Aim: To analyze the long-term effect of microvascular injury various types on the structural and functional parameters of the left ventricle assessed by echocardiography in patients with primary ST-segment elevation myocardial infarction (STEMI).
Materials and methods: The study included 60 patients with primary STEMI admitted within the first 12 hours after the onset of disease who underwent stenting of the infarct-associated coronary artery. Each patient included in the study underwent CMR imaging on the second day post-STEMI. MVO and IMH were assessed using late gadolinium enhancement and T2-weighted CMR imaging. Subsequently, all patients underwent the standard echocardiographic protocol on the 7th day and 3 months after MI.
Results: We divided all patients into 4 groups: the 1st group didn't have any phenomena of IMH and MVO, the 2nd group had only MVO, patients of the 3rd group had only IMH and in the 4th group there was a combination of MVO and IMH. LV ejection fraction was significantly lower in patients with combination of MVO and IMH, if compared to those without it. Correlation analysis showed a moderate inverse correlation between the MVO area and LV contractile function: the larger the area, the lower the LVEF (R=-0,60; p=0,000002).
Conclusions: The combination of IMH and MVO is a predictor of a reduction in LVEF and an increase of volumetric measurements within 3 months after MI. In comparison with patients without microvascular injury isolated MVO is associated with lower LVEF. The size of MVO is directly correlated with the LV contractile function decrease. Isolated IMH was not associated with deterioration of left ventricular function.