Pulmonary Fibrosis and PAH

Respiratory failure is the principle complication of pulmonary fibrosis (PF), leading to a three- to five-year mortality rate for diagnosed patients. Other PF complications include pulmonary arterial hypertension (PAH), heart failure, pneumonia, and lung cancer. Among the complications, pulmonary fibrosis and PAH combined is particularly serious because it can lead to decreased quality of life and mortality.

In the event that PF patients develop PAH, prognosis is usually unpredictable and quite often poor. If PAH is diagnosed later, the initial course and prognosis of the pulmonary fibrosis disease may be altered or hastened.

Pulmonary arterial hypertension (high blood pressure in the lungs) affects only the arteries in the lungs, unlike systemic high blood pressure which affects the systemic arteries. PAH occurs in idiopathic pulmonary fibrosis when scarred lung tissue begins to compress the smallest arteries and capillaries, resulting in higher resistance to the lung’s normal blood flow. The high blood pressure occurs in the pulmonary arteries and right ventricle of the heart.

Management of pulmonary fibrosis and PAH

The prevalence of pulmonary fibrosis and PAH is not fully known. Reports that place the prevalence of PAH in IPF between 32% and 85% offer an inaccurate-at-best view of how common the coexistence of both diseases actually are. Reasons for the difficulty in recognizing underlying PH in IPF point to nonspecific clinical symptoms and unrevealing ancillary testing. The only reliable and current diagnostic method is right heart catheterization.

There is currently no cure for pulmonary fibrosis, but specific treatments for patients with PF and PAH can be prescribed based on factors that include disease severity, functional status, and degree of hypoxemia (low concentration of oxygen in the blood).