Atrial fibrillation at discharge in older cardiac surgery patients: A prospective study of prevalence and associated medication utilization.

BACKGROUND

Although postoperative atrial fibrillation (AF) is prevalent after cardiac surgery, the corresponding medication burden associated with this postoperative arrhythmia is unknown.

METHODS

We conducted a prospective study of 204 patients aged 60 or older (median age 73) undergoing cardiac surgery at two academic medical centers. We defined "AF at discharge" as AF that developed after surgery and was present on the day of discharge. We evaluated the prevalence of anticoagulant and antiarrhythmic use at discharge, and out to 1 year post-discharge. We investigated the association between age and prescription of both classes of medications at discharge.

RESULTS

Ninety-one (45%) patients developed new postoperative AF, which persisted at discharge in 28 (14%) patients. Thirty-four percent of patients with postoperative AF were discharged on warfarin, 62% were discharged on antiarrhythmic medication, and 25% were discharged on both. Eighty-two percent of those discharged on both were older than 72 years of age. Patients with AF present at discharge were more likely to be discharged on anticoagulant agents than patients whose AF resolved prior to discharge (54% versus 26%, p=0.01), and more likely to be discharged on antiarrhythmic agents than patients whose AF resolved prior to discharge, though not significantly so (73% versus 57%, p=0.2). At 12 months, the proportion of patients on antiarrhythmic and anticoagulant medications had still not returned to preoperative rates.

CONCLUSIONS

AF persists at hospital discharge in nearly one-third of affected patients. Cardiac surgery results in the initiation of anticoagulant and antiarrhythmic medications in many older patients annually, often concurrently. Our findings underscore the need for additional studies on the natural history of this arrhythmia and clinical trials investigating different management strategies after discharge. Such research will help to inform development of guidelines addressing duration of use for these medications, to aid physicians in these complicated post-discharge management decisions.