RT Journal Article
SR Electronic
T1 10 A high index of microcirculatory resistance in non-obstructed vessels is associated with ischaemia and lv dysfunction
JF Heart
JO Heart
FD BMJ Publishing Group Ltd and British Cardiovascular Society
SP A6
OP A6
DO 10.1136/heartjnl-2018-BCIS.10
VO 104
IS Suppl 1
A1 A Liu
A1 R Wijesurendra
A1 J Liu
A1 J Langrish
A1 A Lucking
A1 R Choudhury
A1 A Banning
A1 K Channon
A1 S Piechnik
A1 S Neubauer
A1 V Ferreira
A1 R Kharbanda
YR 2018
UL http://heart.bmj.com/content/104/Suppl_1/A6.1.abstract
AB Background The Index of Microcirculatory Resistance (IMR) can identify Coronary Microcirculatory Dysfunction (CMD), but its pathophysiological effects are uncertain. We characterised relations between IMR and downstream myocardial perfusion and LV function.Methods 60 patients with stable coronary disease (67±8 years, 72% male) had adenosine stress Cardiac MRI to assess myocardial perfusion reserve (MPR), systolic and diastolic function (LV strain). All patients had invasive angiography and Fractional Flow Reserve (FFR) and IMR assessment in all possible vessels (135/180).Results In 96 vessels FFR>0.8, IMR was inversely related to MPR (rho −0.65), systolic (rho −0.57) and diastolic strain (rho −0.50), all p<0.001. An IMR cut-off of 25 detected ischaemia (AUC 0.93, p<0.001) (figure 1). In patients with all vessels FFR>0.80, as the number of high IMR (≥25) vessels increased, global myocardial perfusion, systolic and diastolic strain reduced in a step-wise fashion, reflecting increasing severity of CMD (all p<0.01). In vessels FFR≤0.8, IMR was not related to MPR (rho −0.23; p=0.15), systolic (rho −0.14; p=0.45) or diastolic strain (rho −0.12; p=0.49).Abstract 10 Figure 1 Relations of IMR with myocardial perfusion, systolic and diastolic strain on CMRConclusions An IMR of ≥25 is associated with impaired myocardial perfusion, systolic and diastolic dysfunction. The implications of these novel findings deserve further study.