[Coronary microvascular dysfunction in coronary artery disease associated with glucose intolerance]

Coronary flow reserve is used as an indicator to assess coronary microvascular function in the absence of obstructive coronary atherosclerosis. Diabetic patients, even with angiographically normal coronary arteries, show significantly reduced coronary flow reserve. This study evaluated coronary microcirculation in coronary artery disease complicated by glucose intolerance. Thirty-three patients with coronary artery disease were divided into three groups: Fourteen patients without glucose intolerance (control group), 8 with impaired glucose tolerance (IGT group), and 11 with noninsulin dependent diabetes mellitus (DM group). A Doppler guide wire was used to measure phasic coronary blood flow velocity in the left anterior descending artery without significant stenosis (> or = 40% diameter narrowing). Coronary flow reserve was determined by intracoronary 10 mg papaverine hydrochloride administration which induced maximal hyperemia. Coronary flow reserve was decreased in the DM group compared with the control group (2.1 +/- 0.6 vs. 3.1 +/- 0.9, p = 0.004), and that in the IGT group (2.5 +/- 0.9) did not show a significant difference compared with the other two groups. Vessel characteristics, such as infarct- or noninfarct-related artery and previous coronary angioplasty, did not have an influence on the results. Other coronary risk factors, left ventricular function, and hemodynamic findings were comparable in the three groups. This study demonstrates that diabetes mellitus may cause functional microvascular abnormalities in coronary artery disease.