Improved Coronary Microvascular Perfusion 8 Weeks After Acute Myocardial Infarction Is Associated with Improved Cardiovascular Prognosis: Insights from Myocardial Contrast Echocardiography.

OBJECTIVE

Coronary microcirculation dysfunction (CMD) after acute myocardial infarction (AMI) significantly affects cardiovascular prognosis. However, the influence of an improvement in microvascular perfusion (MVP) during the recovery period from AMI on the long-term prognosis remains unclear. This study aims to assess the improvement in MVP during the healing process after percutaneous coronary intervention (post-PCI) for AMI using myocardial contrast echocardiography (MCE), and to investigate its correlation with major adverse cardiovascular events (MACE).

METHODS

A prospective cohort study was conducted to evaluate a total of 114 AMI patients successfully treated with percutaneous coronary intervention (PCI). Patients were classified as having normal MVP (nMVP), delayed MVP (dMVP) or microvascular obstruction (MVO) based on perfusion imaging by MCE between 2 and 7 d post-PCI. Clinical data, MCE and cardiac function at baseline (2-7 d post-PCI) and after 8 wk of recovery were compared among the three groups. MACE was followed up every 6 mo over a 2-y period.

RESULTS

As detected by MCE, there were 26 (22.8%), 50 (43.9%) and 38 (33.4%) AMI patients in the nMVP group, dMVP group and MVO group, respectively. AMI patients with dMVP and MVO suffered from significantly lower global longitudinal strain (GLS, p = 0.006, p = 0.002), lower left ventricular ejection fraction (LVEF, p = 0.023, p = 0.002), higher myocardial perfusion score index (MPSI, p < 0.001, p < 0.001) and more segments of wall motion abnormalities (WMA, p < 0.001, p < 0.001) than nMVP at both baseline and 8 wk. 23/50 (46.00%) patients in the dMVP group and 5/38 (13.16%) patients in the MVO group achieved complete improvement, while 21/38 (55.26%) patients in the MVO group achieved partial improvement in MVP within 8 wk. AMI patients with complete improvement had exhibited significantly greater improvements in GLS (p = 0.017), and experienced fewer MACE (p = 0.044) compared to those with partial or no improvement.

CONCLUSION

Among patients exhibiting abnormal MVP in the early phase following PCI for AMI, a subset demonstrated complete improvement of MVP at 8 wk. Patients with complete MVP improvement showed greater enhancement in myocardial function and a reduced risk of long-term MACE.