Pressure‐Derived Right Ventricular Ejection Fraction During Initial Dual Combination Therapy in Pulmonary Arterial Hypertension

Figure 1. Pressure‐derived estimation of RVEF and response to initial dual PAH‐targeted therapy. (A) Comparison of different pressure‐derived methods to estimate maximal isovolumentric pressure (Piso) and end‐systolic pressure (ESP), with mean and standard deviation (SD) provided. (B) Right ventricular (RV) pressure–time curve demonstrating estimation of Piso using a four‐parametric Weibull distribution function (blue dashed line) and ESP using the time‐varying elastance approach (ESPtve) based on the squared second derivative of the pressure signal (grey line). Pressure‐derived RV ejection fraction (RVEF) was calculated as 1—(ESP/Piso). (C) Treatment‐related changes in pressure‐derived RV metrics in 13 incident PAH patients receiving first‐line dual oral combination therapy with tadalafil and macitentan (p‐values obtained from Wilcoxon matched‐pairs signed‐rank testing). (D) Correlation matrix based on treatment‐related changes (correlation of Δ values) from right heart catheterisation at baseline and following treatment initiation. End‐systolic elastance (Ees) was calculated as (Piso‐ESP)/SV and effective arterial elastance (Ea) as ESP/SV. BL, baseline; CI, cardiac index; FU, follow‐up;…