Background: Atrial fibrillation (AF) and heart failure (HF) are common cardiac disorders associated with substantial morbidity, mortality, and economic cost. AF can lead to HF, and HF can lead to AF.
Hospital admissions for heart failure (HF) have been increasing over the past decade due to an aging population as well as longer survival of patients with chronic heart disease. Atrial fibrillation (AF) is present in up to 50% of patients with HF and both are associated with several common predisposing risk factors and a shared pathophysiology1
Patients with these two diseases may encounter conflicting opinions from physicians based on guidelines on what is the most effective disease management and treatment strategy. Treating AF to restore sinus rhythm has been shown to positively affect long and short-term outcomes in patients suffering from HF. Prospective studies have compared catheter ablation with rate or rhythm control drugs for AF treatment among patients with HF and between the studies had found the former approach to be superior to the latter. One of the largest electrophysiology studies to date, is the Catheter Ablation versus Antiarrhythmic drug therapy for Atrial fibrillation (CABANA) trial. This study randomized more than 2,000 patients to either catheter ablation or drug therapy. It demonstrated catheter ablation as not having a clinical benefit in patients with heart failure. On the other hand, a second multicenter randomized controlled trial, showed that for patients suffering from heart failure, catheter ablation for treatment was associated with a significantly lower rate of death from any cause or hospitalization for worsening heart failure than drug therapy.2 This proposed study aims to provide real-world evidence (RWE) on the treatment options and examine whether or not catheter ablation emerges as superior to drug therapy in a real-world setting.
Objectives: Compare the outcomes between two cohorts: ablation or drug therapy. Outcomes included inpatient admissions (all-cause, cardiovascular and AF), direct current cardioversions and treatment costs in the 12-month post-index period.
Methods/Study design: A retrospective analysis was performed on all adults with a primary or secondary diagnosis of HF and AF in an inpatient or outpatient setting between January 1, 2011 and September 30th, 2016. These patients were identified from the Truven Health MarketScan® Commercial Claims and Encounters (CCAE) (IBM Truven Health Analytics, Ann Arbor, MI). The index episode was defined as their first database recording with HF, defined as the patient’s index date.
A search strategy, using hospital charge codes, allowed for creation of two separate treatment cohorts: catheter ablation cohort or drug cohort. The catheter ablation cohort consisted of a) patients who were >18 years of age, b) patients with a primary procedure of ablation in an inpatient setting with a primary diagnosis of AF and a secondary diagnosis of HF in an inpatient setting OR c) primary diagnosis of HF and a secondary diagnosis of AF in an inpatient setting. For the ablation arm, those who had a previous catheter ablation in the 12 month pre- index date or did not have continuous insurance coverage 12- month post index date were removed.
The drug therapy arm consisted of: a) patients >18 years of age, b) had a primary or secondary diagnosis of AF AND c) used a rhythm or rate control drug from 2011 to 2016 . Patients who had a catheter ablation procedure 12-month pre or post their index date were removed from the arm and considered for the ablation arm.
Statistical analysis was performed to assess outcomes. A propensity score matching was run comparing catheter ablation versus drug therapy on all study outcomes: inpatient admissions (all-cause, cardiovascular and AF) direct current cardioversions and financial costs. Separate Logistic regression models were estimated for all-cause, CV-related, and AF-related admissions) and a generalized linear model was estimated for the cost outcome.
A total of 1,225,988 patients were assessed for eligibility, including HF as a primary or secondary diagnosis. Of those, 169, 846 also had a primary or secondary diagnosis of AF. There were 9, 522 patients that qualified for the ablation cohort. Of this group 65% (6, 191) were retained after primary and secondary diagnosis exclusions were applied as well as all other exclusions regarding age, and previous surgeries. The drug cohort included 45, 748 patients. Following application of exclusion and inclusion criteria, there were 24, 265 remaining in this group.
The propensity score matched (5,800 Ablation Group and 5,800 Drug Therapy) patients were included in the sub-analysis. The Ablation group had significantly lower odds of all-cause (odds ratio [OR] 0.393; 95% CI 0.206 - 0.747) and cardiovascular-related readmissions (OR 0.269; 95% CI 0.096- 0.754), and lower events of DCCV (OR 0.57; 95% CI 0.35–0.93) than those patients in the Drug therapy group.
In conclusion, comparing catheter ablation with drug therapy in HF patients treated for atrial fibrillation, catheter ablation was associated with lower odds of all-cause inpatient readmission. Patients treated with catheter ablation showed at 12-months to have a reduction in burden of atrial fibrillation in forms of lower re-admission rates (All causes, AF/CV-related) and reduced number of direct current cardioversions. There was no significant difference in costs for either group.