부산대학교 도서관

Background: Assessment of distal left anterior descending coronary artery (LAD) flow after reperfused acute myocardial infarction (AMI) may provide important insights in myocardial reperfusion assessment and microcirculatory dysfunction. However, its relation to other echocardiographic parameters describing left ventricular (LV) function after AMI is not well established.Aim: To evaluate LAD flow pattern after reperfused AMI and to analyze its relation with other echocardiographic parameters.Methods: 53 patients (pts) without known coronary artery disease (CAD), 42 men, m=58.5±13.1y, with ST-elevation AMI submitted to primary percutaneous coronary intervention (PCI) 9.8±14.3 hours after the beginning of symptoms. Fibrinolytic therapy was administered in 4pts before PCI and percutaneous thrombus aspiration was achieved in 18pts. A complete transthoracic echocardiogram with LAD flow evaluation was performed between the second and fifth day (m=3.6±1.9days) after the PCI. We evaluated demographic, clinical, angio and echocardiographic parameters [right and left ventricular (LV) function, LV deformation and volumes, filling patterns] between two groups: LAD deceleration time below and above 600ms (A and B respectively), the accepted cut-off value defining microvascular obstruction after recanalization. Therapeutic strategies were compared. We also assessed cardiovascular outcomes between both groups at 18.1±11.2months of follow-up after the event.Results: 37pts (69.8%) had LAD criteria for microvascular dysfunction after PCI (mean deceleration time=266.6±ms, peak flow velocity 42.1±22.9m/s and coronary flow systolic inversion in 4pts). In this group of pts, LV ejection fraction was significantly depressed as compared to group B (85.7% with LV ejection fraction <50% vs. none; p=0.001). We also found significant differences in the wall motion score index (1.77±0.23 vs. 1.55±0.33; p=0.008), global longitudinal strain (-10.41±2.41% vs. -12.62±3.23; p=0.032) and E wave deceleration time (166.6±44.2 vs. 206.9±56.2; p=0.018). Neither fibrinolytic therapy nor thrombectomy and time to PCI were different among the groups. Cardiovascular outcome was also not different among.Conclusion: In these patients with AMI, microvascular dysfunction as assessed by non-invasive coronary flow pattern was associated with several criteria of worse LV performance.