Fig. 4.

Serum circ_0068481 levels were elevated in patients with idiopathic pulmonary arterial hypertension (IPAH) and right heart failure (RHF) and act as a diagnostic and prognostic biomarker for IPAH with RHF. (a) Serum circ_0068481 levels were detected by qRT-PCR in patients with IPAH with or without RHF. ***P < 0.001 vs control; ^###P < 0.001 vs IPAH without RHF. (b) The ability of serum circ_0068481 levels to diagnose IPAH with RHF was assessed using ROC curve analysis. (c) Whether circ_0068481 expression was a risk factor for IPAH with RHF was assessed using Kaplan–Meier analysis. According to the optimal circ_0068481 expression cutoff value (2.97), patients with IPAH were divided into two groups: low group: circ_0068481 expression <2.97, n = 51; high group: circ_0068481 expression ≥2.97, n = 31. (d) Whether circ_0068481 expression was a risk factor for IPAH with RHF was assessed using Kaplan–Meier analysis. According to the median value of ocirc_0068481 expression (2.31), patients with IPAH were divided into two groups: low group: circ_0068481 expression <2.31, n = 41; high group: circ_0068481 expression ≥2.31, n = 41.

AUC: area under the curve; qRT-PCR: real-time quantitative reverse transcription polymerase chain reaction; ROC: receiver operating characteristic.