| dc.description.abstract | Peripheral arterial disease (PAD) is highly associated with atherosclerosis. It has been recommended worldwide to use the ankle-brachial pressure index, also called ankle-brachial index (ABI) to screen for the possibility of PAD in patients with a high risk of atherosclerosis in the past decades. Patients identified to have PAD may benefit from early treatment and strict risk factors modification. ABI has very high specificity in the diagnosis of PAD in patients with significant arterial stenosis. However, the sensitivity in patients with less severe stenosis or calcified arteries has been insufficient. Further measurement of the toe-brachial index (TBI) or the combination of the treadmill exercise test with ABI has been recommended to improve the sensitivity. Photoplethysmography (PPG), a portable optical device, was also used to detect PAD with adequate sensitivity. ABI and PPG detect PAD in different mechanisms. In addition to TBI and treadmill exercise test, our study was to determine the diagnostic value of ABI combined with photoplethysmography (PPG) in detecting PAD. Within 2 years, we included 130 patients from the outpatient department or ward. They all received ABI, PPG, duplex ultrasonography, and 2-year follow up respectively. Sensitivity, specificity, and accuracy were evaluated in ABI, PPG, and both combinations. The final diagnosis of PAD was confirmed by duplex ultrasonography. There were 2 methods for PPG examination in this study, including PPGratio and PPGamp. The overall sensitivity, specificity, and accuracy were 55.9%, 98.6%, and 80.3% in ABI; 78.4%, 87.2%, and 83.4% in PPGratio; 75.7%, 92.6%, and 85.3% in PPGamp; 84.8%, 86.4%, and 85.7% in ABI plus PPGratio combination; 81.1%, 91.2%, and 86.9% in ABI plus PPGamp combination, respectively. Integrating ABI and PPG significantly enhances sensitivity and accuracy in diagnosing PAD compared to using ABI or PPG individually. This combined approach improves diagnostic precision and provides crucial insights into predicting major adverse cardiovascular events (MACE) and all-cause mortality, particularly beneficial for high-risk patients. | en_US |