Risk reduction from AF ablation may be more modest than observed in CASTLE-AF
The benefits of ablation in patients with atrial fibrillation and HF was more modest in clinical practice than reported in the CASTLE-AF trial, according to a study published in HeartRhythm.
As Healio previously reported in 2017, the CASTLE-AF trial found that patients with AF and left ventricular dysfunction who underwent catheter ablation had improved outcomes compared with those who received conventional drug treatment. Data presented in 2018 found that catheter ablation improved AF burden and time to first AF recurrence in patients with AF and HF.
“Randomized clinical trials are the gold standard for evaluating new medical treatments or procedures,” Xiaoxi Yao, PhD, health services researcher at Mayo Clinic, said in a press release. “However, often their results are not necessarily applicable across a more heterogeneous group of people. Sometimes results cannot be replicated or are simply not as striking when interventions are tested across a broader population.”
In this study, Peter Noseworthy, MD, cardiologist at Mayo Clinic, and colleagues analyzed data from 289,831 patients with AF and HF from a large U.S. administrative database who were treated with ablation (n = 7,465) or drug therapy alone (n = 282,366) from 2008 to August 2018.
Patient were categorized as the following:
- eligible for the CASTLE-AF trial;
- failed to meet inclusion criterion such as those with HF with reduced ejection fraction or implantable cardioverter defibrillator; or
- met at least one of the exclusion criteria.
Propensity score overlap weighing was performed to balance patients treated with ablation or drugs using 90 baseline characteristics.
The primary outcome was defined as a composite endpoint of HF hospitalization or all-cause mortality.
Of the patients in the study, 91% did not meet trial inclusion criteria, 15.5% met at least one of the exclusion criteria and 7.8% were eligible for the CASTLE-AF trial.
Patients who underwent ablation had a lower risk for the primary outcome in the overall cohort (HR = 0.81; 95% CI, 0.76-0.87), in the cohort of trial-eligible patients (HR = 0.82; 95% CI, 0.7-0.96) and in those who did not meet inclusion criteria (HR = 0.79; 95% CI, 0.73-0.86). This association was not observed in patients who met exclusion criteria (HR = 0.97; 95% CI, 0.81-1.17).
The RR reduction linked to ablation was consistent regardless of whether a patient had HFrEF.
“Future large randomized controlled trials are needed to confirm the benefit of ablation in a broad population of patients with AF and HF,” Noseworthy and colleagues wrote. – by Darlene Dobkowski
Disclosures: Noseworthy and Yao report no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.