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Algorithm helps to DETECT pulmonary hypertension in systemic sclerosis
Major finding: Only 4% of cases were missed using the two-step algorithm, compared with 29% for guideline-recommended detection.Data source:...
MADRID – Patients with systemic sclerosis should undergo annual screening for pulmonary arterial hypertension using a combination of transthoracic echocardiography and pulmonary function tests, an international expert panel said.
These are the first evidence- and consensus-based recommendations for pulmonary arterial hypertension (PAH) screening in patients with systemic sclerosis, and the panel also called for screening patients with mixed or other connective tissue diseases with scleroderma features. "Our hope is that these recommendations will lead to earlier detection of PAH in connective tissue diseases and improve patient outcomes," Dr. Dinesh Khanna said while presenting the screening recommendations at the annual European Congress of Rheumatology.
About 5%-15% of patients with systemic sclerosis develop PAH, and once PAH occurs, up to 30% of patients will die within 3 years, said Dr. Khanna, director of the scleroderma program at the University of Michigan, Ann Arbor.
"Despite having approved drugs available" to treat systemic sclerosis and other scleroderma-spectrum disorder connective tissue diseases, these treatments "have not had a huge impact on survival. The only thing we can offer patients is screening, followed by early diagnosis and treatment," Dr. Khanna said in an interview.
The new recommendations say that patients with a tricuspid regurgitant velocity measured by transthoracic echocardiography greater than 2.8 m/s require assessment for PAH by right heart catheterization. Right heart catheterization is also needed for patients with a tricuspid regurgitant velocity of 2.5-2.8 m/s if they also have signs or symptoms of PAH such as dyspnea, fatigue, chest pain, dizziness, loud pulmonary sound, or peripheral edema. Another echo finding that should trigger right heart catheterization regardless of signs or symptoms or tricuspid regurgitation is right atrial or ventricular enlargement.
The key measures on pulmonary function tests that trigger right heart catheterization is a forced vital capacity (FVC) to diffusion capacity of lungs for carbon monoxide (DLCO) ratio of more than 1.6, or a DLCO of less than 60% if either appears in the setting of PAH signs or symptoms. Alternatively, meeting either of these pulmonary criteria should lead to right heart catheterization regardless of signs and symptoms if the patient’s most recent blood level of N-terminal pro-brain natriuretic peptide (NT-ProBNP) was greater than twice the upper limit of normal.
The panel also said that patients should undergo right heart catheterization regardless of PAH signs and symptoms if they fulfill the screening algorithm developed for the DETECT study (Ann. Rheum. Dis. 2013 May 18 [doi:10.1036/annrheumdis-2013-203301]).
Dr. Heather Gladue
The panel recommended annual transthoracic echo and pulmonary function test screening, or more frequently if a patient shows new signs or symptoms. Measurement of NT-ProBNP should happen at baseline, and then be repeated if new signs or symptoms of PAH appear. They also recommended applying the full DETECT screening algorithm in patients diagnosed with systemic sclerosis or other scleroderma spectrum connective-tissue disease for more than 3 years and a DLCO that is less than 60%. Right heart catheterization is mandatory to definitively diagnose PAH, Dr. Khanna stressed. The panel also said screening is not needed in patients with mixed- or other connective tissue disorders who did not have scleroderma-like features.
In a separate report at the meeting Dr. Khanna and his associates assessed the ability of transthoracic echocardiography and pulmonary function tests to screen patients with PAH. They used data from 69 patients with PAH in two separate reported series that together had 347 patients with systemic sclerosis who underwent assessment for suspected PAH (J. Rheumatol. 2011;38:2172-9 and J. Rheumatol. 2010;37:2290-8).
The new, retrospective analysis showed that combining transthoracic echo and pulmonary-function test screens can have a negative predictive accuracy of 98% for correctly ruling out PAH in patients with systemic sclerosis, reported Dr. Heather Gladue, a rheumatology fellow at the University of Michigan.
The recommendations panel cautioned that its proposals should not substitute for individualized, direct assessment of each patient. The panel also noted that the cost effectiveness of its recommendations had not yet been assessed. In addition to representatives from the University of Michigan, the task force included members from the University of California, Los Angeles; Massachusetts General Hospital, Boston; Stanford (Calif.) University; the University of Zurich; University Hospital in Lille, France; the University of Paris-South; McGill University, Montreal; Johns Hopkins University, Baltimore; and St. Joseph Hospital, Phoenix.
The task force was supported by the Scleroderma Foundation and the Pulmonary Hypertension Association. Dr. Khanna said that he has been a consultant to several drug companies including Actelion, Bayer, Genentech/Roche, Gilead, Merck, and DIGNA. Dr. Gladue said that she had no disclosures.