Objective: To evaluate the clinical characteristics and implications of stent fracture in drug-eluting stents.
Background: Approximately 2.5 million drug-eluting stents are implanted every year worldwide. In 10 randomized controlled trials involving 2,602 patients, no incidence of stent fracture was recognized or reported.
Methods: From April 2003 to December 2005, 2,728 patients underwent drug-eluting stenting. The angiograms of all 530 patients who underwent repeat angiography were analyzed to identify the presence of stent fracture. We then documented the incidence of adverse events associated with drug-eluting stent fracture and systematically analyzed the clinical, procedural, and structural factors, which might predispose to stent fracture.
Results: Stent fracture was identified in 10 patients. None of these fractures were detectable at the time of stent placement. The median time interval from stent implantation to detection of fracture at repeat angiography was 226 days (range, 7-620 days). Adverse clinical outcomes associated with stent fracture occurred in 7 patients (6 patients had binary restenosis and 1 patient had stent thrombosis), all necessitating repeat intervention. Analysis of potential predisposing clinical, procedural, and structural factors revealed that 4 patients had excessive tortuosity in the proximal segment, and overlapping stents were used in 5 cases. All fractures occurred in sirolimus-eluting stents.
Conclusions: Stent fracture may represent a new potential mechanism of restenosis and stent thrombosis in drug-eluting stents. Predisposing clinical and procedural factors may be vessel tortuosity and use of overlapping stents. The most important predisposing factor, however, may be stent structure, since all fractures occurred in sirolimus-eluting stents.
(c) 2006 Wiley-Liss, Inc.