Acute decompensated heart failure and cardiogenic pulmonary oedema

Acute decompensated heart failure is the rapid onset or worsening of the heart-failure syndrome that needs urgent treatment, and its most dramatic expression is cardiogenic pulmonary oedema — the failing left ventricle cannot handle the venous return, the left-atrial and ventricular filling pressures climb, and the rising hydrostatic pressure forces fluid out through the alveolar capillaries into the lung. The Fellowship candidate must deliver the acute-oedema bundle — oxygen, non-invasive ventilation, a nitrate and a loop diuretic — while reading the patient's haemodynamic phenotype, because the same presentation is managed very differently in the warm, hypertensive patient and in the cold, shocked one.[1]

Definition and classification

Acute heart failure is the rapid onset of, or worsening of, heart-failure symptoms and signs needing urgent therapy. It embraces several overlapping syndromes: acute decompensated chronic heart failure (the commonest), acute pulmonary oedema (cardiogenic), cardiogenic shock, and isolated right-heart failure. Two classifications matter. The first is by ejection fraction — HFrEF (40 per cent or below), HFmrEF (41 to 49), and HFpEF (50 or above) — because long-term therapy differs. The second, more useful to the emergency physician, is by haemodynamic phenotype: the patient is wet or dry (congested or not) and warm or cold (well perfused or hypoperfused). The wet–warm patient is the common decompensated case; the wet–cold patient is in cardiogenic shock and is managed entirely differently. [1]

The Forrester and Stevenson haemodynamic classifications

Two complementary classifications convert the bedside phenotype into a management quadrant, and the Fellowship candidate must be able to draw both. Forrester's original four subsets, derived from invasive haemodynamic data in acute myocardial infarction, plot cardiac output against pulmonary-capillary wedge pressure: subset I (warm and dry, wedge < 18, no pulmonary congestion), subset II (warm and wet, wedge > 18, pulmonary oedema), subset III (cold and dry, wedge < 18, hypovolaemic hypoperfusion), and subset IV (cold and wet, wedge > 18, cardiogenic shock).[6] The Stevenson–Nohria clinical modification replaces the pulmonary-artery catheter with the bedside examination, using congestion (wet or dry, from the JVP, crackles, oedema, and the bedside echo) against perfusion (warm or cold, from the pulse pressure, extremity warmth, and the mental state and urine output).[7] The clinical grid is what guides emergency therapy, because the catheter is now reserved for the haemodynamically opaque patient.

Epidemiology and precipitants

Acute heart failure is a leading cause of hospital admission in older adults and carries a substantial in-hospital mortality and a high 30-day readmission rate. An acute decompensation almost always has a precipitant, and finding it is part of the emergency workup: an acute coronary syndrome (the commonest), an arrhythmia (especially atrial fibrillation), non-adherence to drugs, fluids or a low-salt diet, an infection, anaemia, renal failure, a thyroid disorder, or an offending drug (an NSAID, a calcium-channel blocker, or a negative inotrope). [1]

Identifying and reversing the precipitant is itself treatment, because the decompensation often resolves once the trigger — an ischaemic event, a fast atrial arrhythmia, or a salt-and-fluid excess — is removed, and because a decompensation without a clear precipitant carries a worse prognosis and prompts a search for a new cause such as a silent infarction or an unrecognised arrhythmia. [1]

A precipitant is found in roughly two-thirds of admissions, and a structured search is mandatory because reversing it is itself treatment. The commonest single cause is ischaemia (an acute coronary syndrome), followed by an arrhythmia (most often new or fast atrial fibrillation), and these two account for the majority of identifiable triggers. [1]

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Pathophysiology — why NIV and nitrates work

The failing ventricle cannot generate an adequate output at an acceptable filling pressure, so the filling pressure rises, and the pressure is transmitted back to the pulmonary capillaries. When the hydrostatic pressure exceeds the oncotic pressure, fluid floods the interstitium and then the alveoli, producing ventilation–perfusion mismatch and shunt, and so hypoxia. The hypoxia itself depresses the myocardium, and the sympathetic and renin–angiotensin activation that follows raises the afterload and closes the vicious circle. This is the rationale for the two most powerful emergency manoeuvres: non-invasive ventilation, which raises the intrathoracic pressure and so reduces both the venous return (preload) and the left-ventricular transmural pressure (afterload) while it recruits alveoli; and the nitrates, which reduce the preload and afterload directly.[2]

