What is the recommended initial assessment and step‑by‑step management of cardiogenic shock, including monitoring, pharmacologic and fluid therapy, treatment of the underlying cause, and when to use mechanical circulatory support?

Management of Cardiogenic Shock

Immediate Diagnostic Assessment

Obtain a 12-lead ECG and bedside echocardiography immediately in every patient with suspected cardiogenic shock to identify the cardiac etiology, assess ventricular function, and detect mechanical complications such as ventricular septal rupture or acute mitral regurgitation. 1, 2

Hemodynamic Definition

• Define cardiogenic shock by persistent systolic blood pressure <90 mmHg despite adequate filling, accompanied by signs of hypoperfusion: oliguria <0.5 mL/kg/h, cold extremities, altered mental status, lactate >2 mmol/L, or metabolic acidosis 1, 2, 3
• Hemodynamic criteria include cardiac index <2.2 L/min/m² (often <1.8 L/min/m² in severe cases) and pulmonary capillary wedge pressure >15 mmHg 1, 2, 3
• Cardiac power output <0.6 W is the most critical threshold for identifying refractory shock 1, 3

Essential Monitoring

• Insert an invasive arterial line immediately for continuous, accurate blood pressure measurement 1, 2
• Consider pulmonary artery catheterization when diagnosis remains uncertain or the patient fails to respond to initial therapy, as complete hemodynamic profiling may improve outcomes 1, 2
• Monitor serum lactate, renal function (creatinine, urea), electrolytes, and cardiac biomarkers serially 4, 1

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Step-by-Step Management Algorithm

Step 1: Airway and Respiratory Support

• Provide supplemental oxygen or invasive mechanical ventilation to maintain arterial oxygen saturation >90% as guided by arterial blood gas analysis 1, 2
• Endotracheal intubation with positive end-expiratory pressure is usually required for patients with respiratory failure or pulmonary edema 4, 1

Step 2: Initial Hemodynamic Support

Fluid Management

• In hypotensive patients with normal perfusion and no signs of congestion, administer a cautious fluid challenge of approximately 200 mL over 15–30 minutes after ruling out mechanical complications by echocardiography 1, 2
• Critical pitfall: Avoid volume overload in right-ventricular infarction, as it worsens hemodynamics 1
• Do not give fluids to patients with obvious pulmonary edema or jugular venous distension 4

Vasopressor Therapy

• Norepinephrine is the preferred first-line vasopressor to maintain mean arterial pressure ≥65 mmHg; it is associated with lower mortality and fewer arrhythmias compared with dopamine 1, 2, 5
• Use vasopressors only when strictly necessary to sustain systolic blood pressure with ongoing hypoperfusion 1
• Dopamine may be used as an alternative but carries higher arrhythmia risk 4, 6

Inotropic Therapy

• Dobutamine (starting at 2–3 µg/kg/min, titrated up to 20 µg/kg/min) is the preferred first-line inotrope to increase cardiac output when low output persists after adequate fluid resuscitation 1, 2, 5
• If the combination of norepinephrine and dobutamine is insufficient, consider adding levosimendan (especially in patients on chronic β-blockers) or milrinone in non-ischemic shock 1, 7
• Escalate to mechanical circulatory support rather than layering additional inotropes when pharmacologic therapy fails 1

Step 3: Treat the Underlying Cause

Acute Coronary Syndrome-Related Shock

• Perform emergent percutaneous coronary intervention (PCI) of the culprit artery within 2 hours of admission in all patients with ischemic heart disease presenting with cardiogenic shock, irrespective of symptom-onset time—this is the only therapy proven to reduce mortality 1, 2, 8
• When coronary anatomy is unsuitable for PCI or PCI fails, proceed directly to emergency coronary artery bypass grafting 1
• In STEMI patients where PCI would be delayed >120 minutes, give immediate fibrinolysis, transfer to a PCI-capable center, and perform emergent coronary angiography on arrival regardless of ST-segment resolution 1
• Critical pitfall: Routine multivessel PCI at the time of primary PCI should be avoided, as it increases mortality and renal failure risk; treat only the culprit lesion 1
• Consider complete revascularization during the index procedure only in selected patients 1

