Myocardial perfusion grade predicts final infarct size and left ventricular function in patients with ST-elevation myocardial infarction treated with a pharmaco-invasive strategy (thrombolysis and early angioplasty)

Aims: Primary percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction (STEMI) usually restores TIMI 3 flow in the occluded artery, but microvascular impairment may persist in >30% of patients. Less is known about microvascular reperfusion in STEMI patients treated with tbrombolysis followed by early PCI. We aimed to assess the association between TIMI myocardial perfusion (TMP) at the end of the PCI procedure and left ventricular function (LVEF) and infarct size after three months in such patients. Methods and results: Patients with STEMI treated with thrombolysis and early PCI were included. TMP grade was assessed at the end of the PCI procedure, and MRI was performed after three months. Of the 89 patients included, 92% (n=82) had TIMI 3 flow at the end of the PCI procedure, while only 62% (n=55) had TMP grade 2 or 3. Patients with TMP grade 2-3 had significantly higher LVEF (59% [53-67] vs. 50% [41-56], p<0.0001) and smaller infarct size (8.3 ml [2.7-15.5] vs. 20.7 ml [13.0-36.0], p<0,0001) after three months. Conclusions: In STEMI patients treated with thrombolysis and early PCI, the TMP grade at the end of the PCI procedure was significantly associated with LVEF and infarct size after three months.