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

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).