Peripheral Microangiopathy in Patients with Precapillary Pulmonary Hypertension: Correlation with Cardiac Function and Patients' Functional Capacity. Study Design and Rationale.

Pulmonary hypertension (PH) is a rare, heterogenous clinical entity characterised by a progressive remodelling of pulmonary arterioles, which leads to obstructive pulmonary arteriopathy, increased pulmonary vascular resistance, and eventually, right heart failure. Inflammation, endothelial dysfunction, and microvascular changes of the pulmonary vasculature constitute the hallmarks of pulmonary arterial hypertension (PAH), explaining much of the pathophysiology and clinical manifestations of the disease. Besides pulmonary vasculature, a systemic component of endothelial dysfunction and microcirculation may be involved in PAH, affecting different vascular beds. Nailfold videocapillaroscopy (NVC) is an established method for the assessment of the microvasculature with clinical implications in the diagnostic assessment of individuals with Raynaud syndrome and systemic sclerosis (SSc). Nowadays, growing amounts of evidence suggest that NVC changes in SSc are correlated with other vascular complications such as PAH, supporting a potential link between peripheral and internal organ vasculopathy. The purpose of the current prospective observational study is to explore: 1. the presence of peripheral microangiopathy in precapillary PH using NVC, 2. possible NVC differences among PH subgroups, 3. a potential relationship between NVC morphological abnormalities and clinical, functional, biochemical, echocardiographic and hemodynamic markers of cardiac dysfunction in precapillary PH.