Comparison of the angiographic myocardial blush grade with delayed-enhanced cardiac magnetic resonance for the assessment of microvascular obstruction in acute myocardial infarctions.
BACKGROUND
Both myocardial blush grade (MBG) and cardiac magnetic resonance (CMR) are imaging tools that can assess myocardial reperfusion after primary percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI).


OBJECTIVE
We studied the relation between MBG and gadolinium-enhanced CMR for the assessment of microvascular obstruction (MVO) in patients with acute ST-elevated myocardial infarction (STEMI) treated by primary PCI.


METHODS
MBG was assessed in 39 patients with initial TIMI 0 STEMI successfully treated by PCI, resulting in TIMI 3 flow grade and complete ST-segment resolution. These MBG values were related to MVO determined by CMR, performed between 2 and 7 days after PCI. Left ventricular (LV) volumes were determined at baseline and at 6-month follow-up.


RESULTS
No statistical relation was found between MBG and MVO extent at CMR (P = 0.63). Regarding MBG 0 and 1 as a sign of MVO, the sensitivity and specificity of these scores were 53.8 and 75%, respectively. In this study, CMR determined MVO was the only significant LV remodeling predicting factor (beta = 31.8; P = 0.002), whatever the MBG status was.


CONCLUSIONS
MBG underestimates MVO after an optimal revascularization in AMI compared with CMR. This study suggests the superior accuracy of delayed-enhanced magnetic resonance over MBG for the assessment of myocardial reperfusion injury that is needed in clinical trials, where the principal endpoint is the reduction of infarct size and MVO.
Vicente
J
J
Radiology Department, Hôpital Cardiovasculaire Louis Pradel, Bron cedex, Hospices Civils de Lyon, France.
Mewton
N
N
Croisille
P
P
Staat
P
P
Bonnefoy-Cudraz
E
E
Ovize
M
M
Revel
D
D
D000328:Adult; D000368:Aged; D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects; D003287:Contrast Media; D017023:Coronary Angiography; D003326:Coronary Circulation; D005260:Female; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008536:Meglumine; D008833:Microcirculation; D055806:Microvessels / Q000000981:diagnostic imaging / Q000503:physiopathology; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D015428:Myocardial Reperfusion Injury / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology; D009942:Organometallic Compounds; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D013997:Time Factors; D016896:Treatment Outcome; D020257:Ventricular Remodeling
D003287:Contrast Media; D009942:Organometallic Compounds; D008536:Meglumine; C072417:gadoterate meglumine