Acute vasodilator testing is indicated in patients with hereditary, idiopathic, and anorexigen-induced PAH to determine responsiveness to vasodilators. Although most patients with PAH display minimal response to the vasodilatory challenge during right heart catheterization, a small percentage demonstrate vasodilation to near-normal pressures. In these patients, high-dose calcium channel blockers significantly lower PAP and vascular resistance. A positive acute vasodilator response is defined by a decrease in mean PAP ≥ 10 mm Hg to reach a mean PAP < 40 mm Hg with an improved or stable cardiac output. If an adequate response to calcium channel blockers is not demonstrated, an alternative PAH therapy should be initiated.
Less than 50% of vasoreactive patients will derive a long-term favorable response to calcium channel blockers and should thus undergo close clinical monitoring for disease progression. Calcium channel blockers have not been established as a treatment of PAH associated with connective tissue disease. In addition, less than 1% of vasoreactive patients who have connective tissue disorders respond to calcium channel blockers.
Riociguat, a soluble guanylate cyclase stimulator, is approved for the treatment of PAH and persistent or recurrent chronic thromboembolic pulmonary hypertension. Riociguat is effective in patients with symptoms rated as WHO functional class 2-3 to improve exercise ability and delay clinical worsening. Both riociguat and prostacyclin therapy are used in those who do not have vasoreactive disease.
Learn more about pulmonary arterial hypertension.
Medscape © 2022 WebMD, LLC
Any views expressed above are the author's own and do not necessarily reflect the views of WebMD or Medscape.
Cite this: Vikramjit Khangoora. Fast Five Quiz: Pulmonary Arterial Hypertension Treatment - Medscape - Jun 02, 2022.