Comparison of Subjective versus Objective Lower-Extremity Arterial Plethysmographic Waveform Analysis for the Identification of Hemodynamically Significant Inflow Disease

Abstract

Objective Segmental pressures and subjective air plethysmography waveform (APW) analysis commonly are used in the noninvasive diagnosis of lower-extremity peripheral arterial disease (PAD) and have been used historically to define the extent of PAD. A recent investigation identified objective thigh arterial pulse waveform characteristics for defining hemodynamically significant (>50% diameter) PAD above the level of the common femoral artery (INFLOW). The purpose of this study is to compare subjective and objective APW analysis methodologies for defining INFLOW. Methods Patients who underwent segmental APW analysis and arteriography within 30 days of their noninvasive procedure were studied. Objective APW characteristics obtained from the thigh cuff included acceleration time, maximum amplitude, waveform down-slope curvature, relative amplitude reduction, and gain compensation index. Arteriograms were the basis for comparisons of objective APW criteria versus subjective APW pattern recognition interpretations of INFLOW disease. Results A total of 107 extremities were analyzed. There were statistically significant differences in sensitivity, specificity, positive predictive and negative predictive values, and accuracy for identifying hemodynamically significant INFLOW disease using objective (85%, 93%, 85%, 93%, 91%) versus subjective (53%, 85%, 62%, 80%, 75%) APW analysis, p = 0.0110. Conclusions Objective APW analysis of thigh level waveform characteristics may improve the identification of INFLOW disease in patients undergoing physiologic testing for lower extremity PAD.