Neopterin as a predictive biomarker of postoperative atrial fibrillation following coronary artery bypass grafting

Abstract

Background:The pathophysiology of postoperative atrial fibrillation (POAF) is multifactorial. Inflammation and increased oxidative stress play a significant role in POAF development. Neopterin, a biomarker of cellular immune response that enhances oxidative stress and increases the cytotoxic potential of activated macrophages and dendritic cells, was recently found as an independent predictive biomarker of non-operative atrial fibrillation. However, as far as we know, neopterin has never been investigated in POAF. Aims:The study aimed to assess neopterin concentration as a prognostic biomarker of POAF following coronary artery bypass grafting (CABG).Methods: One hundred one patients (80.2% males, 85% off-pump, 15% on-pump) were included. Blood samples were taken from patients for analysis of serum neopterin and high-sensitive C-reactive protein (hs-CRP) at three time points: (1) before operation (NP0); (2) on the first day after operation (NP1); and (3) between the fifth and eighth day after the procedure (NP5-8). All factors (preoperative, echocardiographic, and surgical), significant in univariate analysis, were included in a multivariable logistic regression analysis.Results: POAF occurred in 30 patients (30%). In the analyzed multivariable logistic regression models, the independent predictors of POAF occurrence were: higher NP0 concentration (odds ratio [OR], 1.16; 95% confidence interval [CI], 1.02-1.38 for continuous and OR, 3.75; 95% CI, 1.39-10.1 for NP0 cut-off >8.7 nmol/l), higher body mass index (OR, 1.15; 95% CI 1.02-1.29), history of pulmonary disease (OR, 6.72; 95% CI 1.57-28), increased diastolic thickness of the interventricular septum (OR, 1.45; 95% CI, 1.14-1.83), and duration of operation (OR, 1.01; 95% CI, 1.03-1.36). Conclusions:We found that elevated neopterin concentration before CABG may be a predictive biomarker of POAF.

Atrial fibrillation post-coronary or cardiac surgery: A transient inflammation-related event or the expression of a pre-existing arrhythmogenic atrial substrate?

“…We think that the findings of the study by Smukowska-Gorynia et al [7] can help to characterize the occurrence of POAF as mainly related to transient inflammatory factors rather than linked to an underlying arrhythmogenic substrate prone to AF. This distinction can be of value for future prospective studies aiming to assess the risk of stroke and adverse outcomes in the long term and the effectiveness of OAC in POAF patients at risk.…”

“…Finally, the findings by Smukowska-Gorynia et al [7] can open the way to prospective studies evaluating the impact of interventions aimed to reduce inflammation in patients at higher risk of POAF, who could be identified by higher baseline neopterin levels. A baseline status prone to more intense activation of the inflammatory pathway may portend a higher risk of POAF and identify a subset of patients who may benefit from specific prophylactic interventions aiming at reducing peri-operative inflammation.…”

“…This distinction can be of value for future prospective studies aiming to assess the risk of stroke and adverse outcomes in the long term and the effectiveness of OAC in POAF patients at risk. Unfortunately, the study by Smukowska-Gorynia et al [7] did not provide information on long-term follow-up. Therefore, long-term clinical implications of high levels of neopterin and the real incidence of AF in the long-term in this cohort of patients remain at present unknown and deserve future prospective studies.…”

“…In the setting of patients undergoing cardiac or coronary surgery, POAF usually occurs within the first 2 weeks, with a peak of incidence on the second and third postoperative day. POAF is considered the expression of an inflammatory process occurring at the cardiac level, which may be transient [5][6][7]. However, it is associated with lengthening of hospitalization, need for acute treatment, and need for anticoagulation [6].…”

“…In the current issue of Kardiologia Polska (Polish Heart Journal), Smukowska-Gorynia et al [7] reported an interesting study on neopterin as a biomarker associated with the occurrence of AF following coronary artery bypass grafting (CABG). Neopterin is a marker of cellular inflammation linked to processes involving macrophages and dendritic cells, and its increase expresses increased oxidative stress [7]. The authors evaluated 101 consecutive patients with advanced coronary artery disease and without a history of AF undergoing CABG.…”