Toya T, Ahmad A, Corban MT, et al. - Researchers investigated the value of resistive reserve ratio (RRR), or the ratio of baseline to hyperemic microvascular resistance, in patients with angina or ischemia with nonobstructive coronary artery disease. A total of 1,692 patients with nonobstructive coronary artery disease who underwent invasive coronary vasoreactivity testing were assessed. Findings revealed superiority of RRR to coronary flow reserve (CFR, the ratio of hyperemic and baseline resting flow velocities) in predicting long‐term survival in these patients. Patients with nonobstructive coronary artery disease with an RRR < 2.62 were noted to be at 1.6 times increased risk of death. Indices of coronary microcirculatory resistive reserve, that comprise flow‐ and pressure‐derived values, may suggest underlying microvascular pathology more clearly than flow‐alone indices like CFR.