Saritas T, et al. - In patients with advanced chronic kidney disease (CKD), researchers investigated if a novel non-invasive reflectance mode photoplethysmography (PPG) sensor would be a valid tool to assess coronary artery disease (CAD). Four patient groups were analyzed: controls (patients without CKD or CAD); CKD alone; CAD alone (confirmed by coronary angiography); and CKD and CAD combined. Using green and infrared wavelengths, PPG signals were generated and recorded from the fingers of 98 patients. Information about the vascular system (arterial stiffness) was obtained. A steeper ascending signal during systole and greater signal decline during diastole were observed with advancing age. A slower signal decline during diastole was noted in CKD patients in association with the presence of CAD vs those without CAD. Lower blood volume amplitude during each cardiac cycle was seen in association with CKD vs those without CKD. Overall, significant differences were seen in PPG signal analyses between the groups. PPG signal analyses may afford a potentially useful tool for the detection of CAD in CKD patients.