LAS VEGAS – It’s okay to skip vasoreactivity testing when working up connective tissue disease patients for suspected pulmonary artery hypertension.
“If you are in a smaller town and your cardiologist doesn’t do vasoreactivity testing, don’t worry about it. You don’t really need it. It’s no longer recommended for patients with scleroderma and connective tissue disease” because they are not vasoreactive, said Dr. Kristin Highland, a pulmonologist and rheumatologist at the Cleveland Clinic.
Right heart catheterization, however, remains the standard for pulmonary artery hypertension (PAH) diagnosis, which requires a mean, resting pulmonary arterial pressure at or above 25 mm Hg with normal pulmonary capillary wedge pressure but increased pulmonary vascular resistance.
Treatment is generally based on functional class, but “I like to look at more data than just the functional class,” Dr. Highland said at the annual Perspectives in Rheumatic Diseases, held by the Global Academy for Medical Education.
Right ventricular heart failure, poor walk tests, and markedly elevated brain natriuretic peptide are among the signs of aggressive disease. Pericardial effusion in the setting of pulmonary hypertension and high right arterial pressure with low cardiac output suggest a dire situation. “If I have any [such findings], I am thinking parenteral and combination therapy;” stand-alone oral therapies are generally for the less sick, she said.
It’s important to rule out pulmonary venous occlusive disease (PVOD) before treating PAH. “These are patients who behave like PAH, but they have pulmonary venule involvement,” as well, and can be thrown into pulmonary edema by specific PAH therapies. Computed tomography can help identify PVOD in scleroderma (Arthritis Rheum. 2012;64[9]:2995-3005). “There are really no good options for these patients except transplant,” Dr. Highland said.
PAH can occur in all connective tissue diseases, but it’s most likely in scleroderma, with a prevalence of about 20%.
Survival improves if disease is caught early, so it’s generally recommended that scleroderma patients be screened by Doppler echocardiography at least yearly. It will capture right-sided hypertrophy, tricuspid regurgitation, pulmonary artery dilation, and other indications that further work-up is warranted.
Although echo is the most useful screening test, there are other noninvasive options. For instance, a decline in the diffusing capacity for carbon monoxide is perhaps one of the earliest signs of pending PAH in scleroderma. Meanwhile, an N-terminal brain natriuretic peptide level of 395 pg/mL has 56% sensitivity and 95% specificity for the presence of PAH. A ratio of forced vital capacity to diffusion capacity above 2 is 71% sensitive and 72% specific (J Rheumatol. 2008;35[3]:458-65).
“Their FVC [forced vital capacity] might be down a little bit, but if their diffusion is way down out of proportion to the FVC, they end up with an elevated ratio. Those patients probably have some pulmonary hypertension along with their interstitial lung disease,” Dr. Highland said.
Dr. Highland is a consultant for Boehringer Ingelheim, an adviser for Bayer Healthcare, and a speaker for Bayer, Actelion, Intermune, Gilead, Genentech, Lung Biotechnology, and United Therapeutics. The Global Academy for Medical Education and this news organization are owned by the same parent company.