SGLT-2 inhibitors reduce cardiovascular mortality in heart failure independent of their glycaemic effects. The principal cardioprotective mechanism currently supported by evidence involves:
- A Reduction in afterload via osmotic diuresis and natriuresis lowering preload
- B Activation of cardiac AMPK, stimulating autophagy and mitophagy
- C Direct inhibition of myocardial fibrosis via suppression of TGF-beta signalling
- D Inhibition of the mitochondrial sodium-hydrogen exchanger (NHE1) in cardiomyocytes, reducing calcium overload ✓
Explanation
Beyond glycaemic and haemodynamic effects, current evidence implicates inhibition of the sodium-hydrogen exchanger isoform 1 (NHE1) in cardiomyocytes as a key direct cardioprotective mechanism. SGLT-2 inhibitors also inhibit cardiac NHE1 (NHE1 activity is upregulated in HF), preventing intracellular Na+ and secondary Ca2+ overload, improving diastolic function and reducing mechanical stress. Haemodynamic effects (preload/afterload reduction via diuresis) contribute but do not fully explain the survival benefit, particularly in HFpEF where volume effects are less. AMPK activation and TGF-beta suppression are real effects but are not the primary mechanism supported by current mechanistic evidence.
Reference: KD Tripathi, Essentials of Medical Pharmacology, 8th ed.
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Written and medically reviewed by the StethoPrep medical team.