Author + information
- aDivision of Cardiology, University of Washington, Seattle, Washington
- bDivision of Cardiology, Loyola University Medical Center, Maywood, Illinois
- ↵∗Address for correspondence:
Dr. Jeanne E. Poole, Division of Cardiology, University of Washington, 1959 Northeast Pacific Street, Box 356422, Seattle, Washington 98195.
Since the seminal work of Haissaguerre et al. (1), catheter ablation for atrial fibrillation (AF) has emerged as among the most important therapeutic advances in arrhythmia therapy over the past 2 decades. With the rising global burden of AF (2) and its impact on health care costs, finding strategies to improve symptoms and outcomes has been a subject of intense focus. Whereas symptoms and quality of life drive patients to seek solutions, health care providers additionally expect that new therapies will be tested against customary approaches to assess safety and comparative benefit for additional important outcomes such as health care costs and mortality.
Set against the disappointing experience with antiarrhythmic drugs (AAD) to impact AF recurrence, and clinical trial results showing no survival advantage with AAD compared with rate control (3), catheter ablation emerged as an attractive alternative. Multiple randomized trials have now largely established AF ablation as superior to medical rhythm management for decreasing AF recurrences and improving quality of life (4–7). Technologic advances in catheter design, the use of advanced imaging and lesion tracking, and risk factor management continue to fuel improvements in ablation outcomes. With acceptably low-procedural risks in experienced hands, and confidence that catheter ablation reduces AF recurrence, more recent trials have focused on the collateral outcomes of hospitalization, stroke, and mortality.
In this issue of JACC: Clinical Electrophysiology, Guo et al. (8) analyzed data using the Truven Health MarketScan database (IBM, Armonk, New York) to evaluate the outcomes of all-cause and cause-specific hospitalizations in 2,720 patients who underwent first-time catheter ablation for AF between 2008 and 2014. This dataset included patients with private insurance as well as those with Medicare plus supplemental insurance. Outcomes were compared during the year prior and the year after the procedure. Additional endpoints included the occurrence of direct current cardioversion and use of AAD. The determination of AAD use was based on whether prescriptions were filled in the 6 months prior to ablation compared with the 12 months after ablation. The primary finding was a 56% significant reduction in all-cause hospitalization in the year following catheter ablation. The reduction was accounted for primarily by a decrease in hospitalizations for management of AF, although significant reductions in both hospitalizations for heart failure (42.6% decrease) and for cerebrovascular disease (47.1% decrease) were additionally observed.
These results are informative despite the nonrandomized observational nature of the study. Two recent important randomized trials, CASTLE-AF (Catheter Ablation for Atrial Fibrillation With Heart Failure) (9) and CABANA (Catheter Ablation Versus Antiarrhythmic Drug Therapy in Atrial Fibrillation) (10), provide an opportunity to consider how these “real-world” results by Guo et al. (8) compare.
The CASTLE-AF study is distinct in that it focused entirely on patients with significant heart failure (HF) (ejection fraction ≤35%, New York Heart Association functional classes II to IV), all of whom had implantable cardioverter-defibrillators (9). Marrouche et al. (9) randomized 363 HF patients with both paroxysmal and persistent AF to catheter ablation or continued rhythm or rate control therapy. After 3 years of follow-up, catheter ablation was associated with a significant reduction in all-cause death or HF hospitalization. Of patients who had been treated with catheter ablation, only 20.7% were hospitalized for worsening HF compared with 35.9% who were medically treated (hazard ratio: 0.56; 95% confidence interval: 0.37 to 0.83; p = 0.004). Significant reductions in cardiovascular hospitalization were also observed, although no difference was seen in all-cause hospitalization. The latter finding likely reflects the older age and greater comorbidities in the CASTLE-AF population.
More recently, the results of the largest randomized trial comparing catheter ablation to medical therapy were reported (10). This trial randomized a much broader population of 2,204 patients with paroxysmal, persistent, and long-standing persistent AF. The age of CABANA patients was 68 years compared with 60 years in the Guo et al. (8) study, and 37% of CABANA patients were female compared with 29%. In both studies, approximately 80% of patients had a history of hypertension, and 25% had diabetes. Only 15% of patients in CABANA had a history of HF, lower than the 23% noted in the Guo et al. study (8). In CABANA, while no difference by intention to treat was found for all-cause mortality, the combined endpoint of death or cardiovascular hospitalization was significantly reduced at 48 months of follow-up. Cardiovascular hospitalization occurred in 51.7% in those randomized to ablation versus 58.1% in medically treated patients (hazard ratio: 0.83; 95% confidence interval: 0.74 to 0.93; log-rank p = 0.001).
Despite the differences in study design and patient characteristics, it is noteworthy that this retrospective observational study derived from an insurance dataset confirms reductions in hospitalizations for cardiovascular reasons that were demonstrated in randomized trials. Details that would have shed further light on the Guo et al. (8) study population include the pattern of AF (paroxysmal or persistent), information on aggressiveness of treatment prior to ablation (number of rhythm control attempts), procedural characteristics, and longer-term follow-up. These issues in part reflect the inherent limitations of administrative databases. Nevertheless, the decrease in number of cardioversions and use of AAD in the year following catheter ablation (∼28% and 38% decreases, respectively) also indicate a declining use of health care resources.
Keeping patients out of the hospital is a critical goal for patients with AF. It has been estimated that the health care costs associated with taking care of patients with AF added $26 billion to overall health care costs (analysis from 2004 to 2006, with projection of costs to 2008), with care directly for AF management costing $5,218 per patient per year beyond the cost of non-AF patients (11). With AF prevalence and incidence rising in an aging population, efforts to decrease hospitalization are critical (12). The reduction in cardiovascular hospitalizations associated with AF ablation is a significant step in this direction, but there is more we need to understand. The magnitude of the effect likely varies by clinical subgroup. Future investigations of large datasets from prospectively collected and broadly inclusive registries could productively focus on more granular outcomes data by subgroup according to AF pattern, age, sex, racial and ethnic minorities, and procedural approach. Crucially, longer-term follow-up is also vital to assess the durability of AF ablation outcomes and benefits.
The results of this study by Guo et al. (8) are encouraging. They provide corroboration from the larger community setting, consistent with recent randomized prospective clinical trials, that cardiovascular hospitalizations can be decreased with a strategy of catheter ablation.
↵∗ Editorials published in JACC: Clinical Electrophysiology reflect the views of the authors and do not necessarily represent the views of JACC: Clinical Electrophysiology or the American College of Cardiology.
Dr. Poole has received honoraria for rhythm adjudication from AtriCure Inc. Dr. Wilber has reported that he has no relationships relevant to the contents of this paper to disclose.
All authors attest they are in compliance with human studies committees and animal welfare regulations of the authors’ institutions and Food and Drug Administration guidelines, including patient consent where appropriate. For more information, visit the JACC: Clinical Electrophysiology author instructions page.
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