PH4.9 | PH4.9 | Heart Failure Pharmacotherapy — Summary & Reflection

KEY TAKEAWAYS

Heart failure pharmacotherapy is governed by the neurohormonal hypothesis: maladaptive RAAS, SNS, and aldosterone activation drives HFrEF progression, and interrupting these pathways with the four evidence-based drug classes — ACEi/ARNI, beta-blockers (carvedilol/bisoprolol/metoprolol succinate ONLY), MRA (spironolactone/eplerenone), and SGLT2 inhibitors (dapagliflozin/empagliflozin) — each independently and additively reduces cardiovascular death and HF hospitalisation. Beta-blockers are CONTRAINDICATED acutely but mandatory once stable — the sequence of initiation is critical. Loop diuretics control congestion but do not prolong survival. Digoxin reduces HHF but not mortality; its narrow therapeutic index requires careful monitoring (target 0.5–0.9 ng/mL) and hypokalaemia is the most dangerous precipitant of toxicity. Ivabradine reduces HHF when HR remains >70 bpm despite maximum beta-blocker. For HFpEF, empagliflozin (EMPEROR-Preserved) is the only drug with proven benefit. Long-term complication prevention requires ICD consideration (LVEF ≤35%), anticoagulation in AF, and nephroprotective strategy.

REFLECT

Return to the opening patient: 62-year-old woman with HFrEF LVEF 28%, on furosemide + ramipril + atorvastatin, no beta-blocker.

1. Her doctor's concern about beta-blockers 'weakening the heart' is a common misconception. Write the one-paragraph explanation you would give a junior colleague: why are beta-blockers life-saving in this patient?
2. Her ramipril is at 2.5 mg — the target dose is 10 mg BD. You also want to eventually switch to sacubitril/valsartan. What must you do before making this switch?
3. She has K of 4.8 mEq/L. Can you start spironolactone safely? At what K level would you hesitate?
4. SGLT2 inhibitor dapagliflozin 10 mg is available. Does she need diabetes to qualify for this drug?
5. At her 3-month follow-up, repeat echo shows LVEF improved to 38%. Does this mean you can reduce or stop the four-pillar drugs?

This patient's trajectory — from undertreated HFrEF to four-pillar-optimised therapy — represents the most satisfying pharmacological success in cardiovascular medicine.