Primary and secondary pulmonary hypertension in systemic lupus erythematosus

Objectives: To describe the aetiology and clinical profile of primary and secondary pulmonary hypertension (PHT) in SLE patients. Methods: A retrospective study of SLE patients with PHT identified from a cohort of 786 SLE patients seen at Tan Tock Seng Hospital, Singapore. Results: 22 patients had primary and 24 patients had secondary PHT, with similar clinical features at presentation and a similar degree of pulmonary pressure elevation. Secondary PHT was due to valvular heart disease (50%), pulmonary embolism (13%), interstitial lung disease (8%) or a combination of these factors (29%). Primary PHT tended to present after a shorter duration of lupus than secondary PHT (8.8 vs 43.2 months, P = 0.118). At presentation, Raynaud's phenomenon was present in 34.8% of subjects with primary or secondary PHT. Among those with secondary PHT, the presence of Raynaud's phenomenon was associated with a trend towards higher pulmonary artery systolic pressures (51.0 vs 40.5 mmHg, P = 0.101). 17% of patients with PKT died, but from causes unrelated to PHT. Conclusion: Primary and secondary PI-IT are equally common in SLE patients. Secondary PHT is often multi-factorial, and Raynaud's phenomenon may be a marker for the severity of PKT in this group of patients.