Unloading the clock: when timing meets physiology in STEMI shock

In this issue of EuroIntervention, Nagai and associates present a registry-based study to analyse the association between the time taken from hospital arrival to the placement of a microaxial flow pump (mAFP) – door-to-unload time – and in-hospital mortality in patients with ST-segment elevation myocardial infarction (STEMI)-related cardiogenic shock (CS).1 The study was based on data from the Japan Registry for Percutaneous Ventricular Assist Devices. In total, 1,783 contemporary STEMI-CS patients who underwent mAFP placement were analysed. Of these 1,783 patients, 73% had no temporary mechanical circulatory support (MCS) at the time of mAFP placement, 23% were on venoarterial extracorporeal membrane oxygenation (VA-ECMO), and a minority of patients were on an intra-aortic balloon pump (IABP). The main analysis merged these cohorts and demonstrated that in-hospital mortality increased with a longer door-to-unload time, from 33% when the door-to-unload time was ≤60 min to 48% when the door-to-unload time exceeded 150 min. The same pattern was found when patients were stratified by no prior MCS or use of an MCS at mAFP placement. Predictors of delayed mAFP placement included older age,...