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

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).

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.

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.

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).

In this case-control analysis, off-label use of DES was independently associated with ST within 1 year, although the increased risk was moderate.