Cardiocirculatory Computational Models for the Study of Hypertension

TL;DR

The results demonstrate that the 3D-0D model yields an accurate representation of cardiocirculatory dynamics in the presence of hypertension, representing a powerful step toward digital twins for real-time hypertension control, providing refined and clinically meaningful insights beyond those achievable with 0D models alone.

Abstract

In this work, we develop patient-specific cardiocirculatory models with the aim of building Digital Twins for hypertension. In particular, in our pathophysiology-based framework, we consider both 0D cardiocirculatory models and a 3D-0D electromechanical model. The 0D model, which consists of an RLC circuit, is studied in two variants, with and without capillaries. The 3D-0D model consists of a three-dimensional electromechanical model of the left ventricle, coupled with a 0D model for the external blood circulation: this representation enables the assessment of additional quantities related to ventricular deformation and stress, and offers a more detailed representation compared to a fully 0D model. Sensitivity analysis is performed on the 0D model, with both a mono- and a multi-parametric approach, in order to identify the parameters that most influence the model outputs and guide the calibration process. We studied three different scenarios, corresponding to systemic, pulmonary and renovascular hypertension, each in three nuances of severity. To maintain a fair comparison among the models, a parameter calibration strategy is developed; the outputs of the 0D model with capillaries are utilized to enhance the 3D-0D model. The results demonstrate that the 3D-0D model yields an accurate representation of cardiocirculatory dynamics in the presence of hypertension; this model represents a powerful step toward digital twins for real-time hypertension control, providing refined and clinically meaningful insights beyond those achievable with 0D models alone.

Figures (14)

• Figure 1: 0D cardiocirculatory models with (center) and without (left) capillaries. The 3D--0D coupling between the left ventricle 3D electromechanical model and the 0D circulation model without capillaries is shown on the right. Source: 3d-0d_ventrlumped:capillary and graphical modifications.
• Figure 2: Most relevant total Sobol indices, computed for $(\mathscr{C}_\text{NC})$. The index $\mathcal{S}_k^{j,\mathcal{T}}$ in position $(k,j)$ quantify the contribution of parameter $p_k$ to the output $y_j$. Only $\mathcal{S}_k^{j,\mathcal{T}}\ge 0.2$ are shown.
• Figure 3: Comparison of the eight loss functions used in this study: on the left, they are represented in linear scale for $\delta\in[0, 1.2]$, while on the right in semi-logarithmic scale on $y$ axis for $\delta\in[1, 10]$.
• Figure 4: Calibration times (in seconds, on the left) and total parameter deviations $\Delta_{r}$ (on the right) at the end of calibration for $(\mathscr{C}_\text{NC})$. The following conditions are studied: systemic, pulmonary and renovascular hypertension with secondary pulmonary hypertension. Three severity levels (mild, moderate and severe) are considered for each condition, and the calibration is performed using different choices for the loss function.
• Figure 5: Workflow illustrating the calibration process of 3D--0D models for a generic clinical scenario.