MUNICH — Systematic screening of patients with systemic sclerosis for pulmonary arterial hypertension can identify patients with this life-threatening complication when it is less severe, based on a screening study with 617 patients.
Diagnosing pulmonary arterial hypertension (PAH) when it is not as advanced makes earlier treatment possible and may lead to better patient outcomes, Dr. Marc Humbert said at the annual congress of the European Society of Cardiology.
Systematic screening of 617 patients at 21 university hospitals in France identified 18 patients with newly diagnosed PAH. When added to the 29 patients from this group who had been previously diagnosed with PAH, there was an overall prevalence of PAH of 7.6% in patients with systemic sclerosis.
This was consistent with prior reports of a PAH prevalence of about 10% in these patients, said Dr. Humbert, a physician in the pulmonology service at Antoine Beclere Hospital, Clamart, France.
The 18 patients with newly diagnosed PAH had an average pulmonary artery pressure at rest of 30 mm Hg, compared with a mean, resting pulmonary artery pressure of 49 mm Hg in the 29 patients with previously diagnosed PAH.
The lower pulmonary artery pressure in the newly diagnosed patients showed that their disease was less advanced, Dr. Humbert said.
The 18 patients with newly-identified PAH had been diagnosed with systemic sclerosis for an average of 8 years.
By comparison, the 29 patients with established PAH had been diagnosed with systemic sclerosis for an average of 12 years.
When PAH develops in patients with systemic sclerosis, it usually appears 6-10 years after the disease manifests.
The screening study organized by Dr. Humbert and his associates enrolled patients who were at least 18 years old and had either diffuse or limited systemic sclerosis. During September 2002 through July 2003, there were 709 patients who met these criteria and were examined at the 21 participating centers.
The key screening measure was an echocardiography examination to assess the tricuspid-valve gradient. Patients who had a tricuspid regurgitation velocity of less than 2.5 m/sec were considered to have a low risk of having PAH and did not undergo additional testing, according to the study protocol.
Patients with a regurgitation velocity of more than 3.0 m/sec had a high risk of PAH and were referred for right heart catheterization.
Patients with a regurgitation velocity that fell within 2.5-3 m/sec were triaged to right heart catheterization if they also had a history of unexplained dyspnea. Patients in this range without a history of unexplained dyspnea did not undergo right heart catheterization.
A total of 92 patients were excluded from the study, mostly because of abnormal lung function or because they had received an incomplete echocardiography examination.
Among the 617 patients who remained in the investigation, 29 had known PAH and did not undergo further testing. Echo examinations of the other 583 patients yielded 51 patients with echo findings consistent with PAH.
Among these 51 patients, 33 agreed to have right heart catheterization, and 18 of these patients were found to have PAH.
An additional three patients were diagnosed with left heart disease.
Among the remaining 12 patients who underwent right heart catheterization, 6 had an elevated pulmonary artery pressure of more than 20 mm Hg, but this elevation failed to meet the minimum criteria for PAH of 25 mm Hg.
Among the 18 patients newly diagnosed with PAH, 14 had mild disease, with a resting pulmonary artery pressure of less than 35 mm Hg.
Another three patients had moderate PAH, with a resting pressure of 35-45 mm Hg, and one patient was diagnosed with severe PAH with a pressure greater than 45 mm Hg.