Association of localized hypersensitivity and in-stent neoatherosclerosis with the very late drug-eluting stent thrombosis

Impact of drug-eluting stent-associated coronary artery spasm on 3-year clinical outcomes: A propensity score matching analysis

BACKGROUND

It has been reported that significant endothelial dysfunction or clinically evident vasospasm can be associated with drug-eluting stents (DESs). However, the impact of DES associated coronary artery spasm (CAS) on long-term clinical outcomes has not been fully elucidated as compared with those of patients with vasospastic angina.

METHODS

A total of 2797 consecutive patients without significant coronary artery lesion (<70%), who underwent the Acetylcholine (Ach) provocation test, were enrolled between Nov 2004 and Oct 2010. DES-associated spasm was defined as significant CAS in proximal or distal to previously implanted DES site at follow-up angiography with Ach test. Patients were divided into two groups (DES-CAS; n = 108, CAS; n = 1878). For adjustment, propensity score matching (PSM) was done (C-statistics = 0.766, DES-CAS; n = 102, CAS; n = 102). SPSS 20 (Inc., Chicago, Illinois) was used to analyze this data.

RESULTS

Baseline characteristics were worse in the DES-CAS group. After PSM, both baseline characteristics and the Ach test results were balanced except higher incidence of diffuse CAS and ECG change in the DES-CAS group. During Ach test, the incidence of diffuse spasm (93.1% vs. 81.3%, p = 0.012) and ST-T change (10.7% vs. 1.9%, p = 0.010) were higher in the DES-CAS group. At 3-year, before and after adjustment, the DES-CAS group showed a higher incidence of coronary revascularization (9.8% vs. 0.0%, p = 0.001), recurrent chest pain requiring follow up coronary angiography (CAG, 24.5% vs. 7.8%, p = 0.001) and major adverse cardiac events (MACEs, 9.8% vs. 0.9%, p < 0.005).

CONCLUSION

In this study, DES associated CAS was associated with higher incidence of diffuse spasm, ST-T change and adverse 3-year clinical outcomes. Special caution should be exercised in this particular subset of patients.

Late peri-stent contrast staining appearance due to rupture of atherogenic neointima following drug-eluting stent

The development of peri-stent contrast staining (PSS) after coronary intervention with implantation of a stent is observed in approximately 1-3% of patients treated with drug-eluting stent. Although the cumulative incidences of late in-stent restenosis and stent thrombosis are significantly higher in lesions with PSS than in those without the finding, the mechanisms for the development of PSS have not yet been fully elucidated. In this report, we describe a case of rapid development of PSS with ulcer formation caused by rupture of atherogenic neointima, which was observed by serial optical coherence tomography examinations over 6 months. Protrusion of the stent-jailed underlying necrotic core toward the lumen by the contracting force might have resulted in formation of atherogenic neointima within the stent. Subsequently, rupture of this necrotic core induced by iatrogenic neointimal injury due to balloon dilation and dissolution of the accumulated necrotic core may have resulted in PSS formation 6 months after the procedure. These findings may be helpful for consideration of etiology and therapeutic strategy for lesions with PSS. <Learning objective: The mechanisms of peri-stent contrast staining (PSS) formation late after drug-eluting stent (DES) implantation are diverse. Rupture of atherogenic neointima with subsequent dissolution of the stent-jailed underlying plaque debris could be one of the mechanisms of rapid PSS formation after implantation of DES. An accurate assessment of lesion morphology within the stent and patient-tailored management can reduce morbidity and mortality in patients who have undergone DES implantation.>.

Neoatherosclerosis and Late Thrombosis After Percutaneous Coronary Intervention: Translational Cardiology and Comparative Medicine from Bench to Bedside

Neoatherosclerosis is a form of accelerated atherosclerosis that occurs within stented segments of the coronary vessel late or very late after drug-eluting stent (DES) implantation via percutaneous coronary intervention (PCI). This proliferation of neointima with a formation of new atheromatous plaque within stent struts lacking re-endothelialization can provoke thrombotic occlusion and lead to catastrophic acute coronary events. Knowing that coronary artery disease is the leading single cause of mortality worldwide and that there is a constant trend of increase in PCI procedures, it is reasonable to conclude that late thrombotic events and neoatherosclerosis post-PCI remain an important therapeutic challenge. For these reasons, early identification of patients at risk through the means of advanced imaging methods or preventive solutions available through novel technological solutions in DES design that target pro-inflammatory pathways and enable optimized arterial healing are central strategies in prevention and treatment of in-stent neoatherosclerosis and thrombosis. Due to this, pre-clinical studies performed on animal models are crucial building blocks that enable the objective and scientific assessment of innovative technological and therapeutic solutions before they are introduced to early stages of human clinical trials. A comparative medicine approach allows designing and executing experiments in animal models with a high degree of similarity with human coronary anatomy possibly promising the translation of encouraging findings to human clinical studies. The aim of this review is to provide contemporary insights on the pathophysiology of neoatherosclerosis and in-stent thrombosis and emergence of novel biomedical and technological solutions used to counter them.

