Clinical assessment of right ventricular (RV) contractility in diseases such as pulmonary arterial hypertension (PAH) has been hindered by the lack of a robust methodology. Here, a novel clinically-viable single-beat method was developed to assess end-systolic elastance (Ees), a measure of RV contractility. We hypothesized that this novel approach reduces uncertainty and interobserver variability in the estimation of the maximum isovolumic pressure (Piso), the key step in single-beat methods. The new method was designed to include a larger portion of the RV pressure data and minimize subjective adjustments by the operator. Data were obtained from right heart catheterization of PAH patients in a multicenter prospective study (Dataset 1) and a single-center retrospective study (Dataset 2). To obtain Piso, three independent observers used an established single-beat method (based on the first derivative of the pressure waveform) and the novel method (based on the second derivative). Interobserver variability analysis included paired t-test, one-way ANOVA, inter-class correlation (ICC) analysis and a modified Bland-Altman analysis. The Piso values obtained from two methods were linearly correlated for both Dataset 1 (R2 = 0.74) and Dataset 2 (R2 = 0.91). Compared to the established method, the novel method resulted in smaller interobserver variability (p < 0.001), nonsignificant differences between observers, and a narrower confidence interval. By reducing uncertainty and interobserved variability, this novel approach may pave the way for more effective clinical management of PAH.
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