Clinical and prognostic value of echocardiography with global longitudinal strain in the first genetically modified porcine to human cardiac xenotransplant

Background: Our institution performed the first genetically modified porcine cardiac xenotransplantation in a human. Due to limited data on monitoring xenografts, our laboratory conducted longitudinal noninvasive imaging for surveillance and clinical evaluation. Methods: We performed weekly transthoracic echocardiograms (TTE) with global longitudinal strain (GLS) over 2 months with endomyocardial biopsy (EMBx) correlation. Results: LV ejection fraction (LVEF) remained normal or hyperdynamic throughout the patient’s clinical course. However, myocardial thickness and GLS varied post-transplant. Initial EMBx, LVEF, and GLS were normal. Despite little change in LVEF, the patient experienced a persistent deterioration in hemodynamic status which correlated with a dramatic increase in LV myocardial thickness (1.1 to 1.6 cm) with echogenicity and change in GLS (-18.2 to -11.5%) (Figure 1). EMBx revealed diffuse capillary damage with extravasated erythrocytes and edema without evidence of antibody or acute cellular rejection. The abrupt increase in myocardial thickness and more positive GLS suggested restriction from myocardial edema and capillary damage as a possible mechanism for xenograft failure. Conclusions: Echocardiography provided real-time clinical and prognostic value in the first transgenic cardiac xenotransplant. Given the tremendous interest and hope for cardiac xenotransplantation, investigation with longitudinal TTEs with GLS will be important for future management.