JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY

VOL. 64, NO. 18, 2014

ª 2014 BY THE AMERICAN COLLEGE OF CARDIOLOGY FOUNDATION

ISSN 0735-1097/$36.00

PUBLISHED BY ELSEVIER INC.

http://dx.doi.org/10.1016/j.jacc.2014.08.028

EDITORIAL COMMENT

Invasive Coronary Microcirculation Assessment During Myocardial Infarction One Step Forward or Two Steps Back?* Gilles Rioufol, MD, PHD, Gérard Finet, MD, PHD

I

n acute coronary occlusion, ST-segment eleva-

(CFR) (5) and the index of microvascular resistance

tion myocardial infarction (STEMI) has been

(IMR) (6–10), making these promising candidates for

experimentally and clinically correlated with

assessing reperfusion lesions.

ischemic myocardial mass (area at risk), coronary

IMR has been of particular interest, as it shows less

reperfusion delay, and collateral circulation (1). Rapid

variation

coronary reperfusion, usually by primary percuta-

correlates with infarct size (6,7,10) and also with

neous coronary intervention (PPCI), provides the

improvement in left ventricular function (6–8,11,12).

principal means of limiting infarct size and improving

Recently, Fearon et al. (13) and Fukunaga et al. (10)

prognosis. It may, however, induce reperfusion

showed that IMR is a prognostic factor for heart

lesions, accounting for up to 40% to 50% of final

failure and death. When resistance is high, IMR

infarct size (2), making this a major research issue

increases and CFR decreases. IMR is typically