Prediction of left ventricular remodeling and analysis of infarct resorption in patients with reperfused myocardial infarcts by using contrast-enhanced MR imaging.
OBJECTIVE
To prospectively evaluate the accuracy of clinical and cardiac magnetic resonance (MR) imaging parameters for predicting left ventricular (LV) remodeling by using follow-up imaging as reference standard, and to prospectively evaluate infarct resorption in patients with reperfused first myocardial infarcts.


METHODS
The study was approved by the institutional ethics committee and all patients gave written informed consent. In 55 patients (48 men, seven women; mean age+/-standard deviation, 56 years+/-13), contrast material-enhanced and cine MR imaging were performed 5 days+/-3 and 8 months+/-3 after myocardial infarction (MI). Microvascular obstruction (MO) and infarct size were estimated at first-pass enhancement (FPE) and delayed enhancement (DE) MR, respectively. Remodeling was defined as an increase in LV end-diastolic volume index of 20% or higher at follow-up. Differences in continuous and categorical data were analyzed by using Student t test and Fischer exact test as appropriate.


RESULTS
Patients with remodeling (n=13, 24%) had higher creatine kinase MB (P<.05), more anterior infarcts (P<.05), more often a reduced Thrombolysis in Myocardial Infarction flow (P<.05), larger infarct size at DE MR (P<.001), a greater extent of MO at FPE MR (P<.01), lower ejection fraction (P<.001) and higher LV end-systolic volume index (P<.01). Infarct size at DE MR was a powerful predictor for remodeling (odds ratio: 1.18, P<.001), demonstrating that the risk for remodeling increased 2.8-fold with each 10% increase in infarct size. Infarct size of 24% or more of LV area predicted remodeling with high sensitivity (92%), specificity (93%), and accuracy (93%). Infarct resorption was larger in patients with remodeling (P<.01).


CONCLUSIONS
Infarct size 24% or more of the LV area constitutes an important threshold to predict remodeling. Patients with remodeling develop disproportionate infarct resorption.
Lund
Gunnar K
GK
Department of Cardiology, University Hospital Eppendorf, Hamburg, Germany. lund@roentgeninstitut.de
Stork
Alexander
A
Muellerleile
Kai
K
Barmeyer
Achim A
AA
Bansmann
Martin P
MP
Knefel
Meike
M
Schlichting
Ulrike
U
Müller
Martin
M
Verde
Pablo E
PE
Adam
Gerhard
G
Meinertz
Thomas
T
Saeed
Maythem
M
D003287:Contrast Media; D005260:Female; D006801:Humans; D007089:Image Enhancement; D008279:Magnetic Resonance Imaging / Q000379:methods*; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D020257:Ventricular Remodeling
D003287:Contrast Media