Aims/hypothesis Coronary flow reserve (CFR) and coronary artery calcium (CAC) represent functional and structural aspects of atherosclerosis. We examined the prevalence of reduced CFR and high CAC scores in three predefined groups of participants without known cardiovascular disease: (1) patients with type 2 diabetes and albuminuria; (2) patients with type 2 diabetes and normoalbuminuria; and (3) non-diabetic controls. Methods In a cross-sectional design, cardiac 82 Rb positron emission tomography/computed tomography was conducted in 60 patients with type 2 diabetes who were free of overt cardiovascular disease and who were stratified by normoalbuminuria (<30 mg/24 h) (n=30; age [mean±SD] 60.9±10.1 years) and albuminuria (≥30 mg/24 h) (n=30; age 65.6±4.8 years), and in 30 healthy, non-diabetic controls (age 59.8±9.9 years). Results In controls, normoalbuminuric and albuminuric patients, CFR was 3.0±0.8, 2.6±0.8 and 2.0±0.5, respectively. Reduced CFR (<2.5) was observed in 16.7%, 40.0% and 83.3% of participants, respectively, and median (interquartile range) CAC scores were 0 (0-81), 36 (1-325) and 370 (152-1,025), respectively (p for trend <0.01). After adjustment, the difference in CFR and CAC between albuminuric patients and controls remained significant (p≤0.001). There were trends t o w a r d s l o w e r C F R a n d h i g h e r C A C s c o r e s i n normoalbuminuric patients vs controls (p≤0.023) and towards higher CAC scores in albuminuric vs normoalbuminuric patients (p=0.026). In multivariate regression analysis, a higher urinary albumin excretion rate (UAER) tended to predict reduced CFR in the total population (p=0.045). When the CAC score was added, there was also a trend (p=0.032) towards an inverse association with reduced CFR. Conclusions/interpretation Type 2 diabetic patients who were free of overt cardiovascular disease had a high prevalence of coronary microvascular dysfunction, especially with concomitant albuminuria, suggesting a common microvascular impairment occurring in multiple microvascular beds. Prospective studies are needed to show the prognostic significance of this finding.

No abstract

No abstract

Nuclear cardiology has for many years been focused on gamma camera technology. With ever improving cameras and software applications, this modality has developed into an important assessment tool for ischaemic heart disease. However, the development of new perfusion tracers has been scarce. While cardiac positron emission tomography (PET) so far largely has been limited to centres with on-site cyclotron, recent developments with generator produced perfusion tracers such as rubidium-82, as well as an increasing number of PET scanners installed, may enable a larger patient flow that may supersede that of gamma camera myocardial perfusion imaging.