Background: Some peripheral artery disease (PAD) patients have normal ankle brachial index (ABI) (0.9 - 1.4), although ABI is a useful parameter for the diagnosis of PAD. We investigated whether other parameters of ABI report sheet are useful to detect these patients.
Methods: We initially enrolled 3,912 patients (7,824 limbs) who underwent ABI for the first time. Subjects who have normal ABI were divided into the PAD group (n = 136) and the non-PAD group (n = 240) by lower extremity ultrasonography. We investigated blood pressures (BP) (systolic (SBP), diastolic (DBP), mean (mBP) and pulse pressure (PP)), heart rate, upstroke time (UT), and %mean arterial pressure (%MAP).
Results: SBP, mBP, PP, UT, and %MAP in the PAD group were significantly higher. A multivariate analysis showed that mBP, DBP, PP, UT and %MAP were independently associated with the presence of PAD (mBP: odds ratio (OR) 2.30, 95% confidence interval (CI) 1.22 - 4.37, P = 0.010; DBP: OR 0.52, 95% CI 0.28 - 0.97, P = 0.039; PP: OR 1.30, 95% CI 0.69 - 2.46, P = 0.041; UT: OR 3.40, 95% CI 2.03 - 5.83, P < 0.001; %MAP: OR 1.77, 95% CI 1.05 - 2.98, P = 0.031). Maximal area under the curve (AUC) of BPs for associating PAD was PP. The cut-off value of PP was 53.0 mm Hg (sensitivity 0.500, specificity 0.721, AUC 0.628, 95% CI 0.569 - 0.687).
Conclusions: The present study demonstrated that BPs are associated with PAD in patients with normal ABI. The measurement of BPs could provide additional information for the diagnosis of PAD.
Keywords: Ankle brachial index; Peripheral artery disease; Pulse pressure; Upstroke time.