Role of BMI on radiation dose in patients undergoing pulmonary vein isolation by pulsed field, cryoballoon and high-power-short-duration radiofrequency ablation

Abstract

Abstract Background Different ablation modalities for pulmonary vein isolation (PVI) have been established. Since recent data from a randomized trial showed non-inferiority for pulse field ablation (PFA) vs. cryoballoon (CBA) or radiofrequency ablation (RFA) it seems reasonable to evaluate procedural parameters of these modalities in specific subgroups. Purpose The aim of this study was to evaluate radiation dose and procedural parameters in patients with body mass index (BMI) >26 kg/m² vs. ≤26 kg/m² undergoing PVI with different modalities. Methods Data of n=409 patients (140 PFA, 125 CBA, 144 RFA) having undergone PVI in three German centers for either paroxysmal or persistent atrial fibrillation were analysed. The primary endpoint was total radiation dose (Dose Area Product, DAP). Patients were analyzed with respect to BMI> vs. ≤26 kg/m² in PFA, CBA and RFA (with high-power short duration applications) groups, respectively. Secondary endpoints were radiation time and procedure time. Results The study included predominantly male patients (63.1%) with a mean age of 67.8±10.5 years. Cardiovascular risk factors were comparable within the groups, while the overall CHA2DS2-VASc-score was higher in CBA patients, which was largely influenced by a higher proportion of women in the CBA group. BMI was well balanced between the modalities (PFA: 28.7±5.6 kg/m² vs CBA: 28.5±6.0 kg/m² vs HPSD-RFA: 28.3±4.8 kg/m², p=0.78) as well as the proportion of patients with extreme obesity (BMI >30 kg/m²). The overall DAP was the lowest in the PFA group (370.2±274.6 µGym2) followed by HPSD-RFA (471.4±385.3 µGym2) and the highest in the CBA (1260.9±1053.5 µGym2) group. The radiation time was longest in the CBA group (16.6±17.0min) while being comparatively lower in PFA and HPSD-RFA groups (9.4±6.8 vs. 9.4±5.8 min). Procedure time was the shortest in the PFA group (79.6±30.5min), while being longest in the HPSD-RFA group (111.9±55.3 min). When stratifying patients according to BMI> 26 kg/m², there was a significant increase in DAP in all modalities, with the lowest mean increase in DAP in the PFA group (Δ143.84 µGym2), followed by HPSD-RFA (Δ329.54 µGym2) and the highest increase in the CBA group (Δ691.17 µGym2) (Figure 1). No difference was observed in radiation or procedure time when stratifying patients to BMI. (Figure 2) Conclusion Our study analyzing differences of radiation exposure according to elevated BMI among various PVI techniques shows that while there is a significant increase of DAP in patients with BMI >26 kg/m² in all modalities, the lowest increase is registered in the PFA collective. These results suggest that PVI performed with PFA, if available, or HPSD-RFA should be the energy sources of choice in obese patients with respect to radiation exposure.