No Reflow-phenomenon: from Current State of the Art to Future Perspectives

Early and successful myocardial reperfusion with primary percutaneous coronary intervention (pPCI) is the optimal therapy for patients presenting with ST segment elevation myocardial infarction (STEMI). Despite successful epicardial reopening of the infarct related artery, myocardial perfusion may not be restored in up to 40-50% of patients. This phenomenon, referred to as no-reflow (NR), recognizes several pathogenetic components including distal atherothrombotic embolization, ischaemic injury, reperfusion damage, intramyocardial hemorrhage and individual susceptibility of coronary microcirculation. However the complexity of pathogenesis remains still unclear. Moreover, cause NR plays a crucial role in patients prognosis, accurate detection is critical and multiple novel diagnostic modalities has been recently assessed. The NR phenomenon represents a challenge in the management of STEMI patients and has recently captured a growing interest of both basic scientists and interventional cardiologists. Although relevant efforts to transfer into real world practice new therapeutic strategies, to date there is still weak evidence of clinical improvement in this setting. Several strategies of prevention and treatment of NR have been proposed in the clinical arena including pharmacological and mechanical interventions. Nevertheless, the complexity of the phenomenon makes extremely unlikely for a single therapy to be effective. Understanding the interaction between the components of this pathway, along with exploring newer and more effective agents may enable patients to be treated with the most appropriate therapy.