Severely impaired microvascular reactivity in diabetic patients with an acute coronary syndrome

Background: Microvascular function is impaired in patients with stable coronary artery disease. The aim was to study microvascular function in patients with diabetes and acute coronary syndrome (ACS). Methods: Microvascular function was evaluated in 83 patients by laser Doppler fluxmetry (LDF) [PU; perfusion unit, median (interquartile range)] measuring resting LDF and peak LDF following a six min heating of the skin to 44 degrees C at the foot, respectively. All patients with ACS and without previously known diabetes underwent oral glucose tolerance test. Thirty-nine patients with type 2 diabetes mellitus free from coronary artery disease served as controls. Results: Peak LDF was significantly (P = 0.03) lower in patients with ACS and diabetes (n = 22; 72 (52)) and diabetes without coronary artery disease (n = 39; 69 (51)) as compared to patients with ACS without diabetes (n = 46; 97 (60)), and patients without ACS (n = 15; 140 (121)), respectively. Patients with ACS (n = 68) had significantly (P = 0.04) lower peak LDF (92 (49)) as compared to patients without ACS (n = 15) (140 (121)). Conclusion: Microvascular reactivity is severely impaired in patients with diabetes and ACS. Diabetes has a major influence on microvascular function in patients with coronary artery disease.