Effect of hyperoxic reperfusion on final infarct size after ST elevation myocardial infarction (STEMI) in old Wistar rats

Abstract Background Diabetes mellitus (DM) significantly increases mortality following myocardial infarction (MI). The underlying mechanism explaining this adverse prognosis is not completely understood. Purpose This study sought to investigate the characteristics of myocardial healing after MI in DM patients. Methods 62 recruited ST-elevation myocardial infarction (STEMI) patients (21 with DM and 41 controls) underwent acute (1–3 days post-STEMI) and 6 months (6M) follow-up cardiac magnetic resonance scans (CMR). Control cases were matched for the peak troponin levels and area at risk on the acute CMR scans. Blood samples were obtained 6, 24, 48 hours and 6 months after STEMI. Results Despite similar severity of the initial ischaemic injury, DM patients had lower myocardial salvage index (MSI) and as a result larger final infarct size at 6 months. Further segment-based analysis of the acute CMR scans showed significantly prolonged T1-mapping values in all segments including non-ischaemic myocardium in DM patients and poorer recovery of the late gadolinium enhancement (LGE) of the infarcted segments in that group. Additionally, DM patients had higher monocyte counts 24 hours post-MI (1.2±0.4x109/μl DM vs 0.88±0.3 x109/μl control, p=0.001). We found that HbA1C correlated with monocyte count measured 24 hours after STEMI (r=0.577, p=0.006, n=21). HbA1C also predicted myocardial salvage index (MSI) at 6M post STEMI in the DM patients (r=0.891, p=0.017, n=13). Conclusions DM patients presenting with STEMI have increased peripheral blood monocytosis and larger final infarct size compared with STEMI patients without DM. Poorly controlled DM predisposes to adverse cardiac remodelling after STEMI. Acknowledgement/Funding OHSRC Research Grant, National Institute for Health Research (NIHR), British Heart Foundation Centre of Excellence Oxford

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Myocardial Perfusion Grade by Coronary Angiography can Predict Final Infarct Size and Left Ventricular Function in Patients with ST-elevation Myocardial Infarction Treated with a Pharmaco-invasive Strategy

Open Access Macedonian Journal of Medical Sciences ◽

10.3889/oamjms.2021.5815 ◽

2021 ◽

Vol 9 (B) ◽

pp. 184-190

Author(s):

Amal Hafez Ahmed ◽

Amr ELHadidy ◽

Mohamed Helmy ◽

Ashraf Hussein ◽

Abdalla Elagha

Keyword(s):

Myocardial Infarction ◽

Myocardial Perfusion ◽

Thrombolytic Therapy ◽

Infarct Size ◽

Left Ventricular ◽

St Elevation Myocardial Infarction ◽

Left Ventricular Ejection ◽

Invasive Strategy ◽

Final Infarct Size ◽

St Elevation

BACKGROUND: Primary percutaneous coronary intervention (PCI) is the reperfusion strategy of choice in ST-elevation myocardial infarction (STEMI). Transfer for early angioplasty after thrombolytic therapy should be done without delay and has been directly related to improved patients’ outcome compared with thrombolysis alone. TIMI myocardial perfusion (TMP) grade provides important prognostic information for epicardial flow. AIM: We studied the relationship between TMP grade (at the end of the PCI procedure) and left ventricular ejection fraction (LVEF) and infarct size within 1 month in such patients. METHODS: A total of forty patients with diagnosis of STEMI (mean age 57.32 ± 10.44, 33 men) were studied, all patients underwent primary PCI. Grading of myocardial perfusion was done immediately post-PCI. Infarction size, end-diastolic volume (EDV), end-systolic volume (ESV), and LVEF were all measured by myocardial perfusion imaging (Gated single-photon emission computed tomography) within 1 month of STEMI. RESULTS: Final infarct size ranged from 0 to 59 cm (mean =19.18 ± 15.8 cm). EDV ranged from 52 to 228 ml (mean = 128.60 ± 51.01 ml). ESV ranged from 16 to 169 ml (mean =72.05 ± 42.09 ml) and EF ranged from 21% to 72% (mean = 46.0 ± 12.80%). Viable but ischemic myocardial area ranged from 0 to 18 cm (mean =3.38 ± 4.45 cm). There was a significant “negative” correlation between the myocardial perfusion grade and the final infarct size. Furthermore, myocardial perfusion grade was significantly inversely related to EDV and ESV, but directly related to EF. Patients who received thrombolytic therapy had significant lesser perfusion grade than who underwent PCI directly. CONCLUSION: Assessment of the myocardial perfusion grade during PCI is a good prognostic marker about the final infarct size, ESV, EDV, and EF in patients with STEMI treated with a pharmaco-invasive strategy (thrombolytic followed by PCI).

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