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18 Relationship of myocardial strain and markers of myocardial injury to predict segmental recovery following acute st-segment elevation myocardial infarction
  1. JN Khan1,
  2. JP Greenwood2,
  3. SA Nazir1,
  4. A Singh1,
  5. C Peebles3,
  6. J Wong4,
  7. AH Gershlick1,
  8. GP McCann1
  1. 1Department of Cardiovascular Sciences, University of Leicester and the NIHR Leicester Cardiovascular Biomedical Research Unit, University Hospitals of Leicester NHS Trust, Glenfield Hospital, Leicester, LE3 9QP, UK
  2. 2Multidisciplinary Cardiovascular Research Centre and the Division of Cardiovascular and Diabetes Research, Leeds Institute of Cardiovascular and Metabolic Medicine (LICAMM), University of Leeds, Leeds, LS2 9JT, UK
  3. 3University Hospital Southampton NHS Foundation Trust and University of Southampton, Southampton SO16 6YD, UK
  4. 4Royal Brompton and Harefield Foundation Trust, Harefield Hospital, Hill End Road, Middlesex UB9 6JH, UK

Abstract

Background Late Gadolinium Enhancement (LGE) predicts functional recovery in stunned myocardium. Acutely post STEMI, LGE overestimates infarct and underestimates potential for functional recovery. There are no large studies comparing CMR predictors of segmental recovery in acute STEMI.

Purpose Determine whether segmental circumferential strain (Ecc), myocardial salvage (MSI), microvascular obstruction (MVO) and intramyocardial haemorrhage (IMH) predict segmental functional recovery and offer incremental predictive value to segmental extent of enhancement (SEE) acutely post-PPCI.

Methods 1.5T CMR was performed in 164 patients (2624 segments) at 48 hr and 9 month post-STEMI. LV function was assessed on wall-motion scoring on SSFP cines. Segmental dysfunction was WMS ≥2, improvement was WMS decrease of ≥1 and normalisation where WMS returned to 1 at follow-up. SEE and MVO were assessed on LGE using full-width half-maximum thresholding. Oedema and IMH were assessed on T2w imaging using Otsu’s Automated Method. Ecc was Feature Tracking-derived. MSI was the proportion of non-infarcted segmental oedema. Accuracy of baseline SEE, segmental Ecc, MSI, MVO and IMH in predicting improvement and normalisation in dysfunctional segments was assessed with Receiver Operator Curves.

Results 32% of segments were dysfunctional at baseline and 19% at follow-up. With increasing SEE, segmental function worsened and proportion of dysfunctional segments recovering decreased. However 33% of SEE >75% segments improved (Figure 1a). SEE was a strong predictor of improvement (AUC 0.708) and normalisation (AUC 0.807). SEE was a stronger predictor than MVO, IMH and Ecc (p < 0.01 for all). MVO, IMH and Ecc were weak predictors. Combining SEE with MVO, IMH, Ecc or MSI did not improve predictive accuracy versus SEE alone (Figure 1b1c).

Abstract 18 Figure 1

(a) Recovery in dysfunctional segments at follow-up CMR by SEE. (b) ROC curve of single and combined predictors of segmental improvement in dysfunctional segments. (c) ROC curve of single and combined predictors of segmental normalisation in dysfunctional segments.

Conclusions This is the largest study assessing CMR predictors of segmental recovery in acute STEMI. Baseline SEE was the strongest predictor. Ecc, MSI, MVO and IMH provided no incremental predictive value to SEE. Functional improvement can occur where SEE >75%.

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