Coronary Stent Strut Fractures: Classification, Prevalence and Clinical Associations

Abstract

Introduction. The frequency, characteristics and clinical implications of Strut fractures (SFs) remain incompletely understood. Methods and results. A total of 185 (160 patients) newer-generation drug-eluting stents (DES) were imaged. SFs were found in 21 DES (11.4%) and were classified in four patterns: one single stacked strut (41%); two or more stacked struts (23%); deformation without gap (27%); transection (9%). In multivariable analysis, calcific and bifurcation lesions were associated with SF in DES (OR: 3.5 [1.1–11] and 4.0 [2.2–7.2], p < 0.05). Device eccentricity and asymmetry as well as optical coherence tomography (OCT) features of impaired strut healing were also associated with SF. The prevalence of fractures was similar in a set of 289 bioresorbable scaffolds (BRS). In a separate series of 20 device thromboses and 36 device restenoses, the prevalence of SF was higher (61.2% of DES and 66.7% of BRS, p < 0.001 for both), with a higher frequency of complex SF patterns (p < 0.0001). In logistic regression analysis, fractures were a correlate of device complications (p < 0.0001, OR = 24.9 [5.6–111] for DES and OR = 6.0 [1.8–20] for BRS). Discussion. The prevalence of OCT-diagnosed SF was unexpectedly high in the setting of elective controls and it increased by about three-fold in the setting of device failure. Fractures were associated with increased lesion complexity and device asymmetry/eccentricity and were more frequent in the setting of device failure such as restenosis and thrombosis.

Coronary Stent Fracture Causing Myocardial Infarction: Case Report and Review of Literature

“…Similar results were obtained by other studies with an incidence of <1.0% up to 18.6% [10,11,[14][15][16][17][18][19][20]]. An analysis with new generation DES by Schochlow et al [21] showed incidental detection of SF in 8% immediately after implantation and almost 60% in the setting of device failure. The largest multicenter study has been carried out by Kan et al [22] reporting an incidence of SF in 12.3% of the 6555 involved patients, 22.0% of stents and 17.2% of vessels.…”

“…Stent overlap was also significantly associated with SF in the large meta-analysis by Chakravarty et al [13]. Finally, stent overexpansion can exceed material capacity and induce strut distortion causing early fatigue and SF [5,12,21,50]. Omar et al [26] report a mean postdilation pressure of 18 atm (IQR 16-20) in fractured stents.…”

Incidence of coronary drug-eluting stent fracture: A systematic review and meta-analysis

“…Titles and abstracts of these records were screened for inclusion. The full texts of 73 records were read, and 46 studies were finally included in the data assessment ( 3 – 8 , 11 – 50 ). Figure 1 shows the PRISMA flow diagram describing the study selection process along with the reasons for exclusion.…”

“…Especially in recent years, the thinner steel beam thickness in the new generation of alloy stents and the wide use of intraluminal imaging technology have led to a significant increase in the incidence of CSF in clinical practice ( 3 – 5 ). In addition, serious clinical cardiovascular events such as in-stent restenosis (ISR), stent thrombus (ST), coronary artery aneurysm and coronary perforation induced by CSF have threatened patients’ health ( 6 – 8 ). In addition, trials assessing the incidence of CSF and related risk factors for CSF have recently been published and added to the evidence base.…”

Intravascular imaging in coronary stent restenosis: Prevention, characterization, and management

“…In a recent case series, our group reported that fracture, classified in four different patterns, typically results in a focal ISR at the fracture point ( Figure 10 ) ( 109 ). In that study, we proposed an OCT-based classification in different patterns of increased severity (from single stacked struts to rupture and gap), and indeed, more complex fracture patterns were more common in the presence of device failure than in incidentally discovered fractures.…”