ATRIAL FIBRILLATION POST CARDIAC SURGERY: INCIDENCE, PREDISPOSING FACTORS AND PROGNOSTIC IMPLICATIONS.

Abstract

postcardiac surgery and is associated with significant morbidity, increased overall hospital stay and cost.
Anecdotal observations suggest very low incidence in Pakistani patients undergoing cardiac surgery
particularly coronary artery bypass graft surgery (CABG). The objective of this study was to assess the
prevalence, morbidity & mortality of post cardiac surgery AF.
METHODS: A prospective study of 201 consecutive patients undergoing cardiac surgery at a tertiary care
center. Clinical characteristics and perioperative data was collected & analyzed. Patients were followed for
presence or absence of atrial fibrillation till hospital discharge.
RESULTS: The overall incidence of AF post cardiac surgery was 6.9 %. AF occurred in 9 of 187 patients
undergoing CABG alone, 3 of 12 patients undergoing valve replacement and 2 of 2 undergoing combined
procedures. Increased left atrial (LA) size had significant association with post cardiac surgery AF (p = 0.01)
as did the use of dopamine and epinephrine post operatively (p = 0.03 & 0.002 respectively). In addition,
significant association was also noted for valvular surgery (p = <0.001). Multiple logistic regression analysis
revealed that increased LA size (odds ratio 0.08, 95% CI 0.008-0.99, p = 0.04) was the only independent
predictor of post cardiac surgery AF with borderline significance for concomitant valvular surgery (odds
ratio 0.89, 95% CI 0.79-0.99, p = 0.05). Mean hospital stay was significantly longer & overall cost was
significantly higher in patients who developed AF (p = <0.001) in addition to higher overall mortality (p
=0.025).
CONCLUSIONS: The incidence of AF post cardiac surgery was quite low in this study cohort. The
occurrence of atrial fibrillation, albeit for short duration, was associated with higher all cause mortality,
significantly longer hospital stay and higher overall cost.