96 The impact of ethnicity on clinical outcomes in patients with heart failure and atrial fibrillation

Introduction Heart failure (HF) and atrial fibrillation (AF) are increasingly prevalent and associated with substantial morbidity. When HF and AF co-exist, the outcome profile is significantly worse than for either condition in isolation. Ethnic background is known to influence disease outcomes and treatment efficacy, but there is limited knowledge about how HF, AF and ethnicity interact on mortality and hospital admission. Methods Individual patient data were obtained from 12 randomized controlled trials (RCTs) in patients with HF. RCT data were harmonised and meta-analysed to investigate the interaction of baseline heart rhythm (sinus rhythm versus atrial fibrillation) and ethnicity (non-white versus white). The primary outcome was all-cause mortality and secondary outcomes included cardiovascular (CV)-related mortality, HF-related mortality, CV hospitalisation, and HF hospitalisation. These were analysed using adjusted Cox regression models and propensity-score matching. Results 16,713 HF patients were included of which 1,899 (11%) were non-white, median age 66 (interquartile range [IQR] 57–73) and 4,703 (28%) women. During median follow-up of 1.4 years (IQR 0.8–2.3), death occurred in 394 (21%) non-white patients and 2,142 (15%) white patients; adjusted hazard ratio (HR) 1.36, 95% CI 1.20–1.54; p<0.001. The impact of ethnicity was greater in patients with coexisting HF and AF (non-white versus white HR 2.05; 95% CI 1.55–2.70; p<0.001), than in those with HF in sinus rhythm (non-white versus white HR 1.24; 95% CI 1.08–1.41; p=0.002). A significant interaction was evident between ethnicity and rhythm status for all-cause mortality (p=0.003) (table 1, figure 1). Sensitivity analysis by propensity-score matching also showed increased risk of all-cause mortality in HF and AF patients (non-white versus white odds ratio 1.23; 95% CI 1.05–1.45; p=0.012), which was not seen in sinus rhythm patients. An exploratory analysis of beta-blockers versus placebo demonstrated divergent efficacy with respect to mortality for non-white (HR 1.00, 95% CI 0.79–1.27; p=0.99) and white patients (HR 0.70, 95% CI 0.63–0.78; p<0.001); p-interaction=0.008 (table 2, figure 2). All secondary outcomes were significantly higher in non-white patients with HF and AF than white patients. However, for these outcomes, the ethnic disparities seen in those with concomitant AF were not statistically significantly greater than in patients with HF in sinus rhythm. Conclusion Non-white patients with HF suffer from substantially higher rates of death and hospitalisation than corresponding white patients. The presence of comorbid AF significantly worsens the ethnicity-related disparity in all-cause mortality. In those with HF in sinus rhythm, beta blockers were found to be significantly less effective at reducing mortality in non-white patients. Conflict of Interest no