Contractile reserve and extent of transmural necrosis in the setting of myocardial stunning: comparison at cardiac MR imaging.
OBJECTIVE
To perform a comparison of cardiac magnetic resonance (MR) imaging-derived ejection fraction (EF) during low-dose dobutamine infusion (EF(D)) with the extent of segments with transmural necrosis in more than 50% of their wall thickness (ETN) for the prediction of major adverse cardiac events (MACEs) and late systolic recovery soon after a first ST-segment elevation myocardial infarction (STEMI).


METHODS
Institutional ethics committee approval and written informed consent were obtained. One hundred nineteen consecutive patients with a first STEMI, a depressed left ventricular EF, and an open infarct-related artery underwent MR imaging at 1 week after infarction. EF(D) and ETN (by using a 17-segment model) were determined, and the prediction of MACEs and systolic recovery at follow-up was assessed by using area under the receiver operating characteristic curve (AUC) and multivariable regression analysis.


RESULTS
During follow-up (median, 613 days; range, 312-1243 days), 18 MACEs (five cardiac deaths, six myocardial infarctions, seven readmissions for heart failure) occurred. MACEs were associated with a lower EF(D) (43% +/- 12 [standard deviation] vs 49% +/- 10, P = .02) and a larger ETN (seven segments +/- three vs four segments +/- three, P < .001). Patients with systolic recovery (increase in EF of >5% at follow-up compared with baseline EF, n = 44) displayed a higher EF(D) (51% +/- 10 vs 47% +/- 9, P = .04) and a smaller ETN (three segments +/- two vs five segments +/- three, P = .002) at 1 week. ETN and EF(D) both related to MACEs (AUC: 0.78 vs 0.67, respectively, P = .1) and systolic recovery (AUC: 0.68 vs 0.62, respectively, P = .3). According to multivariable analysis, ETN was the only MR variable associated with time to MACEs (hazard ratio, 1.38; 95% confidence interval: 1.19, 1.60; P < .001) and systolic recovery (odds ratio, 0.76; 95% confidence interval: 0.64, 0.92; P = .004) independent of baseline characteristics.


CONCLUSIONS
ETN is as useful as EF(D) for the prediction of MACEs and systolic recovery soon after STEMI.
Bodí
Vicente
V
Hospital Clínico Universitario, INCLIVA, Universidad de Valencia, Blasco Ibáñez 17, 46010 Valencia, Spain. vicentbodi@hotmail.com
Husser
Oliver
O
Sanchis
Juan
J
Núñez
Julio
J
López-Lereu
María P
MP
Monmeneu
José V
JV
Mainar
Luis
L
Chaustre
Fabian
F
Riegger
Günter A J
GA
Bosch
María J
MJ
Chorro
Francisco J
FJ
Llácer
Angel
A
D017130:Angioplasty; D019540:Area Under Curve; D006328:Cardiac Catheterization; D002316:Cardiotonic Agents / Q000008:administration & dosage; D016009:Chi-Square Distribution; D003287:Contrast Media; D004280:Dobutamine / Q000008:administration & dosage; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000502:physiology; D009203:Myocardial Infarction / Q000473:pathology* / Q000503:physiopathology / Q000628:therapy; D017682:Myocardial Stunning / Q000473:pathology* / Q000503:physiopathology / Q000628:therapy; D009336:Necrosis; D011446:Prospective Studies; D012044:Regression Analysis; D019233:Retreatment; D015607:Stents
D002316:Cardiotonic Agents; D003287:Contrast Media; D004280:Dobutamine; D019786:Gadolinium DTPA