Ventricular-Arterial Coupling in Patients after Heart Transplantation—A Pressure–Volume Loop Study Using Conductance Catheter Technique

Objectives: In patients after heart transplantation (HT), systemic arterial hypertension and enhanced central aortic stiffness are suspected to increase ventricular afterload which might contribute to graft dysfunction. The aim of our study was to characterize systemic arterial elastance and its impact on LV function and ventricular–arterial (V-A) coupling in a cohort of children, adolescents, and young adults after HT using invasive conductance catheter technique.

Methods: Thirty HT patients (median age: 19.0, [10.8–39.7] years, seven females) underwent invasive cardiac catheterization including pressure–volume loop analysis. Load-independent parameters of systolic (Ees) and diastolic (Eed) function, as well as systemic arterial elastance (Ea; end-systolic pressure/stroke volume) and V-A coupling (Ea/Ees) were assessed at baseline level and during dobutamine infusion (10 μg/kg/min).

Result: Ees showed an appropriate increase under inotropic stimulation from 0.43 (0.11–2.52) to 1.0 (0.20–5.1) mm Hg/mL/m² (p < 0.0001) while Eed remained rather unchanged (0.16 ± 0.10 to 0.12 ± 0.07 mm Hg/mL/m²; p = 0.10). V-A coupling Ea/Ees was abnormal at rest and did not improve significantly under dobutamine (2.0 ± 1.5–1.6 ± 1.2, p = 0.43) due to a simultaneous rise in Ea from 0.78 ± 0.47 to 1.32 ± 0.70 mm Hg/mL/m² (p < 0.0001). Both Ees and Eed were significantly associated with Ea at baseline and under dobutamine infusion.

Conclusion: HT patients show impaired V-A coupling at rest and under inotropic stimulation despite preserved LV contractile reserve. An abnormal response in vascular function resulting in increased afterload seems to represent an important factor that may play a role for the development of late graft failure.

Publication History

Article published online:
21 February 2021