PCI First in STEMI Patients with Cardiogenic Shock
In STEMI patients with cardiogenic shock, immediate PCI of the culprit vessel should be performed first, with MCS considered selectively only in patients with severe or refractory shock—not routinely initiated before revascularization. 1
Primary Strategy: Immediate Culprit Vessel Revascularization
The 2025 ACC/AHA/ACEP/NAEMSP/SCAI guidelines provide clear direction that emergency revascularization of the culprit vessel by PCI (or CABG if PCI not feasible) is indicated as soon as possible in patients with ACS and cardiogenic shock, irrespective of time from symptom onset (Class I, Level B-R). 1 This represents the foundational treatment priority—restoring coronary blood flow to salvage myocardium and reverse the underlying cause of shock.
Key principle: Treatment delays to primary PCI are associated with worse survival in patients with STEMI and hemodynamic instability. 1 Every minute counts, and the focus should be on achieving rapid revascularization rather than routine device insertion that may delay definitive therapy.
MCS Timing and Patient Selection
When MCS Should Be Considered
MCS is not a routine first-line intervention. The 2025 guidelines specify: 1
- Class 2a (reasonable): In selected patients with STEMI and severe or refractory cardiogenic shock, insertion of a microaxial intravascular flow pump (Impella) is reasonable to reduce death 1
- Class 3 (no benefit): Routine use of IABP or VA-ECMO is not recommended due to lack of survival benefit 1
The critical word here is "selected"—meaning MCS should only be considered in patients who remain in severe shock despite initial measures, not as a default pre-PCI strategy.
Evidence Supporting PCI-First Approach
The most recent 2024 individual patient data meta-analysis of randomized trials (n=1,114 patients) found that early routine MCS use did not reduce 6-month mortality (HR 0.87,95% CI 0.74-1.03, p=0.10) and significantly increased major bleeding (OR 2.64) and vascular complications (OR 4.43). 2 This high-quality evidence directly contradicts a routine MCS-first strategy.
However, there is nuance: A 2022 meta-analysis suggested that Impella or VA-ECMO started before PCI was associated with reduced mortality compared to after PCI (OR 0.49 and 0.29 respectively), but this was based on observational data with significant selection bias. 3 The 2024 randomized trial data supersedes this observational evidence.
Clinical Algorithm for Decision-Making
Step 1: Immediate Assessment and PCI Preparation
- Activate catheterization laboratory immediately upon STEMI-CS diagnosis 1
- Initiate vasopressors/inotropes as needed for hemodynamic support 1
- Perform rapid echocardiography to assess LV function and exclude mechanical complications 1
Step 2: Proceed Directly to PCI Unless:
Consider MCS insertion BEFORE PCI only if: 1
- Patient has severe refractory shock (persistent hypotension despite maximal vasopressor support)
- Cardiac arrest requiring ongoing CPR 4
- Profound hemodynamic collapse that precludes safe PCI performance
Otherwise, proceed immediately to culprit vessel PCI 1
Step 3: Culprit-Only Revascularization
- PCI of culprit vessel only is recommended 1
- Do NOT perform multivessel PCI at time of primary PCI in cardiogenic shock—this is associated with higher rates of death or renal replacement therapy (Class 3: Harm) 1
Step 4: Post-PCI MCS Consideration
If shock persists or worsens after successful culprit vessel revascularization: 1
- Consider microaxial flow pump (Impella) for severe/refractory shock
- MCS as bridge to surgery if mechanical complication identified (Class 2a)
- Avoid routine IABP or VA-ECMO (Class 3: No benefit)
Important Caveats and Pitfalls
Common pitfall #1: Delaying PCI to insert MCS device in all shock patients. The 2025 guidelines emphasize that treatment delays worsen survival, and routine MCS is not beneficial. 1, 2
Common pitfall #2: Performing multivessel PCI during the index procedure. The CULPRIT-SHOCK trial definitively showed this increases mortality and renal failure. 1 Stick to culprit-only revascularization.
Common pitfall #3: Using IABP routinely. Despite historical practice patterns, randomized evidence shows no survival benefit, and the 2025 guidelines give this a Class 3 (no benefit) recommendation. 1
Special consideration: The 2024 meta-analysis found that patients with ST-elevation cardiogenic shock without risk of hypoxic brain injury had mortality reduction with MCS (HR 0.77, p=0.024). 2 This suggests careful patient selection is critical—avoid MCS in patients with prolonged cardiac arrest and likely severe neurologic injury.
European Perspective
The 2017 ESC guidelines similarly recommend immediate PCI as the primary intervention (Class I), with MCS considered only for refractory shock (Class IIb for short-term mechanical support). 1 They also note that routine IABP is not indicated (Class III). 1 This international consensus reinforces the PCI-first approach.