Impact of unrecognized myocardial scar detected by cardiac magnetic resonance imaging on event-free survival in patients presenting with signs or symptoms of coronary artery disease.
BACKGROUND
Contrast-enhanced cardiac magnetic resonance imaging (CMR) can determine the extent of myocardial scar from infarction (MI). However, the prognostic significance of unrecognized myocardial scar by CMR in patients without a history of MI is unknown.


RESULTS
One hundred ninety-five patients without a known prior MI underwent CMR for assessment of left ventricular (LV) function and late gadolinium enhancement (LGE). We assessed the prognostic value of LGE and other CMR variables beyond the strongest clinical predictors and built the best overall models for major adverse cardiac events (MACE) and cardiac mortality. During a median follow-up of 16 months, 31 patients (18%) experienced MACE, including 17 deaths. LGE demonstrated the strongest unadjusted associations with MACE and cardiac mortality (hazard ratios of 8.29 and 10.9, respectively; both P<0.0001). Patients in the lowest tertile of LGE-involved myocardium (mean LV mass, 1.4%) experienced a >7-fold increased risk for MACE. By multivariable analyses, LGE was independently associated with MACE beyond the clinical model (P<0.0001) or the clinical model combined with angiographically significant coronary stenosis (P=0.0007), LV ejection fraction (P=0.001), LV end-systolic volume index (P=0.0006), or segmental WMA (P=0.002). LGE remained the strongest predictor selected in the best overall models for MACE and cardiac mortality.


CONCLUSIONS
Among patients with a clinical suspicion of coronary artery disease but without a history of MI, LGE involving a small amount of myocardium carries a high cardiac risk. In addition, LGE provides incremental prognostic value to MACE and cardiac mortality beyond common clinical, angiographic, and functional predictors.
Kwong
Raymond Y
RY
Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, 75 Francis St, Boston, Masssachusetts 02115, USA. rykwong@partners.org
Chan
Anna K
AK
Brown
Kenneth A
KA
Chan
Carmen W
CW
Reynolds
H Glenn
HG
Tsang
Sui
S
Davis
Roger B
RB
D000368:Aged; D002318:Cardiovascular Diseases / Q000401:mortality; D002921:Cicatrix / Q000473:pathology*; D015331:Cohort Studies; D015897:Comorbidity; D003287:Contrast Media; D003327:Coronary Disease / Q000150:complications*; D016757:Death, Sudden, Cardiac / Q000453:epidemiology; D018572:Disease-Free Survival; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D005682:Gadolinium; D006801:Humans; D015993:Life Tables; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008875:Middle Aged; D008955:Models, Cardiovascular; D009206:Myocardium / Q000473:pathology*; D011379:Prognosis; D016016:Proportional Hazards Models; D012306:Risk; D012907:Smoking / Q000453:epidemiology
D003287:Contrast Media; D005682:Gadolinium