Correlation between ankle-arm blood pressure index (AAI) and atherosclerotic vascular involvement in coronary arteries

Summary l reports indicated that presence of peripheral arterial disease (PAD) and low ankle-arm index (AAI) are independently associated with a substantial increase in cardiovascular mortality, particularly from coronary heart disease (CHD). The goal of the study was to evaluate whether the AAI correlates with extension and severity of the atherosclerotic vascular involvement in coronary arteries. One-hundred and sixty-one male inpatients who consecutively underwent coronary angiography were referred to our Vascular Laboratory for ultrasonographic examination of lower extremity arteries. Coronary artery disease (CAD) was classified by its extent (number of major coronary vessels affected by at least one stenosis of 50 % or more) and severity (sum of the maximum percentages of stenosis in each of the major coronary vessels). Differences in AAI and other covariates in relation to extent and severity of CAD were evaluated using univariate and multiple regression analysis. Total cholesterol (p < 0.05) and, inversely, AAI (p < 0.005) were correlated with extent of CAD. Total cholesterol (p < 0.005), LDL-cholesterol (p < 0.05), triglycerides (p < 0.05), diabetes (p < 0.05) and, inversely, AAI (p < 0.005) were correlated with the severity score. After multiple regression analysis including these covariates, AAI was independently and inversely correlated with the extent and severity (for both: p < 0.005) of coronary artery atherosclerotic involvement. The AAI is strongly, independently and inversely correlated with the extent and severity of coronary artery atherosclerosis. We suggest that the determination of the AAI can be of help for identifying patients who are likely to have wide and severe coronary atherosclerosis.