New potential diagnostic biomarkers for pulmonary hypertension

This study aimed to determine whether the vascular endothelial growth factor (VEGF) family members soluble VEGF receptor 1 (also called soluble fms-like tyrosine kinase 1 (sFlt-1)) and placental growth factor (PlGF) could be used as biomarkers for pulmonary hypertension (PH). Consecutive patients undergoing right heart catheterisation were enrolled (those with mean pulmonary arterial pressure ≥25 mmHg were classed as having PH; those with mean pulmonary arterial pressure <25 mmHg acted as non-PH controls). Plasma from the time of PH diagnosis was analysed for PlGF and sFlt-1 using enzyme immunoassays. In total, 247 patients with PH were enrolled: 62 with idiopathic pulmonary arterial hypertension (IPAH), 14 with associated pulmonary arterial hypertension (APAH), 21 with collagen vascular disease (CVD), 26 with pulmonary venous hypertension, 67 with lung disease-associated PH and 57 with chronic thromboembolic PH. The non-PH control group consisted of 40 patients. sFlt-1 plasma levels were significantly higher in patients with IPAH, APAH, CVD and lung disease-associated PH versus controls; PlGF levels were significantly higher in all PH groups versus controls. The combination of sFlt-1 and PlGF resulted in a sensitivity of 83.7% with specificity of 100% for pulmonary arterial hypertension. There was no association between sFlt-1 or PlGF and haemodynamic parameters, 6-min walking distance or survival. In summary, PlGF and sFlt-1 are promising diagnostic biomarkers for PH.