Atrial fibrillation: a risk factor for increased mortality--an AVID registry analysis

Area of Science:

• Cardiology
• Clinical Research
• Epidemiology

Background:

• Atrial fibrillation (AF) is increasingly recognized as a serious arrhythmia.
• Its association with mortality risk, particularly in patients with ventricular tachyarrhythmias, requires further investigation.
• Previous studies may have overestimated AF's impact due to unadjusted confounding factors.

Purpose of the Study:

• To determine if a history of atrial fibrillation/flutter is an independent predictor of mortality in patients within the Antiarrhythmics Versus Implantable Defibrillators (AVID) Trial registry.
• To assess the influence of antiarrhythmic drug use on mortality risk in this patient population.

Main Methods:

• Analysis of 3762 patients from the AVID Trial registry, with follow-up averaging 773 days.
• Baseline variables, including history of atrial fibrillation/flutter, were examined.
• Multivariate Cox regression analysis was employed to adjust for 27 pre-selected co-variables.

Main Results:

• A history of atrial fibrillation/flutter was present in 24.4% of subjects.
• After adjusting for baseline differences, AF/flutter remained a significant independent predictor of mortality (RR=1.20; 95% CI=1.03-1.40; p=0.020).
• Use of antiarrhythmic drugs, excluding amiodarone or sotalol, was also an independent predictor of mortality (RR=1.34; 95% CI=1.07-1.69; p=0.011).

Conclusions:

• Atrial fibrillation/flutter is a significant independent risk factor for increased mortality in patients presenting with ventricular tachyarrhythmias.
• The proarrhythmic effects of certain antiarrhythmic drugs may have previously inflated the perceived mortality risk associated with AF/flutter.