MRI Evaluation of Radiofrequency, Cryothermal, and Laser Left Atrial Lesion Formation in Patients with Atrial Fibrillation

Abstract

Background Catheter ablation utilizing radiofrequency (RF), Cryothermal (Cryo), or Laser energy is effective for treatment of atrial fibrillation (AF). Late gadolinium enhancement magnetic resonance imaging (LGE-MRI) has been used to estimate the burden of LA fibrosis, but no data exists regarding structural changes following each modality. We sought to compare the baseline to post-procedure change in left atrial (LA) scar burden following RF, Cryo, or Laser ablation for treatment of AF. Methods Seventeen patients with AF underwent initial pulmonary vein isolation (PVI) using RF (n=7), Cryo (n=5), and Laser (n=5). LGE-MRI was performed prior to, at 24 hours and 3 months after PVI. Results In a linear mixed-effects model, accounting for intra-patient clustering of data and inter-patient differences in baseline scar, LGE extent was significantly increased at 24 hours post ablation (+14.6±1.9% of LA myocardium, P<0.001), and remained stable from 24 hours to 3 months (+0.12±1.9%, P=0.951). There was no statistically significant difference between the post ablation scar extent among ablation modalities when compared to RF (Cryo +4.5 ± 3.0%, P=0.123; Laser −3.2 ± 3.0%, P=0.291). The PV antral LGE intensity was increased by 25.1±3.8% (P<0.001) 24 hours after ablation and additionally increased by 8.1±3.8 at 3 months (P=0.033). Conclusions Radiofrequency, Cryo, and laser ablation result in increased LGE extent and intensity at 24 hours and 3 months post ablation. No statistically sugnificant difference was noted in the extent of fibrosis induced by any modality.

The lesion characteristics assessed by LGE‐MRI after the cryoballoon ablation and conventional radiofrequency ablation

“…also reported that there was no difference in the PV antral LGE intensity between CB and RF ablation. However, the sample size was rather small (7 patients in the RF group and 5 in the CB group) . The LGE‐MRI acquisition protocol was consistent with other reports; however, the definition of the ablation lesion was still in debate.…”

“…Although the lesions after RF ablation have been reported to be visualized by LGE‐MRI in the previous studies, the difference in the LGE lesions between CB and RF ablation is still in debate . Malcome‐Lawes et al.…”

“…Although the lesions after AF ablation using cryoballoon (CB) catheters are likely wide and homogeneous, the lesions have not been well characterized . It is still in debate whether the lesion formation could differ between the different energy sources . Therefore, we sought to visualize and characterize the lesions created by CB ablation and conventional AF ablation with RF energy using LGE‐MRI.…”

Lesion distribution after cryoballoon ablation and hotballoon ablation: Late‐gadolinium enhancement magnetic resonance imaging analysis

“…We sought to clarify the difference in the lesion characteristics after AF ablation using the two completely different balloon catheters and energy sources. On the basis of the lesion characterization assessed by LGE‐MRI, we would determine the optimal ablation strategy and improve the safety of the balloon catheter …”

Postprocedural LGE‐CMR comparison of laser and radiofrequency ablation lesions after pulmonary vein isolation

“…In a study that was limited by the very small number of patients included, Khurram et al. compared the baseline to postprocedure change in LA scar burden following Laser (n = 5), RF (n = 5), and cryoablation (n = 7), using LGE‐CMR . In their study, late‐gadolinium enhancement showed no differences in scar area between cryoablation and Laser techniques, compared to RF ablation.…”