The predictive value of heart-type fatty acid-binding protein is independent from symptom duration in normotensive patients with pulmonary embolism

Abstract

Heart-type fatty acid-binding protein (H-FABP) is a useful biomarker for risk stratification of patients with pulmonary embolism (PE). In patients with acute myocardial infarction, H-FABP plasma concentrations rise after 30 minutes and return to normal within 20-24 hours. We tested whether the predictive value of H-FABP is affected by the duration of symptoms prior to diagnosis in patients with PE. We prospectively studied 257 consecutive normotensive patients with confirmed symptomatic PE. Patients with acute (<24 hours; n=150) symptom onset presented more often with syncope (28.7% vs. 6.5%; p<0.001) compared to patients with symptoms ≥ 24 hours (n=107); other baseline characteristics, comorbidities, and risk factors were distributed equally. Patients with an adverse 30-day outcome (6.6%) had higher H-FABP levels (11.84 [3.57-19.62] ng/ml) compared to patients with a favorable course (3.42 [1.92-5.42] ng/ml; p<0.001). However, the proportion of patients with H-FABP levels ≥ 6 ng/ml did not differ among patients with acute symptom onset and late presentation (p=0.104). Only tachycardia and elevation of H-FABP were associated with an increased risk of an adverse 30-day outcome both in patients with acute symptom onset (H-FABP: OR, 5.8; 95% CI, 1.4-24.5; p=0.016; tachycardia: 7.0 [1.4-36.0]; p=0.018) and late presentation (H-FABP: 9.3 [2.0-43.2]; p=0.004 and tachycardia: 12.3 [1.5-103.6]; p=0.021). The prognostic value could further be improved by the use of a simple H-FABP-based clinical prediction score. Our findings indicate that H-FABP is a useful biomarker for risk stratification of normotensive patients with PE regardless of symptom duration prior to diagnosis.