Ablation versus Anti-Arrhythmic Therapy for Reducing All Hospital Episodes from Recurrent Atrial Fibrillation (AVATAR-AF): Design and rationale

An Economic Evaluation of a Streamlined Day-Case Atrial Fibrillation Ablation Protocol and Conventional Cryoballoon Ablation versus Antiarrhythmic Drugs in a UK Paroxysmal Atrial Fibrillation Population

BACKGROUND AND AIMS

Symptom control for atrial fibrillation can be achieved by catheter ablation or drug therapy. We assessed the cost effectiveness of a novel streamlined atrial fibrillation cryoballoon ablation protocol (AVATAR) compared with optimised antiarrhythmic drug (AAD) therapy and a conventional catheter ablation protocol, from a UK National Health Service (NHS) perspective.

METHODS

Data from the AVATAR study were assessed to determine the cost effectiveness of the three protocols in a two-step process. In the first stage, statistical analysis of clinical efficacy outcomes was conducted considering either a three-way comparison (AVATAR vs. conventional ablation vs. optimised AAD therapies) or a two-way comparison (pooled ablation protocol data vs. optimised AAD therapies). In the second stage, models assessed the cost effectiveness of the protocols. Costs and some of the clinical inputs in the models were derived from within-trial cost analysis and published literature. The remaining inputs were derived from clinical experts.

RESULTS

No significant differences between the ablation protocols were found for any of the clinical outcomes used in the model. Results of a within-trial cost analysis show that AVATAR is cost-saving (£1279 per patient) compared with the conventional ablation protocol. When compared with optimised AAD therapies, AVATAR (pooled conventional and AVATAR ablation protocols efficacy) was found to be more costly while offering improved clinical benefits. Over a lifetime time horizon, the incremental cost-effectiveness ratio of AVATAR was estimated as £21,046 per quality-adjusted life-year gained (95% credible interval £7086-£71,718).

CONCLUSIONS

The AVATAR streamlined protocol is likely to be a cost-effective option versus both conventional ablation and optimised AAD therapy in the UK NHS healthcare setting.

Ablation versus anti-arrhythmic therapy for reducing all hospital episodes from recurrent atrial fibrillation: a prospective, randomized, multi-centre, open label trial

AIMS

There is rising healthcare utilization related to the increasing incidence and prevalence of atrial fibrillation (AF) worldwide. Simplifying therapy and reducing hospital episodes would be a valuable development. The efficacy of a streamlined AF ablation approach was compared to drug therapy and a conventional catheter ablation technique for symptom control in paroxysmal AF.

METHODS AND RESULTS

We recruited 321 patients with symptomatic paroxysmal AF to a prospective randomized, multi-centre, open label trial at 13 UK hospitals. Patients were randomized 1:1:1 to cryo-balloon ablation without electrical mapping with patients discharged same day [Ablation Versus Anti-arrhythmic Therapy for Reducing All Hospital Episodes from Recurrent (AVATAR) protocol]; optimization of drug therapy; or cryo-balloon ablation with confirmation of pulmonary vein isolation and overnight hospitalization. The primary endpoint was time to any hospital episode related to treatment for atrial arrhythmia. Secondary endpoints included complications of treatment and quality-of-life measures. The hazard ratio (HR) for a primary endpoint event occurring when comparing AVATAR protocol arm to drug therapy was 0.156 (95% CI, 0.097-0.250; P < 0.0001 by Cox regression). Twenty-three patients (21%) recorded an endpoint event in the AVATAR arm compared to 76 patients (74%) within the drug therapy arm. Comparing AVATAR and conventional ablation arms resulted in a non-significant HR of 1.173 (95% CI, 0.639-2.154; P = 0.61 by Cox regression) with 23 patients (21%) and 19 patients (18%), respectively, recording primary endpoint events (P = 0.61 by log-rank test).

CONCLUSION

The AVATAR protocol was superior to drug therapy for avoiding hospital episodes related to AF treatment, but conventional cryoablation was not superior to the AVATAR protocol. This could have wide-ranging implications on how demand for AF symptom control is met.

