Type 2 diabetes and chronic kidney disease combinations in heart failure across the ejection fraction spectrum: clinical associations, medication use, and cause-specific outcomes: a contemporary, real-world analysis of the Swedish Heart Failure Registry.

AIMS: The interactions between heart failure (HF), chronic kidney disease (CKD), type 2 diabetes mellitus (T2DM), and relative drug use remain poorly studied. METHODS: Patients enrolled in the Swedish HF registry 2017-2023 were divided according to CKD and T2DM. HF medication use and all-cause death, cardiovascular death, first HF hospitalization (HHF), their composite, and end-stage renal disease (ESRD) were assessed. RESULTS: Among 54 341 patients (34% females, mean age 73 years), 51% had no CKD/no T2DM, 24% CKD only, 14% T2DM only, and 11% both CKD/T2DM. CKD only and CKD/T2DM prevalences were higher in HF with preserved ejection fraction (HFpEF; 29% and 15%, respectively) than with mildly reduced EF (HFmrEF; 23% and 11%) and reduced EF (HFrEF 22% and 10%). HF medication use, especially of mineralocorticoid receptor antagonists, was generally lower in groups with CKD. Event rates for all outcomes were progressively higher going from no CKD/no T2DM, T2DM only, CKD only, and both CKD/T2DM in all EF categories. Independent risks of mortality and HF outcomes were significantly increased in the presence of CKD/T2DM, whereas for ESRD, T2DM alone did not significantly increase risk, CKD alone increased it threefold, and both CKD and T2DM increased it six-fold. CKD added more to the risk of events in HFrEF than in HFpEF. CONCLUSION: CKD was more common in HFpEF and a strong independent risk factor for all outcomes. T2DM was a moderate independent risk factor for all outcomes. These findings inform drug implementation and future aldosterone-targeting drug trials.