The relation between silent ischemia and coronary artery disease severity in diabetics

Abstract

The aim of this work was to examine the relation between the severity of silent ischemic episodes detected by ambulatory ECG recording and the angiographic severity of coronary artery disease (CAD). Fifty patients with chronic stable angina pectoris and type 2 diabetes mellitus were enrolled in the study.Among the study group, there were 33 males and 17 females; and their mean age was 61 ± 6.5 years. All patients were submitted to 24-hours ambulatory ECG recording and coronary angiography with estimation of Gensini score. According to the frequency of silent ST-segment depression episodes, patients were classified into two groups. Group I: 24 patients with ST-segment depression frequency <8. Group II: 26 patients with ST-segment depression frequency ⩾8. In patients with ST-segment depression frequency ⩾8, there were significantly higher number of left main coronary artery (LMCA) disease, and significantly higher Gensini score (Table 1). Sensitivity of ST-segment depression frequency ⩾8 in predicting Gensini score ⩾20 was 60%, specificity was 56%, positive predictive value was 58%, negative predictive value was 58%, and overall accuracy was 58% (Kappa = 0.412, p = 0.014). Gensini score showed significant positive correlation with ST-segment depression frequency (r = 0.391, p = 0.005), with maximum ST-segment depression (r = 0.346, p = 0.014), and with total ST-segment depression duration (r = 0.495, p = 0.0003). Patients with type 2 diabetes mellitus who had more frequent silent myocardial ischemia by ambulatory ECG recording were found to have angiographically more extensive CAD as assessed by Gensini score. Gensini score was found to be significantly correlated to the frequency of silent ST-depression, maximum ST-depression, and total ST-depression duration.