2025 Pulmonary and Critical Care Medicine Fellows Course (INVITE ONLY)-KHAN

KHAN - PH-ILD in CTD

Pdf Summary

This educational overview discusses pulmonary hypertension (PH) in patients with connective tissue disease-associated interstitial lung disease (CTD-ILD), focusing on differentiating WHO (WSPH) Group 1 and Group 3 PH. The case presented involves a 62-year-old woman with diffuse cutaneous systemic sclerosis and ILD, exhibiting pre-capillary PH with moderate lung impairment (FVC 63%, DLCO 33%), increased pulmonary vascular resistance, and features consistent with ILD on chest CT without honeycombing.<br /><br />Key pathophysiologic mechanisms in PH with CTD-ILD include fibrosis, vascular loss, chronic hypoxic vasoconstriction, inflammation, endothelial dysfunction, smooth muscle proliferation, and vasoactive mediator imbalance.<br /><br />Distinguishing between WHO Group 1 (pulmonary arterial hypertension) and Group 3 (PH due to lung disease) in CTD-ILD is challenging but important, as Group 3 is associated with worse quality of life, poorer survival, and fewer treatment options. The patient’s mild ILD and absence of chronic hypoxia could suggest Group 1 PH; however, her pre-capillary PH plus ILD leads to a Group 3 classification.<br /><br />Clinical indicators favoring Group 1 PH include preserved spirometry with a low DLCO disproportionate to FVC decline, less parenchymal change on CT, and minimal oxygen requirement. Group 3 PH is associated with more impaired lung function, proportional DLCO and FVC reduction, greater hypoxemia, and more extensive lung involvement on imaging.<br /><br />The lesson underscores the phenotypic overlap in CTD-ILD patients with PH and emphasizes individualized evaluation. The patient was treated with sildenafil but experienced progressive right heart failure and died 4.5 years after PH diagnosis.<br /><br />In sum, careful clinical, functional, and imaging assessment is essential to differentiate PH types in CTD-ILD, guiding prognosis and management strategies. This complexity requires awareness of disease nuances and therapeutic implications.

Keywords

pulmonary hypertension

connective tissue disease

interstitial lung disease

systemic sclerosis

WHO Group 1 PH

WHO Group 3 PH

pulmonary arterial hypertension

lung function impairment

differential diagnosis

sildenafil treatment