Moazzami K, Lima BB, Hammadah M, et al. - Researchers undertook this prospective cohort analysis to determine the link between the shift in circulating progenitor cell (CPC) counts during stress testing and the risk of adverse cardiovascular events in patients experiencing stable coronary artery disease (CAD). A total of 454 patients with stable CAD constituting a population-based sample were included who were recruited from Emory University-affiliated hospitals and observed for 3 years. At rest and 30 to 60 minutes following conventional stress testing, myocardial perfusion imaging with technetium Tc 99m sestamibi was performed. Adverse events occurred in 24 patients (5.2%). Among CAD patients, a worse disease prognosis was observed in correlation with a reduction in CPC counts during exercise vs the presence of stress-induced myocardial ischemia.