A single centre analysis of antiarrhythmic drug therapy in older patients with atrial fibrillation and coronary artery disease has found it is associated with increased rehospitalisation at one year, and recommends safer and more effective therapies for symptom control in this group.
US researchers led by Benjamin Steinberg (Duke Center for Atrial Fibrillation, Durham, USA) write: “Antiarrhythmic drug therapy in patients with coronary artery disease raises several safety concerns including toxic side effects and the potential for fatal proarrhythmia.” However they point out that few data are available in older patients; therefore, they analysed antiarrhythmic drug therapy and outcomes in 1,738 patients aged over 65 with atrial fibrillation and coronary artery disease.
The study, published ahead-of-print in Europace, identified patients from the Duke Databank for Cardiovascular Disease who had undergone cardiac catheterisation with coronary angiography from 2000 to 2010 when they were 65 or older. All had obstructive or non-obstructive coronary artery disease and a diagnosis of atrial fibrillation. Of the 1,738 patients studied, 609 were treated with an antiarrhythmic drug. The most commonly-taken drug was amiodarone (taken by about 60% of the antiarrhythmic drug group) followed by sotalol (6.3% of all patients) and dofetilide (2.2% of all patients). After one year, only 35% of patients on antiarrhythmic drug therapy at baseline remained on the therapy.
The researchers found that mortality rates were highest in patients aged over 75, while rehospitalisation rates were highest in patients on antiarrhythmic therapy. The use of antiarrhythmic drug therapy was not significantly associated with increased mortality (adjusted hazard ratio 1.23) or cardiovascular mortality (adjusted hazard ratio 1.27) in the year following cardiac catheterisation. However, it was associated with increased all-cause rehospitalisation (adjusted hazard ratio 1.20) and cardiovascular rehospitalisation (adjusted hazard ratio 1.20).
In patients who were event-free at one year and had additional follow-up, antiarrhythmic drug use at baseline did not appear to affect adverse outcomes over the subsequent four years. However, the researchers point out that these patients were at very high risk of death (55% of those over 75 and on antiarrhythmic drug therapy) and all-cause rehospitalisation (87% of those over 75 and on antiarrhythmic drug therapy).
Steinberg et al conclude: “Treatment with antiarrhythmic drug therapy was associated with increased risk of hospitalisation at one year. These data highlight the need for improved therapies for symptom control in this population.” They also write that “Older patients with atrial fibrillation and coronary artery disease are at high risk of long-term death and rehospitalisation, irrespective of antiarrhythmic drug therapy.”
With regards to alternative therapies that can be implemented in this patient population, Steinberg told Cardiac Rhythm News: “There is some evidence that catheter ablation can be performed safely and effectively in older patients. While the proper role for an invasive strategy in this population deserves further study, it might be one option.”
The study was funded by the Duke Clinical Research Institute.