FABP1 and pulmonary arterial hypertension: Resting FABP1 levels were also correlated with poorer LV diastolic reserve (e’, r = − 0.46, p = 0.007), higher LV filling pressure (E/e’ ratio; r = 0.50, p = 0.003), more severe pulmonary hypertension and RA hypertension (mPAP; r = 0.34, p = 0.03; PASP, r = 0.46, p = 0.001; and RAP, r = 0.35, p = 0.02), and lower CO (r = − 0.49, p = 0.0007) during peak exercise (Figs. 2, 4).