Ablation Versus Drugs: What Is the Best First-Line Therapy for Paroxysmal Atrial Fibrillation?

Heart failure risk in patients with atrial fibrillation treated with catheter ablation vs antiarrhythmic drugs

Background

Atrial fibrillation (AF) increases heart failure (HF) risk. Whereas the risk of HF-related hospitalization and mortality are known in the setting of AF, the impact of AF treatment on HF development is understudied.

Objective

The purpose of this study was to compare HF incidence among AF patients treated with antiarrhythmic drugs (AADs) vs catheter ablation (CA).

Methods

AF patients with 1 prior AAD usage were identified in 2014-2022 Optum Clinformatics database. Patients were classified into 2 cohorts: those receiving CA vs those receiving a different AAD prescription. The 2 cohorts were matched on sociodemographic and clinical covariates using propensity score matching technique. Cox regression model was used to compare incident HF risk in the 2 cohorts. Subgroup analyses were performed by race/ethnicity, sex, AF subtype, and CHA2DS2-VASc score.

Results

After matching, 9246 patients were identified in each cohort (AAD and CA). Patients receiving CA had a 57% lower risk of incident HF than those treated with AADs (hazard ratio [HR] 0.43; 95% confidence interval [CI] 0.40-0.46). Subgroup analysis by race/ethnicity depicted similar results, with non-Hispanic White (HR 0.43; 95% CI 0.40-0.46), non-Hispanic Black (HR 0.46; 95% CI 0.35-0.60), Hispanic (HR 0.53; 95% CI 0.40-0.70), and Asian (HR 0.46; 95% CI 0.24-0.92) patients treated with CA (vs AAD) having significantly lower risk of HF, respectively. The effect size of CA remained significant in subgroups defined by sex, AF subtypes, and CHA2DS2-VASc score.

Conclusion

AF patients receiving CA had ∼57% lower risk of developing HF than those receiving AAD. The lower risk of HF associated with CA vs AAD persisted across different race/ethnicity, sex, AF subtypes, and CHA2DS2-VASc score.

Limited duration of antiarrhythmic drug use for newly diagnosed atrial fibrillation in a nationwide population under age 65

INTRODUCTION

Antiarrhythmic drugs (AADs) are commonly used for the treatment of newly diagnosed symptomatic atrial fibrillation (AF), however initial AAD choice, duration of therapy, rates of discontinuation, and factors associated with a durable response to therapy are poorly understood. This study assesses the initial choice and duration of antiarrhythmic drug therapy in the first 2 years after diagnosis of AF in a younger, commercially insured population.

METHODS

A large nationally representative sample of patients age 20-64 was studied using the IBM MarketScan Database. Patients who started an AAD within 90 days of AF diagnosis with continuous enrollment for 1-year pre-index diagnosis and 2 years post-index were included. A Cox proportional hazards model was used to determine factors associated with AAD discontinuation.

RESULTS

Flecainide was used most frequently (26.8%), followed by amiodarone (22.5%), dronedarone (18.3%), sotalol (15.8%), and propafenone (14.0%), with other AADs used less frequently. Twenty-two percent of patients who started on an AAD underwent ablation within 2 years, with 79% discontinuing the AAD after ablation. Ablation was the strongest predictor of AAD discontinuation (hazard ratio [HR], 1.70; 95% confidence interval [CI]: 1.61-1.80), followed by the male gender (HR, 1.10; CI: 1.02-1.19). Older patients (HR, 0.76; CI: 0.72-0.80; reference age 18-49) and those with comorbidities, including cardiomyopathy (HR, 075; CI: 0.61-0.91), diabetes (HR, 0.83; CI: 0.75-0.91), and hypertension (HR, 0.87; CI: 0.81-0.94) were less likely to discontinue AADs.

CONCLUSION

Only 31% of patients remained on the initial AAD at 2 years, with a mean duration of initial therapy 7.6 months before discontinuation.

Trends and predictors of early ablation for Atrial Fibrillation in a Nationwide population under age 65: a retrospective observational study

BACKGROUND

Catheter ablation (CA) has emerged as an effective treatment for symptomatic atrial fibrillation (AF). However practice patterns and patient factors associated with referral for CA within the first 12 months after diagnosis are poorly characterized. This study examined overall procedural trends and factors predictive of catheter ablation for newly-diagnosed atrial fibrillation in a young, commercially-insured population.

METHODS

A large nationally-representative sample of patients age 20 to 64 from years 2010 to 2016 was studied using the IBM MarketScan® Commercial Database. Patients were included with a new diagnosis of AF in the inpatient or outpatient setting with continuous enrollment for at least 1 year pre and post index visit. Patients were excluded if they had prior history of AF or had filled an anti-arrhythmic drug (AAD) in the pre-index period.

RESULTS

Early CA increased from 5.0% in 2010 to 10.5% in 2016. Patients were less likely to undergo CA if they were located in the Northeast (OR: 0.80, CI: 0.73-0.88) or North Central (OR: 0.91, CI: 0.83-0.99) regions (compared with the West), had higher CHA2DS2-VASc scores, or had Charlson Comorbidity Index (CCI) score of 3 or greater (OR: 0.61; CI: 0.51-0.72).

CONCLUSIONS

CA within 12 months for new-diagnosed AF increased significantly from 2010 to 2016, with most patients still trialed on an AAD prior to CA. Patients are less likely to be referred for early CA if they are located in the Northeast and North Central regions, have more comorbidities, or higher CHA2DS2-VASc scores.

Atrial Fibrillation: The Science behind Its Defiance

Atrial fibrillation (AF) is the most prevalent arrhythmia in the world, due both to its tenacious treatment resistance, and to the tremendous number of risk factors that set the stage for the atria to fibrillate. Cardiopulmonary, behavioral, and psychological risk factors generate electrical and structural alterations of the atria that promote reentry and wavebreak. These culminate in fibrillation once atrial ectopic beats set the arrhythmia process in motion. There is growing evidence that chronic stress can physically alter the emotion centers of the limbic system, changing their input to the hypothalamic-limbic-autonomic network that regulates autonomic outflow. This leads to imbalance of the parasympathetic and sympathetic nervous systems, most often in favor of sympathetic overactivation. Autonomic imbalance acts as a driving force behind the atrial ectopy and reentry that promote AF. Careful study of AF pathophysiology can illuminate the means that enable AF to elude both pharmacological control and surgical cure, by revealing ways in which antiarrhythmic drugs and surgical and ablation procedures may paradoxically promote fibrillation. Understanding AF pathophysiology can also help clarify the mechanisms by which emerging modalities aiming to correct autonomic imbalance, such as renal sympathetic denervation, may offer potential to better control this arrhythmia. Finally, growing evidence supports lifestyle modification approaches as adjuncts to improve AF control.