The investigators aim to assess whether SGLT2i (in addition to IV loop diuretic) results in greater diuresis and decongestion compared to the standard practice of treatment with the thiazide-like diuretic metolazone (in addition to IV loop diuretic) in patients hospitalised for heart failure, with both renal impairment and diuretic resistance. Dapagliflozin has received National Institute for Health and Care Excellence (NICE) approval as an add-on option to optimised standard care in patients with HFrEF. The investigators primary focus is patients with HFrEF as it is in ambulatory patients with this phenotype that SGLT2 inhibition has already been shown to reduce morbidity and mortality (DAPA-HF).However, the investigators will also enrol patients with HFpEF in an ancillary study as they present the same management challenges as patients with HFrEF and the study hypothesis and aims are as clinically relevant in HFpEF as in HFrEF. HFpEF patients in the ancillary study will undergo the same protocol as the main study. One recent trial demonstrating benefit of a SGLT1/2 inhibitor, the Effect of Sotagliflozin on Cardiovascular Events in Patients With Type 2 Diabetes Post Worsening Heart Failure (SOLOIST-WHF), included patients with both HFrEF and HFpEF hospitalised with worsening heart failure (NCT03521934). This trial demonstrated similar efficacy of sotagliflozin on cardiovascular death and worsening heart failure in patients with a LVEF <50% and ≥50%.There are other large trials currently underway specifically with SGLT2i in ambulatory patients with HFpEF underway. These trials are either fully recruited, or close to full enrolment. Both already have extensive follow-up of several thousand patients and are due to complete follow up in the next 1-2 years (EMPEROR-Preserved and DELIVER). Therefore, the findings will be contemporaneous and complementary to the results of those trials.
To assess the effect of dapagliflozin compared with metolazone, added to furosemide, on diuresis and decongestion in hospitalised heart failure patients with diuretic resistance, and renal impairment. The primary analysis will be in patients with HFrEF but patients with HFpEF will also be recruited in an ancillary study and included in supplementary analyses.