Moazzami K, Lima BB, Hammadah M, et al. - In patients with stable coronary artery disease, researchers explored the connection between the change in circulating progenitor cell (CPC) counts during stress testing and the risk of adverse cardiovascular events. The sample consisted of 454 individuals (mean [SD] age, 63 [9] years) with stable coronary artery disease who were selected between June 1, 2011, and August 15, 2014, at Emory University-affiliated hospitals and followed up for 3 years. According to this prospective cohort study, the adverse event risk more than doubled for every 50% decline in CPC counts during exercise stress. Stress-induced ischemia was no longer related to outcomes after stress-induced changes in CPC counts were involved in the analysis. A decrease in CPC counts during exercise was linked to a worse prognosis and was a stronger factor in outcomes than the presence of stress-induced myocardial ischemia among patients with coronary artery disease.