The potentially underestimated influence of atrial fibrillation on NT-proBNP in chest pain

Abstract

Abstract Introduction/Purpose NT-proBNP is a widely used diagnostic marker in the emergency department (ED). The main objective of the current study was to determine the association of NT-proBNP in patients with chest pain presenting with sinus rhythm (SR) compared to atrial fibrillation (AFib). Hereby, a focus was the evaluation of serum NT-proBNP head-to-head to urinary NT-proBNP. Methods In this study, urinary as well as blood concentrations of NT-proBNP were measured in a total of 601 patients, who presented with acute chest pain in the ED (mean age = 61.1 y, SD = 16.9 y). In the initial ECG 68 patients suffered from AFib and 533 showed SR. The participants were categorized according to their diagnosis into acute coronary syndrome (ACS, AFib n = 28, SR n = 261), acute decompensated heart failure (ADHF, AFib n= 16, SR n = 21), non-ischemic chest pain without congestion (NICP, AFib n = 24, SR n = 96) or chest-wall syndrome (CWS, SR n = 155). Results In the overall study cohort, patients with AFib showed significantly higher concentrations of urinary as well as blood NT-proBNP compared to those in sinus rhythm (each p < 0.001). Additionally, among patients with acute coronary syndrome (ACS), there were significantly increased biomarker concentrations in patients presenting with AFib compared to sinus rhythm (each p < 0.001, AUCblood = 0.801, AUCurine = 0.701), similarly for patients categorized into NICP (each p < 0.001, AUCblood = 0.833, AUCurine = 0.756). The same pattern was observed among the ACS subcategories (each p < 0.001). Regarding ROC analysis, promising predictive values were shown for detection of AFib: STEMI (AUCblood = 0.902, AUCurine = 0.867), NSTEMI (AUCblood = 0.757, AUCurine = 0.696) and UA (AUCblood = 0.821, AUCurine = 0.681). Comparing ROC curves, significant differences were noted in UA (p < 0.001), opposite to STEMI as well as NSTEMI (each p = n. s.). Regarding ADHF, paradoxically higher NT-proBNP concentrations were noted among patients showing sinus rhythms compared to AFib. Furthermore, a multivariate binary regression analysis showed blood NT-proBNP and age as independent predictors of atrial fibrillation (p < 0.05), opposite to urinary NT-proBNP, high-sensitivity troponin T and diabetes (each p = n. s.). Conclusion Urinary and to a larger extent blood NT-proBNP showed significantly higher concentrations in AFib. In conclusion, in ED patients elevated NT-proBNP may potentially be frequently caused by a coexisting AFib. Regarding ADHF patients, the effect of AFib might be consumed by other conditions that have a greater impact on NT-proBNP.