A Needle in a Hypertension Haystack: New Pulmonary Arterial Hypertension Guidelines

The American College of Chest Physicians (CHEST) has published a new guideline for the management of pulmonary arterial hypertension (PAH) in adults.

Pharmacologic Therapy for Pulmonary Arterial Hypertension in Adults helps clinicians manage PAH with 79 recommendations and expert consensus statements. It also describes appropriate use of the latest drug therapies for PAH, an area the authors recognize as important as new agents become available. The full guideline appears free-of-charge in the August 2014 issue of Chest.

PAH (mean pulmonary arterial pressure greater than 25 mm Hg at rest or greater than 30 mm Hg during exercise) causes progressive and sustained increase in pulmonary vascular resistance that may eventually lead to right ventricular (RV) failure. Patients at risk for PAH include those with connective tissue diseases (e.g. scleroderma, liver disease); HIV-infected patients; or in patients who have a known genetic mutation that places them at risk.

PAH is difficult to distinguish from other forms of pulmonary hypertension (PH), and pharmacotherapy for PAH may be harmful to patients with other forms of PH. The new guidelines refer readers to previous ones that guide evaluation of PH and diagnosis of PAH. The guideline recommends referring patients with suspected or confirmed PAH to an expert in the field quickly.

Just 15 years ago, only epoprostenol was FDA-approved for PAH. Today, clinicians and patients can choose from several drug- and delivery-route options. The guideline addresses the 8 FDA-approved agents for PAH symptoms (prostanoids, endothelin antagonists, phosphodiesterase inhibitors, and a soluble guanylate cyclase stimulator), and also discusses calcium channel blockers (CCBs), which are not FDA-approved for PAH but used often.

Only 9 of the 79 recommendations are evidence-based, mainly due to the few studies that provide high-quality or replicated findings.

“While these guidelines highlight the best options for treatment today, the process of creating these guidelines shines a light on the lack of sufficient evidence to support stronger recommendations,” Darren Taichman, MD, PhD, FCCP, Adjunct Associate Professor of Medicine, University of Pennsylvania and PAH guideline panel chair, said in a statement. “There are still considerable gaps in trials, research, and understanding the disease.”

Because of the inherent risks of clinical studies and the limited number of PAH patients who are eligible for research enrollment, the research community will need to choose studies carefully and focus on the most important clinical questions. This guideline notes that there are no therapeutics for the failing right ventricle although right-sided heart failure is the major cause of death in PAH patients. Development of right ventricular-specific therapies will be a major priority in upcoming years.