Coronary microcirculation evaluation with transesophageal echocardiography Doppler in type II diabetics

Evaluation of coronary microvascular function can be obtained through coronary flow reserve measurements. The aim of this study was to evaluate the coronary microvascular function by using transesophageal-Doppler echocardiographic assessment of coronary flow reserve. The study included 32 normotensive patients with type II diabetes mellitus (group A) of short duration (6.1+/-3.8 years) aged 55.4+/-9.4 years and 14 healthy volunteers matched for age, gender and BMI (group B). No patients had clinical evidence of coronary artery disease and all of them produced a negative recent stress ECG test. Excluded from the study were patients with anemia, left ventricular hypertrophy, arrhythmia, congenital, or acquired structural heart disease. All subjects underwent transesophageal-Doppler echocardiography. Satisfactory coronary blood flow velocity recordings could be obtained from the initial segment of the left anterior descending coronary artery in healthy volunteers and in 27 patients at baseline and 2 min after dipyridamole infusion (0.56 mg/kg, for 4 min). In the remaining 5 patients no satisfactory recordings were available. The indexes of coronary flow reserve, i.e. the ratios of dipyridamole over basal maximum and mean diastolic velocities were calculated. Dipyridamole/rest maximal coronary reserve (Table 3) was 1.946+/-0.743, while this ratio for the mean diastolic velocity was 1.969+/-0.805 in group A. The respective values for group B, were 2.811+/-0.345 (P=0.000 vs. group A) and 2.914+/-0.303 (P=0.000 vs. group A). Thus, the increase in coronary flow reserve although present in both groups, it was more impressive in the normal group. Multiple regression logistic analysis of: age, sex, smoking, glucosylated hemoglobin, duration of diabetes and type of therapy, did not show any correlation of these parameters with the above ratios. This study shows that coronary flow reserve, as measured with transesophageal echocardiography-Doppler, is severely impaired in normotensive patients with type II diabetes, with relatively short duration of the disease.