In vivo molecular imaging of cardiac angiogenesis in persons with and without type 2 diabetes: A cross-sectional ⁶⁸Ga-RGD-PET study

Aims To assess cardiac angiogenesis in type 2 diabetes by positron emission tomography (PET) tracer [Ga-68]Ga-NODAGA-E[(cRGDyK)](2) (Ga-68-RGD) imaging. Methods Cross-sectional study including 20 persons with type 2 diabetes and 10 non-diabetic controls (CONs). Primary prespecified outcome was difference in cardiac angiogenesis (cardiac Ga-68-RGD mean target-to-background ratio [TBRmean]) between type 2 diabetes and CONs. Secondary outcome was to investigate associations between cardiac angiogenesis and kidney function and other risk factors. Results Participants with type 2 diabetes had a mean +/- SD age of 61 +/- 9 years, 30% were women, median (IQR) diabetes duration of 11 (6-19) years and 3 (15%) had a history of cardiovascular disease. The CONs had comparable age and sex distribution to the participants with type 2 diabetes, and none had a history of coronary artery disease. Myocardial flow reserve was lower in type 2 diabetes (2.7 +/- 0.6) compared with CONs (3.4 +/- 1.2) ( p = 0.03) and coronary artery calcium score was higher (562 [142-905] vs. 1 [0-150] p = 0.04). Cardiac Ga-68-RGD TBRmean was similar in participants with type 2 diabetes (0.89 +/- 0.09) and CONs (0.89 +/- 0.10) ( p = 0.92). Cardiac Ga-68-RGD TBRmean was not associated with estimated glomerular filtration rate, urine albumin creatinine ratio, cardiovascular disease, coronary artery calcium score or baroreflex sensitivity, neither in pooled analyses nor in type 2 diabetes. Conclusions Cardiac angiogenesis, evaluated with Ga-68-RGD PET, was similar in type 2 diabetes and CONs. Cardiac angiogenesis was not associated with kidney function or other risk markers in pooled analyses or in analyses restricted to type 2 diabetes.