Archive for the ‘Stent thrombosis’ Category

Scaffold Thrombosis in Routine PCI

Wykrzykowska et al report a randomized clinical trial of metallic stent v bioresorbable vascular scaffold in routine percutaneous coronary intervention. They found significantly higher risk of device thrombosis with BVS. The editorial is available here.



Bioresorbable vascular scaffolds were developed to overcome the shortcomings of drugeluting stents in percutaneous coronary intervention (PCI). We performed an investigator-initiated, randomized trial to compare an everolimus-eluting bioresorbable scaffold with an everolimus-eluting metallic stent in the context of routine clinical practice.


We randomly assigned 1845 patients undergoing PCI to receive either a bioresorbable vascular scaffold (924 patients) or a metallic stent (921 patients). The primary end point was target-vessel failure (a composite of cardiac death, target-vessel myocardial infarction, or target-vessel revascularization). The data and safety monitoring board recommended early reporting of the study results because of safety concerns. This report provides descriptive information on end-point events.


The median follow-up was 707 days. Target-vessel failure occurred in 105 patients in the scaffold group and in 94 patients in the stent group (2-year cumulative event rates,11.7% and 10.7%, respectively; hazard ratio, 1.12; 95% confidence interval [CI], 0.85 to 1.48; P = 0.43); event rates were based on Kaplan–Meier estimates in time-to-event analyses. Cardiac death occurred in 18 patients in the scaffold group and in 23 patients in the stent group (2-year cumulative event rates, 2.0% and 2.7%, respectively), target-vessel myocardial infarction occurred in 48 patients in the scaffold group and in 30 patients in the stent group (2-year cumulative event rates, 5.5% and 3.2%), and target-vessel revascularization occurred in 76 patients in the scaffold group and
in 65 patients in the stent group (2-year cumulative event rates, 8.7% and 7.5%). Definite or probable device thrombosis occurred in 31 patients in the scaffold group as compared with 8 patients in the stent group (2-year cumulative event rates, 3.5% vs. 0.9%; hazard ratio, 3.87; 95% CI, 1.78 to 8.42; P<0.001).


In this preliminary report of a trial involving patients undergoing PCI, there was no significant difference in the rate of target-vessel failure between the patients who received a bioresorbable scaffold and the patients who received a metallic stent. The bioresorbable scaffold was associated with a higher incidence of device thrombosis than the metallic stent through 2 years of follow-up.




Stent Fracture in Everolimus Eluting Stents and Clinical Outcome

November 23, 2012 2 comments

Stent fracture in EES  and clinical outcome are explored in this paper.

Journal Club 28 March 2012


Clinical Presentation, Management, and Outcomes of Angiographically Documented Early, Late, and Very Late Stent Thrombosis





The aim of this study was to describe differences in treatment and in-hospital mortality
of early, late, and very late stent thrombosis (ST).
Background Early, late, and very late ST may differ in clinical presentation, management, and inhospital

We analyzed definite (angiographically documented) ST cases identified from February
2009 to June 2010 in the CathPCI Registry. We stratified events by timing of presentation: early (1
month), late (1 to 12 months), or very late (12 months) following stent implantation. Multivariable
logistic regression modeling was performed to compare in-hospital mortality for each type of ST
after adjusting for baseline comorbidities.

During the study period, 7,315 ST events were identified in 7,079 of 401,662 patients (1.8%)
presenting with acute coronary syndromes. This ST cohort consisted of 1,391 patients with early ST
(19.6%), 1,370 with late ST (19.4%), and 4,318 with very late ST (61.0%). Subjects with early ST had a
higher prevalence of black race and diabetes, whereas subjects with very late ST had a higher prevalence
of white race and a lower prevalence of prior myocardial infarction or diabetes. In-hospital mortality
was significantly higher in early ST (7.9%) compared with late (3.8%) and very late ST (3.6%, p  0.001).
This lower mortality for late and very late ST persisted after multivariable adjustment (odds ratio:
0.53 [95% confidence interval (CI): 0.36 to 0.79] and 0.58 [95% CI: 0.43 to 0.79], respectively).

Significant differences exist in the presentation and outcomes of early, late, and very late ST.
Among patients with acute coronary syndromes who are undergoing percutaneous coronary intervention for
angiographically documented ST, early ST is associated with the highest in-hospital mortality.

Summary of Discussion

  • This was part 2 of 2 (see Journal Club 21 March 2012)
  • The collated large number of stent thromboses from this multicentre registry was noted. However, a number of limitations were noted:
    • the number of patients excluded because the time of stent implantation could not be established was significant. It  would have been instructive to know the mortality of this cohort.
    • 27% of patients did not have stent type documented
    • predictors of the events and differences in relation to timing were not presented and important issues such as duration of antiplatelet therapy were not presented
  • The dominant conclusions regarding mortality were acknowledged and the clinical characteristics noted.

Journal Club 21 March 2012

March 21, 2012 1 comment


Lower risk of stent thrombosis and restenosis with unrestricted use of ‘new-generation’ drug-eluting stents: a report from the nationwide Swedish Coronary Angiography and Angioplasty Registry (SCAAR)





SCAAR: Scandinavian registry of percutaneous coronary intervention.




Survival analysis (Cox proportional hazards) for restenosis, stent thrombosis (ARC definition), mortality for bare metal stents, ‘old’ drug eluting stents (includes Endeavor) and ‘new’ drug eluting stents (24 months).


Discussion Summary 

  • The limitations of registry data were discussed, even with adjustment for important covariates.
  • The prevalence of bare metal stent use was higher than local practice.
  • The low rate of adverse events for new drug eluting stents in the diverse context of a registry was reassuring from a pragmatic viewpoint.
  • The lower mortality rate for drug eluting stents is hypothesis generating. Confounders such as higher prevalence of nare metal stent use in ST elevation myocardial infarction were raised.
  • Another important limitations: no data regarding the duration of dual antiplatelet therapy; reasons for use of stent types; management of restenosis
  • Modelling to determine ‘optimal’ rate of drug eluting stent use based on efficacy data from the randomized clinical trials using cost effectiveness considerations was thought to be valuable. Data from the Melbourne Interventional Group suggested high drug eluting stent use than the the Scandinavian registry and found no difference in clinical outcomes between DES and BMS. The ambiguity of interpretation of this finding was discussed.

The supplementary information is available here. See also the previous post regarding insights from a US registry.

Update 26 March 2012

A meta-analysis comparing everolimus eluting stent with bare metal stent and other drug eluting stents was published in the Lancet. The editorial is available here. Excerpts from the meta-analysis are presented below:


Insights into stent thrombosis from a US National registry

March 19, 2012 1 comment

Armstrong et al provide insights into stent thrombosis (early, late and very late stent thrombosis) from a US multicentre registry.  7315 events in 7079 patients of 401662 patients (1.8%) were identified and characterised. Differences in-hospital mortality were noted (as tabulated below). Clinical characteristics and correlates are discussed.

Stent thrombosis category In-hospital Mortality (%)
Early 7.9
Late 3.8
Very late 3.6