Racial trends in outcomes and access to treatment for mitral regurgitation: a South London population cohort study.

BACKGROUND

Racial disparities in valvular heart disease are well-documented, yet evidence specific to mitral regurgitation (MR) remains fragmented. This study examined racial differences in mortality and treatment access among patients with moderate-severe MR within a universal healthcare system.

METHODS

This retrospective cohort study utilised digital health records from a South London tertiary centre using natural language processing (NLP), including demographic, clinical, echocardiographic and socioeconomic data. Adult patients with moderate or greater MR diagnosed between 2010 and 2023 were stratified by ethnicity (White, Black, Asian). Primary outcomes were all-cause mortality and surgical/transcatheter intervention rates. Multivariable Cox regression and competing risk analyses adjusted for demographics, MR characteristics, comorbidities and socioeconomic deprivation.

RESULTS

The cohort (n=6665) comprised 5331 (80.0%) White, 958 (14.4%) Black and 376 (5.6%) Asian patients with under-represented minority proportions relative to local demographics. Black patients presented younger (65.4 vs 72.2 years; p <0.001) with greater socio-economic deprivation (median IMD decile 3 vs 5), higher comorbidity burden and predominantly secondary MR (91% vs 85%; p <0.001). Crude mortality rates were 103.8, 88.1 and 80.4 per 1000 person-years for White, Black and Asian patients respectively. After adjustment, ethnicity was not independently associated with mortality (Black vs White: HR 0.90; 95% CI 0.80 to 1.00; p=0.06) or intervention (OR 0.81; 95% CI 0.59 to 1.11; p=0.18). Socioeconomic deprivation was independently associated with mortality (HR 0.97/IMD decile increase; p <0.001) and intervention rates. Crude intervention rates were lower in Black than in White patients (6.9% vs 12.7%), this difference attenuated after adjustment for MR aetiology, comorbidities and socioeconomic deprivation and did not persist as an independent association (OR 0.81; 95% CI 0.59 to 1.11; p=0.18).

CONCLUSION

MR appears under-detected among minority patients relative to local demographics and occurs at a younger age and with a greater prevalence of secondary MR and comorbidity. Once identified, clinical factors and socioeconomic deprivation rather than ethnicity itself drive outcomes and treatment access, with no statistically independent association between ethnicity and either mortality or intervention, although modest but clinically relevant differences cannot be excluded given the cohort sizes. These findings highlight the need for enhanced valve disease detection in diverse communities alongside strategies addressing socioeconomic determinants of cardiovascular health.