Automated Ankle-Brachial Pressure Index Measurement by Clinical Staff for Peripheral Arterial Disease Diagnosis in Nondiabetic and Diabetic Patients

OBJECTIVE

Peripheral arterial disease (PAD) is a prognostic marker in cardiovascular disease. The use of Doppler-measured ankle-brachial pressure index (Dop-ABI) for PAD diagnosis is limited because of time, required training, and costs. We assessed automated oscillometric measurement of the ankle-brachial pressure index (Osc-ABI) by nurses and clinical staff.

RESEARCH DESIGN AND METHODS

Clinical staff obtained Osc-ABI with an automated oscillometric device in 146 patients (83 with diabetes) at the time of Dop-ABI measurement and ultrasound evaluation.

RESULTS

Measurements were obtained in most legs (Dop-ABI 98%; Osc-ABI 95.5%). Dop- and Osc-ABI were significantly related in diabetic and nondiabetic patients with good agreement over a wide range of values. When Dop-ABI ≤0.90 was used as the gold standard for PAD, receiver operating characteristic curve analysis showed that PAD was accurately diagnosed with Osc-ABI in diabetic patients. When ultrasound was used to define PAD, Dop-ABI had better diagnostic performance than Osc-ABI in the whole population and in diabetic patients (P = 0.026). Both methods gave similar results in nondiabetic patients. The cutoff values for the highest sensitivity and specificity for PAD screening were between 1.0 and 1.1. Estimation of cost with the French medical care system fees showed a potential reduction by three of the screening procedures.

CONCLUSIONS

PAD screening could be improved by using Osc-ABI measured by clinical staff with the benefit of greater cost-effectiveness but at the risk of lower diagnostic performance in diabetic patients.Peripheral arterial disease (PAD) is a frequent manifestation of atherosclerosis in the general population and is two to four times more prevalent in diabetic patients (1). A continuous wave Doppler-measured ankle-brachial pressure index (Dop-ABI) ≤0.90 is commonly used for diagnosing PAD (2,3). Ankle-brachial pressure index (ABI) sensitivity is 79% and specificity is 96% for detection of ≥50% reduction in vascular lumina (4). Moreover, Dop-ABI has prognostic value for cardiovascular morbidity and mortality and for coronary heart disease in particular (5). Despite the apparent simplicity of Dop-ABI measurements, they are time consuming and require technical skill and a dedicated device (2,6,7), which preclude routine use of ABI measurements in general practice (6). PAD remains largely underdiagnosed (1), particularly in diabetic patients in whom it is frequently associated with lower limb complications (8).Automated oscillometric determination of blood pressure is commonly used for screening for hypertension (9). Devices are widely available and reliable (9,10). Several studies reported automated oscillometric ankle-brachial pressure index measurement (Osc-ABI) with good agreement with Dop-ABI results (11,12), suggesting that it might be used for PAD screening.In this study, we evaluated Osc-ABI and Dop-ABI for PAD screening with ultrasound as a reference diagnostic procedure in diabetic and nondiabetic patients. Furthermore, we assessed the possible utility of involving nurses and clinical staff in PAD screening.