Clinical presentation

The classic presentation is acute respiratory distress: dyspnoea, orthopnoea, paroxysmal nocturnal dyspnoea, a productive cough with frothy or pink sputum, and wheeze (the cardiac asthma of bronchial-wall oedema). The patient is anxious, pale, sweaty and clammy, and sits upright fighting for breath. The examination shows tachypnoea and hypoxia, a raised jugular venous pressure, bibasal inspiratory crackles, a third heart sound, and oedema; the peripheries distinguish the warm (well-perfused) from the cold (hypoperfused) phenotype. In the elderly the presentation may be atypical — confusion and fatigue rather than breathlessness. A rising respiratory rate with fatigue and accessory-muscle use signals exhaustion and impending arrest. [1]

Differential diagnosis

The breathless, hypoxic patient has a differential, and the natriuretic peptide, the chest radiograph and the echo sort it out. [1]

Bedside assessment

Assess the airway and the breathing first — exhaustion and a falling respiratory rate are pre-arrest signs. Determine the phenotype: feel the peripheries for warmth (well perfused) or coldness (hypoperfused), and assess the congestion (raised JVP, crackles, oedema) against the dry state. Look for the precipitant: an ischaemic ECG, an irregularly irregular pulse of atrial fibrillation, a fever, the stigmata of chronic lung disease. [1]

Investigations and the targets

The ECG seeks the cause (an acute coronary syndrome, atrial fibrillation, left-ventricular hypertrophy). The chest radiograph shows cardiomegaly, Kerley B lines (the interstitial phase), the perihilar bat-wing alveolar oedema, and pleural effusions. The natriuretic peptide — BNP or NT-proBNP — is the single most useful single test: a low value largely excludes heart failure, while a high one supports it (BNP below about 100 is a strong rule-out, above 400 supports the diagnosis; interpret with the picture, as sepsis, renal failure and obesity distort it). The troponin identifies an ischaemic cause, the bedside echo distinguishes a reduced from a preserved ejection fraction and seeks a valve lesion, a regional wall-motion abnormality or a pericardial effusion, and the blood gas quantifies the hypoxia and detects the rising carbon dioxide of the tiring patient. Urea, creatinine and electrolytes guide the diuretic and the cause. [1]

Immediate management — the acute-oedema bundle, phenotype-led

Resuscitation and specific therapy begin together. Sit the patient upright and give high-flow oxygen to a saturation target of 94 to 98 per cent (88 to 92 in the chronic type-2 respiratory failure of COPD). Then the bundle, modified by the phenotype: [1]

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Non-invasive ventilation is first-line for respiratory distress or persistent hypoxia. The 3CPO trial showed no mortality benefit but a real reduction in breathlessness and in the need for intubation, so NIV is applied early for symptom relief and respiratory support rather than delayed in the hope of a survival difference.[2] Morphine (2.5 to 5 mg intravenously) is no longer routine — registry data link it to respiratory depression, ICU admission and worse outcomes — and is reserved for genuine distress or ischaemic pain. Treat the precipitant throughout: an acute coronary syndrome is reperfused, atrial fibrillation is rate- or rhythm-controlled, an infection is treated.

The diuretic strategy — dose, bolus, infusion

Loop diuretics are the cornerstone of decongestion. Give the first dose intravenously because gut-wall oedema impairs absorption. The standard initial dose is furosemide 40 to 80 mg IV for a patient not on chronic diuretics; for a patient already taking oral loop diuretics, give 1 to 2.5 times the total daily oral dose intravenously, because chronic use induces a rightward dose–response shift (the "braking phenomenon"). The DOSE-AHF trial randomised patients to high-dose (2.5× the home dose) versus low-dose (1×) furosemide and to bolus every 8 hours versus continuous infusion: high-dose produced faster fluid loss and greater dyspnoea relief with no significant difference in the composite primary endpoint or in renal dysfunction, and bolus and continuous infusion were equivalent.[3] The ROSE-AHF trial showed that neither low-dose dopamine nor low-dose nesiritide augmented decongestion or protected renal function in acute heart failure with renal dysfunction — so routine renal-dose dopamine is not supported.[4]

