Primary mechanical unloading in high-risk myocardial infarction: Perspectives in view of a paradigm shift

The improvement achieved in recent years in early myocardial infarction (MI) mortality poses several new clinical challenges, owing to late consequences of myocardial loss and the significant incidence of heart failure (HF) observed thereafter. A still unaddressed residual reperfusion injury (RI) contributes to final infarct size, acute MI mortality and longer-term HF development. Despite many cardioprotective lines of research in the setting of MI, no treatment has significantly altered clinical practice or convincingly improved outcomes either. Left ventricular mechanical unloading before culprit vessel reopening may reduce RI and prime (biologically and mechanically) the myocardium for reperfusion, thus limiting infarct size and preventing subsequent adverse remodeling. Aim of this review is to summarize key pre-clinical and clinical experiences furnishing a rationale to the approach of mechanical unloading before myocardial reperfusion with a translational outlook on its implications for the management of MI patients.