke, or death both immediately following TP and within 30 days of the procedure. In patients with intracardiac devices, no device-related complications were observed.

CONCLUSION

TP can be safely and effectively performed without the need for fluoroscopy.