Cryoballoon versus radiofrequency ablation for paroxysmal atrial fibrillation in hemodialysis patients

Comparison of P-wave parameter changes after radiofrequency ablation and cryoballoon ablation for paroxysmal atrial fibrillation: An observational cohort study

BACKGROUND

Pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (PAF) can be performed using one-shot cryoballoon ablation (cryo) or point-by-point radiofrequency ablation (RF). This study compares the changes in P-wave parameters between both ablation methods.

METHODS

This single-centre retrospective study included contact force RF and second-generation cryo for PAF between 2018 and 2019. Procedure success was defined by freedom of ECG-documented AF at 12 months. Digital 12‑leads ECGs with 1-50 hertz bandpass filters were monitored directly during the procedure. Corrected P-wave duration (PWDc), P-wave voltage (PWV), P-wave dispersion (PWDisp), and P-wave terminal force in V1 (PTFV1) were measured and compared between RF and cryo. Additional ablations outside pulmonary veins were excluded.

RESULTS

The final analysis included 226 patients, and the freedom of AF rate was similar at the 12-month follow-up between RF and cryo (76 % vs 74 %, P = 0.12). PWDc and PWV increased and decreased, respectively in both arms. PTFV1 decreased in RF (-3.3 mm.s to -4.6 mm.s, P < 0.001) and cryo (-3.4 mm.s to -5.3 mm.s,P = 0.002). There were similar changes after RF and cryo in PWDc (F11, 1032 = 0.80, P = 0.85), PWV (F11, 1032 = 0.19,P = 0.06), and PWDisp (F11, 1032 = 0.16,P = 0.34) and PTFV1 (P = 0.39). Increased PWDc was correlated with failure of RF (hazard ratio [2.3], 95 % confidence interval [CI]: 1.4-5.9, p = 0.01) and cryo (HR: 2.1, 95 % CI (1.3-4.6), p = 0.02). Results were similar when patients on antiarrhythmic drugs were excluded.

CONCLUSION

RF and cryo caused similar freedom of AF rate at 12 months in PAF and similar P-wave parameter changes.

Radiofrequency Catheter Ablation for Atrial Fibrillation Patients on Hemodialysis (From the Kansai Plus Atrial Fibrillation Registry) - Clinical Impact of Early Recurrence

BACKGROUND

Catheter ablation (CA) for atrial fibrillation (AF) in patients on hemodialysis (HD) is reported to have a high risk of late recurrence (LR). However, the relationship between early recurrence (ER) within a 90-day blanking period after CA in AF patients and LR in HD patients remains unclear.

METHODS AND RESULTS

Of the 5,010 patients in the Kansai Plus Atrial Fibrillation Registry, 5,009 were included in the present study. Of these patients, 4,942 were not on HD (non-HD group) and 67 were on HD (HD group). HD was an independent risk factor for LR after the initial CA (adjusted hazard ratio 1.6; 95% confidence interval 1.1-2.2; P=0.01). In patients with ER, the rate of sinus rhythm maintenance at 3 years after the initial CA was significantly lower in the HD than non-HD group (11.4% vs. 35.4%, respectively; log-rank P=0.004). However, in patients without ER, there was no significant difference in the rate of sinus rhythm maintenance at 3 years between the HD and non-HD groups (67.7% vs. 74.5%, respectively; log-rank P=0.62).

CONCLUSIONS

ER in HD patients was a strong risk factor for LR. However, even HD patients could expect a good outcome without ER after the initial CA.

Atrial fibrillation ablation: the position of computed tomography in pre-procedural imaging

Atrial fibrillation (AF) is the most common supraventricular arrhythmia. Despite significant advances in its treatment, it still remains one of the leading causes of cardiovascular morbidity and mortality. In the last two decades, pulmonary vein isolation (PVI) was developed as the most effective treatment option. The reported effectiveness of a single ablation procedure ranges from 40% to 69% with single, and up to 88% with repeated procedures, with acceptable safety profile. The PubMed database was searched, using terms including ‘atrial fibrillation ablation’, ‘pulmonary vein isolation’, ‘computed tomography’, ‘pulmonary vein anatomy’ and ‘ovality index’. Papers were reviewed for relevance and scientific merit. Different imaging techniques are used for pre-procedural assessment of left atrial (LA) anatomy, of which computed tomography (CT) is the most common. It allows assessing pulmonary vein (PV) anatomy, the LA wall thickness in different regions and the left atrial appendage (LAA) anatomy, together with excluding the presence of intracardiac thrombi. Pre-procedural PVs imaging is important regardless of the selected ablation technique, however, cryoballoon (CB) ablation seems to be particularly anatomy-dependent. Additionally, CT also permits assessment of several PVs characteristics (geometry, dimensions, angulations, the ostium area, orientation and ovality index (OI), which are essential for the patients’ qualification and designing the strategy of AF ablation. In this paper, we have reviewed the role of CT imaging in patients undergoing ablation procedure due to recurrent/symptomatic atrial fibrillation. Moreover, we discussed the relevant literature.

