Revascularisation after discharge in patients with acute myocardial infarction complicated by cardiogenic shock

Abstract Background Multivessel coronary artery disease frequently occurs in patients with acute myocardial infarction complicated by cardiogenic shock (AMICS), which is associated with a higher mortality rate. Previous studies have focused on revascularisation during the initial admission. The need for revascularisation after discharge has not yet been well-studied. Purpose To determine the incidence of revascularisation after discharge in patients initially hospitalised with AMICS compared to ST-elevation myocardial infarction (STEMI) patients without CS. Methods Data from a cohort of individually validated AMICS patients admitted to two tertiary cardiac centres in Denmark between 2010 and 2017 - the RETROSHOCK cohort - were included (fig.1). Data were cross-linked with The National Patient Register, containing diagnostic and procedural codes for all hospital contacts for Danish citizens. For comparison, an age- and sex-matched cohort of STEMI patients (4:1 ratio) without CS treated at the same centres and within the same timeframe was established from The National Patient Register. The incidence of revascularisation (percutaneous coronary intervention (PCI) and/or coronary artery bypass grafting (CABG)) was assessed in patients surviving a "blanking period" of 60 days after discharge to take staged elective revascularisation into account and until a maximum follow-up of 5 years. The cumulative incidence function with death as a competing event was used. Gray’s test was used for comparison of incidence functions. Results A total of 1,716 AMICS patients were included, of whom 753 (44%) survived to 60 days after discharge – of those, 538 (71%) patients had STEMI. Revascularisation was performed during follow-up and after the 60-day ‘blanking period’ in 68 patients (9%) – median follow-up time was 3.4 years in the AMICS group and 3.5 years in the control group. Multivessel disease, out-of-hospital cardiac arrest and hyperlipidaemia at index hospitalisation were more prevalent in patients revascularised during the follow-up period (69% vs. 52% p=0.009, 62% vs. 47% p=0.018 and 42% vs. 27% p=0.014) for revascularised vs. not-revascularised). No significant differences in sex or age were present in revascularised vs. not-revascularised patients. The five-year cumulative incidence rate for revascularisation after discharge was 10.0% (95% Confidence Interval (CI) 7.9-12.7%), which was similar compared to the matched STEMI cohort without CS (11.5% 95% (CI) 10.7-12.4%), HR 0.88 95% (CI) 0.68-1.13, p=0.319) (fig.1a). The finding was similar in a subgroup analysis of STEMI-only patients with CS compared to the non-CS cohort. Conclusions The cumulative incidence of revascularisation after discharge for AMICS patients was comparable to STEMI patients without CS during five years follow-up. Multivessel disease, out-of-hospital cardiac arrest and hyperlipidaemia at index admission were more prevalent in patients who were revascularised during follow-up.