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Vasodilators — when and how

Nitrates are added to the warm–wet, hypertensive patient (systolic above about 110 mmHg). Glyceryl trinitrate is started at 5–20 micrograms per minute and titrated up every few minutes (to 200 micrograms per minute) against the blood pressure and the dyspnoea. The mechanism is venodilation (preload reduction) and, at higher doses, arteriolar dilation (afterload reduction), which together drop the pulmonary-capillary wedge pressure faster than a diuretic alone. Sublingual GTN (0.4–0.8 mg) is a useful bridge while the infusion is set up. The Cotter trial established that a high-dose nitrate, low-dose diuretic strategy outperforms the reverse in hypertensive pulmonary oedema.[5] Sodium nitroprusside is reserved for the hypertensive emergency with severe afterload or aortic/mitral regurgitation, and requires arterial-line monitoring. Nesiritide (BNP analogue) showed no mortality or readmission benefit and is not routine. Serelaxin, tested in RELAX-AHF, improved dyspnoea but did not reduce cardiovascular mortality at 180 days in the definitive trial, and is not universally approved.[9]

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Inotropes and vasopressors for the cold phenotype

The cold–wet patient (cardiogenic shock) has low cardiac output with congestion and hypotension, and needs an inotrope rather than a venodilator. The choice is guided by the dominant problem — low output versus low pressure — and by whether the patient is also vasodilated. A bedside echo showing a small, underfilled, poorly contracting left ventricle helps; a pulmonary-artery catheter is justified when the haemodynamics remain opaque. [1]

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The acute-oedema bundle as a sequence

Subtypes and special scenarios

The hypertensive acute decompensated heart failure (warm–wet with a high pressure) responds best to a nitrate and a diuretic and has the best prognosis. Cardiogenic shock (wet–cold) is the other extreme and needs inotropes and mechanical circulatory support as a bridge to definitive treatment. Right-heart failure (cor pulmonale) shows a raised JVP with clear lungs and oedema. Peripartum cardiomyopathy presents in late pregnancy or the early postpartum period in a young woman and adds bromocriptine to the therapy. [1]

Complications and pitfalls

The complications are cardiogenic shock, acute kidney injury (from low output and the diuretic), respiratory failure and arrest, and arrhythmia. The pitfalls are the dangerous inverse of the bundle: giving a nitrate to the hypotensive patient; withholding NIV when it is indicated; over-diuresing the dry patient; using morphine routinely; missing the precipitant (an infarction that needs reperfusion); and mistaking a pulmonary embolism or ARDS for cardiogenic oedema. [1]

Prognosis and disposition

In-hospital mortality is around 4 to 10 per cent, much higher with cardiogenic shock; the 30-day readmission rate approaches 25 per cent. Every patient is admitted to cardiology or a high-dependency bed, the precipitant is treated, and guideline therapy is optimised before discharge — for the reduced-ejection-fraction patient, the four pillars of a beta-blocker, an ACE inhibitor or ARNI, a mineralocorticoid antagonist, and an SGLT2 inhibitor. [1]

Special populations

The elderly present atypically and have renal impairment that complicates the diuretic. Chronic kidney disease causes diuretic resistance and distorts the natriuretic peptide, so the clinical picture and the echo weigh more. COPD overlap is common; the natriuretic peptide and the chest radiograph distinguish a heart failure exacerbation from a COPD exacerbation. Peripartum cardiomyopathy is a young-woman presentation with its own therapy. [1]

Evidence and regional guidelines

The contemporary framework is the 2021 ESC heart-failure guideline with the 2023 focused update.[1] The non-invasive-ventilation evidence is the 3CPO trial.[2] The bundle and the four-pillar long-term therapy are global; the local cardiology and heart-failure pathways govern the agent choices and the disposition.

Discharge criteria and transition to oral therapy

The goal of the admission is not merely symptom relief but a euvolaemic, haemodynamically stable patient on optimised oral guideline therapy before discharge — because the 30-day readmission rate approaches 25 per cent and most readmissions are driven by residual congestion or incomplete uptitration. The transition from intravenous to oral diuretic is made once the oral route is reliably absorbed and the patient is clinically euvolaemic; the oral dose is typically half to two-thirds of the IV dose that achieved decongestion, and the weight, the JVP and the renal function are watched daily. [1]

