Should I add a Sodium-Glucose Cotransporter 2 (SGLT2) inhibitor to the treatment regimen of a patient with Congestive Heart Failure (CHF) and a reduced ejection fraction exacerbation who also has diabetes?

SGLT2 Inhibitors in Heart Failure with Reduced Ejection Fraction and Diabetes

Direct Recommendation

Yes, you should absolutely add an SGLT2 inhibitor (specifically dapagliflozin 10 mg daily or empagliflozin 10 mg daily) to this patient's treatment regimen immediately. This is a Class I, Level A recommendation for patients with heart failure and reduced ejection fraction, regardless of diabetes status, and the presence of diabetes makes this even more compelling. 1, 2

Evidence-Based Rationale

Mortality and Morbidity Benefits

SGLT2 inhibitors provide substantial reductions in the outcomes that matter most:

• Cardiovascular death is reduced by 18% in patients with HFrEF treated with SGLT2 inhibitors 2
• Heart failure hospitalizations are reduced by 27-39% across multiple large clinical trials, demonstrating a consistent class effect 2
• The combined endpoint of worsening heart failure or cardiovascular death is reduced by 26% based on the DAPA-HF trial 2
• These benefits occur within days to weeks of initiation, with empagliflozin showing a 58% relative risk reduction at just 12 days 2, 3

Specific Evidence for Your Patient Population

For patients with both HFrEF and diabetes (your exact scenario):

• The 2019 ESC Guidelines give SGLT2 inhibitors (empagliflozin, canagliflozin, and dapagliflozin) a Class I, Level A recommendation to lower risk of HF hospitalization in patients with diabetes 1
• The 2022 AHA/ACC/HFSA Guidelines recommend SGLT2 inhibitors as Class 2a, Level B-R for HFmrEF (LVEF 41-49%) and even stronger for HFrEF 1
• Benefits are independent of diabetes status, meaning your patient gets dual benefit from both the HF and diabetes indications 1, 2

Which SGLT2 Inhibitor to Choose

Choose either dapagliflozin 10 mg daily or empagliflozin 10 mg daily - both have the strongest evidence from dedicated heart failure outcome trials (DAPA-HF and EMPEROR-Reduced). 2, 3

Do NOT use ertugliflozin - it lacks dedicated heart failure outcome trials and has no evidence base for HF treatment. 2

Canagliflozin and sotagliflozin have some evidence but are not the preferred first-line agents based on current guidelines. 1, 2

Timing of Initiation

Initiate the SGLT2 inhibitor during this hospitalization once the patient is stabilized:

• No increase in IV diuretics for 6 hours 2
• No IV vasodilators or inotropes for 24 hours 2
• Do not defer initiation - studies show that deferring results in many eligible patients never receiving the medication within 1 year 2
• Early initiation is critical given the rapid onset of benefit 2, 3

Safety Considerations and Monitoring

SGLT2 inhibitors are remarkably safe in this population:

• No dose titration required - unlike ACE inhibitors, beta-blockers, or MRAs 2
• Minimal impact on blood pressure, heart rate, or potassium levels 2
• Renal protective effects - can be used with eGFR as low as 20 mL/min/1.73m² 1, 2
• A mild, transient decrease in eGFR may occur but does not indicate kidney injury and should not prompt discontinuation 2

Monitor for:

• Volume depletion/hypotension (occurs in ~5.7% of patients) 2
• Genital mycotic infections (1.5-1.7%) and UTIs (2.3-2.7%) - generally manageable 2
• Diabetic ketoacidosis risk is significantly lower in the context of HF compared to other settings 2

Integration with Other Heart Failure Therapies

SGLT2 inhibitors work synergistically with standard HF medications:

• Benefits are independent of background therapy with ACE inhibitors/ARBs/ARNI, beta-blockers, and MRAs 4, 3
• They actually reduce risk of hyperkalemia, which facilitates tolerance of renin-angiotensin system inhibitors and MRAs 3
• Unlike loop diuretics alone, SGLT2 inhibitors increase electrolyte-free water clearance without excessive sodium loss 5

Critical Pitfall to Avoid

Do not discontinue the SGLT2 inhibitor once started - analyses show that benefits decline rapidly after discontinuation, and persistence of treatment is essential for sustained benefit. 6

Do not wait to optimize other medications first - SGLT2 inhibitors should be initiated early as first-line therapy, not reserved for patients who have failed other treatments. 3