What are the guidelines for choosing between percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) in patients with non-ST elevation myocardial infarction (NSTEMI)?

Revascularization Strategy Selection in NSTEMI: PCI vs CABG

Primary Recommendation

For NSTEMI patients with multivessel coronary disease, CABG is the preferred revascularization strategy over PCI, particularly in patients with diabetes, left ventricular dysfunction (LVEF <40%), left main disease, or complex three-vessel disease (SYNTAX score >22), as this approach significantly reduces long-term mortality, myocardial infarction, and repeat revascularization. 1, 2

Decision Framework Based on Coronary Anatomy and Patient Characteristics

CABG is Strongly Favored When:

• Three-vessel disease with diabetes mellitus - CABG reduces cardiovascular events and improves survival compared to PCI 1
• Left main disease >50% stenosis - CABG is the standard approach unless the patient is not a surgical candidate 1
• LVEF <40% - CABG provides superior long-term outcomes in patients with reduced ventricular function 1, 3
• SYNTAX score ≥23 - Higher anatomical complexity favors surgical revascularization 1, 3
• Proximal LAD involvement with multivessel disease - CABG offers better complete revascularization 1

The most recent and highest quality evidence from the 2025 SWEDEHEART registry analysis of 57,097 NSTEMI patients demonstrated that CABG was associated with a 33% reduction in mortality risk (aOR 0.60, inverse of 1.67) and 49% reduction in MI (aOR 0.66, inverse of 1.51) compared to PCI over a median 7.1-year follow-up 2. This survival benefit was particularly pronounced in patients under 70 years of age, those with left main disease, and those with left ventricular dysfunction 2.

PCI is Reasonable When:

• Single or two-vessel disease without proximal LAD involvement - PCI and CABG have equivalent outcomes 1
• Focal saphenous vein graft lesions in patients who are poor candidates for reoperative surgery 1
• Emergent hemodynamic instability requiring immediate intervention when CABG cannot be performed urgently 1
• Patient is not a CABG candidate due to severe comorbidities, advanced age with frailty, or anatomical factors (porcelain aorta, poor conduits) 1

Timing Considerations

Immediate Invasive Strategy (<2 hours):

• Hemodynamic instability or cardiogenic shock 1
• Refractory chest pain despite medical therapy 1
• Life-threatening arrhythmias 1
• Mechanical complications of MI 1
• ST-segment depression >1mm in ≥6 leads with ST elevation in aVR/V1 1

Early Invasive Strategy (within 24 hours):

• Elevated troponin with NSTEMI diagnosis 1, 4
• TIMI risk score >4 or GRACE score >140 5
• New or worsening heart failure 1, 4
• Sustained ventricular tachycardia 1, 4

The choice between PCI and CABG should be made during or immediately after diagnostic angiography, with Heart Team discussion recommended for complex cases 1. The 2020 ESC Guidelines emphasize that the same criteria used for stable CAD patients should guide revascularization strategy selection in stabilized NSTEMI patients 1.

Evidence Quality and Nuances

The 2014 AHA/ACC Guidelines specifically state that in older patients (≥75 years), CABG over PCI is reasonable particularly in those with diabetes or complex three-vessel disease to reduce cardiovascular events and improve survival 1. This recommendation is supported by real-world registry data showing CABG provides a 20% absolute reduction in 5-year mortality compared to PCI in NSTEMI patients with multivessel disease (19.3% vs 36.7%) 6.

A critical caveat: The 2019 real-world registry of 1,104 NSTEMI patients with left main or multivessel disease showed that while CABG trended toward better outcomes (31% vs 21% 5-year mortality, adjusted HR 1.52 for PCI), this did not reach statistical significance in the overall population 3. However, subgroup analysis confirmed CABG superiority in left main disease, proximal LAD disease, SYNTAX ≥23, and LVEF <40% 3.

Critical Pitfalls to Avoid

• Do not perform multivessel PCI routinely at initial intervention - culprit lesion-only PCI remains standard unless the patient is in cardiogenic shock 4
• Do not delay CABG evaluation in appropriate candidates - the 2025 SWEDEHEART data shows CABG's survival benefit is most pronounced within 15 years, particularly in younger patients 2
• Do not choose PCI for convenience in diabetic patients with multivessel disease - this population derives the greatest benefit from CABG 1
• Do not underestimate bleeding risk with PCI in elderly patients - consider bivalirudin over GP IIb/IIIa inhibitors plus UFH 1

Adjunctive Considerations

For patients undergoing PCI, intravenous GP IIb/IIIa inhibitors are generally recommended, particularly in those with elevated troponin 1, 4. Radial artery access should be used when possible to decrease access site complications 1. All revascularization decisions must account for the patient's ability to tolerate dual antiplatelet therapy, as DAPT contraindications favor CABG 1.

The selection process requires calculation of both SYNTAX score for anatomical complexity and STS score for surgical risk assessment in high-risk patients 1. When in doubt with complex multivessel disease, defer to Heart Team discussion rather than defaulting to PCI 1.