What is the role of SGLT2 (sodium-glucose cotransporter 2) inhibitors, such as empagliflozin (Empagliflozin) or canagliflozin (Canagliflozin), in managing tachycardia-induced cardiomyopathy with improved ejection fraction from 40% to 65%?

SGLT2 Inhibitors in Tachycardia-Induced Cardiomyopathy with Normalized Ejection Fraction

SGLT2 inhibitors are beneficial and should be continued in patients with a history of tachycardia-induced cardiomyopathy whose ejection fraction has normalized from 40% to 65%. 1

Evidence-Based Rationale

The 2022 AHA/ACC/HFSA Heart Failure Guidelines provide clear direction for this clinical scenario:

• SGLT2 inhibitors have demonstrated significant benefits in patients with heart failure across the spectrum of ejection fractions, including those with:
  • Previously reduced EF that has improved (your patient's case)
  • Current EF >40% (which applies to your patient with current EF of 65%)

Key Benefits of SGLT2i in This Patient Population

1. Reduction in Heart Failure Hospitalizations:

   • The EMPEROR-Preserved trial showed a 29% reduction in heart failure hospitalizations in patients with EF >40% 1
   • This benefit was independent of diabetes status

2. Cardiovascular Mortality Reduction:

   • Class 2a recommendation (Level of Evidence: B-R) for SGLT2i in patients with EF >40% to decrease cardiovascular mortality 1

3. Prevention of Heart Failure Recurrence:

   • Particularly important in tachycardia-induced cardiomyopathy where recurrence risk exists if rate control is not maintained

Medication Selection

Both empagliflozin and canagliflozin are appropriate options:

• Empagliflozin: 10mg daily is the dose used in the EMPEROR-Preserved trial that demonstrated benefit 1, 2
• Canagliflozin: Also an effective SGLT2 inhibitor with similar mechanism of action 3

Clinical Application Algorithm

1. For patients with history of tachycardia-induced CM with normalized EF:

   • Continue SGLT2i therapy despite EF normalization
   • Monitor for recurrence of tachycardia and heart failure symptoms
   • Maintain appropriate rate control therapy

2. Additional therapies to consider (Class 2b recommendation):

   • Evidence-based beta blockers (particularly important for rate control in tachycardia-induced CM)
   • ACEi/ARB/ARNi
   • MRAs (mineralocorticoid receptor antagonists)

Important Considerations and Pitfalls

• Do not discontinue SGLT2i when EF normalizes: The benefits extend beyond the acute recovery phase
• Monitor renal function: While SGLT2i are renoprotective, they should be used cautiously with eGFR <20 mL/min/1.73m² 1
• Avoid in Type 1 diabetes: SGLT2i are contraindicated in Type 1 diabetes due to DKA risk
• Counsel on genital mycotic infections: Most common side effect, more frequent with SGLT2i 4

Mechanism of Benefit

SGLT2i provide cardiovascular benefits through multiple mechanisms beyond glycemic control:

• Reduced sodium reabsorption
• Decreased preload and afterload
• Improved cardiac energetics
• Reduced sympathetic activity 2
• Decreased intraglomerular pressure

The benefits in tachycardia-induced cardiomyopathy likely relate to these hemodynamic and neurohormonal effects, which remain relevant even after EF normalization.