• Heart disease is responsible for ~18% of deaths worldwide.  This number jumps to 20% in the US

• Consequently, the number of patients awaiting a heart transplant is steadily growing, and has increased from ~5500 in 2009 to ~7400 in 202 (34% growth)

• However, the number of donor heats available has been stagnant for quite some time, at around 2500/year

• To accommodate this difference, many patients are fitted with left ventricular assist devices (LVADs) to provide mechanical support for the failing heart

• Historically, LVADs were used for so-called "bridge to transplant", meaning that they were intended to provide support until a donor heart was available.  However, due to the lack of donor hearts, and improvements in LVAD technology, the predominant use is now "destination therapy," meaning that the LVAD recipient is not expected to receive a donor heart.  Rather, they will live with the LVAD

• Also noteworthy that many patients requiring a donor heart are not transplant eligible, due to age or other constraints, and thus never make it to the transplant list.  For these patients, an LVAD may be the only option

• LVADs, and all related devices, are associated with intrapump and/or intracardiac thrombus

  • This results in an elevated risk of stroke​

• Heavy anticoagulation is required to prevent thrombosis, at the expense of an increased risk of gastrointestinal bleeding (GIB)​

  • 25-30% of patients have ca. 10-day hospitalization for treatment of GIB, at a cost of typically $31k/stay​

  • About 50% of these patients will have additional GIB episodes per year

• Currently there is no biomarker or therapeutic endpoint to assess intra-LVAD/cardiac thrombus, and to use to adjust anticoagulant levels​

• FibroScint, a fibrin-targeted nuclear imaging agent, is intended to address these unmet medical needs

• The figure below contains images of an LVAD that has been removed from a human patient that was admitted for pump exchange.  The device has been removed, and implanted into a 70 kg calf as a model system.  FibroScint was then administered, and the resultant image acquired.  The bright white region seen at the bottom of the images is a large deposit of thrombus that has accumulated in the neck of the LVAD

​

​