Longitudinal peak strain detects a smaller risk area than visual assessment of wall motion in acute myocardial infarction.
BACKGROUND
Opening of an occluded infarct related artery reduces infarct size and improves survival in acute ST-elevation myocardial infarction (STEMI). In this study we performed tissue Doppler analysis (peak strain, displacement, mitral annular movement (MAM)) and compared with visual assessment for the study of the correlation of measurements of global, regional and segmental function with final infarct size and transmurality. In addition, myocardial risk area was determined and a prediction sought for the development of infarct transmurality >or=50%.


METHODS
Twenty six patients with STEMI submitted for primary percutaneous coronary intervention (PCI) were examined with echocardiography on the catheterization table. Four to eight weeks later repeat echocardiography was performed for reassessment of function and magnetic resonance imaging for the determination of final infarct size and transmurality.


RESULTS
On a global level, wall motion score index (WMSI), ejection fraction (EF), strain, and displacement all showed significant differences (p <or= 0.001, p <or= 0.001, p <or= 0.001 and p = 0.03) between the two study visits, but MAM did not (p = 0.17). On all levels (global, regional and segmental) and both pre- and post PCI, WMSI showed a higher correlation with scar transmurality compared to strain. We found that both strain and WMSI predicted the development of scar transmurality >or=50%, but strain added no significant information to that obtained with WMSI in a logistic regression analysis.


CONCLUSIONS
In patients with acute STEMI, WMSI, EF, strain, and displacement showed significant changes between the pre- and post PCI exam. In a ROC-analysis, strain had 64% sensitivity at 80% specificity and WMSI around 90% sensitivity at 80% specificity for the detection of scar with transmurality >or=50% at follow-up.
Rosendahl
Lene
L
Department of Clinical Physiology, Ryhov County Hospital, Jönköping, Sweden. lene.rosendahl@lj.se
Blomstrand
Peter
P
Brudin
Lars
L
Tödt
Tim
T
Engvall
Jan E
JE
D000368:Aged; D015906:Angioplasty, Balloon, Coronary; D015150:Echocardiography, Doppler / Q000379:methods* / Q000592:standards* / Q000706:statistics & numerical data; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000628:therapy*; D015588:Observer Variation; D011237:Predictive Value of Tests; D012372:ROC Curve; D020127:Recovery of Function; D015203:Reproducibility of Results; D012307:Risk Factors; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D013318:Stroke Volume