Observational study on initiation of dapagliflozin in heart failure with reduced ejection fraction in the United Kingdom

Background Sodium–glucose cotransporter-2 inhibitor (SGLT2i) dapagliflozin has shown favourable outcomes in trials for heart failure with reduced ejection fraction (HFrEF), but little is known about real-world prescribing practices, tolerability, or impact on patient quality of life (QoL) in the United Kingdom. Methods This study was an observational longitudinal cohort study of adult patients with HFrEF in the UK, following the date of first initiation of dapagliflozin. Baseline patient characteristics, concomitant medication prescribed at enrolment, and changes to these treatments were recorded at 3, 6, 9 and 12 months following initiation. Patients completed KCCQ-23, MARS-5 and WPAI patient-reported outcome measures to assess QoL, treatment adherence and work/activity impairment, respectively, at enrolment and follow-up. Results N = 237 patients were enrolled, with n = 231 remaining at study end. Mean (95% confidence interval) age was 69.3 (67.8–70.8), 70.0% were male and 91.6% White. Mean time from HFrEF diagnosis to initiation of dapagliflozin was 20.9 (15.3–26.4) months. Dapagliflozin discontinuation rate was 11.7/100 patient-years, most commonly due to adverse drug reactions (65.0%). The majority of patients received four treatment pillars at enrolment and 12-months (54.4% and 58.4% respectively). At enrolment and 12 months, 33.8% and 30.5% respectively received three out of four pillars. Mean overall KCCQ-23 scores ranged from 67.6 (64.3–70.9) to 71.6 (67.3–74.9), and patients reported high levels of adherence, with MARS-5 scores of 23.1 (22.3–23.9) or above. Overall work impairment ranged from 31.2% (18.5–43.9%) at enrolment to 16.3% (7.4–25.2%) at 12 months, and overall activity impairment from 40.5% (36.3–44.7%) to 36.8% (32.1–41.5%). Conclusions Patients receiving dapagliflozin recorded low levels of discontinuation, suggesting high tolerability. Many patients do not receive all four recommended treatment pillars, highlighting an opportunity for further treatment optimization. Patients had fair-to-good QoL throughout the study, indicating good patient experience during HFrEF treatment including dapagliflozin.