TRIAL REGISTRATION

Clinical Trials Registration: NCT02459574.

Long-term outcomes of index cryoballoon ablation or point-by-point radiofrequency ablation in patients with atrial fibrillation and systolic heart failure

Catheter ablation is an established effective approach for the treatment of atrial fibrillation (AF) in patients with heart failure, however, the role of cryoablation in this setting is unclear. Procedural success and left ventricular systolic dysfunction (LVEF) improvement in patients with LVEF ≤ 45% undergoing index catheter ablation with cryoablation were evaluated. Freedom from AF recurrence was seen in 43% rising to 59% following repeat procedure. There were significant improvements in LVEF and functional status at long-term follow-up. Results were comparable to a contemporaneous cohort of heart failure patients undergoing index ablation with radiofrequency ablation. Cryoablation is an effective first-line AF ablation approach in the setting of heart failure.

Same-day discharge after cryoballoon ablation of atrial fibrillation: A multicenter experience

BACKGROUND

It is common practice to observe patients during an overnight stay (ONS) following a catheter ablation procedure for the treatment of atrial fibrillation (AF).

OBJECTIVES

To investigate the safety and economic impact of a same-day discharge (SDD) protocol after cryoballoon ablation for treatment of AF in high-volume, geographically diverse US hospitals.

METHODS

We retrospectively reviewed 2374 consecutive patients (1119 SDD and 1180 ONS) who underwent cryoballoon ablation for AF at three US centers. Baseline characteristics, acute procedure-related complications, and longer-term evaluations of safety were recorded during routine clinical follow-up. The mean cost of an ONS was used in a one-way sensitivity analysis to evaluate yearly cost savings as a function of the percentage of SDD cases per year.

RESULTS

The SDD and ONS cohorts were predominately male (69% vs. 67%; p = .3), but SDD patients were younger (64 ± 11 vs. 66 ± 10; p < .0001) with lower body mass index (30 ± 6 vs. 31 ± 61; p < .0001) and CHA₂ DS₂ -VASc scores (1.4 ± 1.0 vs. 2.2 ± 1.4; p < .0002). There was no difference between SDD and ONS in the 30-day total complication rate (n = 15 [1.26%] versus n = 24 [2.03%]; p = .136, respectively). The most common complication was hematoma in both the SDD (n = 8; 0.67%) and ONS (n = 11; 0.93%) cohorts. Sensitivity analysis demonstrated that when 50% of every 100 patients treated were discharged the same day, hospital cost savings ranged from $45 825 to $83 813 per year across US hospitals.

CONCLUSIONS

SDD following cryoballoon ablation for AF appears to be safe and is associated with cost savings across different US hospitals.

The effect of second-generation cryoablation without electrical mapping in persistent AF using continuous monitoring

BACKGROUND

Second-generation cryoballoon ablation is safe and effective in patients with persistent atrial fibrillation (AF). The aim of this study is to report the real long-term AF burden and freedom from AF post-cryoablation using continuous monitoring, and to assess whether intraoperative confirmation of pulmonary vein isolation using electrical mapping is necessary.

METHODS

A total of 33 patients (mean age 75.7 ± 5.6 years, 16 men) with persistent AF who underwent second-generation cryoablation without electrical mapping were reviewed. All patients had a cardiac implantable device and were followed up for a mean of 755 ± 170 days.

RESULTS

AF burden significantly decreased from 67.51% ± 34.90% to 18.28% ± 26.65% at 1-year follow-up, and this reduction was maintained at final follow-up (18.26% ± 23.70%, p < 0.001). Continuous monitoring revealed a freedom from AF rate of 33% and 24% at 1-year and full follow-up, respectively. Patients who remained in persistent AF at final follow-up had a trend towards higher pre-ablation AF burden (81.6% ± 29.7% vs 57.3% ± 36.4%, p = 0.08).

CONCLUSION

Second-generation cryoablation without confirming pulmonary vein isolation using electrical mapping is effective leading to significant reductions in AF burden based on continuous beat-to-beat monitoring at 1-year and long-term follow-up.