Mechanical Complications

• Identify and treat mechanical complications (ventricular septal rupture, acute mitral regurgitation, free-wall rupture) early after Heart Team discussion 1, 2
• These complications require urgent surgical repair, often with temporary mechanical circulatory support as a bridge 1

Arrhythmias

• Place a temporary pacemaker in patients with bradyarrhythmias or high-grade atrioventricular block 1
• Identify and treat tachyarrhythmias promptly 1

Step 4: Mechanical Circulatory Support (MCS)

Indications for MCS

• Consider short-term MCS in refractory cardiogenic shock defined by persistent tissue hypoperfusion despite adequate doses of two vasoactive medications and treatment of the underlying etiology 1, 2
• Specific hemodynamic criteria: cardiac power output <0.6 W, cardiac index <2.2 L/min/m², systolic blood pressure <80 mmHg despite maximal therapy 1, 3

Device Selection by Phenotype

• Left-ventricular dominant shock (cardiac power output <0.6 W, PCWP >15 mmHg, right-atrial pressure <15 mmHg): use Impella pump or veno-arterial extracorporeal membrane oxygenation 1, 3
• Right-ventricular dominant shock (cardiac power output <0.6 W, right-atrial pressure >15 mmHg, PCWP <15 mmHg): use right-ventricular support devices 1, 3
• Biventricular shock (cardiac power output <0.6 W, both right-atrial and PCWP >15 mmHg): consider combined support (ECPELLA) 1, 3

Intra-Aortic Balloon Pump (IABP)

• Routine IABP therapy is not indicated in cardiogenic shock, as randomized trials have shown no mortality benefit 1, 2, 9
• IABP may be considered selectively for shock caused by mechanical complications such as ventricular septal rupture or acute mitral regurgitation 1, 2

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Pharmacologic Adjuncts

• Administer standard antithrombotic therapy: aspirin, a P2Y12 inhibitor (ticagrelor or prasugrel preferred over clopidogrel), and appropriate anticoagulation 1
• Intravenous GP IIb/IIIa inhibitors have demonstrated benefit in observational studies 1
• For patients with pulmonary congestion but adequate blood pressure (systolic blood pressure >90 mmHg), consider intravenous diuretics and nitrates 4

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Hemodynamic Targets

• Mean arterial pressure ≥65 mmHg 1
• Systolic blood pressure >90 mmHg 1, 3
• Cardiac index >2.0 L/min/m² 4, 1
• Pulmonary capillary wedge pressure <20 mmHg 4, 1
• Urine output >0.5 mL/kg/h 1
• Lactate clearance and normalization 1, 2

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Systems-Based Approach

• All cardiogenic shock patients should be transferred urgently to a tertiary center with 24/7 cardiac catheterization capability and an ICU equipped for short-term mechanical circulatory support 1, 2
• Patients presenting to hospitals without PCI capability must be transported emergently to a PCI center; lack of transfer is associated with markedly higher mortality 1
• Implement a multidisciplinary shock team (cardiology, cardiac surgery, critical care, nursing) and standardized protocols, which have been associated with improved 30-day all-cause mortality 1, 2

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Critical Pitfalls to Avoid

• Do not delay revascularization; in-hospital mortality in cardiogenic shock remains 40–50% despite modern therapies 1, 10, 9
• Do not use routine IABP, as randomized trials have shown no mortality benefit 1, 2, 9
• Do not perform multivessel PCI at the time of primary PCI; treat only the culprit lesion 1
• Avoid negative inotropes and vasodilators that can worsen hemodynamics 1
• Do not delay diagnosis—patients can quickly transition from hemodynamic shock to treatment-resistant hemometabolic shock 5, 10
• Revascularization attempts may be futile in patients with severe multiorgan failure and should be reconsidered 1
• Prolonged attempts at medical optimization should be avoided; escalate to MCS within 1 hour if no response 3