Table2_Differences in right ventricular function and response to targeted therapy between patients with IPAH and PAH-CHD.DOCX

Background and aims: Pulmonary arterial hypertension (PAH) is a chronic pulmonary vascular disorder characterized by elevated pulmonary vascular resistance (PVR) and pulmonary arterial pressure (PAP). Right heart failure is a life-threatening complication of PAH and predicts a poor prognosis. PAH associated with congenital heart disease (PAH-CHD) and idiopathic PAH (IPAH) are two prevalent PAH subtypes in China. In this section, we set out to explore baseline right ventricular (RV) function and its response to targeted agents between IPAH and PAH-CHD.
Methods and results: Consecutive patients diagnosed with IPAH or PAH-CHD by right heart catheterization (RHC) in the Second Xiangya Hospital from November 2011 to June 2020 were included. All patients received PAH-targeted therapy and the RV function was assessed by echocardiography at baseline and during follow-up. A total of 303 patients (age, 36.23 ± 13.10 years; women, 213 (70.3%); mean PAP [mPAP], 63.54 ± 16.12 mmHg; PVR, 14.74 ± 7.61 WU) with IPAH (n = 121) or PAH-CHD (n = 182) were included in this study. Compared with PAH-CHD, patients with IPAH had worse baseline RV function. As of the latest follow-up, forty-nine patients with IPAH and six patients with PAH-CHD died. Kaplan-Meier analyses showed better survival in PAH-CHD versus IPAH. After PAH-targeted therapy, patients with IPAH had less improvement in 6 MWD, World Health Organization functional class, and RV functional parameters compared with patients with PAH-CHD.
Conclusion: Compared with patients with PAH-CHD, patients with IPAH had worse baseline RV function, unfavourable prognosis, and inadequate response to targeted treatment.

背景与目的：肺动脉高压（Pulmonary arterial hypertension, PAH）是一类以肺血管阻力（Pulmonary vascular resistance, PVR）和肺动脉压（Pulmonary arterial pressure, PAP）升高为特征的慢性肺血管疾病。右心衰竭是PAH的致死性并发症，且提示不良预后。先天性心脏病相关性肺动脉高压（Pulmonary arterial hypertension associated with congenital heart disease, PAH-CHD）与特发性肺动脉高压（idiopathic pulmonary arterial hypertension, IPAH）是我国两种常见的PAH亚型。本部分旨在探究IPAH与PAH-CHD患者的基线右心室（Right ventricular, RV）功能及其对靶向药物的应答情况。
方法与结果：本研究纳入2011年11月至2020年6月期间，于湘雅二医院经右心导管（Right heart catheterization, RHC）确诊为IPAH或PAH-CHD的连续性患者。所有患者均接受PAH靶向治疗，并于基线及随访期间通过超声心动图评估右心室功能。本研究共计纳入303例患者，年龄为36.23±13.10岁，其中女性213例（占70.3%），平均肺动脉压（mean PAP, mPAP）为63.54±16.12 mmHg，肺血管阻力（PVR）为14.74±7.61伍德单位（WU）；IPAH患者121例，PAH-CHD患者182例。与PAH-CHD患者相比，IPAH患者的基线右心室功能更差。截至末次随访，IPAH患者中有49例死亡，PAH-CHD患者中有6例死亡。Kaplan-Meier分析显示，PAH-CHD患者的生存率优于IPAH患者。接受PAH靶向治疗后，与PAH-CHD患者相比，IPAH患者在6分钟步行距离（6MWD）、世界卫生组织功能分级及右心室功能参数方面的改善程度均更弱。
结论：与PAH-CHD患者相比，IPAH患者的基线右心室功能更差，预后不良，且对靶向治疗的应答不充分。