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?P?Conclusion 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.

Key points

? 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