Cook CM, et al. - Researchers examined the association of measurements of physiological stenosis severity with angina-limited exercise time in patients with stable angina and coronary stenosis. In this cohort study, the patients underwent invasive measurements of fractional flow reserve (FFR), instantaneous wave-free ratio (iFR), hyperemic stenosis resistance (HSR), and coronary flow reserve (CFR). Immediately following this, patients maximally exercised on a catheter-table–mounted supine ergometer until the development of rate-limiting angina. Most patients underwent percutaneous coronary intervention subsequently, followed by repeat maximal supine exercise testing. Outcomes suggest no significant correlation of anatomical stenosis characteristics with angina-limited exercise time. Conversely, angina-limited exercise time was noted to be correlated with FFR, iFR, HSR, as well as with CFR to varying degrees.