The New England Journal of Medicine September 22, 2022

Dapagliflozin in Heart Failure with Mildly Reduced or Preserved Ejection Fraction (DELIVER)

Scott D. Solomon, John J.V. McMurray, Brian Claggett, et al.

Bottom Line

In patients with heart failure and a mildly reduced or preserved ejection fraction (>40%), dapagliflozin significantly reduced the composite risk of cardiovascular death or worsening heart failure compared to placebo, regardless of diabetes status or baseline ejection fraction.

Key Findings

1. The primary composite outcome of worsening heart failure or cardiovascular death occurred in 16.4% of patients in the dapagliflozin group compared to 19.5% in the placebo group (HR 0.82; 95% CI 0.73-0.92; P<0.001).
2. Worsening heart failure (unplanned hospitalization or urgent visit) was significantly reduced, occurring in 11.8% of the dapagliflozin group versus 14.5% of the placebo group (HR 0.79; 95% CI 0.69-0.91).
3. The incidence of cardiovascular death was not significantly different between the groups (7.4% vs 8.3%; HR 0.88; 95% CI 0.74-1.05).
4. Treatment benefits were consistent across all prespecified subgroups, including patients with or without diabetes, those with heart failure with improved ejection fraction, and those with a left ventricular ejection fraction above or below 60%.

Study Design

Design
RCT
Double-Blind
Sample
6,263
Patients
Duration
2.3 yr
Median
Setting
20 countries
Population Patients with symptomatic chronic heart failure (NYHA class II-IV), a left ventricular ejection fraction >40%, structural heart disease, and elevated natriuretic peptides, with or without type 2 diabetes.
Intervention Dapagliflozin 10 mg once daily
Comparator Matching placebo
Outcome Composite of worsening heart failure (unplanned hospitalization or urgent visit for heart failure) or cardiovascular death

Study Limitations

The reduction in the primary composite outcome was predominantly driven by a decrease in worsening heart failure events rather than a reduction in cardiovascular mortality.
The relatively short median follow-up of 2.3 years limits the ability to assess long-term survival benefits and extended safety profiles.
Patients with severe valvular heart disease, recent cardiovascular events, or very recent acute decompensated heart failure were excluded, limiting generalizability to these acute cohorts.
Despite multinational enrollment, Black patients and certain other minority demographics were underrepresented.

Clinical Significance

The DELIVER trial cemented the role of SGLT2 inhibitors as a foundational, guideline-directed medical therapy across the entire spectrum of heart failure. By proving efficacy not only in mildly reduced and preserved ejection fraction but also in those whose ejection fraction had improved, it demonstrated that dapagliflozin can be initiated safely and effectively in symptomatic heart failure patients irrespective of left ventricular ejection fraction.

Historical Context

Originally developed as oral hypoglycemics for type 2 diabetes, SGLT2 inhibitors unexpectedly demonstrated profound cardiovascular benefits. Trials like DAPA-HF and EMPEROR-Reduced established their role in heart failure with reduced ejection fraction (HFrEF). Later, EMPEROR-Preserved showed that empagliflozin was effective in mildly reduced (HFmrEF) and preserved (HFpEF) ejection fractions, but subgroup analyses suggested the benefit might wane at the highest ejection fractions (LVEF ≥65%). DELIVER was a landmark trial that definitively showed dapagliflozin's efficacy in HFmrEF and HFpEF, critically proving that the clinical benefits extended even to patients with the highest ejection fractions and those with previously reduced but improved ejection fractions (HFimpEF).

Guided Discussion

High-yield insights from every perspective

Med Student
Medical Student

What is the proposed mechanism by which dapagliflozin, originally developed as an antidiabetic medication, provides cardiovascular benefits in patients with heart failure regardless of their diabetes status?

Key Response

SGLT2 inhibitors block glucose and sodium reabsorption in the proximal tubule. Cardiovascular benefits are independent of glucose lowering and involve osmotic diuresis, reduced preload and afterload, improved myocardial energetics via a shift to ketone utilization, reduction in sympathetic nervous system activity, and inhibition of the Na+/H+ exchanger in the myocardium.

Resident
Resident

A 72-year-old patient with an LVEF of 55%, NYHA class II symptoms, and no history of diabetes presents for a follow-up. Based on the DELIVER trial results, how does initiating dapagliflozin alter their management plan, and what baseline labs should be checked before starting?

Key Response

DELIVER showed dapagliflozin reduces cardiovascular death or worsening HF in HFpEF and HFmrEF regardless of diabetes status. Initiation requires checking baseline renal function (eGFR greater than 25 ml/min/1.73m2 in DELIVER) and assessing volume status. It provides a targeted disease-modifying pharmacologic option where previous therapies showed limited or mixed efficacy.

