Microvascular Obstruction In PCI - A Review

Abstract

IntroductionSuccessful revascularization of the epicardial coronary artery can be achieved in over 90% of percutaneous coronary intervention procedures. However, post procedural microvascular obstruction, despite the presence of normal epicardial flow, remains an important limitation which substantially reduces the beneficial effects of percutaneous coronary intervention. In this review article, a number of different methods available to diagnose microvascular obstruction after percutaneous coronary intervention are outlined. We also discussed the various pharmacological and mechanical strategies to reduce the occurrence of microvascular obstruction. In this regard, pretreatment with antiplatelet therapy remains crucial. In urgent percutaneous coronary intervention for acute myocardial infarction, available data suggest that manual thrombus aspiration device is beneficial in reducing the occurrence of procedure-related microvascular obstruction and possibly improve long-term clinical outcomes.In the setting of ST-segment elevation myocardial infarction (STEMI), urgent PCI restores coronary perfusion, reduces myocardial damage, and improves survival. Over the last decade, the paradigm has shifted from epicardial artery patency to microvascular perfusion Distal embolization of atherosclerotic and/or thrombotic materials is most likely the predominant pathophysiological mechanism leading to post-PCI microvascular obstruction Other proposed contributing factors include coronary spasm, dissection, endothelial dysfunction, and inflammation. The relative contribution of these factors may differ in different clinical settings. Microvascular obstruction after PCI is associated with adverse long-term clinical outcomes, including higher risk of death and myocardial infarction. As a result, various pharmacological and nonpharmacological strategies have been evaluated to prevent post-PCI microvascular obstruction. Recently, lesion composition determined by IVUS(necrotic core and thin-cap fibroatheroma) MSCT has been shown to be of predictive value for occurrence of post-PCI microvascular obstruction.