The effect of ethnicity and socioeconomic status on outcomes after resuscitated out-of-hospital cardiac arrest - Findings from a tertiary centre in South London.

BACKGROUND: Out-of-hospital cardiac arrest is a common cause of morbidity and mortality, and ethnic variation in outcomes is recognised. We investigated ethnic and socioeconomic differences in arrest circumstances, rates of coronary artery disease, treatment, and outcomes in resuscitated OOHCA.

METHODS: Patients with resuscitated OOHCA of suspected cardiac aetiology were included in the King's Out-of-Hospital Cardiac Arrest Registry between 1-May-2012 and 31-December-2020.

RESULTS: Of 526 patients (median age 62.0 years, IQR 21.1, 74.1% male), 414 patients (78.7%) were White, 35 (6.7%) were Asian, and 77 (14.6%) were Black. Black patients had more co-existent hypertension ( p  = 0.007) and cardiomyopathy ( p  = 0.003), but less prior coronary revascularisation ( p  = 0.026) compared with White/Asian patients. There were no ethnic differences in location, witnesses, or bystander CPR, but Black patients had more non-shockable rhythms ( p  < 0.001). Black patients received less immediate coronary angiography ( p  < 0.001) and percutaneous coronary intervention ( p  < 0.001) but had lower rates of CAD ( p  = 0.004) than White/Asian patients. All-cause mortality at 12 months was highest amongst Black patients, followed by Asian and then White patients (57.1% vs 48.6% vs 41.3%, p  = 0.032). In Black patients, excess mortality was driven by higher rates of multi-organ dysfunction but lower cardiac death than White/Asian patients, with cardiac death highest amongst Asian patients ( p  = 0.009). Socioeconomic status had no effect on mortality, and in a multivariable logistic regression, age, location, witnesses, and Black compared to White ethnicity were independent predictors of mortality, whilst social deprivation was not.

CONCLUSION: In this single-centre study, Black patients had higher mortality after resuscitated OOHCA than White/Asian patients. This may be in part due to differing underlying aetiology rather than differences in arrest circumstances or social deprivation.