Prescription patterns of diabetes medications influencing clinical outcomes of heart failure patients with reduced ejection fraction

Aims: We collected the different prescription patterns of diabetes medications in a cohort of patients with heart failure with reduced ejection fraction (HFrEF) and analysed the impact of different prescription patterns on clinical outcomes. Methods and results: Consecutive diabetic patients with HFrEF from a heart failure referral centre were retrospectively analysed between 2015 and 2016. Exclusion criteria include being lost to follow-up, not receiving diabetes medications, and having severe renal impairment with a glomerular filtration rate < 30 mL/min/1.73 m². Prescription of diabetes medications and the respective clinical outcomes were collected between 2016 and 2018. Among 381 patients (mean age, 64.8 ± 12.8 years; 71.9% male; mean left ventricular ejection fraction, 27.6 ± 7.0%; mean body mass index, 26.1 ± 4.7 kg/m²), the prescription rates of sodium-glucose co-transporter 2 inhibitor (SGLT2i) increased from 10.3% in 2016 to 17.6% in 2017 and 26.5% in 2018 (P < 0.001); the prescription rates of metformin, sulfonylurea, insulin, and dipeptidyl peptidase-4 inhibitors did not change significantly over time. The prescription rates of metformin and SGLT2i were significantly higher in patients managed by cardiologists than non-cardiologists (in 2018, 71.1% vs. 44.2% for metformin, 45.4% vs. 9.9% for SGLT2i, both P < 0.001). During the study period, annualized event rates of cardiovascular death or first unplanned HF hospitalization were 19.0 per 100 patient-years. After a multivariate analysis, prescriptions of metformin {odds ratio (OR): 0.49 [95% confidence interval (CI) 0.27–0.51], P < 0.001} and SGLT2i [OR: 0.52 (95% CI 0.28–0.98), P = 0.042] were independently associated with lower annualized event rates of cardiovascular death or unplanned HF hospitalization. Conclusions: Prescription patterns of diabetes medications in diabetics with HFrEF were diverse among different specialists. Prescriptions of metformin and SGLT2i were associated with favourable clinical outcomes. Our finding indicates the importance of awareness of beneficial effect of different classes of diabetes medications and collaboration between specialists in the management of diabetic HFrEF patients.