Impact of Baseline Heart Failure and Heart Failure Subtype on Brain Natriuretic Peptide Levels in Patients with Acute Pulmonary Embolism

Introduction: Among patients with acute pulmonary embolism (PE), elevated levels of brain natriuretic peptide (BNP) correlate with right ventricular dysfunction and increased morbidity and mortality. Suggested BNP cut-offs for PE risk stratification in the general population range from 90-100 pg/mL. It is unclear whether this BNP cut-off should be used for PE risk stratification among patients with heart failure (HF), who may have elevated BNP at baseline. Methods: Patients diagnosed with acute PE between 2010 and 2015 at the University of Toledo Medical Center were identified. Patients were categorized as: no HF, heart failure with reduced ejection fraction (HFrEF), or heart failure with preserved ejection fraction (HFpEF). No HF was defined as having no prior history of HF and an ejection fraction (EF) ≥ 50%. HFrEF was defined as history of HF and an EF < 50%. HFpEF was defined as history of HF and an EF ≥ 50%. HF was defined as subjects with HFrEF or HFpEF. Results: One hundred and eighty-three patients with acute PE were identified for this study. One hundred and forty-two patients were classified as no HF (median BNP 112 [interquartile range (IQR) 49-355] pg/mL), while 41 were classified as HF (median BNP 422 [IQR 179-940] pg/mL) (p<0.0001). When HF was further sub-categorized, we found significant differences in BNP levels between subjects with HFrEF (median BNP 923 [IQR 464-2296] pg/mL) vs. subjects with HFpEF (median BNP 247 [IQR 88-726] pg/mL) (p=0.002). Median BNP among patients with HFrEF was significantly higher compared to patients with no HF (p<0.0001). Median BNP among patients with HFpEF was not significantly different compared to patients with no HF (p=0.416). Conclusions: Patients with HFrEF who present to the hospital with acute PE have significantly higher median BNP compared to patients with HFpEF or no HF. These results suggest that risk stratification for PE using current BNP cut-off guidelines may not be optimal for patients with HFrEF.