Impact of Left Ventricular‐Vascular Interaction on Long‐Term Outcome After Heart Transplantation

Figures

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  FIGURE 1. Left ventricle pressure‐volume diagram from which effective arterial elastance (Ea) and end‐systolic elastance (Ees) are derived. Ea is calculated from the ratio between end‐systolic pressure (ESP—approximated as systolic blood pressure [SBP] * 0.9) and stroke volume (SV), and represents the negative slope of the line joining the end‐diastolic volume and the end‐systolic pressure point. Ees is calculated from the ratio between ESP and end‐systolic volume (ESV), and represents the slope of the end‐systolic pressure‐volume relationship passing through the volume intercept with x‐axis (V0). Ventricular‐arterial coupling (VAC) is defined as the ratio between Ea and Ees and describes the interaction between the vascular and heart systems. The red area represents cardiac stroke work (SW), which is the useful fraction of ventricular energy delivered to the arterial system for maintaining forward blood flow and providing adequate transport of oxygen and nutrients to peripheral organs. The blue area represents the potential energy (PE), which is the elastic energy stored in the ventricle at the end of the systole and is dissipated as heat during isovolumetric relaxation. Pressure‐volume…

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  FIGURE 2. Study flow chart.

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  FIGURE 3. Kaplan‐Meier curves for 30‐year cumulative graft and patient survival according to ventricular‐arterial coupling (VAC), ventricular elastance (Ees), and arterial elastance (Ea) value. (A) entire population; (B) according to VAC above or below 0.59; (C) according to Ees above or below 6.75 mmHg/mL/m2; (D) according to Ea above or below 4.0 mmHg/mL/m2.

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  FIGURE 4. Performance of the two survival prediction models among HT patients. Age at transplant, donor ischemic time, L‐VAD before transplant, and hemoglobin level were identified as independent predictors of cardiac mortality (referred to as Model 1) (χ [2 ] = 55.374, p < 0.001). The inclusion of Ea and Ees into Model 1 resulted in an increased prognostic value (χ [2 ] = 73.243, p < 0.001, De Long p = 0.04), improving the prediction of survival among HT patients.