Abstract 15130: Sweat Lactate Sensor for Detecting Anaerobic Threshold in Paitents With Heart Failure: Prospective Clinical Trial (LacS-001)

Abstract

Background: Exercise is essential for good health and prevention of exacerbations in patients with heart failure (HF). To determine ventilatory threshold (VT); a key to detect appropriate exercise intensity, our team developed a small, easy-to-use device for non-invasive, simple, and real-time visualization of sweat lactate dynamics during exercise. Clinical Question: Could our sweat lactate sensor (GI-1) provide a safe and accurate means of detecting VT in patients with HF in a clinical setting? Aim: This prospective clinical trial (clinical trial; jRCT2032220057) was designed to investigate the safety of a sweat lactate sensor (GI-1) and the correlation between the lactate threshold in sweat (sLT), as assessed using our sweat lactate sensor, and the VT. Methods: We recruited 50 patients with HF and New York Heart Association functional classification I-II, with a median age of 63.5 years (interquartile range: 58.0-72.0 years). Incremental exercise tests were conducted and changes in sweat lactate levels were monitored simultaneously. The sLT was defined as the first steep increase in lactate levels from baseline as seen on graphical plots and was evaluated by three independent investigators. The primary outcome measures were a correlation coefficient of 0.6 or greater between sLT and VT, the similarities as assessed by the Bland-Altman analysis, and the standard deviation of the difference between the two within 15 W. Results: Among the 50 patients, a correlation coefficient of 0.651 (95% confidence interval, 0.391-0.815) was achieved in 32 cases. The difference between the sLT and VT was -4.9±15.0 W, and no comparative error was noted in the Bland-Altman plot. No device-related adverse events were reported among the registered patients. Conclusions: Our sweat lactate sensor, GL-1, provides a safe and accurate means of detecting VT in patients with HF in a clinical setting, thereby offering valuable additional information for treatment.