Molecular imaging along the heart-kidney axis.

Cardiorenal syndrome (CRS) involves bidirectional crosstalk between the failing heart and the kidneys. Depending on the primum movens (primary cardiac or renal injury), systems-based interactions in the secondary affected organ may include pro-fibrotic signaling, overzealous inflammation, impaired nerve integrity or overactivity of specific renal transporters mediating glucose absorption. Those pathophysiological pillars can be investigated by molecular imaging using SPECT or PET agents. Targeted whole-body molecular imaging may allow for a) systems-based analysis along the heart-kidney axis, b) may provide prognostic information on longitudinal organ-based functional decline or c) may be used for guidance of reparative intervention based on peak activation identified on PET (paradigm of cardiorenal theranostics). We will discuss the current state of translational molecular imaging for CRS, along with future clinical aspects in the field.