Cardiogenic shock is more prevalent in racialised and newcomer populations and associated with higher mortality
Authors: Brahmbhatt D H , Hassan R , Scolari F L , Wang V N , Ibrahimova N , Nissar M , Keon K A , Shin E , De Pellegrin Overgaard A I , Fung N , Billia F , Overgaard C , Luk A 
Published: October 2024

Abstract

Background
The World Health Organization (WHO) has recognised social determinants of health (SDH) as non-medical factors that affect health outcomes. These SDH have a significant effect on health inequities, whereby more marginalised populations often have worse outcomes due to unfair and avoidable differences in health status. The Ontario Marginalization index (ON-Marg) is an area-level index derived from 42 census variables identifying differences in marginalisation, allowing identification of inequities between population groups and geographical areas. The ‘racialised and newcomer populations’ dimension of the ON-Marg characterises the proportions of recent immigrants and/or people belonging to ‘visible minority’ groups in geographical locales. These data can be used as a surrogate for individual patient data to investigate health outcomes related to this dimension. This study investigated the prevalence and mortality associated with racial marginalisation in patients admitted with cardiogenic shock at a quaternary cardiac referral centre.

Methods
A single-centre registry of CS admissions from 2014-2023 at a quaternary referral centre cardiac intensive care unit (CICU) in Ontario, Canada was studied. Patient postal codes were identified and mapped to ON-Marg ‘racialised and newcomer populations’ data using the Postal Code Conversion File. The ON-Marg data are categorised into equal quintiles, which was used to determine differences in distribution of CS cases and inpatient survival using the Chi-squared test and Kaplan-Meier methods. Only the index CS hospitalisation was included in the analysis.

Results
We identified 1513 patients, including 456 (30.1%) females, aged 60.2±16.1 years, with 333 (24.8%) due to acute myocardial infarction CS. The majority of patients were SCAI stage D (69.2%) with 488 (32.3%) dying and 186 (12.3%) receiving a heart transplant or durable ventricular assist device (VAD) before discharge. CS patients were more likely to be in the higher quintiles for marginalisation racialised and newcomer populations and these individuals had higher mortality (p=0.005, figure 1). In a survival analysis, with right-censoring for transplant or VAD, there were significant differences between marginalisation quintiles (figure 2).

Conclusions
Patients admitted with CS to a large cardiac centre were more likely to be from populations with higher levels of racialised and newcomer individuals. Increasing marginalisation was associated with higher mortality. This identifies a need for delineating whether these differences are aetiological or whether there are barriers in accessing high-quality care in a timely fashion. This could allow an improvement in outcomes for these patient groups. While census-based area-level marginalisation indices can be helpful for identifying possible barriers to equitable care, individualised patient-level data are needed to confirm these findings.