Submaximal Cardiopulmonary Exercise Testing for Detection of Myocardial Injury After Noncardiac Surgery

A serum derived measure of myocardial injury. Threshold value of 14ng/L.

FDA-approved device uses breath by breath sampling during calibration and exercise challenge. Analysis is performed using a differential pressure pneumotach method for volume calibration and measurement, an infrared sensor for CO2 and a paramagnetic sensor for O2 measurements. Automated calibration using a calibration gas mixture (15.6% O2/5% CO2) is performed at regular intervals. The Shape II calculations used to differentiate causes of exertional dyspnea are Artificial Intelligence (AI) based algorithms and measurements have been previously validated to conventional cardiopulmonary exercise testing methods. Brief smCPET is comprised of a 2-minute calibration phase, 3 minutes of graded exercise using a stair-step and a 1 minute recovery phase for a total of 6 minutes. An instant report is then generated.

A validated measure of preoperative functional capacity which will be utilized to cross-validate smCPET peak VO2. Low DASI score has been found to estimate peak oxygen uptake (VO2), predict MINS, myocardial infarction, and inducible myocardial ischemia on myocardial perfusion scintigraphy.