Should patients presenting with ST-elevation myocardial infarction (STEMI) undergo thrombectomy at the time of percutaneous coronary intervention (PCI) according to the most recent American College of Cardiology (ACC)/American Heart Association (AHA) guidelines?

Routine Thrombectomy During Primary PCI for STEMI is Not Recommended

According to the most recent ACC/AHA guidelines, routine aspiration thrombectomy before primary PCI for STEMI is not recommended (Class III: No Benefit). 1

Current Guideline Recommendations

The 2015 ACC/AHA/SCAI focused update on primary PCI for STEMI patients specifically addresses thrombectomy with the following recommendations:

1. Routine aspiration thrombectomy - Class III: No Benefit (Level of Evidence: A)

   • Routine aspiration thrombectomy before primary PCI is not useful and should not be performed 1

2. Selective or bailout aspiration thrombectomy - Class IIb (Level of Evidence: C-LD)

   • The usefulness of selective and bailout aspiration thrombectomy in patients undergoing primary PCI is not well established 1

Evidence Behind the Recommendations

The current recommendation represents a significant change from previous guidelines. Prior to 2015, aspiration thrombectomy had a Class IIa recommendation, suggesting it was reasonable for patients undergoing primary PCI 1.

This change was based on several large randomized trials:

1. TASTE trial (n=7,244): Found no significant differences in 30-day or 1-year outcomes between aspiration thrombectomy plus PCI versus PCI alone 1

2. TOTAL trial (n=10,732): Demonstrated no reduction in the composite primary endpoint of cardiovascular death, recurrent MI, cardiogenic shock, or heart failure at 180 days. More concerning, there was a small but statistically significant increase in the rate of stroke in the thrombectomy group 1, 2

3. Meta-analysis of 17 trials (n=20,960): Found no significant reduction in death, reinfarction, or stent thrombosis with routine aspiration thrombectomy 1

Understanding the Rationale

The theoretical benefit of thrombectomy during primary PCI is based on the concept that removing thrombus before stent placement could:

• Reduce distal embolization
• Improve microvascular perfusion
• Decrease the "no-reflow" phenomenon
• Improve myocardial salvage

However, the TOTAL OCT substudy revealed that manual thrombectomy did not significantly reduce pre-stent thrombus burden at the culprit lesion compared with PCI alone 3. Both strategies resulted in similarly low thrombus burden after the initial intervention to restore flow.

Special Considerations

1. Bailout thrombectomy: The guidelines define "bailout" aspiration thrombectomy as thrombectomy that was initially unplanned but was later used during the procedure because of unsatisfactory initial result or procedural complication 1. This remains a Class IIb recommendation.

2. High thrombus burden: Despite previous beliefs that patients with higher thrombus burden might benefit more from thrombectomy, subgroup analyses from the TASTE and TOTAL trials did not show relative benefit in these patients 1.

3. Rheolytic thrombectomy: The guidelines specifically note that no clinical benefit has been demonstrated for routine rheolytic thrombectomy in STEMI patients undergoing primary PCI 1.

Clinical Implications

When managing STEMI patients requiring primary PCI:

• Focus on achieving rapid reperfusion with primary PCI (door-to-balloon time <90 minutes)
• Do not routinely perform aspiration thrombectomy
• Consider selective thrombectomy only in bailout situations when initial PCI results are unsatisfactory
• Be aware of the potential increased risk of stroke associated with thrombectomy procedures
• Remember that the primary goal remains achieving TIMI 3 flow and adequate myocardial perfusion

The current evidence clearly demonstrates that routine aspiration thrombectomy does not improve clinical outcomes and may increase stroke risk, supporting the Class III: No Benefit recommendation in the most recent guidelines.