What is the difference between Drug-Eluting Stents (DES) and Bare Metal Stents (BMS) for clinical use in coronary artery disease management?

Drug-Eluting Stents (DES) vs. Bare Metal Stents (BMS) for Clinical Use

DES should be the default choice for nearly all patients undergoing percutaneous coronary intervention, with BMS reserved exclusively for patients who cannot tolerate or comply with 12 months of dual antiplatelet therapy (DAPT). 1, 2, 3

Primary Decision Algorithm

The stent selection decision hinges on a single critical question: Can the patient safely tolerate and comply with 12 months of DAPT? 1, 3

If YES → Use DES

• DES are superior for preventing restenosis, reducing target vessel revascularization, and improving long-term outcomes 1
• No difference exists between DES and BMS in mortality or myocardial infarction rates 1
• No difference in stent thrombosis risk when DAPT is maintained 1

If NO → Use BMS

BMS must be chosen when any of these contraindications to prolonged DAPT exist: 1, 3

• Financial barriers preventing 12 months of DAPT 1
• Social barriers limiting medication compliance 1
• High bleeding risk (e.g., requiring chronic anticoagulation) 1, 3
• Anticipated surgery within 12 months requiring DAPT discontinuation 1, 3

Clinical Efficacy Differences

Restenosis and Revascularization

• DES reduce target lesion revascularization by approximately 3-5% absolute risk reduction compared to BMS 1
• In STEMI patients, DES reduce ischemia-driven target vessel revascularization from 8.7% to 5.8% (NNT = 33 at 1 year) 1
• Binary restenosis rates: DES 10% vs. BMS 22.9% 1

Safety Profile

• No difference in death, myocardial infarction, or stent thrombosis between DES and BMS when DAPT is maintained 1
• Stent thrombosis risk is highest in the first year (0.7-2.0%), then decreases to 0.2-0.4% per year 1, 2
• The greatest risk factor for DES thrombosis is premature discontinuation of DAPT 1

High-Risk Scenarios Where DES Are Strongly Preferred

When DAPT can be maintained, DES are particularly beneficial in these anatomic and clinical scenarios: 1, 2, 3

• Left main coronary artery disease - restenosis consequences are catastrophic 1, 2
• Small vessels (<2.5mm diameter) - higher restenosis risk with BMS 1, 2
• Bifurcation lesions - complex anatomy increases restenosis 1, 2
• Diabetes mellitus - inherently higher restenosis risk 1, 2
• Long lesions - greater surface area for neointimal proliferation 1, 2
• Multiple lesions - cumulative restenosis risk 1, 2
• Saphenous vein grafts - prone to restenosis 1, 2
• In-stent restenosis - repeat BMS has unacceptably high failure rates 1

DAPT Duration Requirements

For BMS

• Minimum 1 month of DAPT required 1, 3
• Can discontinue after 1 month if clinically necessary 1

For DES

• Minimum 6 months for stable ischemic heart disease 1, 2
• Minimum 12 months for acute coronary syndrome (STEMI or NSTE-ACS) 1, 3, 4
• Extended DAPT (18-36 months) reduces stent thrombosis and ischemic events by 1-2% absolute risk but increases bleeding by 1% 1

DAPT Regimen

• Aspirin 75-100 mg daily (not 325 mg for chronic therapy) 1, 4
• Clopidogrel 75 mg daily, or ticagrelor, or prasugrel (depending on ACS vs. stable disease) 1

Critical Pitfalls to Avoid

Emergency Situations

• In STEMI, the greatest challenge is determining DAPT candidacy in an emergency setting 1
• Must rapidly assess: bleeding history, upcoming surgeries, medication compliance likelihood, financial resources 1
• When uncertain, default to BMS in true emergencies if DAPT compliance is questionable 1

Surgical Planning

• If surgery is anticipated within 12 months, use BMS 1, 3
• Premature DAPT cessation for surgery after DES placement carries catastrophic stent thrombosis risk 1
• If DES already placed and surgery needed, continue DAPT perioperatively unless bleeding risk dramatically outweighs thrombosis risk 5

Anticoagulation Considerations

• Patients requiring chronic warfarin or DOACs should preferentially receive BMS 1, 3
• Triple therapy (DAPT + anticoagulation) substantially increases bleeding risk 1
• BMS allows shorter triple therapy duration (2-4 weeks vs. 3-6 months) 3

Cost-Effectiveness

• DES are substantially more expensive upfront than BMS 2
• However, DES reduce total healthcare costs by avoiding repeat revascularization procedures 2
• Cost-effectiveness strongly favors DES when restenosis risk is high 1, 2

Contemporary Evidence Summary

Second-generation DES (everolimus-eluting, zotarolimus-eluting) demonstrate superior outcomes to first-generation DES 1, 2, with target lesion failure rates of 4.2% vs. 6.8% at 1 year 2. These newer-generation stents may require shorter minimum DAPT duration (6 months vs. 12 months for first-generation) in stable disease 1.