Plasma Levels of Brain Natriuretic Peptide Predict Postoperative Atrial Fibrillation in Patients Undergoing Heart Surgery

Kwon, Jin Tae; Jung, Tae Eun; Lee, Jang Hoon; Lee, Dong Hyup

Abstract

BACKGROUND: The brain natriuretic peptide (BNP) level has been reported in some studies to be associated with the occurrence of atrial fibrillation (AF). The aim of this study is to evaluate the potential usefulness of the BNP level as a predictor of the occurrence of postoperative (postop) AF and to assess the relationship of the BNP level with the onset of AF and the restoration of sinus rhythm. MATERIAL AND METHOD: From January 1, 2005 to February 28, 2006, 82 patients without a history of atrial arrhythmia that had undergone cardiac surgery were enrolled in the study. Blood samples for plasma BNP were drawn daily for all these patients from the preoperative (preop) day to the 7th postop day. The patient records were reviewed and postop EKGs were checked daily for AF until the time of discharge. RESULT: Patients were divided into two groups based on development of postop AF. Postoperative AF developed in 26 patients (31.7%). There was no significant statistical difference in age, sex distribution, preop left ventricle ejection fraction, hypertension, left ventricular hypertrophy, or the use of beta blockers between the non-postop AF and postop AF group. More patients in the AF group had undergone valve surgery (39.3% versus 76.9%, p=0.002). The preop left atrium size was significantly larger in the AF patients (43.8+/-10.3 mm versus 49.8+/-11.5 mm, p=0.029). The preop plasma BNP levels were higher in the postop AF patients (144.1+/-20.8 pg/mL versus 267.5+/-68 pg/mL, p=0.034). In the postop AF group, the plasma BNP level was the highest on the 3rd postop day. Postop AF developed in most patients by the 3rd postop day; restored sinus rhythm developed by the 7th postop day.
CONCLUSION
Elevated plasma BNP levels may lead to the occurrence of postop AF in patients undergoing cardiac surgery. Patients who have a high risk of postop AF should be considered for aggressive prophylactic antiarrhythmic therapy.