Cardiopulmonary functional profiles in systemic lupus erythematosus–associated pulmonary hypertension: a spirometric and echocardiographic study

Background Pulmonary hypertension (PH) is a serious and potentially life-threatening complication of systemic lupus erythematosus (SLE). Functional characterization may facilitate the differentiation of the heterogeneous phenotypes of systemic lupus erythematosus–associated pulmonary hypertension (SLE-PH). Methods Sixty patients with SLE-PH were prospectively analyzed and classified into four groups: SLE-associated pulmonary arterial hypertension (SLE-PAH; n = 15), SLE with left ventricular (LV) dysfunction ( n = 20), SLE with interstitial lung disease–associated pulmonary hypertension (ILD-PH; n = 21), and chronic thromboembolic pulmonary hypertension (CTEPH; n = 4). Spirometric, echocardiographic, and clinical variables were compared using one-way analysis of variance (ANOVA) with least significant difference (LSD) post-hoc testing and Fisher’s exact test. Results Airflow indices were comparable across groups. In contrast, forced vital capacity (FVC) differed significantly ( p = 0.017), with reduced values observed in the ILD-PH subgroup. The LV dysfunction subgroup demonstrated markedly reduced ejection fraction (EF) ( p < 0.001) and elevated estimated pulmonary artery pressure (EPAP) ( p = 0.037). Post-hoc analysis identified significant pairwise differences in forced expiratory volume in 1 s (FEV₁), FEV₁/FVC ratio, and EPAP. Dyspnea severity also differed significantly among groups ( p = 0.018). Conclusions SLE-PH demonstrates distinct cardiopulmonary functional phenotypes. The combined use of spirometry and echocardiography provides a practical, non-invasive approach for early phenotypic characterization, with potential implications for risk stratification and individualized management.