CABANA: AF ablation potentially superior to drug therapy among underrepresented groups
Patients from underrepresented racial and ethnic groups benefited significantly from catheter ablation compared with drug therapy for the treatment of atrial fibrillation, according to new data from the CABANA trial.
The researchers also found that, among patients who were randomly assigned to drug therapy for AF, major adverse events were more prevalent among individuals from historically underrepresented groups compared with non-Hispanic white or Asian patients.
“This paper presents the first randomized multicenter assessment of the efficacy and safety of catheter ablation for the treatment of AF in North American racial and ethnic minorities,” Kevin L. Thomas, MD, electrophysiologist at the Duke Electrophysiology Consultative Clinic at Kernodle Clinic, and colleagues wrote. “Among racial and ethnic minority participants with AF, catheter ablation relative to drug therapy produced significant reductions in the combined primary endpoint.
“Catheter ablation, compared with drug therapy, in racial and ethnic minorities resulted in clinically meaningful reductions in the primary endpoint of death, disabling stroke, severe bleeding and cardiac arrest, as well as in all-cause mortality,” Thomas and colleagues wrote. “These clinical benefits were not seen in nonminority participants and appear to be due primarily to worse mortality outcomes in racial and ethnic minority participants randomized to the drug therapy arm.”
As Healio previously reported, in the main results of CABANA, catheter ablation for AF conferred better outcomes compared with drug therapy in on-treatment and per-protocol analyses, but not in an intention-to-treat analysis.
According to data presented at the 2018 Heart Rhythm Society Scientific Sessions, this difference was attributed to the fact that 30% of patients who were assigned to drug therapy eventually underwent catheter ablation anyway, and 10% of those assigned to ablation did not undergoing the procedure.
In this secondary analysis of the CABANA trial, researchers only included participants in North America (n = 1,280), and subsequently classified them as underrepresented racial and ethnic groups or non-Hispanic white or Asian, based on NIH definitions. The primary endpoint was a composite of death, disabling stroke, major bleeding or cardiac arrest.
For this analysis, underrepresented racial and ethnic groups included self-identified Black, American Indian, Alaska Native, Hawaiian or other Pacific Islander, multiracial, Hispanic or Latino/Latina patients.
Within the North American cohort, 9.9% of participants were categorized as being from an underrepresented racial and ethnic group.
Adverse events after ablation vs. drug therapy
Researchers reported that individuals of underrepresented racial and ethnic groups were typically younger (65.6 vs. 68.5 years) and had greater prevalence of symptomatic HF (37% vs. 22%), hypertension (92.1% vs. 76.8%) and ejection fraction less than 40% (20.8% vs. 7.1%) compared with non-Hispanic white or Asian patients.
According to the study, patients from underrepresented racial and ethnic groups who underwent AF ablation experienced a 68% lower risk for the primary endpoint (adjusted HR = 0.32; 95% CI, 0.13-0.78) and a 72% lower risk for all-cause mortality (aHR = 0.28; 95% CI, 0.1-0.79) compared with the drug therapy group during a median follow-up of 48 months.
Although risk for the primary endpoint was similar between patients from underrepresented racial and ethnic groups and non-Hispanic white or Asian patients randomly assigned to AF ablation (4-year Kaplan-Meier event rates, 12.3% vs. 9.9%), individuals of underrepresented racial and ethnic groups randomly assigned to drug therapy experienced a higher event rate compared with their non-Hispanic white or Asian counterparts (27.4% vs. 9.4%).
A ‘call to action’
“Gaining a better understanding of racial differences in treatment of AF and its relationship to outcomes is essential for developing comprehensive practice guidelines and eliminating racial disparities in the treatment of underrepresented populations with AF,” Cardiology Today Editorial Board Member Andrea M. Russo, MD, director of the cardiac electrophysiology and arrhythmia service at Cooper Medical School of Rowan University in Camden, New Jersey, and past president of the Heart Rhythm Society, wrote in a related editorial. “This paper should be a ‘call to action’ to ensure that all treatment options, including catheter ablation, are widely accessible to provide the highest quality of care for all patients with AF.”