Pulmonary hypertension in systemic lupus erythematosus: an independent predictor of patient survival

BACKGROUND/AIMS We investigated whether transthoracic echocardiography-suspected pulmonary hypertension (PH) affects survival in systemic lupus erythematosus (SLE) patients and examined factors associated with PH occurrence and survival. METHODS This retrospective single-center study included 154 Korean SLE patients fulfilling the American College of Rheumatology criteria (January 1995 to June 2013). Student t test, Mann-Whitney U test, Kaplan-Meier curves, and log-rank tests were used for comparisons. RESULTS A total of 35 SLE patients with PH (SLE/PH+) and 119 without PH (SLE/PH-) were analyzed. Higher percentages of interstitial lung disease, Raynaud's phenomenon (RP), World Health Organization functional classification III/IV, and cardiomegaly were found in SLE/PH+ compared to SLE/PH-. Furthermore, the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index was significantly higher in SLE/PH+ (2.46 ± 1.245 vs. 1.00 ± 1.235), whereas survival rates were significantly higher in SLE/PH- in log-rank tests (p = 0.001). In multivariate analysis, the adjusted mortality hazard ratio (HR) for SLE/PH+ patients was 3.10. Subgroup analysis demonstrated a higher percentage of lupus nephritis in the SLE/PH+ patients who died (p = 0.039) and low complement-3 levels (p = 0.007). In univariate analysis, the mortality HR for SLE/PH+ patients with lupus nephritis was 4.62, whereas the presence of RP decreased the mortality risk in multivariate analysis; adjusted HR, 0.10. CONCLUSIONS PH is an independent factor predicting survival in SLE patients. The presence of lupus nephritis resulted in an increased trend for mortality, whereas coexistence of RP was associated with a better survival prognosis in SLE/PH+ patients.