Impact of epicardial anterior fat pad retention on postcardiothoracic surgery atrial fibrillation incidence: the AFIST-III Study.
OBJECTIVE
We conducted a randomized, blinded, controlled study evaluating the impact of anterior fat pad (AFP) maintenance on postoperative atrial fibrillation (POAF) incidence.


BACKGROUND
Drugs with antiadrenergic effects reduce POAF. Because the epicardial AFP is parasympathetically innervated, its routine excision during coronary artery bypass grafting (CABG) might precipitate autonomic imbalance and induce POAF.


METHODS
Patients (n = 180, mean age = 66 +/- 10 years, 80% men, 5% with previous atrial fibrillation) undergoing CABG surgery were randomized to either AFP maintenance or AFP removal. Routine prophylaxis against POAF with beta-blockers (85%) and amiodarone (28%) was allowed on the basis of caregivers' discretion. The development of POAF, total hospital costs, and heart rate variability was compared between groups.


RESULTS
Anterior fat pad maintenance did not reduce POAF incidence (34.8% vs. 35.2%, p = 0.950) or total hospital costs (data as medians with 25%, 75% percentiles: 22,940 dollars [17,629 dollars, 29,274 dollars] vs. 23,866 dollars [18,602 dollars, 30,370 dollars], p = 0.647) but was associated with higher heart rate variability (SD of normal-to-normal RR intervals [SDNN]: 31.7 +/- 24.6 vs. 22.7 +/- 8.3, p = 0.05 and SD of all 5-min mean RR intervals [SDANN 5]: 17.1 +/- 11.9 vs. 10.1 +/- 5.5, p = 0.003) than AFP removal.


CONCLUSIONS
Maintaining the AFP prevents attenuation of parasympathetic tone after CABG but does not reduce POAF or total hospital costs in any appreciable way.
White
C Michael
CM
Division of Cardiology, Hartford Hospital, Hartford, Connecticut 06102-5037, USA.
Sander
Stephen
S
Coleman
Craig I
CI
Gallagher
Robert
R
Takata
Hiroyoshi
H
Humphrey
Chester
C
Henyan
Nickole
N
Gillespie
Effie L
EL
Kluger
Jeffrey
J
D000273:Adipose Tissue / Q000294:innervation* / Q000502:physiology; D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D000368:Aged; D000638:Amiodarone / Q000627:therapeutic use; D000704:Analysis of Variance; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000453:epidemiology* / Q000517:prevention & control; D001026:Coronary Artery Bypass / Q000009:adverse effects* / Q000379:methods; D003327:Coronary Disease / Q000175:diagnosis / Q000601:surgery*; D004311:Double-Blind Method; D015716:Electrocardiography, Ambulatory; D005260:Female; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D010496:Pericardium / Q000294:innervation / Q000502:physiology; D011182:Postoperative Care; D011183:Postoperative Complications / Q000517:prevention & control; D011336:Probability; D011446:Prospective Studies; D018570:Risk Assessment; D016896:Treatment Outcome
D000319:Adrenergic beta-Antagonists; D000638:Amiodarone