Pulmonary hypertension in idiopathic pulmonary fibrosis: epidemiology, diagnosis and therapeutic implications

A significant proportion of patients with idiopathic pulmonary fibrosis have concurrent pulmonary hypertension. In most, elevations in pulmonary pressures are modest, but approximately 10 % have disproportionately elevated pulmonary pressures. Pulmonary hypertension is associated with decreased functional status and increased mortality. The etiology remains incompletely understood, but likely involves a complex interplay of abnormal angiogenesis, vascular ablation, remodeling, and vasoconstriction. Transthoracic echocardiogram, six-minute walk testing, pulmonary function testing and biomarkers may suggest pulmonary hypertension, but none are sensitive or specific enough to rule in or exclude the diagnosis. Right heart catheterization remains the diagnostic gold standard. Supplemental oxygen should be provided if required and sleep-disordered breathing should be addressed. Small trials suggest that vasodilator therapy may improve exercise tolerance, but no mortality benefit has been demonstrated. Patients with disproportionate pulmonary hypertension should be encouraged to enroll in clinical trials of vasodilator therapy so that the role of these agents can be better defined. Ultimately, genetic profiling technology may serve to individualize therapy in such patients.