High risk of stent thrombosis in the first 6 months after coronary stenting: Do not discontinue clopidogrel early after ACS

OBJECTIVES

To estimate the incidence of stent thrombosis (ST) after early discontinuation of clopidogrel.

BACKGROUND

Premature discontinuation of clopidogrel is the strongest risk factor for ST. In contrast, recent studies suggest that shorter dual antiplatelet therapy (DAPT) can be discontinued as soon as 3 months after stenting. However, these studies included very few ACS patients and were not powered for ST. Hence, little is known about the occurrence of ST in high-risk populations when DAPT is discontinued early.

METHODS

This is a subanalysis of The Dutch ST Registry 437 ST cases (mainly first-generation DES and BMS). Acute coronary syndrome was the indication for index-PCI in 74% of the patients. Clopidogrel discontinuation rates in ST patients and matched controls were used to calculate the absolute incidence of ST after early clopidogrel discontinuation.

RESULTS

The overall rate of ST after cessation of clopidogrel was 4.6% (95%CI: 3.9-5.4%), as compared to 1.7% (95%CI: 1.5-1.9%) in patients who did not discontinue clopidogrel. The incidence of ST was 35.4% when clopidogrel was discontinued in the first 30 days after index-PCI declining to 11.7% when clopidogrel was discontinued in the first 180 days.

CONCLUSIONS

This dedicated ST registry shows that ST rates were very high when clopidogrel was discontinued before 6 months after index-PCI and therefore suggests that clopidogrel discontinuation in the first 6 months after ACS should be avoided.

The different features of angiographic peri-stent contrast staining after implantation of sirolimus-eluting stents

If we had a case with angiographic peri‐stent contrast staining(PSS)s after the first‐generation sirolimus‐eluting stent, we need a further observation using coronary imaging modalities to evaluate the risk of very late stent thrombosis due to PSSs and to continue or to resume the dual antiplatelet therapy if necessary.

Techniques in Vascular and Interventional Radiology Drug Delivery Technologies in the Superficial Femoral Artery

Peripheral arterial disease (PAD) affects over 8 million people in the United States alone. Although great strides have been made in reducing the burden of cardiovascular disease the prevalence of PAD is expected to rise with the age of global population. PAD characterized by narrowing of arterial blood can be asymptomatic or cause limb threatening claudication. It has been classically treated with bypass, but these techniques have been supplanted by endovascular therapy. Plain old balloon angioplasty has been successful in helping revascularize lesions, but its effect has not been durable because of restenosis. This prompted the creation of several technologies aimed at reducing restenosis. These advances slowly improved outcomes and the durability of endovascular management. Among the main tools used in current endovascular practice are drug-delivery devices aimed at inhibiting the inflammatory and proliferative pathways that lead to restenosis. This article examines the current drug-delivery technologies used in the superficial femoral artery.

Stent Fracture After Sirolimus-Eluting Stent Implantation

Background—

Stent fracture (SF) after sirolimus-eluting stent implantation is reported to be associated with target lesion revascularization (TLR) and stent thrombosis. We aimed to assess the clinical impact of SF at 8 years.

Methods and Results—

Between 2002 and 2005, 972 patients (1795 lesions) underwent sirolimus-eluting stent implantation and follow-up angiography within 1 year after index procedure. SF, defined as the complete separation of stent segments or stent struts at follow-up angiography, was observed in 105 lesions (5.8%). The study sample comprised 954 patients (1630 lesions), excluding 147 lesions undergoing TLR and 18 patients (18 lesions) who died or in whom stent thrombosis developed within 1 year after sirolimus-eluting stent implantation. The median follow-up duration was 9.1 years (the first and third quarters, 8.7 and 9.4 years). The primary end point was defined as any TLR. The 8-year cumulative rates of adverse events were estimated by Kaplan–Meier methods with P values from log-rank tests. Between patients with and without SF, there were no significant differences in the cumulative rates of all-cause death (23.5% versus 27.6%, P =0.35) and cardiac death (4.7% versus 9.1%, P =0.14), whereas patients with SF had significantly higher cumulative rates in myocardial infarction (10.1% versus 3.3%, P =0.001), very late stent thrombosis (6.8% versus 0.7%, P <0.001), any TLR (38.1% versus 10.8%, P <0.001), and clinically driven TLR (26.2% versus 6.6%, P <0.001).

Conclusions—

SF after sirolimus-eluting stent implantation was consistently associated with higher rates of adverse cardiac events during the 8-year follow-up.