Milrinone use is associated with postoperative atrial fibrillation after cardiac surgery.
BACKGROUND
Postoperative atrial fibrillation (AF), a frequent complication after cardiac surgery, causes morbidity and prolongs hospitalization. Inotropic drugs are commonly used perioperatively to support ventricular function. This study tested the hypothesis that the use of inotropic drugs is associated with postoperative AF.


RESULTS
We evaluated perioperative risk factors in 232 patients who underwent elective cardiac surgery. All patients were in sinus rhythm at surgery. Sixty-seven patients (28.9%) developed AF a mean of 2.9+/-2.1 days after surgery. Patients who developed AF stayed in the hospital longer (P<0.001) and were more likely to die (P=0.02). Milrinone use was associated with an increased risk of postoperative AF (58.2% versus 26.1% in nonusers; P<0.001). Older age (63.4+/-10.7 versus 56.7+/-12.3 years; P<0.001), hypertension (P=0.04), lower preoperative ejection fraction (P=0.03), mitral valve surgery (P=0.02), right ventricular dysfunction (P=0.03), and higher mean pulmonary artery pressure (27.1+/-9.3 versus 21.8+/-7.5 mm Hg; P=0.001) also were associated with postoperative AF. In multivariable logistic regression, age (P<0.001), ejection fraction (P=0.02), and milrinone use (odds ratio, 4.86; 95% confidence interval, 2.31 to 10.25; P<0.001) independently predicted postoperative AF. When only data from patients with pulmonary artery catheters were analyzed and pulmonary artery pressure was included in the model, age, milrinone use (odds ratio, 4.45; 95% confidence interval, 2.01 to 9.84; P<0.001), and higher pulmonary artery pressure (P=0.02) were associated with an increased risk of postoperative AF. Adding other potential confounders or stratifying analysis by mitral valve surgery did not change the association of milrinone use with postoperative AF.


CONCLUSIONS
Milrinone use is an independent risk factor for postoperative AF after elective cardiac surgery.
Fleming
Gregory A
GA
Division of Pediatric Cardiology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
Murray
Katherine T
KT
Yu
Chang
C
Byrne
John G
JG
Greelish
James P
JP
Petracek
Michael R
MR
Hoff
Steven J
SJ
Ball
Stephen K
SK
Brown
Nancy J
NJ
Pretorius
Mias
M
D000328:Adult; D000368:Aged; D001281:Atrial Fibrillation / Q000139:chemically induced* / Q000453:epidemiology*; D006348:Cardiac Surgical Procedures / Q000706:statistics & numerical data*; D002316:Cardiotonic Agents / Q000009:adverse effects*; D003327:Coronary Disease / Q000188:drug therapy / Q000601:surgery; D017558:Elective Surgical Procedures / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D006973:Hypertension / Q000453:epidemiology; D007902:Length of Stay; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D020105:Milrinone / Q000009:adverse effects*; D008944:Mitral Valve Insufficiency / Q000453:epidemiology / Q000601:surgery; D015999:Multivariate Analysis; D011183:Postoperative Complications / Q000139:chemically induced* / Q000453:epidemiology*; D011669:Pulmonary Wedge Pressure; D012307:Risk Factors
D002316:Cardiotonic Agents; D020105:Milrinone