Alteration of the ankle brachial index, follow-up of patients at risk of peripheral arterial disease, a descriptive longitudinal study

Background The objective of this study was to detect peripheral arterial disease (PAD) by measuring the ankle-brachial index (ABI) in patients attending medical offices in primary health care who presented a moderate or high risk on the risk scale of Framingham. Design longitudinal descriptive. Setting urban health center. Materials and methods Patients at risk of peripheral arterial disease of the lower limbs: diabetes mellitus (DM), cardiovascular disease (CVD), high cardiovascular risk (HCR) (SCORE>5%), and/or compatible symptoms. Consecutive sampling, n=136 (expected prevalence 8%, alpha 0.05, precision 0.95, projected losses 20%). Dependent variable: ankle-brachial index (ABI). Independent variables: hypertension (HBP), age, sex, CVD, DM, glycosylated hemoglobin (HbA1C), hyperlipidemia (HLP), LDL cholesterol (LDL), smoking, body mass index (BMI), pulses, treatment. Multivariate analysis: linear regression. Confidence level 95%. Results From a sample of 136 patients, 90 were male (66.2%) and 46 were female (33.8%), with a mean age of 72.2 years (in 2021), and a standard deviation (SD) of 7. The prevalence of abnormal ABI (ABI <0.9) was 11%, with a mean ABI of 0.7 (SD 0.18). The bivariate analysis showed a significant relationship between abnormal ABI and pulse palpation (p<0.0001). Excluding patients with ABI ≥ 1.4, in the multivariate analysis (coefficient of determination 0.977), the B coefficients and their 95% confidence intervals (CI) are as follows: age B=0.006, 95% CI (0.002-0.010) (p=0.003); diabetes B=0.289, 95% CI (0.1-0.479) (p=0.003); pulse palpation B= -0.199, 95% CI (-0.289- -0.11) (p<0.0001). Conclusions Doctor consultations in primary care are a favorable context for making an early diagnosis of PAD, by measuring the ABI. The performance of the ABI should be included as part of the annual examination for chronic patients who regularly attend consultations, particularly those with moderate or high cardiovascular risk. In this way, preventive measures could be intensified to prevent future cardiovascular complications in these patients. The predictors of ABI are age, diabetes, and palpation of pulses.