The survival rates of patients with systemic sclerosis who have pulmonary hypertension have improved as compared to years past, but patients with pulmonary hypertension with secondary to left heart dysfunction or isolated post-capillary pulmonary hypertension (WHO2), are more likely to die from scleroderma-related causes, researchers report.
Writing in a presentation given at the 2016 American College of Rheumatology annual meeting, researchers from the Hospital for Special Surgery in New York, reported that this group of patients (with WHO2) have different features that separate them from systemic sclerosis patients with pulmonary arterial hypertension (WHO1).
The authors utilized the Pulmonary Hypertension Assessment and Recognition of Outcomes in Scleroderma (PHAROS) registry, a prospective longitudinal cohort study conducted with the aim of understanding the natural history of pulmonary hypertension in systemic sclerosis.
335 systemic sclerosis patients were identified in the PHAROS data with pulmonary hypertension. Pulmonary hypertension was defined as a mean pulmonary artery pressure greater than or equal to 25mmHg derived via right heart catheterization.
The authors found that world health organization class two patients with systemic sclerosis have similar characteristics as class three patients but not class one subjects. These similarities include: African American race, presence of diffuse systemic sclerosis, and scl70 marker positivity. The main difference between WHO2 and WHO1 patients was the presence of lower forced vital capacities (FVC), and FVC%/DLCO% ratios in WHO2 participants. WHO2 patients also had much larger left atrial dimension and preserved ejection fractions. The defining characteristic of WHO2 patients is their high pulmonary capillary wedge pressures (PCWP).
Survival estimates for world health organization class 1, 2, and 3 patients in the PHAROS registry at 1 year were: 92.5%, 86%, and 85.6% respectively, at 3 years: 73.8%, 67.5%, and 68.4% respectively, and at 5 years: 58.1%, 64.5%, and 61.1% respectively. There was no statistical difference between groups for survival (p=0.28).
It was further found that WHO2 patients died more frequently due to complications of scleroderma than WHO1 patients (p0.02). The most common causes of death by type were: WHO1-pulmonary arterial hypertension (PAH) 50%, WHO2- pulmonary capillary hypertension (PH) 37%, WHO3- pulmonary fibrosis 46%.
“Clinical Characterization of Patients with World Health Organization Group 2 Pulmonary Hypertension in the Pulmonary Hypertension Assessment and Recognition of Outcomes in Scleroderma Cohort,” Jessica K. Gordon. Nov. 13, 2016. American College of Rheumatology annual meeting. Abstract 973.