Heart Failure Explained: Ejection Fraction, the Four Pillars of Treatment, Why You Weigh Yourself Daily, and the Kidney Dilemma

What heart failure is

Heart failure (HF) is a syndrome in which a structural or functional cardiac problem means the heart cannot pump enough blood, or can only do so at high filling pressures, producing the triad of breathlessness, fatigue and fluid retention [1][2]. Around 64 million people live with it worldwide [3]. It is not "the heart stopping"; it is a chronic condition most people can live with for many years — provided the right drugs and self-care are in place.

Symptoms: breathless, swollen, tired — and night-time signals

Typical features [1][2]:

• Breathlessness on exertion, progressively worsening.
• Breathless lying flat (orthopnoea) needing extra pillows, or waking at night gasping (paroxysmal nocturnal dyspnoea).
• Leg swelling: pitting oedema at the ankles and shins, worse in the evening.
• Rapid weight gain: more than 2 kg in 3 days is usually fluid, not fat.
• Fatigue, reduced exercise tolerance, poor appetite, bloating (liver and gut congestion).
• More night-time urination.

Doctors describe severity with the NYHA class: I no symptoms → II symptoms with ordinary activity → III with minimal activity → IV at rest [2].

Ejection fraction: three kinds of heart failure

Left-ventricular ejection fraction (LVEF) on echocardiography is central to classification [1][2]:

Normal EF is about 55–70%. A normal EF does not exclude heart failure — HFpEF is nearly half of all cases and had no proven therapy until SGLT2 inhibitors [6].

Blood NT-proBNP/BNP (hormones released when the heart is stretched) aids diagnosis; NT-proBNP <125 pg/mL makes HF unlikely [1]. Reduced kidney function raises NT-proBNP, so interpret alongside eGFR [1].

The "four pillars" for HFrEF: each lowers mortality

Both the 2021 ESC and 2022 AHA/ACC/HFSA guidelines recommend starting all four classes early and together, rather than maximising one before adding the next [1][2]:

Diuretics relieve congestion (without changing mortality); ivabradine, vericiguat, hydralazine/nitrate, ICDs and CRT are added in selected patients [1][2].

HFpEF and HFmrEF: the 2023 ESC update and the 2022 US guideline make SGLT2 inhibitors first-line (EMPEROR-Preserved and DELIVER: ≈18–21% lower CV death or hospitalisation) [2][6]; other treatment targets hypertension, atrial fibrillation and congestion.

Daily self-care: five things that keep you out of hospital

Structured self-care reduces admissions [1][2]:

1. Weigh yourself every morning (after urinating, before breakfast, same scale). A gain of >2 kg over 3 days or >1 kg in a day → contact your team; diuretics may need adjusting.
2. Limit salt: avoid >5 g salt/day (≈2 g sodium). Very strict restriction (<1.5 g sodium) showed no extra benefit in trials and may harm nutrition [7].
3. Fluids: strict restriction is usually unnecessary; 1.5–2 L/day may be advised in severe HF or low sodium [1].
4. Take medicines as prescribed and never stop on your own — feeling better is proof they work.
5. Exercise: once stable, cardiac rehabilitation under supervision improves symptoms and quality of life [1][2].

Also: influenza, pneumococcal and COVID-19 vaccination; stop smoking; limit alcohol; avoid NSAIDs (fluid retention and worsening heart and kidney function) [1][2].

Heart and kidney: the cardiorenal syndrome

About 40–50% of HF patients also have CKD, and each worsens the other: low cardiac output reduces kidney perfusion; kidneys that cannot excrete salt and water overload the heart [8]. What this means for kidney patients:

• SGLT2 inhibitors are a double win, protecting heart and kidney (DAPA-CKD, EMPA-KIDNEY), usable down to eGFR ≥20. An initial eGFR dip of 2–4 mL/min is haemodynamic, not damage [4][5].
• After starting ACEi/ARB/ARNI or MRA, a creatinine rise ≤30% with potassium <5.5 is acceptable; larger changes need adjustment [1].
• Diuretic doses often need to be higher in CKD (reduced response).
• Dialysis patients: trial evidence is limited; ultrafiltration, dry-weight setting and interdialytic fluid control are the main levers, decided jointly by nephrology and cardiology.
• Anaemia (common in CKD) worsens HF symptoms and should be addressed.

When to seek care immediately

Call emergency services [1][2]:

• Severe breathlessness at rest, unable to lie down, blue lips.
• Chest pain lasting >15 minutes or with cold sweat (possible heart attack).
• Fainting or confusion.
• Very fast, irregular heartbeat with dizziness.

Contact your team today:

• Weight up >2 kg in 3 days; markedly worse swelling.
• New night-time breathlessness or needing more pillows.
• Clearly reduced urine output.

Questions to ask your doctor

1. What is my EF, and which type of HF do I have?
2. How many of the four pillars am I on? If not all, why (low BP, high potassium, kidney function)?
3. Can I take an SGLT2 inhibitor?
4. At what weight gain should I call? May I adjust my diuretic myself?
5. Am I a candidate for cardiac rehabilitation?

References

1. McDonagh TA, et al. 2021 ESC Guidelines for acute and chronic heart failure. Eur Heart J. 2021;42(36):3599–3726. https://doi.org/10.1093/eurheartj/ehab368 ; 2023 Focused Update. Eur Heart J. 2023;44(37):3627–3639. https://doi.org/10.1093/eurheartj/ehad195
2. Heidenreich PA, et al. 2022 AHA/ACC/HFSA Guideline for the Management of Heart Failure. Circulation. 2022;145(18):e895–e1032. https://doi.org/10.1161/CIR.0000000000001063
3. GBD 2017 Disease and Injury Incidence and Prevalence Collaborators. Lancet. 2018;392(10159):1789–1858. https://doi.org/10.1016/S0140-6736(18)32279-7
4. McMurray JJV, et al. DAPA-HF. N Engl J Med. 2019;381(21):1995–2008. https://doi.org/10.1056/NEJMoa1911303
5. Packer M, et al. EMPEROR-Reduced. N Engl J Med. 2020;383(15):1413–1424. https://doi.org/10.1056/NEJMoa2022190
6. Solomon SD, et al. DELIVER. N Engl J Med. 2022;387(12):1089–1098. https://doi.org/10.1056/NEJMoa2206286
7. Ezekowitz JA, et al. SODIUM-HF. Lancet. 2022;399(10333):1391–1400. https://doi.org/10.1016/S0140-6736(22)00369-5
8. Rangaswami J, et al. Cardiorenal syndrome. AHA Scientific Statement. Circulation. 2019;139(16):e840–e878. https://doi.org/10.1161/CIR.0000000000000664

This article compiles publicly available medical information for educational purposes only. It is not medical advice and has not been reviewed by a practising physician. For any health or medication question, consult a qualified professional. For chest pain, sudden breathlessness, one-sided weakness or slurred speech, call your local emergency number or go to the emergency department immediately.