American Board of Internal Medicine (ABIM) Certification Practice Exam

When treating patients with pulmonary arterial hypertension and a negative vasoreactivity test, which agents are recommended?

1. Calcium channel blockers

2. Erythropoietin-stimulating agents

3. Phosphodiesterase-5 inhibitors and endothelin receptor antagonists

4. Beta-blockers

The correct answer is: Phosphodiesterase-5 inhibitors and endothelin receptor antagonists

In patients with pulmonary arterial hypertension (PAH) who have a negative vasoreactivity test, the preferred treatment options include phosphodiesterase-5 inhibitors and endothelin receptor antagonists. Phosphodiesterase-5 inhibitors, such as sildenafil and tadalafil, work by enhancing the vasodilatory effects of nitric oxide, leading to improved pulmonary artery pressure and symptoms. These agents are commonly used in PAH due to their favorable safety profile and efficacy in improving exercise capacity and quality of life. Endothelin receptor antagonists, such as bosentan, ambrisentan, and macitentan, block the effects of endothelin-1, a potent vasoconstrictor that is often elevated in patients with PAH. By inhibiting the action of endothelin-1, these medications help to reduce pulmonary vascular resistance and improve hemodynamics. In contrast, calcium channel blockers are typically only recommended for patients who demonstrate a positive vasoreactivity test. Erythropoietin-stimulating agents are more targeted for conditions involving anemia or chronic kidney disease rather than for treating PAH directly. Beta-blockers are not generally indicated as a primary treatment for PAH; they may even worsen symptoms in some patients