Estudo comparativo do Índice Tornozelo-Braquial em diabéticos e não diabéticos com isquemia crítica.

Background: Calcification of the arterial tunica media can falsely elevate the Ankle-Brachial Index (ABI) in diabetics, making it difficult to assess arterial disease. Objective: To compare ABI values in diabetics and non-diabetics with critical ischemia. Methods: A total of 140 patients (60% diabetics) with critical ischemia due to infrainguinal peripheral arterial obstructive disease were recruited from the vascular surgery service at the Complexo Hospitalar Universitário Professor Edgard Santos. Mean ABI values for the two groups of patients were compared and correlated with severity of ischemia, according to the Rutherford Classification. Statistical analysis was conducted using EPI-INFO. Results: A majority of the 140 patients (77%) were classified as Rutherford Category 5,6% as Category 4 and 17% as Category 6. Nine diabetics (11%) and one non-diabetic (2%) exhibited ABI > 1.15 (p = 0.02) and were excluded from the comparative analysis of mean ABIs. For the 130-patient sample, the 75 diabetic patients had a mean ABI for the posterior tibial artery of 0.26, vs. 0.28 for the 55 non-diabetic patients (p = 0.6); while mean ABIs for the dorsalis pedis artery were 0.32 vs. 0.23 respectively (p = 0.06). When the patients were stratified by Rutherford categories, there were no differences in mean ABIs in categories 4 or 5. Only mean ABI for the dorsalis pedis artery in Category 6 patients was significantly higher among diabetics (0.44 vs. 0.16; p = 0.03). Conclusions: The diabetic patients had a higher prevalence of falsely elevated ABI, but when these cases were excluded, mean ABI values were similar to those of non-diabetic patients, with the exception of ABI measured at the dorsalis pedis artery in patients with category 6 ischemia. [ABSTRACT FROM AUTHOR]