Angiography-derived index of microcirculatory resistance (IMRangio) as a novel pressure-wire-free tool to assess coronary microvascular dysfunction in acute coronary syndromes and stable coronary artery disease
SHANMUGANATHAN M., Scarsini R., DE MARIA G.
To investigate the diagnostic accuracy of (1) hyperaemic angiography-derived index of microcirculatory resistance (IMRangio) in defining coronary microvascular dysfunction (CMD) across patients with acute coronary syndromes (ST-elevation myocardial infarction [STEMI]; non-ST elevation acute coronary syndrome [NSTE-ACS]) and stable chronic coronary syndrome [CCS]) and (2) the accuracy of non-hyperaemic IMRangio (NH-IMRangio) to detect CMD in STEMI. 145 patients (STEMI = 66; NSTEMI = 43; CCS = 36) were enrolled. 246 pressure-wire IMR measurements were made in 189 coronary vessels. IMRangio and NH-IMRangio was derived using quantitative flow ratio. In patients with STEMI, cardiac magnetic resonance was performed to quantify microvascular obstruction (MVO). IMRangio was correlated with IMR (overall rho = 0.78, p