Recipients undergo intraoperative circulation phenotyping using pulse contour monitoring and fluid responsiveness testing. Vasoactive support is assigned according to phenotype: vasopressin infusion for Hyperdynamic physiology, norepinephrine infusion for Mixed Physiology, calcium chloride and/or low-dose dopamine for Poor Contractility, and fluid-guided support for Normal physiology.

Recipients undergo intraoperative circulation phenotyping using pulse contour monitoring and flow-pressure coupling testing. Vasoactive support is assigned according to phenotype: vasopressin infusion for Hyperdynamic physiology, norepinephrine infusion for Mixed Physiology, calcium chloride and/or low-dose dopamine for Poor Contractility, and fluid-guided support for Normal physiology.

Proportion of positive flow-pressure coupling responses among recipients classified intraoperatively as Hyperdynamic. Flow-Pressure coupling is defined as demonstrating both fluid responsiveness and pressure responsiveness following a fluid responsiveness test. Fluid responsiveness is defined as >= 10% increase in the stroke volume (ml/beat) and pressure responsiveness is defined as >= 15% in the mean arterial pressure (mmHg) 2 minutes after conclusion of the fluid responsiveness test. Hyperdynamic phenotypes are defined as having the following hemodynamics: CI >4.0 L/min/m², SVRI <1970 dyn·s·cm-⁵/m², and dP/dt >1000 mmHg/s .

Measurement of positive rate of FPC per FRT in all remaining circulatory phenotypes. These phenotypes are defined by the following hemodynamics: • Normal phenotype: CI 2.5-4.0 L/min/m² and SVRI 1970-2390 dyn·s·cm-⁵/m² ; • Mixed physiology: CI 2.5-4.0 L/min/m², SVRI <1970 dyn·s·cm-⁵/m², and dP/dt <1000 mmHg/s and • Poor Contractility: CI <2.5 L/min/m² and dP/dt <1000 mmHg/s .