Upstroke time is a more useful marker of atherosclerosis than percentage of mean arterial pressure for detecting coronary artery disease in subjects with a normal ankle-brachial index

Abstract

Upstroke time (UT) and percentage of mean arterial pressure (%MAP) at the ankle have been shown to serve as atherosclerotic markers. The purpose of this study was to directly compare the diagnostic accuracy of UT with that of %MAP for clinical coronary artery disease (CAD) in subjects with a normal ankle-brachial index (ABI) in both legs. We measured UT and %MAP in 1953 subjects with a normal ABI. The optimal cutoff values of UT and %MAP derived from a receiver operating characteristic (ROC) curve to diagnose CAD were 148 ms and 40.4%, respectively. Multivariable analyses revealed that both UT ≥ 148 ms (odds ratio [OR], 2.72; p < 0.001) and %MAP ≥ 40.4% (OR, 1.28; p = 0.003) were significantly associated with CAD. When the subjects were divided into four groups according to the cutoff values of UT and %MAP, there was no significant difference in the risk of CAD between subjects with UT ≥ 148 ms and %MAP < 40.4% and those with UT ≥ 148 ms and %MAP ≥ 40.4% (OR, 1.45; p = 0.09). ROC curve analyses revealed that the area under the curve value of UT was significantly higher than that of %MAP (0.69 vs. 0.53, p < 0.001). The addition of UT to traditional risk factors significantly improved the diagnostic accuracy for CAD (0.82 to 0.84, p = 0.004), whereas the addition of %MAP to traditional risk factors did not improve the diagnostic accuracy for CAD (0.82 to 0.82, p = 0.84). UT is more useful than %MAP for identifying individuals with CAD among those with a normal ABI.

Fundamentals of utilizing upstroke time and percentage mean arterial pressure of ankle pulse volume recording as cardiovascular indexes

“…The authors of the present study previously reported that an ankle UT ≥ 180 msec could be useful as a marker for CAD [9] and also, for CAD or CVD among patients with diabetes mellitus who often have incompressible calcified arteries [10]. The present study enrolled patients with a normal ABI (1.0 ≤ ABI < 1.4) in both legs and examined the optimal cut-off values of ankle UT and % MAP for detecting patients with CAD [5]. As the result, the cut-off values were set to UT ≥ 148 msec and %MAP ≥ 40.4%.…”

“…It is well known that pulse volume recording (PVR) sense proximal arterial stenosis earlier than ABI with its deformation characterized by an absence of a dicrotic notch, a prolonged systolic downslope, a rounded systolic peak, and a flattened wave with a delayed upstroke and run-off. As mentioned in the present manuscript, the automated oscillometric device records pulse volume waveforms of the limbs for 10 s by air plethysmography after measuring limb pressures [4,5]. PVR does not require arterial compression and is less affected by arterial calcification.…”

“…In addition, the device calculates the upstroke time (UT) and percentage mean arterial pressure (%MAP) of each limb as the index of PVR. The calculation method of %MAP is expressed in the present manuscript [5]. That is, %MAP is the percentage of enclosed pulse volume area relative to the rectangle with the pulse's base and amplitude [7].…”

“…Fig. 1 Ankle pulse volume recordings (PVR) and calculation methods of upstroke time (UT) and percentage mean arterial pressure (%MAP).A broken line with two-headed arrows indicates the height at which the enclosed pulse wave area (pink area) is flattened in the rectangle (blue box) (See details of the formulas in the text and previous[7] and present manuscript[5]). Ankle PVRs of normal adults show a sharp and high first peak.…”