AIMS: SPARCL1 was recently identified as a biomarker of right ventricular (RV) maladaptation in patients with pulmonary hypertension (PH), and N-terminal pro-brain natriuretic protein (NT-proBNP) is an established biomarker of RV failure in PH. The present study investigated whether NT-proBNP and SPARCL1 concentrations are associated with load-independent parameters of RV function and RV-to-pulmonary artery (RV-PA) coupling as measured using invasive pressure-volume (PV) loops in the RV. METHODS: SPARCL1 and NT-proBNP were measured in the plasma of patients with idiopathic pulmonary artery hypertension (IPAH, n = 73). Participants without LV or RV abnormalities served as controls (n = 28). All patients underwent echocardiography and right heart catheterization with invasive PV loop measurements. RESULTS: Our cohort had more females with IPAH than the control group (64% vs. 35%
P = 0.01) and was older [69 (interquartile range, IQR 57-76) vs. 51 (IQR 35-62) years
P <
0.001]. SPARCL1 and NT-proBNP levels were significantly higher in patients with IPAH as compared with controls (P <
0.0001). Patients with IPAH and maladaptive RV remodelling had higher SPARCL1 and NT-proBNP concentrations than those with adaptive RV remodelling (P <
0.01). Both SPARCL1 and NT-proBNP were good predictors of maladaptive RV remodelling in receiver operating characteristic analysis [area under the curve (AUC) (AUC CONCLUSIONS: SPARCL1 and NT-proBNP are good predictors of maladaptive RV remodelling and RV-PA uncoupling in IPAH patients. SPARCL1 may be a better predictor of early maladaptive RV remodelling than NT-proBNP.