Magnetic resonance-derived circumferential strain provides a superior and incremental assessment of improvement in contractile function in patients early after ST-segment elevation myocardial infarction.
BACKGROUND
We evaluate whether circumferential strain derived from grid-tagged CMR is a better method for assessing improvement in segmental contractile function after STEMI compared to late gadolinium enhancement (LGE).


METHODS
STEMI patients post primary PCI underwent baseline CMR (day 3) and follow-up (day 90). Cine, grid-tagged and LGE images were acquired. Baseline LGE infarct hyperenhancement was categorised as ≤25 %, 26-50 %, 51-75 % and >75 % hyperenhancement. The segmental baseline circumferential strain (CS) and circumferential strain rate (CSR) were calculated from grid-tagged images. Segments demonstrating an improvement in wall motion of ≥1 grade compared to baseline were regarded as having improved segmental contractile-function.


RESULTS
Forty-five patients (aged 58 ± 12 years) and 179 infarct segments were analysed. A baseline CS cutoff of -5 % had sensitivity of 89 % and specificity of 70 % for detection of improvement in segmental-contractile-function. On receiver-operating characteristic analysis for predicting improvement in contractile function, AUC for baseline CS (0.82) compared favourably to LGE hyperenhancement (0.68), MVO (0.67) and baseline-CSR (0.74). On comparison of AUCs, baseline CS was superior to LGE hyperenhancement and MVO in predicting improvement in contractile function (P < 0.001). On multivariate-analysis, baseline CS was the independent predictor of improvement in segmental contractile function (P < 0.001).


CONCLUSIONS
Grid-tagged CMR-derived baseline CS is a superior predictor of improvement in segmental contractile function, providing incremental value when added to LGE hyperenhancement and MVO following STEMI.


CONCLUSIONS
Baseline CS predicts contractile function recovery better than LGE and MVO following STEMI. Baseline CS predicts contractile function recovery better than baseline CSR following STEMI. Baseline CS provides incremental value to LGE and MVO following STEMI.
Discipline of Medicine, University of Adelaide, Adelaide, Australia, drdenniswong@yahoo.com.au.
Dennis T L
DT
Wong
Darryl P
DP
Leong
Michael J
MJ
Weightman
James D
JD
Richardson
Benjamin K
BK
Dundon
Peter J
PJ
Psaltis
Michael C H
MC
Leung
Ian T
IT
Meredith
Matthew I
MI
Worthley
Stephen G
SG
Worthley
D000368:Aged; D003287:Contrast Media; D042241:Early Diagnosis; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D005682:Gadolinium; D019786:Gadolinium DTPA; D006801:Humans; D007089:Image Enhancement; D009682:Magnetic Resonance Spectroscopy / Q000379:methods* / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000502:physiology*; D009203:Myocardial Infarction / Q000473:pathology / Q000503:physiopathology / Q000628:therapy; D015588:Observer Variation; D062645:Percutaneous Coronary Intervention; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012372:ROC Curve
D003287:Contrast Media; D005682:Gadolinium; D019786:Gadolinium DTPA