AF Ablation in Patients With HF

Oct 04, 2021   |  Bassel S Lakkis, MD; Marwan Refaat, MD, FACC

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  • Subgroup analysis from the CABANA trial showed benefit of catheter ablation in the patients with clinical HF. When looking at the subgroups, ablation reduced mortality by 60% relative to drug therapy in HF patients with EF ≥50% (3.3% vs. 8.6%, respectively).
  • AF recurrence and AF burden were significantly reduced in the ablation arm as compared to the drug therapy arm. Similarly, the mean AFEQT summary scores, the mean MAFSI frequency scores, and the MAFSI severity scores favored ablation over drug therapy.

Despite the CABANA (Cather Ablation vs Antiarrhythmic Drug Therapy for Atrial Fibrillation) trial trial results showing non-statistically significant decrease in mortality, stroke, bleeding, and cardiac arrest with catheter ablation versus antiarrhythmic therapy in the overall population, subgroup analysis of the study population showed benefit in the patients with clinical heart failure (HF).1,2 To further delineate this benefit, the CABANA investigators published the findings in the subgroup of patients considered to have HF. Among the 2204 patient randomized in the CABANA trial, 778 (35%) patients had New York Heart Association (NYHA) class ≥II at baseline. Those patients were the target population of the article published by Packer et al. (the CABANA investigators).3

Of the 778 patients, 378 patients were assigned to ablation and 400 to drug therapy. Baseline ejection fraction (EF) was available for 73% of those patients. A minority (9.3%) had an EF <40%, 11.7% had an EF between 40 and 50%, and the remaining (78.9%) had an EF >50%. Two validated assessment scores for AF symptoms were calculated: the AFEQT (Atrial Fibrillation Effect on Quality of Life) and the MAFSI (Mayo Atrial Fibrillation-Specific Symptom Inventory). In parallel, besides the NYHA classification, HF classification was also performed using the Duke Activity Status Index, and the 36-Item Short Form Survey physical functional scale. The results of the study in an intention-to-treat analysis revealed significant reduction in the primary outcome of death, disabling stroke, serious bleeding, or cardiac arrest (9% vs. 12.3% for the HF patients in catheter ablation group and HF patients in drug therapy group, respectively [HR 0.64, 95% CI 0.41-0.99). Further, death from any cause was also reduced in the ablation group as compared to the drug therapy group (6.1% vs. 9.3%, respectively [HR 0.57, CI 0.33-0.96). However, there was non-statistically significant change in composite of death from cardiovascular causes (3.2% vs. 3.5%), composite of death from HF (6 patients vs. 4 patients), composite of death or hospitalization (56.1% vs. 61.3%) and composite of HF hospitalization (9.0% vs. 9.3%). In a per-protocol analysis, the ablation arm had significant reduction in the primary composite end point, all-cause mortality, the composite of death or cardiovascular hospitalization, and the composite of death or HF hospitalization.

When looking at the subgroups, ablation reduced mortality by 60% relative to drug therapy in HF patients with EF ≥50% (3.3% vs. 8.6%, respectively). AF recurrence and AF burden were significantly reduced in the ablation arm as compared to the drug therapy arm. Similarly, the mean AFEQT summary scores, the mean MAFSI frequency scores, and the MAFSI severity scores favored ablation over drug therapy.

The results of this study show a clear all-cause mortality benefit of ablation for AF in patients with clinical HF compared to patients with HF and AF who received antiarrhythmic drug therapy (43% relative risk reduction), as well as a significant reduction in AF recurrence and AF burden, and a significant improvement in QoL maintained over 5 years. The major addition to the literature from this study is the fact that the enrolled patients with HF had predominantly preserved EF (78.9% of the patients). Previous randomized trials included patients with predominantly reduced EF, and had relatively small populations.4-6 Similar to the results of the previous randomized trials, this study showed no evidence of increased risk of procedural complications in patients with HF undergoing ablation for AF.

More data is still needed regarding the benefit of AF ablation in patients with HFpEF. This study has few limitations. First, it did not have a baseline assessment of the EF and filling pressures on all the patients, and the diagnosis of HF was mainly dependent on the treating physician's clinical judgment and the NYHA classification. Furthermore, 76% of the patients were classified as NYHA II, which reflects only mild limitations in activities, and it is well-established that assessing filling pressures and diastolic function has great limitations in AF, which potentially affects the validity of the echocardiographic assessment and limits reproducibility of the findings.7 Finally, this study depends on a subgroup of patients rather than a target population. A larger, dedicated trial for patients with HFpEF and AF is needed to validate the results of this study.

References

  1. Packer DL, Mark DB, Robb RA, et al. Catheter ablation versus antiarrhythmic drug therapy for atrial fibrillation (CABANA) trial: Study rationale and design. Am Heart J 2018;199:192-9.
  2. Packer DL, Mark DB, Robb RA, et al. Effect of catheter ablation vs antiarrhythmic drug therapy on mortality, stroke, bleeding, and cardiac arrest among patients with atrial fibrillation: The CABANA randomized clinical trial. JAMA 2019;321:1261-74.
  3. Packer DL, Piccini JP, Monahan KH, et al. Ablation versus drug therapy for atrial fibrillation in heart failure: Results from the CABANA trial. Circulation 2021;143:1377-90.
  4. Di Biase L, Mohanty P, Mohanty S, et al. Ablation versus amiodarone for treatment of persistent atrial fibrillation in patients with congestive heart failure and an implanted device: Results from the AATAC multicenter randomized trial. Circulation2016;133:1637-44.
  5. Kuck KH, Merkely B, Zahn R, et al. Catheter ablation versus best medical therapy in patients with persistent atrial fibrillation and congestive heart failure: The randomized AMICA trial. Circ Arrhythm Electrophysiol 2019;12:e007731.
  6. Marrouche NF, Brachmann J, Andresen D, et al. Catheter ablation for atrial fibrillation with heart failure. N Engl J Med 2018;378:417-27.
  7. The Criteria Committee of the New York Heart Association. Nomenclature and Criteria for Diagnosis of Diseases of the Heart and Great Vessels, 9th Edition. Boston, MA: Little, Brown; 2994:253-6.

Clinical Topics: Arrhythmias and Clinical EP, Heart Failure and Cardiomyopathies, Noninvasive Imaging, Implantable Devices, EP Basic Science, SCD/Ventricular Arrhythmias, Atrial Fibrillation/Supraventricular Arrhythmias, Acute Heart Failure, Echocardiography/Ultrasound

Keywords: Anti-Arrhythmia Agents, Atrial Fibrillation, Heart Failure, Stroke Volume, Intention to Treat Analysis, Risk, Reproducibility of Results, Catheter Ablation, Stroke, Recurrence, Heart Arrest, Hospitalization, Echocardiography, Physicians, Surveys and Questionnaires, Judgment


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