Invited Commentary

Abstract

Atrial fibrillation occurring after cardiac operations is associated with prolonged recovery and increased morbidity. Several interventions have been shown to reduce the risk of postoperative atrial fibrillation. These interventions are not without risk, however, and therefore are not routinely used in all patients. Ideally, prophylactic therapy should be directed at a group of high-risk patients, thereby avoiding any possible adverse effects of therapy in patients with a low risk of atrial fibrillation. Brain natriuretic peptide (BNP), as measured in the retrospective study of Tavakol and colleagues [1Tavakol M. Hassan K.Z. Abdula R.K. et al.Utility of brain natriuretic peptide as a predictor of atrial fibrillation after cardiac operations.Ann Thorac Surg. 2009; 88: 802-808Abstract Full Text Full Text PDF PubMed Scopus (8) Google Scholar], is a readily available assay that has been proposed as an indicator of postoperative atrial fibrillation risk.The study showed BNP was not useful as a predictor of postoperative atrial fibrillation. Two features of this study should be considered when interpreting this data. One may argue that the primary use of BNP would be to make a decision about whether a pharmacologic agent such as amiodarone should be prescribed; therefore, the use of amiodarone in 34% patients considered to be at high risk of postoperative atrial fibrillation on the basis of other risk factors complicates the analysis. One indication for prophylactic amiodarone was poor left ventricular function, a risk factor associated with high BNP. The study might have demonstrated a predictive effect of BNP if this strategy had not been used.A second important feature of this study is the definition of atrial fibrillation. Any documented atrial fibrillation was included as an end point, regardless of its clinical significance. The significance of a self-limiting episode lasting 30 minutes or less is not as great as an episode requiring electrical cardioversion and prolongation of the hospital stay.The results of this study suggest that measurement of BNP does not predict the occurrence of atrial fibrillation of any duration. However, we do not know whether it is useful for the identification of a subgroup of patients with highly significant episodes of atrial fibrillation. Further studies will be required to refine our understanding of these problems. Atrial fibrillation occurring after cardiac operations is associated with prolonged recovery and increased morbidity. Several interventions have been shown to reduce the risk of postoperative atrial fibrillation. These interventions are not without risk, however, and therefore are not routinely used in all patients. Ideally, prophylactic therapy should be directed at a group of high-risk patients, thereby avoiding any possible adverse effects of therapy in patients with a low risk of atrial fibrillation. Brain natriuretic peptide (BNP), as measured in the retrospective study of Tavakol and colleagues [1Tavakol M. Hassan K.Z. Abdula R.K. et al.Utility of brain natriuretic peptide as a predictor of atrial fibrillation after cardiac operations.Ann Thorac Surg. 2009; 88: 802-808Abstract Full Text Full Text PDF PubMed Scopus (8) Google Scholar], is a readily available assay that has been proposed as an indicator of postoperative atrial fibrillation risk. The study showed BNP was not useful as a predictor of postoperative atrial fibrillation. Two features of this study should be considered when interpreting this data. One may argue that the primary use of BNP would be to make a decision about whether a pharmacologic agent such as amiodarone should be prescribed; therefore, the use of amiodarone in 34% patients considered to be at high risk of postoperative atrial fibrillation on the basis of other risk factors complicates the analysis. One indication for prophylactic amiodarone was poor left ventricular function, a risk factor associated with high BNP. The study might have demonstrated a predictive effect of BNP if this strategy had not been used. A second important feature of this study is the definition of atrial fibrillation. Any documented atrial fibrillation was included as an end point, regardless of its clinical significance. The significance of a self-limiting episode lasting 30 minutes or less is not as great as an episode requiring electrical cardioversion and prolongation of the hospital stay. The results of this study suggest that measurement of BNP does not predict the occurrence of atrial fibrillation of any duration. However, we do not know whether it is useful for the identification of a subgroup of patients with highly significant episodes of atrial fibrillation. Further studies will be required to refine our understanding of these problems. Utility of Brain Natriuretic Peptide as a Predictor of Atrial Fibrillation After Cardiac OperationsThe Annals of Thoracic SurgeryVol. 88Issue 3PreviewAtrial fibrillation (AF) occurs frequently after coronary bypass grafting and valve operations. Brain natriuretic peptide (BNP) has been shown to predict recurrence of AF in congestive heart failure. It is a potential biomarker for preoperative risk stratification for development of AF in at-risk patients. Full-Text PDF