Rehospitalization Risk and Medication Therapy for Atrial Fibrillation and Coronary Artery Disease

DALLAS —Nov. 20, 2013 -- Antiarrhythmic drug therapy was associated with increased risk of rehospitalization in a population of elderly patients with atrial fibrillation (AF) and coronary artery disease (CAD), according to study results presented at the 2013 American Heart Association Scientific Sessions.

During a poster presentation on November 19, 2013, Benjamin Steinberg, MD, and colleagues from Duke University Medical Center reported findings from a study on antiarrhythmic drug therapy and clinical outcomes in elderly patients with concomitant atrial fibrillation and CAD, which are highly prevalent among this patient group.

Researchers sought to determine if antiarrhythmic drug therapy poses increased risks for rehospitalization and/or death for elderly patients, many of whom take multiple medications for a range of comorbid conditions and health issues.

For the study, researchers collected data on antiarrhythmic drug therapy use and clinical outcomes in 1,738 older patients (age ≥65) with atrial fibrillation and CAD in the Duke Databank for Cardiovascular Disease.

Primary outcomes for the study were “adjusted hazards of mortality and rehospitalization at one and five years.”

The researchers reported that more than one-third (35%) of patients were on antiarrhythmic drug therapy at study initiation. Forty-three percent of participants were female and 85% were white. Many patients had experienced prior cardiovascular events, including myocardial infarction (31%) and heart failure (41%).

The most commonly prescribed antiarrhythmic drug therapy among this cohort was amiodarone (21%), followed by pure class III agents such as sotalol (6.3%) and dofetilide (2.2%), according to the study. Many patients had trouble adhering to their treatment regimen, with only about one in five patients (21%) continuing on their medications after one year.

Analysis of data showed that higher unadjusted mortality rates were associated with older age. Rehospitalization rates were highest in patients on antiarrhythmic drug therapy.

Adjusted data showed baseline use of antiarrhythmic drug therapy “was not associated with mortality (adjusted HR 1.23, 95% CI 0.94-1.60)” or cardiovascular mortality (adjusted HR 1.27, 95% CI 0.90-1.80) at one year.

However, according to the authors, antiarrhythmic drug therapy use “was associated with increased all-cause rehospitalization (adjusted HR 1.20, 95% CI 1.03-1.39) and cardiovascular rehospitalization (adjusted HR 1.20, 95% CI 1.01-1.43) at 1 year. This association did not persist at 5 years of follow-up.”

These results led the authors to conclude that older patients with atrial fibrillation and CAD “are at high risk of death and rehospitalization. Antiarrhythmic drug therapy was associated with increased risk of rehospitalization at one year. Alternative therapies for symptom control in this population are warranted.”