SGLT2 Inhibitors in Heart Failure: Evidence, Dosing, and Clinical Decision Points

Extending to HFpEF: DELIVER and EMPEROR-Preserved

The DELIVER trial demonstrated dapagliflozin reduced the primary composite endpoint by 18% in patients with HFpEF (LVEF > 40%), while EMPEROR-Preserved showed a 21% reduction with empagliflozin. These trials established SGLT2 inhibitors as the first drug class to show benefit across the full ejection fraction spectrum of heart failure.

Why HFpEF Results Matter So Much

The HFpEF results carry outsized clinical importance because HFpEF has been a therapeutic desert for decades. Unlike HFrEF, where ACE inhibitors, beta-blockers, MRAs, and ARNIs all demonstrated clear mortality benefit, HFpEF lacked any pharmacotherapy with robust outcomes data. Trial after trial in HFpEF — from irbesartan in I-PRESERVE to spironolactone in TOPCAT — produced disappointing or equivocal results. DELIVER and EMPEROR-Preserved broke that pattern. For the first time, clinicians managing HFpEF patients have a drug class with consistent, replicated evidence of benefit across two large randomized trials.

The practical implication is straightforward: SGLT2 inhibitors should now be considered for every heart failure patient, whether their ejection fraction is 20% or 60%. The only relevant question is whether the individual patient can tolerate the drug — not whether their particular phenotype of heart failure is eligible.

Practical Prescribing: Dosing, Monitoring, and When to Start

Both dapagliflozin 10 mg and empagliflozin 10 mg are taken once daily, with or without food. No dose titration is required. Initiation can occur during a heart failure hospitalization (supported by EMPULSE and DAPA-ACT HF-TIMI 68 data). Monitor renal function and potassium at baseline and 1-2 weeks after initiation. The expected transient dip in eGFR of 3-5 mL/min is hemodynamic, not nephrotoxic, and does not warrant discontinuation. The KDIGO 2026 guidelines have further expanded renal indications for SGLT2 inhibitors.

In-Hospital vs. Outpatient Initiation

The data supporting in-hospital initiation are an important counterpoint to the common clinical instinct to stabilize first and optimize later. Many clinicians defer adding new medications during a heart failure hospitalization, preferring to adjust diuretics and neurohormonal agents before introducing additional drugs in the outpatient setting. The EMPULSE data challenge that instinct: patients who started empagliflozin during the index hospitalization achieved clinical benefit by day 90 compared to those who waited. Starting before discharge eliminates the gap in care where patients are lost to follow-up, forget to schedule outpatient appointments, or simply never get the prescription filled.

Choosing Between Dapagliflozin and Empagliflozin

The honest answer is that there is no clinically meaningful difference between the two agents for heart failure. Both are dosed at 10 mg daily, both have robust outcomes data, and both carry similar side effect profiles. The choice often comes down to formulary availability, insurance coverage, and patient copay. If one is significantly cheaper or more readily available for your patient, that is the one to prescribe. Do not let the choice between agents delay initiation — the gap between either SGLT2 inhibitor and no SGLT2 inhibitor is far larger than the gap between the two drugs.

Where SGLT2 Inhibitors Fit in the Heart Failure Algorithm

For HFrEF, current guidelines position SGLT2 inhibitors as one of the four pillars of foundational therapy alongside ACE inhibitors or ARNIs, beta-blockers, and MRAs. The goal is to get all four drug classes on board as quickly as possible, ideally within the first few weeks of diagnosis. There is no mandated order, and many clinicians now start an SGLT2 inhibitor early because it requires no titration, has a favorable side effect profile, and delivers benefit quickly. For HFpEF, SGLT2 inhibitors are the strongest evidence-based option and should be considered first-line alongside diuretics for symptom management.

Open Questions and Limitations

Despite the strength of the evidence base, several questions remain. The optimal duration of therapy is not established — all trials ran for 1-3 years, and whether the benefit persists or changes with longer-term use is an assumption, not a proven fact. The mechanism of cardiac benefit is still incompletely understood, which is unusual for a drug class with this level of clinical evidence. And while subgroup analyses consistently show no interaction by diabetes status, age, or sex, the trials enrolled predominantly white populations, and representation of other demographic groups was variable across studies. Clinicians should feel confident prescribing SGLT2 inhibitors for heart failure, but should also recognize that our understanding of why and for whom they work best is still evolving.