Background Systemic sclerosis (SSc) is characterized by vasculopathy, inflammation and fibrosis, and carries one of the worst prognoses if patients also develop pulmonary arterial hypertension (PAH). Although PAH is a known prognosticator, SSc-PAH patients demonstrate disproportionately high mortality, presumably due to cardiac involvement. In this cross-sectional study, the relation between cardiac involvement revealed by cardiovascular magnetic resonance (CMR) and systemic microvascular disease severity measured with nailfold capillaromicroscopy in SSc-PAH patients is evaluated, and compared to idiopathic PAH (IPAH) patients. Methods SSc-PAH and IPAH patients underwent CMR, echocardiography, and nailfold capillaromicroscopy with post-occlusive reactivity hyperaemia (PORH)-testing on the same day. CMR imaging included T2- (oedema), native and postcontrast T1-mapping to measure the extracellular volume fraction (ECV, fibrosis), and adenosine-stress perfusion imaging measuring the relative myocardial upslope (microvascular coronary perfusion). Measures of peripheral microvascular function were related to CMR indices of oedema, fibrosis and myocardial perfusion. Results SSc-PAH patients (n=20) had higher T2, and a trend towards a higher ECV, compared to IPAH patients (n=5), and lower nailfold capillary density (NCD) and reduced capillary recruitment after PORH. NCD correlated with ECV, and T2 (r=-0.443, and -0.464, respectively, p<0.05 for all), and with markers of diastolic dysfunction on echocardiography. PORH-testing, but not NCD, correlated with the relative myocardial upslope (r=0.421, p<0.05). Conclusions SSc-PAH patients showed higher markers of cardiac fibrosis and inflammation, compared to IPAH patients. These markers correlated well with peripheral microvascular dysfunction, suggesting that SSc-driven inflammation and vasculopathy concurrently affect peripheral microcirculation and the heart. This may contribute to the disproportionate high mortality in SSc-PAH.

中文翻译：

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周围微血管功能与系统性硬化症相关肺动脉高压的 CMR 心脏受累有关

背景 系统性硬化症 (SSc) 的特点是血管病变、炎症和纤维化，如果患者同时出现肺动脉高压 (PAH)，那么系统性硬化症是最糟糕的预后之一。尽管 PAH 是已知的预后因素，但 SSc-PAH 患者的死亡率却异常高，可能是由于心脏受累所致。在这项横断面研究中，评估了 SSc-PAH 患者中心血管磁共振 (CMR) 显示的心脏受累与甲襞毛细血管显微镜测量的全身微血管疾病严重程度之间的关系，并与特发性 PAH (IPAH) 患者进行了比较。方法 SSc-PAH 和 IPAH 患者在同一天接受 CMR、超声心动图和甲襞毛细血管显微镜检查以及闭塞后反应性充血 (PORH) 测​​试。CMR 成像包括 T2（水肿）、天然和对比后 T1 映射，以测量细胞外体积分数（ECV、纤维化），以及腺苷应激灌注成像，测量相对心肌上升（微血管冠状动脉灌注）。外周微血管功能的测量与水肿、纤维化和心肌灌注的 CMR 指数相关。结果 与 IPAH 患者 (n = 5) 相比，SSc-PAH 患者 (n = 20) 具有较高的 T2 和较高的 ECV 趋势，以及较低的甲襞毛细血管密度 (NCD) 和 PORH 后毛细血管募集减少。NCD与ECV和T2相关(分别为r＝-0.443和-0.464，所有p＜0.05)，并且与超声心动图上的舒张功能障碍标志物相关。PORH 测试（而非 NCD）与相对心肌上斜率相关（r=0.421，p＜0.05）。结论 与 IPAH 患者相比，SSc-PAH 患者显示出更高的心脏纤维化和炎症标志物。这些标志物与外周微血管功能障碍密切相关，表明 SSc 驱动的炎症和血管病变同时影响外周微循环和心脏。这可能导致 SSc-PAH 死亡率过高。