Because patients with pulmonary arterial hypertension that is not responsive to vasodilator treatment can develop potentially fatal problems when given calcium channel blockers, physicians should use caution in prescribing an agent in that class, according to new evidence-based guidelines issued by the American College of Chest Physicians and endorsed by four other organizations including the American Heart Association. The caution is especially important with patients who are not hemodynamically stable.

The American College of Chest Physicians Diagnosis and Management of Pulmonary Arterial Hypertension: ACCP Evidence-Based Clinical Practice Guideline provides recommendations for diagnosing and treating the condition. Published in the July issue of CHEST, the guidelines were developed by a multidisciplinary panel of experts from five medical specialties and endorsed by the American College of Cardiology Foundation, American College of Rheumatology, American Heart Association, and the Pulmonary Hypertension Association.

Panel members recommend against the empiric use of calcium channel blockers or their use in patients who do not respond to acute pulmonary vasodilator testing, citing an increased risk of adverse and potentially fatal events related to the use of the medication. Due to the severity of the disease, the panel also advises genetic testing for patients with a family history of pulmonary arterial hypertension and advance screening for patients with certain chronic diseases who are predisposed to it.

“Calcium channel blockers are regularly used to treat high blood pressure because they limit calcium entry into the cells and dilate the constricted systemic blood vessels, thereby lowering blood pressure. This rationale is frequently applied to their use in pulmonary arterial hypertension; however, when they are used in patients with pulmonary arterial hypertension whose narrowed pulmonary arteries are not caused by dynamic vessel constriction, the side effects can be fatal,” said Panel Chair Lewis J. Rubin, MD.

“When left untreated, pulmonary arterial hypertension can cause serious health problems, such as difficulty breathing, blood clots, and fluid retention due to right-sided heart failure. Moreover, patients in specific populations, such as women who are pregnant and patients with respiratory disease, are at greater risk of developing severe complications as a result of pulmonary arterial hypertension. Genetic testing can help to identify patients who are most at risk for developing pulmonary arterial hypertension, allowing clinicians to closely monitor patients and begin treatment at the first sign of the disease.”

The evidence-based guideline is based on a structured review of all available guidelines and published research related to the condition. The guideline provides specific recommendations for screening, early detection and diagnosis, medical therapies, surgical interventions, sleep-disordered breathing, and prognosis. Recommendations were graded in regard to the quality of evidence available or expert opinion and the benefit of the diagnostic or therapeutic procedure for the patient population.

Aside from genetic testing, the guideline recommends that patients with unexplained pulmonary arterial hypertension undergo testing for connective tissue disease and HIV infection, conditions that may predispose patients. Patients who are evaluated for pulmonary arterial hypertension also are advised to undergo assessment for sleep-disordered breathing, a potential independent risk factor or complicating factor for the condition.

In addition, the guideline supports the continued use of right-heart catheterization to confirm the presence of the disorder and establish the severity of disease. In regard to medical therapies, the guideline recommends that affected women avoid becoming pregnant due to the high maternal and fetal mortality rates associated with the disease.

Although the true incidence is unknown, it is estimated that over 100,000 people in the United States suffer from the disorder and several thousand new cases are diagnosed each year. Pulmonary hypertension can develop in patients of all ages and ethnic groups, and both genders; however, women ages 20 to 40 years have the highest incidence of pulmonary arterial hypertension.

The guidelines are available at the American College of Chest Physicians web site, http://www.chestnet.org.