Revascularisation after discharge in patients with acute myocardial infarction complicated by cardiogenic shock
Authors: Bjerg Andersen M , Kunkel J B , Graversen P L , Josiassen J , Helgestad O K L , Schmidt H , Holmvang L , Frydland M , Thoegersen M , Fosboel E , Ravn H B , Moeller J E , Hassager C , Soeholm H , Jensen L O 
Published: October 2024

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.