When to add SGLT2 (sodium-glucose cotransporter 2) inhibitors in heart failure?

When to Add SGLT2 Inhibitors in Heart Failure

SGLT2 inhibitors should be added to standard therapy for all patients with heart failure regardless of ejection fraction (HFrEF, HFmrEF, or HFpEF), as they significantly reduce cardiovascular mortality and heart failure hospitalizations across the spectrum of heart failure. 1, 2

Patient Selection and Timing

Immediate Candidates (Add SGLT2i Now):

• Patients with established heart failure (NYHA class II-IV) with any ejection fraction 1, 2
• Patients recently hospitalized for heart failure (initiate before discharge or within 3 days after) 1
• Patients with heart failure and diabetes mellitus 1, 3

Eligibility Criteria:

• Age ≥18 years
• eGFR ≥20 mL/min/1.73m² (preferred ≥30 mL/min/1.73m²) 1
• Stable clinical status (no supplemental oxygen requirement, SBP ≥100 mmHg, no IV inotropes) 1

Contraindications:

• Type 1 diabetes 1
• eGFR <20 mL/min/1.73m² 1
• Pregnancy/breastfeeding
• History of severe genital mycotic infections

Rationale for Early Initiation

1. Early Clinical Benefits: SGLT2 inhibitors demonstrate benefits within days to weeks of initiation, with significant reduction in mortality and hospitalizations evident as early as 12 days after starting therapy 1

2. Comprehensive Outcome Benefits:

   • 21-25% reduction in composite of cardiovascular death or heart failure hospitalization 4, 5
   • Consistent benefits across HFrEF, HFmrEF, and HFpEF populations 2
   • Slows decline in renal function 4

3. In-Hospital Initiation Advantages:

   • Failure to initiate SGLT2i during hospitalization results in >75% chance of therapy never being started within the next year 1
   • Improves post-discharge medication adherence 1
   • Reduces early post-discharge events 1

Implementation Algorithm

1. For Hospitalized HF Patients:

   • Assess eligibility (eGFR ≥20 mL/min/1.73m², stable clinical status)
   • Initiate before discharge when clinically stable 1
   • Start with empagliflozin 10mg daily or dapagliflozin 10mg daily 1, 3

2. For Outpatient HF Patients:

   • Add SGLT2i at next clinical encounter if not already prescribed
   • Prioritize addition regardless of diabetes status 1
   • No need to adjust other heart failure medications when adding SGLT2i

3. Monitoring After Initiation:

   • Check renal function within 2-4 weeks
   • Monitor for genital mycotic infections
   • No routine dose adjustments needed for most patients

Current Prescribing Gaps

Despite strong evidence and guideline recommendations, SGLT2 inhibitors remain significantly underprescribed. A recent study found only 15.7% of eligible heart failure patients were prescribed an SGLT2i at hospital discharge, despite 94.8% being eligible 6.

Common Pitfalls to Avoid

1. Delaying Initiation: Waiting for outpatient follow-up significantly reduces the likelihood of patients ever receiving this life-saving therapy 1

2. Overemphasis on Diabetes Status: Benefits are consistent regardless of diabetes status; don't limit use to only patients with diabetes 1, 2

3. Concerns About Polypharmacy: Despite patients on SGLT2i having more medications overall (15.78 vs 12.05), the mortality benefit outweighs concerns about pill burden 6

4. Excessive Concern About Hypotension: SGLT2i have minimal impact on blood pressure in euvolemic patients; they can be safely added to other heart failure therapies 1

5. Withholding Due to Mild Renal Impairment: SGLT2i are beneficial and safe in patients with eGFR ≥20 mL/min/1.73m² 1

By implementing SGLT2 inhibitors early in the treatment course for all eligible heart failure patients, clinicians can significantly improve mortality, reduce hospitalizations, and enhance quality of life across the spectrum of heart failure.