Pulmonary arterial hemodynamic assessment by a novel index in systemic lupus erythematosus patients: pulmonary pulse transit time

Objective: Systemic lupus erythematosus (SLE) is a chronic, inflammatory, and autoimmune connective tissue disease. One of the leading causes of mortality among SLE patients is pulmonary hypertension. The aim of this study was to evaluate the association between echocardiographic findings, including the pulmonary pulse transit time and pulmonary hypertension parameters, in SLE patients. Methods: Thirty SLE patients (aged 39.9 +/- 11 years, 28 females) as the study group and 34 age-and sex-matched healthy volunteers (aged 37.9 +/- 11.5 years, 31 females) as the control group were included in the study. After detailed medical histories were recorded, 12-lead electrocardiography, blood tests, and echocardiography were performed in the groups. In addition to basic echocardiographic measurements, other specialized right ventricular indicators [i.e, Tricuspid Annular Plane Systolic Excursion (TAPSE), estimated pulmonary artery systolic pressure (ePASP), right ventricular dimensions, and myocardial performance index (MPI)] were measured. The pulmonary pulse transit time was defined as the time interval between the R-wave peak in ECG and the corresponding peak late-systolic pulmonary vein flow velocity. Results: The mean disease duration was 121.1 +/- 49.9 months. The mean age at diagnosis was 35.0 +/- 15.4 years. The mean RV MPI was higher (p=0.026), mean TAPSE measurements were shorter (p=0.021), and mean ePASP was higher (p=0.036) in the SLE group than in the control group. In addition, pPTT was significantly shorter in the SLE group (p=0.003). pPTT was inversely correlated with disease duration (p<0.001), MPI (p=0.037), and ePASP (p=0.02) and positively correlated with TAPSE (p<0.001). Conclusion: SLE patients have higher pPTT values than controls. Further, pPTT shows an inverse correlation with disease duration, MPI, and ePASP and a positive correlation with TAPSE.