A Comparative Study Regarding BNP Levels in Heart Failure with Preserved Ejection Fraction in Patients in Normal Sinus Rhythm Versus Those with Atrial Fibrillation

Background: Due to overlap in symptoms and risk factors, it may be difficult to diagnose Heart Failure with Preserved Ejection Fraction (HFpEF) in the presence of atrial fibrillation (AF). Additionally, both AF and HF affect the concentrations of biomarkers, including circulating natriuretic peptides. The aim of this work was to compare BNP levels in HFpEF patients presented with HFpEF in AF versus those in normal sinus rhythm (SR) and to propose a cut-off level of BNP for diagnosis of HFpEF in patients in SR and in AF. Methods: This cross-sectional observational control study was conducted included 120 patients. Patients were allocated into four equal groups Group A: HFpEF patients in normal SR. Group B: HFpEF patients with AF. Group C: A control group without HFpEF and in SR. Group D: control group without HFpEF and in AF. Results: Circulating BNP levels are significantly higher among AF group of patients who were diagnosed with HFpEF. This may impact the previously proposed cutoff value for HFpEF diagnosis in this specific group of patients. Using the Roc curve analysis for BNP to propose a cutoff value for diagnosis of HFpEF in AF cases. The best cutoff point to discriminate HFpEF cases in AF was BNP> 459 pg/ml with a sensitivity and specificity of 76.67% and 83.33% respectively and area under curve of 0.813. While a cut off value of 89 pg/ ml can be used as a cut off level for HFpEF diagnosis in SR. Higher LV filling pressures and more symptoms were detected in HFpEF patients with AF. Also a positive correlation was detected between BNP levels and non-invasively estimated filling pressures in the form, of “LAVI, TR velocity and LA volume index with an r value of 0.8, 0.84 and 0.83 respectively and p value <0.001. Conclusions: Circulating BNP levels are significantly higher among AF group of patients who were diagnosed with HFpEF. BNP at a cutoff value for diagnosis of HFpEF showed that the area under the curve was 0.813 and the best cutoff point to discriminate HFpEF cases in AF was BNP> 459 pg/ml with a sensitivity of 76.67% and a specificity of 83.33 PPV of 82.1, NPV of 78.1 and P-value <0.001 and a cutoff level of 89 pg/ ml for HFpEF diagnosis in SR.