Endothelial Dysfunction in Diabetic Patients with Abnormal Myocardial Perfusion in the Absence of Epicardial Obstructive Coronary Artery Disease

Abstract

In patients with diabetes mellitus, myocardial perfusion defects are often observed in the absence of obstructive epicardial coronary artery disease (CAD), thereby presenting a diagnostic problem. We hypothesized that these perfusion abnormalities may be explained by endothelial dysfunction or occult coronary atherosclerosis. Methods: Prospectively, 130 asymptomatic patients with diabetes mellitus underwent cardiovascular screening by coronary artery calcium (CAC) scoring, multislice CT coronary angiography, and myocardial perfusion imaging by SPECT. Multislice CT images were evaluated for the presence of obstructive epicardial CAD ($50% luminal narrowing). To quantify abnormal myocardial perfusion on SPECT images, we determined the summed stress score for each patient. The presence of abnormal myocardial perfusion was defined as a summed stress score of 3 or more. In addition, flow-mediated dilatation of the brachial artery, a marker of endothelial function, was determined using ultrasonography. Results: In 35 patients (27%), obstructive epicardial CAD was observed on multislice CT, and these patients were excluded from further analysis. In the remaining 95 patients, abnormal myocardial perfusion was observed in 30 (32%) of patients. Flow-mediated dilatation was significantly lower in patients with abnormal myocardial perfusion (3.6% 6 2.4%) than in those with normal myocardial perfusion (6.4% 6 2.6%) (P , 0.001). Importantly, flow-mediated dilatation remained a significant predictor of the extent of abnormal myocardial perfusion after correction for cardiovascular risk factors and CAC score (P , 0.001). In contrast, no association was observed between nonobstructive plaque burden as reflected by CAC scores and extent of abnormal myocardial perfusion. Conclusion: In patients with diabetes mellitus, myocardial perfusion abnormalities in the absence of obstructive epicardial CAD are associated with endothelial dysfunction.

Effects of type 2 diabetes mellitus on coronary microvascular function and myocardial perfusion in patients without obstructive coronary artery disease

“…This is consistent with previous findings using nuclear imaging techniques that demonstrate the effects of endothelial dysfunction on myocardial perfusion [27][28][29][30][31]. In particular, Djaberi et al [28] reported regional perfusion defects on adenosine-MPS in 32% of 95 diabetic patients without obstructive CAD on multislice CT angiography that were associated with abnormal brachial artery flowmediated dilation. Storto et al [30] and Marini et al [27] also found, using dipyridamole MPS, homogeneously impaired vascular function in diabetic patients, showing regional perfusion defects in about 30% of them.…”

Analysis of Coronary Plaque Morphology by 64-Multislice Computed Tomography Coronary Angiography and Calcium Scoring in Patients with Type 2 Diabetes Mellitus

“…In the recent years the presence of diabetes has been recognized as a cardiovascular disease (CVD) equivalent and represents for sure a major indication for further cardiovascular risk assessment in these patients (19,20).…”

Myocardial perfusion at rest in uncomplicated type 2 diabetes patients without coronary artery disease evaluated by 320-multidetector computed tomography

“…In asymptomatic diabetic patients, stress-induced myocardial ischemia has been widely identified by radionuclide imaging. [ 4 – 6 ] Nevertheless, the issue of myocardial perfusion changes at rest in these patients remains disputable. Djaberi et al [ 4 ] proved that abnormal myocardial perfusion in diabetic patients without obstructive epicardial CAD was associated with endothelial dysfunction, and also proposed myocardial hypoperfusion may occur during rest.…”

“…[ 4 – 6 ] Nevertheless, the issue of myocardial perfusion changes at rest in these patients remains disputable. Djaberi et al [ 4 ] proved that abnormal myocardial perfusion in diabetic patients without obstructive epicardial CAD was associated with endothelial dysfunction, and also proposed myocardial hypoperfusion may occur during rest. However, a single-photon emission computed tomography (SPECT) research demonstrated normal resting myocardial perfusion in T2DM patients without CAD.…”