Cardiac hemodynamic status: an interpretable one-look Windkessel index of arterial health

Cardiovascular assessment typically relies on fragmented single-parameter measures that fail to capture the coordinated interplay between cardiac output (CO), systemic vascular resistance (SVR), and arterial compliance (AC). The cardiac hemodynamic status (CHS) was developed as a practical index integrating these parameters into a single "one-look" assessment of arterial health suitable for bedside monitoring. CHS was represented as a physiologically scaled vector in CO-SVR-AC space, yielding magnitude (CHS_mag) and inclination angle (CHS_θ) coordinates. Healthy aging simulations (HA-Sim, <i>n</i> = 4,374), aneurysm simulations (AA-Sim, <i>n</i> = 8,748), and two young in vivo cohorts (YH-Vivo, <i>n</i> = 140; UY-Vivo, <i>n</i> = 12) were analyzed. Group differences were assessed using ANOVA/Tukey's tests, distributions were visualized in polar space, and discrimination was evaluated via ROC/AUC analysis. CHS_θ provided exceptional discrimination between pathological and healthy states (AUC = 0.866; 95% CI: 0.859-0.873), whereas CHS_mag showed physiological variation across cohorts. Arterial status was shifted toward higher CHS_θ (approaching 90°) with aging, indicating progressive stiffening without proportional hemodynamic load increases. CHS_θ was confirmed to be dominated by arterial compliance through sensitivity analysis, whereas CHS_mag was found to reflect primarily SVR-CO balance. Rapid assessment of whether cardiovascular changes stem from arterial stiffening versus altered flow-resistance dynamics is enabled by this two-coordinate system. CHS provides a two-coordinate, physiologically grounded fingerprint that separates stiffness orientation from overall hemodynamic load. The index complements established stiffness measures and may support screening, triage, and longitudinal tracking while enabling future bedside estimation from common biosignals.<b>NEW & NOTEWORTHY</b> This study introduces the cardiac hemodynamic status (CHS), an interpretable index combining cardiac output, systemic vascular resistance, and arterial compliance into a single polar representation. CHS separates arterial stiffness orientation from overall hemodynamic load. The angle (CHS_θ) discriminates healthy versus pathological states (AUC = 0.866), whereas the magnitude reflects flow-resistance balance. This Windkessel-consistent index offers a practical tool for cardiovascular screening and longitudinal monitoring, with potential for bedside estimation from common biosignals.