Limited flow reserve in non-obstructed bypass grafts supplying infarcted myocardium: implications for cardiovascular magnetic resonance imaging protocols.
We evaluated flow reserve in non-obstructed bypass grafts supplying infarcted and noninfarcted myocardium. Bypass grafts were examined by phase-contrast flow measurements and myocardial viability was assessed with late enhancement technique. Flow reserve was higher in bypasses supplying normal myocardium compared to those supplying infarcted myocardium (2.9 vs. 1.5, p<.0001). This difference remained significant after adjusting for co-variables. Bypass grafts supplying infarcted myocardium were more likely to have lower flow reserve than those supplying normal myocardium (flow reserve < or =2, 84% vs 18%, p = .0003). Flow reserve is reduced in non-stenosed bypasses supplying infarcted myocardium, likely due to altered microcirculation. Thus, cardiovascular magnetic resonance based bypass assessment must include myocardial viability testing.
Spies
Christian
C
Rush University Medical Center Section of Cardiology 1653 West Congress Parkway Chicago, IL 60612 USA. christian_spies@rush.edu
Mohrs
Oliver K
OK
Madison
James R
JR
Fach
Andreas
A
Nowak
Bernd
B
Voigtländer
Thomas
T