Secular trends in the utility of SGLT-2 inhibitors in heart failure patients with type 2 diabetes mellitus across Metro South Health hospitals in South-East Queensland

Background: The 2018 Australian Heart Failure (HF) guidelines strongly recommended commencing sodium-glucose co-transporter-2 inhibitors (SGLT-2is) in HF patients with type 2 diabetes mellitus (T2DM). The uptake of SGLT-2is for HF patients with T2DM in our health service is unknown. Aims: To determine the adoption of the 2018 HF guidelines by assessing the temporal trends of SGLT-2is' usage in HF patients with T2DM at Metro South Health (MSH) hospitals, in South-East Queensland. Methods: Retrospective analysis of all HF patients (ejection fraction (EF) < 50%) with T2DM who were managed within MSH hospitals between June 2018 and June 2021. Results: A total of 666 patients met the inclusion criteria with 918 HF encounters. Mean age was 72 years and 71% were male (473/666). Mean EF was 30% (SD ± 11%), and mean estimated glomerular filtration rate was 48 mL/min/1.73 m² (SD ± 25). Fifty-four per cent (362/666) had contraindications to SGLT-2is. Among those without contraindications, there was a five-fold increase in the utility of SGLT-2is, 7% (2/29) before versus 38% (103/275) after implementation of the HF guidelines (P < 0.001). Patients on SGLT-2is were younger (64 years vs 69 years, P = 0.002) and had a lower number of HF hospitalisations (1.1 vs 2.1, P = 0.01). Conclusions: During the study period, 54% of our HF patients with T2DM were not on SGLT-2is due to prescribing guidelines/limitations in the Australian context. We observed a five-fold significant increase in the uptake of SGLT-2is before and after implementation of HF guidelines among patients without contraindications to SGLT-2is. There were significantly fewer HF hospitalisations among patients on SGLT-2is compared to those without.