Microvascular obstruction in acute myocardial infarction: an old and unsolved mystery

Abstract

In the setting of acute myocardial infarction, flow restoration in the culprit epicardial coronary artery is not synonymous with efficient reperfusion. Microvascular obstruction occurs in 50% of cases and represents a predictor of a long-term unfavorable outcome. Its prevalence has remained constant in recent years despite various treatment attempts. However, the success of targeted therapies could be mainly a problem of timing.
 Recent data bring evidence with regard to the role of pre-procedural distal embolization and highlight the relation between distal embolism, microvascular obstruction and intramyocardial inflammation. As a result, early detection of microvascular injury represents the first step in the development of targeted, individualized therapeutic approaches.
 In this context, the identification of new invasive surrogate parameters for the timely assessment and quantification of microvascular obstruction in the catheterization laboratory has become an important subject of current research. Among these, coronary wedge pressure is the most practical and revealing in the setting of primary percutaneous coronary intervention. It may offer comprehensive details on the mechanisms of microvascular injury and may therefore offer guidance for appropriate treatment selection.

Left ventricular function and coronary microcirculation in patients with mild reduced ejection fraction after STEMI

“…This result reveals that the coronary microcirculation status in patients with HFmrEF is comparable to that in patients with HFrEF, but poorer than that in patients with LVEF > 50%. The presence of CMD after STEMI predicts adverse prognoses such as rehospitalization, HF, and mortality [ 23 , 24 ]. It is also a powerful predictor of LV adverse remodeling [ 25 ].…”

Comparison of intracoronary versus intravenous tirofiban in acute ST-elevation myocardial infarction patients undergoing primary percutaneous coronary intervention

“…Yet, regardless of intervention, no-reflow, and the coronary slow-flow phenomenon are common and can occur after PPCI [3][4][5][6][7][13][14][15][16]. Indeed, in severe instances, this is termed thromboembolic syndrome [13][14][15][16][17][18]. Studies found that GPI administration improved TIMI flow, ameliorated myocardial reperfusion injury, prevented myocardial ischemia, reduced MACEs, and improved prognosis [5,11,[19][20][21].…”

“…Antiplatelet therapy is also a cornerstone of AMI treatment. Yet, regardless of intervention, no-reflow, and the coronary slow-flow phenomenon are common and can occur after PPCI [3][4][5][6][7][13][14][15][16]. Indeed, in severe instances, this is termed thromboembolic syndrome [13][14][15][16][17][18].…”

Comparison of Intracoronary Versus Intravneous Tirofiban in Acute STEMI Patients Undergoing Primary PCI

“…Yet, regardless of intervention, no-re ow is common and can occur after PPCI [3][4][5][6][7]. Indeed, in severe instances this is termed thromboembolic syndrome [12][13][14][15][16][17]. Studies found that GPI administration improved TIMI ow, ameliorated myocardial reperfusion injury, prevented myocardial ischemia, reduced MACEs, and improved prognosis [5,[18][19][20][21].…”