Predictive Value of Pulmonary Arterial Compliance in Systemic Lupus Erythematosus Patients With Pulmonary Arterial Hypertension

Pulmonary arterial hypertension is a serious complication of systemic lupus erythematosus. It is characterized by increased right ventricular afterload which mainly comprises pulmonary arterial compliance (PAC) and pulmonary vascular resistance. The role of PAC in predicting the outcome of systemic lupus erythematosus-associated pulmonary arterial hypertension has not been investigated yet. Between February 2012 to December 2016, 120 consecutive patients diagnosed with systemic lupus erythematosus-associated pulmonary arterial hypertension based on right heart catheterization were enrolled, prospectively. Baseline clinical characteristics and hemodynamic assessment were analyzed. Baseline right ventricular afterload was stratified according to the PAC and pulmonary vascular resistance. The end point was a composite of all-cause mortality and clinical worsening. Among them, end points occurred in 49 (41%) patients after 15 months (interquartile range, 8.5-24.0). Patients with a PAC <1.39 mL/mm Hg had a 3.09-fold higher risk (95% CI, 1.54-6.20,P=0.001) of the end point events than the patients with a PAC >= 1.39 mL/mm Hg. Multivariable Cox regression analysis showed that stratified right ventricular afterload was the only independent predictor for the end point (hazard ratio, 2.009 [95% CI, 1.390-2.904],P<0.001). A 3-group prediction risk was created. The patients with the highest right ventricular afterload (PAC <1.39 mL/mm Hg and pulmonary vascular resistance >= 10.3Wood Unit) had the highest risk (chi(2), 6.10;P<0.014) of experiencing the end point. Our results suggest that PAC is a good predictor of mortality and clinical worsening in systemic lupus erythematosus-associated pulmonary arterial hypertension. PAC, in addition to pulmonary vascular resistance, may be an attractive tool for screening high-risk populations in these patients.