Clinical Characteristics of Coronary Drug-Eluting Stent Fracture: Insights from a Two-Center DES Registry

Abstract

Stent fracture (SF) has been implicated as a risk factor for in-stent restenosis, but its incidence and clinical characteristics are not well established. Therefore we investigated the conditions associated with stent fracture and its clinical presentation and outcome. Between 2004 and 2007, consecutive cases of SF were collected from the Seoul National University Hospital. Clinical characteristics and outcome of patients with fractured stents were compared with a ten-fold cohort of age and gender matched controls (n = 236). A total of 4,845 patients received percutaneous coronary intervention and 3,315 patients (68.4%) underwent angiographic follow-up. Twenty-eight fractured stents were observed in 24 patients. The incidence of SF was 0.89% for sirolimus-eluting stents (SES) and 0.09% for paclitaxel-eluting stents. Chronic kidney disease, stent implantation in the right coronary artery (RCA), and SES use were independent predictors of drug-eluting stent fracture by multivariate analysis. SF was significantly associated with binary restenosis (11.4% vs 41.7%, P < 0.001) and increased risk of target lesion revascularization (8.1% vs 33.3%, P = 0.001). Patients with SF but without significant restenosis showed excellent outcome despite only medical treatment. In conclusion, SF is associated with increased rates of restenosis and repeat revascularization. Significant risk factors include chronic kidney disease, RCA intervention, and SES use.

Impact of stent mis-sizing and mis-positioning on coronary fluid wall shear and intramural stress

“…There has been increasing awareness of stent fractures, especially in the DES era (9,26). Because angiography has limited resolution to detect cracks and fractures, there has been under-recognition of stent fractures (1,25).…”

Stent fracture: How frequently is it recognized?

“…[47] In one study, chronic kidney disease was found as an independent predictor of DES fracture. [48] …”

“…In a study by Park et al .,[48] the clinical presentation of patients with SF did not differ from those without SF, including the severity of angina, the incidence of Acute coronary syndrome [ACS], and event silent ischemia. Despite that, it is important to mention that in this study, 50% of SFs were of type 1, and overall, types 1, 2, and 3 represented 96.1% of all cases, while type 4 represented only 3.9% and there were no type 5 fractures.…”

“…[54] In one study, among 24 patients with fractured stents, 8 patients required TLR, where 3 patients were treated with balloon angioplasty only, 3 with PES, and 2 with zotarolimus-eluting stent (ZES). [48]…”

Structural Mechanics Predictions Relating to Clinical Coronary Stent Fracture in a 5 Year Period in FDA MAUDE Database

“…Stent strut fracture is an increasingly recognized phenomenon, with rates ranging from 2.6%, for severe, transectional disruption on angiography, 1 to 29% when all types of fracture are included at autopsy. 24,37 Clinical investigations have demonstrated that fracture rates rise with stent and lesion length, 23,24,37,42,43 multiple, overlapping stents, 10,17,20,23,37,43 sirolimus release, 39 calcified complex lesions, 20,30 relative vessel angulation and “hinge” motion, 24,42 higher balloon inflation pressures, 35,45 and right coronary artery (RCA) implantation, 1,39 in particular in the ostium. 42 When fracture occurs it is associated with higher rates of in-stent restenosis, 10,24,39,44,51 thrombosis, 7,37,40 and target vessel revascularization 10,24,39,42,51 —outcomes which may be exacerbated by more severe, transectional fractures.…”