Ethnic differences in atrial fibrillation in patients with heart failure from Asia-Pacific.

Objective: Ethnic differences in the prevalence of atrial fibrillation (AF) in heart failure (HF) remain unclear. We compared the prevalence and clinical correlates of AF among different ethnicities in an Asian-Pacific population with HF.
Methods: Patients with validated HF were prospectively studied across Singapore and New Zealand (NZ).
Results: Among 1746 patients with HF (62% Asian, 26% women, mean age 66 (SD 13) years, mean ejection fraction (EF) 37 (SD 16%), 39% had AF. The prevalence of AF was markedly lower in Singapore-Asians than NZ-Europeans (24% vs 63%; p<0.001), even after adjusting for age, clinical and echocardiographic covariates, regardless of EF group (p _interaction for EF=0.39). Patients with AF were older, had higher body mass index and were more likely to have a history of hypertension, stroke, peripheral vascular disease, renal disease, chronic respiratory disease and increased alcohol intake, but less likely to have diabetes. Clinical correlates were similar for Asians and NZ-Europeans, except diabetes: Asian diabetic patients with HF had less AF compared with Asian patients without diabetes (OR 0.66, 95% CI 0.50 to 0.88), whereas among NZ-Europeans there was no significant association between diabetes and AF (OR 1.22, 95% CI 0.85 to 1.75) (p _interaction for ethnicity=0.01). AF was associated with a higher crude composite outcome of mortality and HF hospitalisations at 2 years (HR 1.19, 95% CI 1.02 to 1.38).
Conclusion: There is a strikingly lower prevalence of AF among Asian compared with NZ-European patients with HF. The underlying mechanisms for the lower prevalence of AF among Asians, particularly in the presence of diabetes, deserve further study.
Trial Registration Number: ACTRN12610000374066.
Competing Interests: Competing interests: CSPL reports grants from National Medical Research Council of Singapore during the course of the study, research support from Boston Scientific, Bayer, Thermofisher, Medtronic, Vifor Pharma; personal fees from consultation for Bayer, Novartis, Takeda, Merck, AstraZeneca, Janssen Research & Development, Menarini, Boehringer Ingelheim, Abbott Diagnostics, Corvia, Stealth BioTherapeutics, Roche and Amgen, outside the submitted work; RT reports grants from Roche Diagnostics and Merck outside the submitted work; RND reports grants from Health Research Council of NZ, New Zealand Heart Foundation and Auckland Medical Research Foundation, during the conduct of the study; AMR reports grants from Government and Charitable Funding Bodies, non-financial support from Roche Diagnostics during the conduct of the study; personal fees and non-financial support from Roche Diagnostics outside the submitted work; KP reports grants from Heart Foundation of New Zealand and Health Research Council of New Zealand, outside the submitted work; ML reports grants from Health Research Council, Auckland Medical Research Foundation, and New Zealand Lottery Grants Board, during the conduct of the study; VAC reports grants from Health Research Council of New Zealand, during the conduct of the study.
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