Background: Evaluating right ventricular dysfunction, pulmonary artery systolic pressure (PASP), and exercise tolerance is critical in patients with systemic lupus erythematosus (SLE) because of the high mortality rate in such patients with pulmonary arterial hypertension (PAH). The aim of this study was to use the flow propagation velocity (FPV) of early diastolic tricuspid inflow to evaluate exercise tolerance and PAH severity and to predict readmission in patients with SLE.
Methods: A total of 66 patients with SLE with or without PAH and 30 healthy control subjects were enrolled. Controls were age-matched to patients with SLE and without PAH. All patients completed the 6-minute walking distance (6MWD) test and underwent standard echocardiography. Tricuspid FPV was measured in the modified parasternal short-axis view using the color M-mode technique. PAH was defined as PASP > 35 mm Hg using the tricuspid regurgitant method.
Results: Patients with SLE and PAH had significantly lower tricuspid FPVs and 6MWDs than patients in the other 2 groups (both P values < .001). Tricuspid FPV was well correlated with 6MWD (r = 0.748, P < .001). In multivariate analysis, right atrial pressure was the only independent factor affecting tricuspid FPV (R(2) = 0.394, P < .001), and 6MWD was affected only by tricuspid FPV and PASP (R(2) = 0.629, P < .001). Patients with SLE who had been readmitted had lower tricuspid FPVs than those who had not (P = .035). Furthermore, FPV > or = 35.4 cm/s predicted 6MWD > or = 350 m and a lower 1-year readmission rate with good sensitivity and specificity.
Conclusion: The tricuspid FPV technique provides a simple method for predicting exercise tolerance, the severity of PAH, and readmission among patients with SLE.