Correlation between the Ankle – Brachial and Toe – Brachial Indexes and Coronary Artery Disease in Patients with Type 2 Diabetes

Atherosclerotic coronary vascular disease (CVD) is a major cause of mortality and morbidity among diabetic patients. The ankle-brachial pressure index (ABI) is a simple screening procedure used in primary care settings for high risk populations, such as in diabetic patients, in whom medial arterial calcification results in falsely elevated ABI, which complicates?? the value of ABI in predicting CVD. The aim of this study was to determine whether ABI or Toe-brachial index (TBI) abnormalities can be used to identify asymptomatic type 2 diabetic patients with CVD. 
Materials &Methods: In this case control study, 91 patients with Type 2 DM were selected. All the patients, who had documented evidence for presence or absence of CVD, completed a questionnaire regarding medical history, following which TBI and ABI were measured using a handheld ultrasound Doppler. ABI values less than 0.9 and TBI less than 0.7 considered abnormal. 
Results: Forty-four persons (patient group) had documented CVD and 47 had normal angiography (control group). ABI < 0.9 was present in 13.6% of the patient group and in 8.5% of control group; TBI < 0.7 was present in 34.1% of the patients group and 23.4% of controls. There was no significant difference between abnormal ABI and abnormal TBI in the patients or and controls. Sensitivity and specificity of abnormal results in prediction of CVD was 13.6% and 91.4% for ABI and 34% and 76.5% for TBI.
Conclusion: Our study shows lack of sensitivity of ABI and TBI in identifying diabetic patients with CVD due to accelerated atherosclerosis.