Importance of the Mean Rate of Pressure Change of the Pulmonary Artery (dP/dt mean PA) in Patients with Pulmonary Arterial Hypertension.

Background  Pulmonary arterial hypertension (PAH) is a rare disease of cardiopulmonary circulation characterized by elevated pressure in the pulmonary artery. The right-heart catheter is the gold standard for diagnosis, but there is interest in identifying additional prognostic indicators. The aim of this study was to examine the importance of the rate of pressure change of the pulmonary artery (dP/dt mean PA) in patients with PAH. Methods  We retrospectively analyzed data from 142 patients with PAH (exclusively clinical group 1) and examined the statistical correlation of dP/dt mean PA with vascular, right ventricular, and clinical parameters. Data was collected mostly from the right heart catheterization and the transthoracal echocardiography at presentation. Results  dP/dt mean PA showed a significant correlation with systolic pressure of the pulmonary artery ( n = 142, R ²  = 56%, p  < 0.001), pulmonary vascular resistance ( n  = 142, R ²  = 51%, p  < 0.001), the rate of pressure change in the right ventricle ( n  = 142, R ²  = 53%, p  < 0.001), and the right ventricular fractional area change ( n  = 110, R ²  = 51%, p  < 0.001). Receiver operating characteristic curve analysis showed that dP/dt mean PA had the highest prognostic value in predicting increase in the 6-minute walk test and decrease in the N-terminal-probrain natriuretic peptide after the initiation of PAH therapy, with an area under the curve of 0.73. Conclusion  Our findings suggest that dP/dt mean PA may be a useful prognostic indicator in the treatment of patients with PAH, and further research is warranted to validate this parameter.