FDA approval of drug-eluting stents (DES) in 2002, was based on data obtained from several pivotal, short-term (< one year) randomized control trials that evaluated their efficacy in reducing in-stent restenosis when used in treatment of coronary artery lesions compared with bare metal stents (BMS). These trials excluded patients with complex coronary lesions. When the FDA approved use of DES in treatment of coronary artery lesions, the on-label indications only applied to a very limited subset of simple lesions.
Immediate advantages of DES were observed in clinical practice for on-label indications, specifically in their ability to significantly reduce in-stent restenosis after PCI. The increased short-term safety and efficacy seen in on-label clinical cases soon led clinicians to expand the use DES to more complex lesions. These complex indications, not included in the pivotal FDA trials, are considered off-label. Off-label indications include bifurcation lesions, ostial lesions, lesions greater in length and diameter than those approved by the FDA, implantation in saphenous vein grafts, and lesions in the left main coronary artery. Currently, DES use for treatment of lesions presenting off-label indications may comprise as much as 60% of clinical cases. However, early evidence that DES may play a role in adverse safety outcomes, has led many to question the use of DES outside their on-label indications.
This paper sought to evaluate some of the current research investigating first generation DES use in four different off-label indications: coronary artery bypass graft lesions, saphenous vein graft lesions, ostial lesions, and chronic total coronary occlusions. In particular, it looked at studies, which compared the efficacy and clinical outcomes of DES and BMS treatment of each of the different lesion types.
The results of this evaluation were very promising in that of the four specific off-label indications evaluated, all of them showed to be superior in reduction of neointimal growth and subsequent in-stent restenosis. Additionally, DES treatment of left main coronary artery lesions, saphenous vein graft lesions, and chronic total coronary occlusions showed to be superior in reducing the incidence rate of major adverse cardiac events and target vessel revascularization over various follow-up durations. The only scenario that DES did not prove to be superior to BMSs was the treatment of ostial lesions.
Long-term randomized control trials with large study populations should be performed to further elucidate the effects of DES treatment of specific off-label lesions.
| Identifer | oai:union.ndltd.org:bu.edu/oai:open.bu.edu:2144/15044 |
| Date | 22 January 2016 |
| Creators | Shea, Corey Matthew |
| Source Sets | Boston University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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