What is the best choice of Mechanical Circulatory Support (MCS) in a patient with Coronary Heart Disease (CHD) and cardiogenic shock?

Choice of Mechanical Circulatory Support in Coronary Heart Disease and Cardiogenic Shock

Direct Recommendation

For patients with STEMI and cardiogenic shock (SCAI stages C, D, or E) who are non-comatose with adequate peripheral vasculature, use a microaxial flow pump (Impella) to reduce mortality, based on the 2025 DanGer-SHOCK trial showing absolute risk reduction in 6-month mortality despite increased bleeding and vascular complications. 1

Device Selection Algorithm Based on SCAI Shock Stage

SCAI Stage B (Beginning Shock)

• IABP is the first-line device for patients with early hemodynamic compromise 1
• Provides diastolic augmentation and afterload reduction with relatively easy insertion 1
• Limitation: Insufficient support in marked cardiac failure; cannot mobilize patients 1
• Consider early escalation if hypotension persists or lactate remains >2.5 mmol/L 1

SCAI Stage C (Classic Shock)

• Microaxial flow pump (Impella) is reasonable for patients meeting DanGer-SHOCK criteria: 1
  • STEMI with cardiogenic shock <24 hours duration
  • Hypotension (SBP <100 mmHg or requiring vasopressors)
  • Lactate ≥2.5 mmol/L and/or SvO2 <55%
  • LVEF <45%
  • Non-comatose (Glasgow Coma Scale ≥8)
  • Adequate peripheral vasculature for large-bore access
• Critical timing consideration: Placement timing relative to PCI is unclear from trial data, but do not delay revascularization 1, 2

SCAI Stage D-E (Deteriorating/Extremis Shock)

• VA-ECMO may be considered only at experienced centers with established shock teams 2
• Key contraindication: Routine or prophylactic use is NOT recommended 1, 2
• The ECLS-SHOCK trial showed no mortality benefit and increased bleeding/vascular complications 1
• Reserve for: Refractory shock despite maximal medical therapy and inadequate response to other MCS 2
• Requires concurrent LV venting (with IABP or Impella) to prevent LV distension 3

Critical Decision Points

When IABP is Insufficient

Escalate to microaxial flow pump if: 1, 3

• Persistent hypotension despite IABP and vasopressors
• Cardiac power output <0.6 W
• Shock index (HR/SBP) >1.0
• Lactate not improving or rising
• Urine output remains <30 mL/h

When to Avoid Routine MCS

Do NOT use IABP or VA-ECMO routinely in AMI with cardiogenic shock without mechanical complications—no survival benefit demonstrated 1, 4

Special Circumstance: Mechanical Complications

For ventricular septal rupture or acute mitral regurgitation: 1

• IABP is first-line for hemodynamic stabilization as bridge to surgery 1
• Reduces left-to-right shunting in VSD 1
• Improves hemodynamics in acute ischemic MR 1
• Transfer immediately to facility with cardiac surgical expertise (Class I recommendation) 1
• Avoid VA-ECMO unless IABP fails—associated with increased mortality (OR 2.80) in mechanical complications 1

Hemodynamic Targets During MCS

Maintain these parameters regardless of device: 1, 5

• Mean arterial pressure >65 mmHg 1
• Cardiac index >2.2 L/min/m² 1
• SvO2 >65% (or ScvO2 >70%) 5
• Lactate normalization within 24 hours 5
• Urine output >30 mL/h 1, 5

Common Pitfalls to Avoid

Never delay revascularization to place MCS—PCI/CABG remains definitive therapy 2

Do not escalate vasopressors indefinitely—consider MCS when requiring high-dose or multiple vasopressors, as this correlates with increased mortality 3

Avoid comatose patients (GCS <8) for microaxial flow pump—excluded from DanGer-SHOCK trial 1

Do not use dobutamine beyond 48 hours—no evidence for safety or efficacy in longer-term use 6

Multidisciplinary Team Requirements

All MCS decisions require input from: 1

• Interventional cardiology
• Heart failure specialists
• Cardiac surgery
• Critical care
• Palliative care (for goals of care discussion)

Transfer to quaternary center if: 1, 5

• Refractory shock despite maximal medical therapy
• Need for advanced MCS beyond IABP
• Consideration of durable LVAD or transplantation

Device-Specific Complications to Monitor

Microaxial flow pump (Impella): 1

• Bleeding (increased risk vs. no MCS)
• Limb ischemia
• Need for renal replacement therapy

VA-ECMO: 1, 2

• Bleeding requiring intervention
• Peripheral vascular complications
• LV distension (requires venting strategy)
• Neurologic complications

IABP: 1

• Arterial complications with prolonged use
• Limited duration of support
• Inability to mobilize patient