Infarct size by contrast enhanced cardiac magnetic resonance is a stronger predictor of outcomes than left ventricular ejection fraction or end-systolic volume index: prospective cohort study.
OBJECTIVE
Ejection fraction (EF) and end-systolic volume index (ESVI) are established predictors of outcomes following ST-segment elevation myocardial infarction (STEMI). We sought to assess the relative impact of infarct size, EF and ESVI on clinical outcomes and left ventricular (LV) remodelling.


METHODS
Prospective cohort study.


METHODS
Academic hospital in Chicago, USA.


METHODS
122 patients with STEMI following acute percutaneous reperfusion.


METHODS
Death, recurrent myocardial infarction (MI) and heart failure.


METHODS
Cardiac magnetic resonance imaging was obtained within 1 week following STEMI in 122 subjects. ESVI, EF and infarct size were tested for the association with outcomes over 2 years in 113 subjects, and a repeat study was obtained 4 months later to assess LV remodelling in 91 subjects.


RESULTS
Acute infarct size correlated linearly with the initial ESVI (r = 0.69, p<0.001), end-diastolic volume index (EDVI) (r = 0.42, p<0.001) and EF (r = -0.75, p<0.001). All were independently associated with outcomes (one death, one recurrent MI and 16 heart failure admissions). However, infarct size was the only significant predictor of adverse outcomes (p<0.05) by multivariate analysis. The smallest infarct size tertile had an increased EF (49% (SD 8%) to 53% (6%); p = 0.002) and unchanged EDVI (p = 0.7). In contrast, subjects with the largest infarct tertile also had improved EF (32% (9%) to 36% (11%); p = 0.002) at the expense of a dramatic increase in EDVI (86 (19) to 95 (21) ml/m(2); p = 0.005).


CONCLUSIONS
Infarct size, EF and ESVI can predict the development of future cardiac events. Acute infarct size, which is independent of LV stunning and loading, directly relates to LV remodelling and is a stronger predictor of future events than measures of LV systolic performance.
Wu
E
E
Feinberg Cardiovascular Research Institute, Division of Cardiology, Department of Medicine, Feinberg School of Medicine, Northwestern University, 201 East Huron, Galter 10-240, Chicago, IL 60611-2908, USA. ed-wu@northwestern.edu
Ortiz
J T
JT
Tejedor
P
P
Lee
D C
DC
Bucciarelli-Ducci
C
C
Kansal
P
P
Carr
J C
JC
Holly
T A
TA
Lloyd-Jones
D
D
Klocke
F J
FJ
Bonow
R O
RO
D003287:Contrast Media; D017023:Coronary Angiography; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000473:pathology* / Q000503:physiopathology; D013318:Stroke Volume / Q000502:physiology; D013599:Systole / Q000502:physiology; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology*; D020257:Ventricular Remodeling / Q000502:physiology*
D003287:Contrast Media