Mortality risk following ischaemic and non-ischaemic heart failure in people with type 2 diabetes: Observational study in England, 2000-2021.

Aims: To investigate the association between type 2 diabetes and all-cause mortality in people with ischaemic and non-ischaemic heart failure (HF).

Methods: Using the Clinical Practice Research Datalink primary care data, linked to hospital and mortality records, we identified newly diagnosed adults with type 2 diabetes between 2000 and 2021 and matched to up to four people without diabetes by sex, year of birth and general practice. We defined incident HF events as ischaemic if they followed an ischaemic heart disease event; otherwise, as non-ischaemic. We calculated sex-specific incidence rates and hazard ratios (HRs, adjusted for sociodemographic and clinical confounders) for all-cause mortality following HF diagnosis, comparing people with type 2 diabetes to those without diabetes.

Results: In 73 344 people with HF (18 296 [24.9%] with ischaemic HF), 9584 and 31 800 deaths occurred in those with ischaemic and non-ischaemic HF, respectively. Age-standardised mortality rates following ischaemic HF were higher in people with type 2 diabetes (19.2 [95% CI: 18.1-20.3] and 20.4 [19.5-21.4] per 100 person-years in women and men, respectively) compared to those without diabetes (15.1 [14.4-15.8] and 16.5 [15.9-17.1], respectively). Corresponding rates in those with non-ischaemic HF were: 19.5 (19.0-20.1), 22.0 (21.4-22.6), 16.6 (16.2-17.0) and 19.4 (18.9-19.8). The HR for mortality was similar among HF types and between men and women: for ischaemic HF, 1.26 (1.17-1.36) in women and 1.23 (1.15-1.31) in men; for non-ischaemic HF, 1.24 (1.19-1.29) and 1.20 (1.15-1.25), respectively.

Conclusion: Our findings indicate broadly similar mortality rates in people with ischaemic and non-ischaemic HF, with higher rates in people with type 2 diabetes compared to those without diabetes in both women and men.