Fellow
Fellow

How does the DELIVER trial's inclusion of patients with heart failure with improved ejection fraction (HFimpEF) impact our understanding of the trajectory of heart failure, and how does dapagliflozin's efficacy in this specific subgroup compare to those with consistently preserved LVEF?

Key Response

DELIVER was unique in explicitly including patients whose LVEF had improved from less than 40% to greater than 40%. Dapagliflozin showed consistent benefit in this HFimpEF group. This emphasizes that HF with improved LVEF is a state of remission rather than a cure, and these patients still require and benefit from GDMT, specifically SGLT2 inhibition, similar to primary HFmrEF/HFpEF.

Attending
Attending

Previous heart failure trials in HFpEF, such as PARAGON-HF and TOPCAT, demonstrated an attenuation of benefit at the highest LVEF ranges (e.g., LVEF greater than 60%). Did the DELIVER trial show a similar attenuation of benefit with dapagliflozin at higher ejection fractions, and how does this influence your clinical phenotype approach?

Key Response

Unlike PARAGON-HF or TOPCAT, the DELIVER trial demonstrated that the benefit of dapagliflozin extended across the entire spectrum of LVEF, without attenuation even in patients with LVEF greater than 60%. This shifts the clinical paradigm to treating all patients with HFmrEF and HFpEF with an SGLT2 inhibitor as foundational therapy, without needing to withhold therapy based on high normal LVEF.

Scholarly Review

Critical appraisal through the lens of expert reviewers and guideline development

PhD
PhD

The DELIVER trial used a time-to-first-event analysis for its primary composite endpoint but also performed recurrent event analyses. What are the methodological advantages of using a win ratio or recurrent event analysis in a trial like DELIVER compared to traditional time-to-first-event Cox proportional hazards models?

Key Response

Time-to-first-event analyses ignore subsequent events, such as recurrent HF hospitalizations, which are highly prevalent and clinically meaningful in HFpEF. Recurrent event models provide a more comprehensive assessment of the total disease burden and treatment effect over time, capturing the full morbidity-reducing potential of the intervention.

Journal Editor
Journal Editor

While the primary composite endpoint in DELIVER was significantly reduced, this was primarily driven by a reduction in worsening heart failure rather than cardiovascular death alone. How does this component-driven significance affect the overall strength of the trial's conclusions, and what concerns might a peer reviewer raise regarding the mortality data?

Key Response

An editor would note that the composite endpoint success masks the lack of statistically significant reduction in cardiovascular death alone (HR 0.88, 95% CI 0.74-1.05). Reviewers often challenge the clinical impact of an intervention that primarily reduces hospitalizations rather than hard mortality outcomes, noting that pooled meta-analyses are often required to overcome power limitations for mortality in modern HFpEF trials.

Guideline Committee
Guideline Committee

Considering the results of the DELIVER trial alongside EMPEROR-Preserved, how should the AHA/ACC/HFSA guidelines for Heart Failure be updated regarding the strength of recommendation and level of evidence for SGLT2 inhibitors in patients with LVEF greater than 40%?

Key Response

Prior to these trials, guidelines had weak recommendations for HFpEF, mostly symptom management with diuretics. Post-DELIVER and EMPEROR-Preserved, the evidence justifies a Class 1 or 2a, Level of Evidence A recommendation for SGLT2 inhibitors to decrease hospitalizations and CV mortality in HFmrEF and HFpEF. The 2022 ACC/AHA/HFSA guidelines gave SGLT2is a Class 2a recommendation for HFpEF, which is strongly reinforced and supported for an upgrade to Class 1 based on the totality of reproducible, robust data from DELIVER.

Clinical Landscape

Noteworthy Related Trials

2019

DAPA-HF

n = 4,744 · NEJM

Tested

Dapagliflozin 10 mg once daily

Population

Patients with heart failure and reduced ejection fraction

Comparator

Placebo

Endpoint

Composite of worsening heart failure or cardiovascular death

Key result: Dapagliflozin reduced the risk of worsening heart failure or cardiovascular death by 26% among patients with HFrEF, regardless of diabetes status.
2019

PARAGON-HF

n = 4,796 · NEJM

Tested

Sacubitril/valsartan

Population

Patients with heart failure and preserved ejection fraction

Comparator

Valsartan

Endpoint

Composite of total hospitalizations for heart failure and cardiovascular death

Key result: Sacubitril/valsartan did not significantly reduce the primary composite outcome in the overall HFpEF population, though benefits were seen in specific subgroups.
2021

EMPEROR-Preserved

n = 5,988 · NEJM

Tested

Empagliflozin 10 mg once daily

Population

Patients with heart failure and preserved ejection fraction

Comparator

Placebo

Endpoint

Composite of cardiovascular death or hospitalization for heart failure

Key result: Empagliflozin significantly reduced the combined risk of cardiovascular death or hospitalization for heart failure by 21% compared to placebo.

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