Pulmonary hypertension in systemic lupus erythematosus: prevalence, predictors and diagnostic strategy

Objectives: To investigate the prevalence and predictors of pulmonary hypertension (PH) in patients with systemic lupus erythematosus (SLE) and to validate a diagnostic strategy.

Methods: 245 patients with SLE entered a screening program. Possible PH was defined as two consecutive systolic pulmonary arterial pressure (PAP) values ≥ 40mmHg by echocardiography. The subsequent diagnostic procedure, including right heart catheterization if needed, confirmed or excluded the diagnosis of PH secondary to cardiopulmonary disease or SLE-related pulmonary arterial hypertension (PAH). Independent predictors of PH were identified by multivariant multiple linear or logistic regression models. The sensitivity (S), specificity (SP), positive (PPV) and negative predictive values (NPV) were calculated for different screening cutoff values.

Results: 88% patients were women. The mean (SD) age at the time of enrolment was 45 (16) years. 12 cases of PH were detected, all secondary, with a resulting prevalence of 5%. Two consecutive echocardiographic PAP measurements ≥ 40mmHg performed best as the cutoff point for screening (S 100%, SP 97%, PPV 70, NPV 100), as compared with single PAP measurements ≥ 30mmHg or ≥ 40mmHg The age at the time of enrolment was the only variable independently associated with PAP values (p=0.0001), with the SLICC damage index score showing a borderline association (p=0.08). Only the age at the time of enrolment showed an independent association with PH (OR 1.10, 95% CI 1.06-1.17).

Conclusion: We found a low prevalence of PH. Screening echocardiograms in asymptomatic lupus patients are thus not recommended. Two consecutive PAP values ≥ 40mmHg by echocardiogram is the best screening cutoff for starting investigations in SLE patients with suspected PH.