Risk Stratification of Patients With NonObstructive Coronary Artery Disease Using Resistive Reserve Ratio.

Background Resistive reserve ratio (RRR), or the ratio of baseline to hyperemic microvascular resistance, has prognostic implications in predicting clinical outcomes in patients with obstructive coronary artery disease. However, its value in patients with angina or ischemia with nonobstructive coronary artery disease is unknown. Methods and Results We included 1692 patients with nonobstructive coronary artery disease who underwent invasive coronary vasoreactivity testing.

Prognostic impact and clinical outcomes of coronary flow reserve and hyperaemic microvascular resistance.

Background: Most studies dichotomise indices of coronary microvascular function to assess their prognostic values.

Aims: We aimed to investigate whether coronary flow reserve (CFR) and hyperaemic microvascular resistance (HMR) as continua predict major adverse cardiovascular events (MACE), comprising all-cause death, myocardial infarction, revascularisation, and stroke in patients with ischaemia and non-obstructive coronary artery disease.

Methods: A total of 610 patients were included and followed up over a median of 8.