Characterization of the peri-infarct zone by contrast-enhanced cardiac magnetic resonance imaging is a powerful predictor of post-myocardial infarction mortality.
BACKGROUND
Accurate risk stratification is crucial for effective treatment planning after myocardial infarction (MI). Previous studies suggest that the peri-infarct border zone may be an important arrhythmogenic substrate. In this pilot study, we tested the hypothesis that the extent of the peri-infarct zone quantified by contrast-enhanced cardiac magnetic resonance (CMR) is an independent predictor of post-MI mortality.


RESULTS
We studied 144 patients with documented coronary artery disease and abnormal myocardial delayed enhancement (MDE) consistent with MI. A computer-assisted, semiautomatic algorithm quantified the total infarct size and divided it into the core and peri-infarct regions based on signal-intensity thresholds (>3 SDs and 2 to 3 SDs above remote normal myocardium, respectively). The peri-infarct zone was normalized as a percentage of the total infarct size (%MDE(periphery)). After a median follow-up of 2.4 years, 29 (20%) patients died. Patients with an above-median %MDE(periphery) were at higher risk for death compared with those with a below-median %MDE(periphery) (28% versus 13%, log-rank P<0.01). Multivariable analysis showed that left ventricular systolic volume index and %MDE(periphery) were the strongest predictors of all-cause mortality (adjusted hazard ratio [HR] for %MDE(periphery), 1.45 per 10% increase; P=0.002) and cardiovascular mortality (adjusted HR, 1.51 per 10% increase; P=0.009). Similarly, after adjusting for age and left ventricular ejection fraction, %MDE(periphery) maintained strong and independent associations with all-cause mortality (adjusted HR, 1.42; P=0.005) and cardiovascular mortality (adjusted HR, 1.49; P=0.01).


CONCLUSIONS
In patients with a prior MI, the extent of the peri-infarct zone characterized by CMR provides incremental prognostic value beyond left ventricular systolic volume index or ejection fraction. Infarct characteristics by CMR may prove to be a unique and valuable noninvasive predictor of post-MI mortality.
Yan
Andrew T
AT
Cardiovascular Magnetic Resonance Imaging Program, Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, 75 Francis St, Boston, Massachusetts 02115, USA.
Shayne
Adolphe J
AJ
Brown
Kenneth A
KA
Gupta
Sandeep N
SN
Chan
Carmen W
CW
Luu
Tuan M
TM
Di Carli
Marcelo F
MF
Reynolds
H Glenn
HG
Stevenson
William G
WG
Kwong
Raymond Y
RY
D000368:Aged; D003287:Contrast Media; D003324:Coronary Artery Disease / Q000150:complications; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications / Q000401:mortality* / Q000473:pathology*; D010865:Pilot Projects; D011237:Predictive Value of Tests; D011379:Prognosis; D018570:Risk Assessment; D018487:Ventricular Dysfunction, Left / Q000209:etiology
D003287:Contrast Media; D019786:Gadolinium DTPA