Remote Myocardium Characterisation by Pre-contrast T1 and T2* Mapping Post Myocardial Infarction

Abstract Background A number of studies suggest that acute myocardial ischaemia triggers a non-specific systemic inflammatory response of remote myocardium through the increase of plasma concentrations of acute-phase proteins, which causes myocardial oedema. As ticagrelor has been shown to significantly decrease the circulating levels of several pro-inflammatory cytokines in patients after acute myocardial infarction with ST elevation (STEMI), we sought to investigate a potential suppressive effect of ticagrelor over prasugrel on cardiac magnetic resonance (CMR) T1 and T2 values in remote myocardium. Methods Ninety patients presenting with acute STEMI were prospectively included and randomised to receive either ticagrelor or prasugrel maintenance treatment after successful primary percutaneous coronary intervention (PPCI). The patients underwent CMR 2–7 days after the PPCI. Studies were done on a 1.5 T clinical scanner, the protocol included long and short axis cine imaging, T1 mapping through the infarct core using a single breath-hold Shortened Modified Look-Locker Inversion Recovery (ShMOLLI), T2 mapping and late gadolinium enhancement imaging. Results After excluding 30 patients due to either missing images or insufficient quality of T1 or T2 maps, 60 patients were included in our analysis. Of those, 29 patients have been randomised to the ticagrelor arm and 31 patients to the prasugrel arm of the study. The mean age at inclusion was 61±10 years, 81.7% of included patients were men, the distribution was even between the two groups. There were no statistically significant differences between groups regarding past medical history and medication prior to the inclusion in the study. CMR scans were performed 5.03±1.96 days after successful PPCI in the ticagrelor group, and 5.10±0.87 days in the prasugrel group. Remote myocardium T1: The mean T1 value of the remote myocardium was 937±27 ms in the ticagrelor group and 936±23 ms in the prasugrel group, showing no statistical difference (p=0.85) between the groups receiving different P2Y12 inhibitor after PPCI. Remote myocardium T2: The mean T2 value of the remote myocardium was 53.8±4.6 ms in the ticagrelor group and 53.6±4.7 ms in the prasugrel group, showing no statistical difference (p=0.86) between compared groups. Both T1 and T2 values of the remote myocardium were above normal values published in literature. Conclusion In patients with STEMI after PPCI, ticagrelor maintenance therapy did not show superiority to prasugrel in preventing early remote myocardial inflammation as assessed by T1 and T2 mapping. Additionally, findings support the premise of remote myocardial oedema following STEMI. Funding Acknowledgement Type of funding source: Other. Main funding source(s): Presented abstract is from a sub-study of the REDUCE-MVI study, which was conducted with financial support from Astra Zeneca through an unrestricted research grant. In addition, the study was financed by the Ministry of Economic Affairs of the Netherlands by means of a PPP Allowance made available by the Top Sector Life Sciences & Health to stimulate public-private partnerships. The first author was awarded the ESC training grant in 2019; this research was conducted during the training for which the grant was awarded.

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Serial native T1- and T2-mapping to quantitatively monitor resorption of myocardial edema following acute myocardial infarction

Journal of Cardiovascular Magnetic Resonance ◽

10.1186/1532-429x-17-s1-p101 ◽

2015 ◽

Vol 17 (S1) ◽

Author(s):

Enver Tahir ◽

Martin R Sinn ◽

Ulf K Radunski ◽

Dennis Säring ◽

Christian Stehning ◽

...

Keyword(s):

Myocardial Infarction ◽

Acute Myocardial Infarction ◽

T2 Mapping ◽

Myocardial Edema ◽

Native T1 ◽

T1 And T2

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R2 prime (R2′) magnetic resonance imaging for post-myocardial infarction intramyocardial haemorrhage quantification

European Heart Journal - Cardiovascular Imaging ◽

10.1093/ehjci/jez306 ◽

2019 ◽

Vol 21 (9) ◽

pp. 1031-1038 ◽

Cited By ~ 1

Author(s):

Xavier Rossello ◽

Pedro Lopez-Ayala ◽

Rodrigo Fernández-Jiménez ◽

Eduardo Oliver ◽

Carlos Galán-Arriola ◽

...

Keyword(s):

Myocardial Infarction ◽

Magnetic Resonance ◽

T2 Mapping ◽

Post Myocardial Infarction ◽

Myocardial Oedema ◽

Accurate Identification ◽

Tissue Samples ◽

Linear Regressions ◽

Histological Validation

Abstract Aims To assess whether R2* is more accurate than T2* for the detection of intramyocardial haemorrhage (IMH) and to evaluate whether T2′ (or R2′) is less affected by oedema than T2* (R2*), and thus more suitable for the accurate identification of post-myocardial infarction (MI) IMH. Methods and results Reperfused anterior MI was performed in 20 pigs, which were sacrificed at 120 min, 24 h, 4 days, and 7 days. At each time point, cardiac magnetic resonance (CMR) T2- and T2*-mapping scans were recorded, and myocardial tissue samples were collected to quantify IMH and myocardial water content. After normalization by the number of red blood cells in remote tissue, histological IMH increased 5.2-fold, 10.7-fold, and 4.1-fold at Days 1, 4, and 7, respectively. The presence of IMH was correlated more strongly with R2* (r = 0.69; P = 0.013) than with T2* (r = −0.50; P = 0.085). The correlation with IMH was even stronger for R2′ (r = 0.72; P = 0.008). For myocardial oedema, the correlation was stronger for R2* (r = −0.63; P = 0.029) than for R2′ (r = −0.50; P = 0.100). Multivariate linear regressions confirmed that R2* values were significantly explained by both IMH and oedema, whereas R2′ values were mostly explained by histological IMH (P = 0.024) and were little influenced by myocardial oedema (P = 0.262). Conclusion Using CMR mapping with histological validation in a pig model of reperfused MI, R2′more accurately detected IMH and was less influenced by oedema than R2* (and T2*). Further studies are needed to elucidate whether R2′ is also better suited for the characterization of post-MI IMH in the clinical setting.

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