Cryoballoon ablation of atrial fibrillation is effectively feasible without previous imaging of pulmonary vein anatomy: insights from the 1STOP project

Effect of Left Atrial Pulmonary Vein Angiography on Safety and Efficacy for High-Power, Short-Duration Pulmonary Vein Isolation in Patients with Atrial Fibrillation

Imaging of pulmonary vein (PV) anatomy by angiography before pulmonary vein isolation (PVI) for atrial fibrillation (AF) has long been standard practice in many centers. Nowadays, very accurate anatomical maps can be generated by the use of high-resolution mapping catheters, and very effective ablation lesions can be generated by the use of the high-power, short-duration (HPSD) technique. In our center, PV angiography was routinely performed before PVI. However, since there is no clear evidence for this, we refrained from performing PV angiography. This study aimed to investigate whether PV angiography is still necessary when using high-resolution mapping catheters after ablation in the high-power, short-duration (HPSD) technique. A total of 139 consecutive patients with atrial fibrillation (66.25 ± 11.68 years old, 62.39% male) undergoing radiofrequency PVI were included in the study. Ablation was performed with the HPSD technique using a fixed protocol for energy delivery of 50 watts (contact force 3-20 g). We observed no significant effect on the efficacy, efficiency and complications of the ablation procedure if pulmonary vein angiography was omitted before HPSD PVI. Thus, using our protocol, it may be useful that PV angiography is avoided, especially in young patients and those with chronic renal disease.

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 cryoballoon ablation for the treatment of paroxysmal and persistent AF in a real-world global setting: Results from the Cryo AF Global Registry

BACKGROUND

Cryoballoon ablation is a commonly used approach to treat patients with atrial fibrillation (AF).

OBJECTIVES

Report on the safety and efficacy of cryoballoon ablation for the treatment of AF in the largest global cohort of cryoablated patients prospectively studied within a single registry.

METHODS

The Cryo AF Global Registry is a prospective, multi-center registry. Patients with paroxysmal AF (PAF) or persistent AF (PsAF) were treated with the cryoballoon catheter according to routine practices at 93 sites across 36 countries. Primary efficacy endpoints included freedom from AF and freedom from AF/atrial flutter (AFL)/atrial tachycardia (AT) ≥30 seconds. The primary safety endpoint was serious device- or procedure-related adverse events over 12 month follow-up.

RESULTS

During this evaluation window, 2922 subjects completed an index cryoballoon procedure, and 1440 completed 12 month follow-up. The cohort was 61 ± 12 years of age, 36.3% female, and 78.7% PAF. Serious device- and procedure-related adverse event rates were 1.5% and 3.4%, respectively. Freedom from AF/AFL/AT after the 90 day blanking period was 86.4% (95% CI: 84.3%-88.3%) in patients with PAF and 70.9% (95% CI: 64.6%-76.4%) in patients with PsAF. Freedom from AF/AFL/AT in first-line PAF and PsAF was 90.0% (95% CI: 86.4%-92.7%) and 72.9% (95% CI: 58.6%-83.0%) at 12 months, respectively.

CONCLUSIONS

The Cryo Global AF Registry is the largest evaluation to demonstrate cryoablation is an efficient, safe, and effective treatment for patients with AF worldwide. Cryoablation was commonly used to treat patients prior to an AAD failure and may facilitate earlier therapy for patients on the AF disease continuum.

Intra-procedural three-dimensional rotational angiography in cryoballoon ablation for atrial fibrillation

Cryoballoon (CB) is an established technology for atrial fibrillation (AF) ablation and is usually performed using solely fluoroscopy. We aimed to study the feasibility of three-dimensional rotational angiography (3DRA) as intra-procedural imaging in CB ablation. Analyzed data were retrospectively collected from patients that underwent second generation CB ablation from February 2015 to August 2017. We studied 68 consecutive patients that received 3DRA (3DRA group). Sixty-six patients who received conventional X-ray imaging served as a control group. 3DRA was performed via an introducer placed in the left atrium. Angiographic images were segmented and fused with live fluoroscopy to guide the ablation. We have analyzed 134 CB patients (73.8% male, 56.9 ± 11.4 years). Paroxysmal AF was present in 77.6% of patients. 3DRA was successfully performed in all 3DRA group patients. The mean procedure time was significantly shorter in the control group (82.4 ± 26.3 min) than in the 3DRA group (121.1 ± 21.4 min) (p < 0.0001). Total radiation dose (419.3 ± 317.9 vs 998.3 ± 673 mGy, p < 0.0001) and contrast administration (83.2 ± 22.3 mL vs 191.6 ± 33.4 mL, p < 0.0001) were significantly lower in control group. There was no significant difference in 2-year success rate, 35.2% of patients had AF recurrence in the 3DRA group and 30.3% in the control group (p = 0.584). Major complications occurred in 2.9% and 1.5% of patients in 3DRA group and control group, respectively (p = 1.000). 3DRA is a feasible method of intra-procedural imaging to guide CB ablation. However, it prolongs procedure time, increases radiation dose and contrast administration with no significant effect on procedure outcomes and complication rates.