Association between off-label use of drug-eluting stents and subsequent stent thrombosis: A case-control analysis

Objectives: We sought to examine the association between off-label drug-eluting stent (DES) use and stent thrombosis (ST) in unselected patients undergoing percutaneous coronary intervention (PCI). Background: DES are frequently used in clinical and angiographic scenarios not initially tested and approved by the FDA (off-label use) resulting in lingering concerns about the higher risk of ST in these situations. Methods: Out of 5,383 patients undergoing PCI at a single center between 2004 and 2006, 380 had death or myocardial infarction within 1 year. After adjudication using Academic Research Consortium definitions, patients with possible, probable or definite ST were termed cases. Cases were matched with controls, free of ST at 1 year, using geographic and temporal similarities. Off-label usage was defined using manufacturer's instructions and other standard criteria. Results: Overall, the proportion of off-label usage was higher among cases than controls (58% vs. 43%; p = 0.002) and both cases with definite/probable ST (77% vs. 59%; p = 0.08) and possible ST (54% vs. 37%; p = 0.002) had a higher off-label use than respective controls. Off-label use among cases with ST remained higher within the following subgroups: off-label by manufacturer's criteria (36% vs. 27%; p = 0.05), left main stent implantation (2% vs. 0%; p = 0.01), ostial (12% vs. 6%; p = 0.04) and bifurcated lesions (26% vs. 9%; p < 0.001). In multivariate analysis, being a case independently predicted off-label use (OR 1.68, 95% CI: 1.10-2.57; p = 0.02). Conclusions. In this case-control analysis, off-label use of DES was independently associated with ST within 1 year, although the increased risk was moderate.