From the Guidelines
For ischemia-driven target lesion revascularization in patients with bare metal stents (BMS), dual antiplatelet therapy (DAPT) with aspirin 81 mg daily and a P2Y12 inhibitor like clopidogrel 75 mg daily is recommended for at least 1 month, but preferably up to 12 months after stent placement, as supported by 1 and 1. After the first year, patients should continue indefinite aspirin therapy while the P2Y12 inhibitor can be discontinued. During years 1-5 post-BMS placement, routine revascularization is not recommended unless there are clinical symptoms of recurrent ischemia or objective evidence of ischemia on non-invasive testing. If ischemia is detected, coronary angiography should be performed to evaluate for in-stent restenosis or disease progression. The decision for repeat revascularization should be based on symptoms, functional significance of the lesion, and overall coronary anatomy. BMS typically develop restenosis within the first 6-9 months if it occurs, with rates stabilizing after 1 year, due to neointimal hyperplasia, which is the primary mechanism of BMS failure, as noted in 1 and 1. After 1 year, new events are more likely due to disease progression elsewhere rather than late stent failure. Recent studies, such as 1 and 1, have highlighted the importance of intravascular imaging in optimizing PCI outcomes, but the primary approach to managing BMS remains focused on antiplatelet therapy and symptom-driven revascularization. Key considerations include:
- The use of DAPT for at least 1 month, but preferably up to 12 months, after BMS placement, as recommended by 1.
- The discontinuation of the P2Y12 inhibitor after 1 year, with continued indefinite aspirin therapy, as suggested by 1.
- The role of coronary angiography in evaluating in-stent restenosis or disease progression if ischemia is detected, as discussed in 1 and 1.
- The importance of symptom-driven revascularization, rather than routine revascularization, during years 1-5 post-BMS placement, as supported by the overall evidence base, including 1 and 1.
From the Research
Ischemia-Driven Target Lesion Revascularization for Bare Metal Stents
Overview of Revascularization Rates
- The rate of target lesion revascularization (TLR) for bare metal stents (BMS) is a critical factor in determining the effectiveness of stent placement in patients with coronary artery disease.
- Studies have shown that the incidence of clinically-indicated TLR is less than 5% at 1 year for unselected percutaneous coronary intervention (PCI) patients 2.
- Angiographic variables, such as vein graft PCI, in-stent restenosis lesion, longer stent length, and smaller stent diameter, significantly improve TLR risk assessment when added to clinical variables alone 2.
Predictors of Target Lesion Revascularization
- Clinical predictors of TLR include younger age, female sex, diabetes, prior PCI, and prior bypass surgery 2.
- Angiographic predictors of TLR include vein graft PCI, in-stent restenosis lesion, longer stent length, and smaller stent diameter 2.
- A predictive model using commonly collected variables can identify patients who may derive the greatest benefit in TLR reduction from drug-eluting stents (DES) compared to BMS 3.
Comparison of Bare Metal Stents and Drug-Eluting Stents
- Drug-eluting stents have been shown to reduce the risk of restenosis compared to BMS, but require prolonged dual antiplatelet therapy 2, 3.
- The risk of TLR is lower with DES compared to BMS, with an odds ratio of 0.35 (95% CI 0.25-0.49) in one meta-analysis 4.
- However, the marked reduction in restenosis with DES may counterbalance the potential excess risk from late stent thrombosis with DES 5.
Long-Term Outcomes
- Sirolimus-eluting stents have been shown to demonstrate enduring 1-year angiographic and clinical benefit compared to BMS in patients with critical limb ischemia 6.
- The application of sirolimus-eluting stents reduces the restenosis rate in the infrapopliteal arteries and the rate of repeat endovascular procedures the first year after treatment 6.