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Exam practice

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Exam pearls

• Sit up, oxygen, NIV, GTN (if the pressure holds), furosemide — and read the phenotype first.
• NIV reduces preload and afterload and recruits alveoli; 3CPO showed symptom and intubation benefit, not a mortality difference — so use it early.
• Nitrates only if the blood pressure is adequate — the cold, hypotensive (wet–cold) phenotype has cardiogenic shock and wants an inotrope or a vasopressor and mechanical support.
• No routine morphine — respiratory depression, worse outcomes.
• BNP rules out heart failure; the chest radiograph shows Kerley B lines and bat-wing oedema.
• Find the precipitant — an acute coronary syndrome needs reperfusion, atrial fibrillation needs rate control.
• Forrester and Stevenson at the bedside — congestion (wet/dry) × perfusion (warm/cold) guides everything; the wet–warm is the bundle patient, the wet–cold is the shock patient.[6][7]
• Diuretic dosing — 40–80 mg IV if naïve; 1–2.5× the oral dose if already on a loop (DOSE-AHF); bolus and continuous infusion are equivalent.[3]
• A narrow pulse pressure (< 25% of systolic) marks a low stroke volume — a cold phenotype even before the blood pressure falls.
• The cotter principle — in hypertensive pulmonary oedema the nitrate does the heavy lifting; high-dose isosorbide/GTN + low-dose diuretic beats high-dose diuretic + low-dose nitrate.[5]
• Renal-dose dopamine has no role — ROSE-AHF showed no augmentation of decongestion or renal protection.[4]
• Atrial fibrillation is the classic arrhythmic precipitant — loss of the atrial kick plus a fast rate tips the failing ventricle; rate (or rhythm) control is part of the resuscitation.
• NSAIDs cause fluid and salt retention — a top iatrogenic precipitant; stop them on admission and counsel against them at discharge.
• An S3 gallop is the auscultatory hallmark of volume overload and a failing ventricle — together with a raised JVP it is highly specific for cardiogenic oedema.
• BiPAP over CPAP when there is hypercapnia (CO₂ retention, the tiring patient, COPD overlap) — otherwise CPAP is simpler and equally effective for pure cardiogenic oedema.
• Discharge only the euvolaemic patient — stable weight 24–48 h off IV diuretic, normalising renal function, and the four HFrEF pillars initiated; residual congestion drives the 25% 30-day readmission rate.
• Cardiac asthma — wheeze from bronchial-wall oedema can mimic COPD; the raised JVP, S3 and BNP distinguish the failing heart.
• Cotter, DOSE, ROSE, RELAX — the four trials an examiner expects: nitrates win, high-dose diuretic speeds decongestion, dopamine/nesiritide add nothing, serelaxin relieves dyspnoea but not mortality.[3][4][5][9]

Red flags

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References

1. [1]McDonagh TA, Metra M, Adamo M, et al. [2023 Focused update of the 2021 ESC Guidelines for the diagnosis and treatment of acute and chronic heart failure] G Ital Cardiol (Rome), 2024.PMID 38410903
2. [2]Gray A, Goodacre S, Newby DE, et al. Noninvasive ventilation in acute cardiogenic pulmonary edema N Engl J Med, 2008.PMID 18614781
3. [3]Felker GM, Lee KL, Bull DA, et al. Diuretic strategies in patients with acute decompensated heart failure N Engl J Med, 2011.PMID 21366472
4. [4]Chen HH, Anstrom KJ, Givertz MM, et al. Low-dose dopamine or low-dose nesiritide in acute heart failure with renal dysfunction: the ROSE acute heart failure randomized trial JAMA, 2013.PMID 24247300
5. [5]Cotter G, Metzkor E, Kaluski E, et al. Randomised trial of high-dose isosorbide dinitrate plus low-dose furosemide versus high-dose furosemide plus low-dose isosorbide dinitrate in severe pulmonary oedema Lancet, 1998.PMID 9482291
6. [6]Forrester JS, Diamond G, Chatterjee K, et al. Medical therapy of acute myocardial infarction by application of hemodynamic subsets (second of two parts) N Engl J Med, 1976.PMID 790194
7. [7]Nohria A, Mielniczuk LM, Stevenson LW Evaluation and monitoring of patients with acute heart failure syndromes Am J Cardiol, 2005.PMID 16181821
8. [8]Berbenetz N, Wang Y, Brown J, et al. Non-invasive positive pressure ventilation (CPAP or bilevel NPPV) for cardiogenic pulmonary oedema Cochrane Database Syst Rev, 2019.PMID 30950507
9. [9]Teerlink JR, Cotter G, Davison BA, et al. Serelaxin, recombinant human relaxin-2, for treatment of acute heart failure (RELAX-AHF): a randomised, placebo-controlled trial Lancet, 2013.PMID 23141816