Heart transplant, which is carried out when patients have reached the latest stage of heart failure/disease, can also benefit from a treatment involving MBs exposed to ultrasound, as shown by detecting the presence of acute cardiac transplant rejection (AR) with MB targeting intercellular adhesion molecule-1 (ICAM-1) [118], or T lymphocytes [21], which both increase in number following AR. Here, ICAM1 is linked to heart failure.