Diastolic Dysfunction Accompanies Alterations in Myocardial Structure, Cellular Composition and Macrophage Polarization in Survivors of Ionizing Radiation Exposure

Rationale: Radiation-induced heart disease (RIHD) is a significant, delayed/late effect of ionizing radiation exposure. Objective: To determine the cardiac effects of total body irradiation (TBI) in male rhesus macaques, a translational non-human primate (NHP) model. Methods and Results: Echocardiography was performed on survivors of a single dose (6.4-8.5 Gy) of TBI (n=34) and non-irradiated controls (n=26) divided into long (LT IRR) and short term (ST IRR) survivors and controls to assess the effects of time since TBI on phenotypes. LT IRR had increased Doppler transmitral early filling velocities (E), decreased early mitral annular descent velocities (e9), and higher E/e9 ratio compared to LT CTL (all p