Improvement in Quality of Life via Catheter Ablation for Atrial Fibrillation in Patients Undergoing Hemodialysis Therapy

Background

Methods

Results

Conclusions

Chronic Kidney Disease with Mild and Mild to Moderate Reduction in Renal Function and Long-Term Recurrences of Atrial Fibrillation after Pulmonary Vein Cryoballoon Ablation

The aim of this research was to evaluate if patients with chronic kidney disease (CKD) and mild or mild to moderate depression of renal function have an increased risk of atrial fibrillation (AF) recurrences after cryoballoon (CB) ablation. We performed a retrospective analysis of AF patients undergoing pulmonary vein isolation (PVI) by CB. The cohort was divided according to the KDIGO CKD-EPI classification into a (1) normal, (2) mildly decreased, or (3) mild to moderate reduction in estimated glomerular filtration rate (eGFR). Freedom from AF recurrences was the primary endpoint. A total of 1971 patients were included (60 ± 10 years, 29.0% females, 73.6% paroxysmal AF) in the study. Acute success and complication rates were 99.2% and 3.7%, respectively, with no significant differences among the three groups. After a follow-up of 24 months, AF recurrences were higher in the mildly and mild to moderate CKD groups compared to the normal kidney function group (23.4% vs. 28.3% vs. 33.5%, p < 0.05). Mild to moderate CKD was an independent predictor of AF recurrences after the blanking period (hazard ratio:1.38, 95% CI 1.02−1.86, p = 0.037). In conclusion, a multicenter analysis of AF patients treated with cryoablation revealed mild to moderate reductions in renal functions were associated with a higher risk of AF recurrences. Conversely, the procedural success and complication rates were similar in patients with normal, mildly reduced, or mild to moderate reduction in eGFR.

Lesion size and adjacent tissue damage assessment with high power and short duration radiofrequency ablation: comparison to conventional radiofrequency ablation power setting

There is increased interest in creating high-power short duration (HPSD) ablation lesions in the field of atrial fibrillation (AF) radiofrequency ablation (RFA). We evaluated the lesion characteristics and collateral damage using two separate RFA protocols setting (HPSD: 50 W and 7 s vs control: 25 W and 30 s) in vitro model. Sixteen freshly killed porcine hearts were obtained, and the atrium and ventricle slabs were harvested for ablation. The each slabs were placed in a tissue bath with circulating 0.9% NaCl at maintained temperature 37 °C. RFA was performed with 4 mm tip irrigated force sensing catheter. All lesions were ablated under recording the electrical parameters using with Ensite Navx system (St. Jude Medical, St. Paul, Minnesota). After RFA, lesion characteristics were assessed for each lesion. Thirty-five lesions were made for each ablation protocol (total 70 lesions for analysis). Ablation parameters were similar between two groups (HPSD vs control; impedance drop (Ω): 34.2 ± 13.1 vs 36.1 ± 8.65 P = 0.49, contact force (g): 13.9 ± 4.37 vs 14.6 ± 5.09, P = 0.51, lesion size index: 4.8 ± 0.52 vs 4.73 ± 0.59, P = 0.62). Although the lesion volume was similar, the HPSD ablation creates wider but more shallower lesions compared to control group (HPSD vs control; lesion volume: 29.6 ± 18.1 mm³ vs 35.5 ± 17.1 mm³ P = 0.16, lesion diameter: 4.98 ± 0.91 mm vs 4.45 ± 0.74 mm P = 0.0095, lesion depth: 2.2 ± 0.76 mm vs 2.8 ± 1.56 mm P = 0.046). Of these, 38 lesions were assessed for adjacent tissue damage and adjacent tissue damages were more frequent seen in control group (HPSD vs control; 1/19 (5.26%) vs 6/19 (31.5%), P = 0.036). Effective lesions were made with HPSD, thereby reducing RFA procedure time. Although the lesion volume was similar between two groups, collateral damage was less seen in HPSD group attributed by lesion characteristics.

Comparison between cryoballoon ablation and radiofrequency catheter ablation for atrial fibrillation in patients on hemodialysis

Background

Difficulties are often encountered while controlling atrial fibrillation (AF), especially in hemodialysis (HD) patients. Previous data revealed that cryoballoon ablation (CBA) for treating paroxysmal atrial fibrillation (PAF) was not inferior to radiofrequency ablation (RFA); however, HD patients were excluded in this prior trial. Thus, the efficacy of CBA for HD patients is still unknown.

Methods

This retrospective study analyzed HD patients who underwent catheter ablation (CA) for AF from August 2011 to June 2019. Patients who received CBA (CBA group) and those who received RFA (RFA group) were compared. The primary endpoint was defined as freedom from a composite outcome (a documented recurrence of any atrial tachyarrhythmia or a prescription of antiarrhythmic drugs) at one year after CA.

Results

The RFA and CBA groups were composed of 21 and 23 patients, respectively. Freedom from a composite outcome was 58.4% in the RFA group and 68.2% in the CBA group (Log-rank: p = 0.571).

Conclusion

Our results suggest that patients on HD with AF who were treated with CBA tended to have better outcomes than patients treated with RFA. Therefore, CBA could be a suitable ablation method for HD patients.