Peri-stent contrast staining and very late stent thrombosis after sirolimus-eluting stent implantation: an observation from the RESTART (REgistry of Stent Thrombosis for review And Re-evaluaTion) angiographic substudy

Successful treatment of very late drug-eluting stent thrombosis using bare-metal stent evaluated using intravascular ultrasound and optical frequency domain imaging

A 65-year-old man who underwent percutaneous coronary intervention with sirolimus-eluting stents (SESs) 2 years ago was admitted with recurrent acute chest pain. Coronary angiography showed thrombotic occlusion within the SESs. After aspiration thrombectomy, multi-focal peri-stent contrast staining (PSS) was observed. Optical frequency domain imaging (OFDI) showed intracoronary thrombus, incomplete stent apposition (ISA), and multiple inter-strut hollows. Intravascular ultrasound (IVUS) images showed positive vessel remodeling. We deployed bare-metal stents in the SESs. Follow-up angiography showed no in-stent restenosis or PSS. OFDI showed well-covered stent surface with homogeneous neointima, without ISA. Additionally, IVUS images showed that the vessel remodeling had not worsened.

Comparison of Long-Term Clinical Outcomes of Lesions Exhibiting Focal and Segmental Peri-Stent Contrast Staining

Background

Peri‐stent contrast staining (PSS) after metallic drug‐eluting stent deployment is associated with target lesion revascularization and very late stent thrombosis. However, the type of PSS that influences the clinical outcomes is unknown. Therefore, we aimed to reveal which PSS type was influencing clinical outcomes.

Methods and Results

This study included 5580 de novo lesions of 4405 patients who were implanted with a first‐ or second‐generation drug‐eluting stent and who were evaluated using follow‐up angiography within 12 months after stent implantation. We compared the clinical outcomes of patients divided into focal PSS and segmental PSS groups for 6 years after stent implantation. Total PSS was observed in 97 lesions (2.2%), of which 42 and 55 lesions were focal and segmental PSS, respectively. Baseline characteristics were similar between groups, except for intraoperative chronic total occlusion (segmental PSS=47.3% versus focal PSS=11.9%, P=0.0001). The incidence of segmental PSS tended to be higher in patients with a first‐generation drug‐eluting stent (83.6% versus 16.4%, P=0.05). The cumulative incidence of stent thrombosis in the 6 years of segmental PSS group was significantly higher than that of the focal PSS group (13.9% versus 0%, P=0.04). The cumulative incidence of overall target lesion revascularization for restenosis, excluding target lesion revascularization procedures for stent thrombosis, was significantly higher in the segmental PSS group (38.0% versus 0%, P=0.01).

Conclusions

The incidence of segmental PSS tended to be higher in patients with a first‐generation drug‐eluting stent and appeared to be significantly associated with target lesion revascularization and stent thrombosis.

Risk Factors and Clinical Impacts of Peri-Stent Contrast Staining After Second-Generation Drug-Eluting Stent Implantation

BACKGROUND

Peri-stent contrast staining (PSS) after sirolimus-eluting stent implantation is associated with target lesion revascularization (TLR) and very late stent thrombosis. However, the risk factors and clinical sequelae of PSS after second-generation DES implantation remain unclear.

METHODS AND RESULTS

This study comprised 2,090 patients with 2,883 lesions treated with second-generation DES from April 2009 to February 2013. Angiographic findings and clinical outcomes were compared between PSS and non-PSS groups. Follow-up angiography was available for 2,411 lesions. PSS was observed in 23 lesions: 4 in biolimus-eluting stents, 4 in zotarolimus-eluting stents (ZES), and 15 in everolimus-eluting stents (EES). Right coronary artery lesions, chronic total occlusion (CTO), and lesions with severe angulation (>90°) were more frequent in the PSS group compared with the non-PSS group. Lesions were longer and the cumulative TLR incidence at 3 years was higher in the PSS group than those in the non-PSS group (27.9 mm vs. 19.4 mm, P < 0.0001; 27.4% vs. 8.6%, P = 0.0002). There was no significant difference in stent thrombosis between the two groups. Multivariable analysis identified CTO [odds ratio (OR) 3.75, 95%CI 1.52-8.88, P = 0.005] as an independent predictor of PSS.

CONCLUSIONS

PSS after second-generation DES implantation was associated with an increased risk of subsequent TLR. CTO was the independent predictor of PSS.

The clinical characteristics and prognosis of lesions with in-stent eccentric tissue proliferation and strong signal attenuation detected by optical coherence tomography

There are still some patients who require repeat revascularization despite of drug-eluting stent (DES) implantation. The present study aimed to investigate the relationship between optical coherence tomography (OCT) findings and recurring target lesion revascularization (TLR) after percutaneous coronary intervention (PCI) for in-stent restenosis (ISR). We reviewed 50 patients (54 coronary lesions) who underwent PCI for ISR, which included 25 DES-ISR lesions. The PCI strategy depended on the interventionalist's discretion, and DES implantation was performed for 38 (70 %) lesions. Tissue characteristics were assessed qualitatively and quantitatively using the frame showing maximal lumen narrowing (minimal lumen area). In qualitative analysis, OCT detected coexistence of eccentric tissue proliferation and strong signal attenuation (ESA). ESA was observed in six lesions (11 %) in five patients (10 %). Hemodialysis (80 vs. 20 %, p = 0.013) and DES-ISR (100 vs. 40 %, p = 0.0069) were significantly more frequent in ESA patients/lesions than in others. One-year follow-up revealed that re-TLR was more frequently performed for ESA lesions (83 vs. 8 %, p = 0.0002). The findings reveal that ESA detected in OCT images of ISR is related to TLR after PCI for DES-ISR especially in patients undergoing maintenance hemodialysis.

The usefulness of a perfusion balloon in a case of late stent thrombosis that caused simultaneous double vessel occlusion

Simultaneous stent thrombosis in different coronary arteries requires rapid management. A 70-year-old man experienced simultaneous stent thrombosis at the left anterior descending and circumflex arteries. We used a perfusion balloon to prevent thrombus production at the left anterior descending artery, and completed percutaneous coronary intervention at the left circumflex artery in 10 min. The perfusion balloon was dilated during the procedure. In both vessels, Thrombolysis in myocardial infarction flow grade 3 was achieved after balloon deflation. Thus, use of a perfusion balloon for simultaneous double vessel occlusion helped avoid the need for redundant stent placement and shortened the procedure time.

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

BACKGROUND

Localized hypersensitivity reaction, delayed arterial healing, and neoatherosclerosis inside the stent have been suggested as the underlying pathologic mechanisms of very late stent thrombosis (VLST) of drug-eluting stent (DES). The present study sought to explore the prevalence of inflammatory cell infiltrates and evidence for fragments of atherosclerotic plaques in the aspirated thrombi in patients with DES VLST.

METHODS AND RESULTS

From April 2004 to September 2012, 48 patients with stent thrombosis (ST) of DES underwent thrombus aspiration with retrieved material sufficient for the histopathologic analysis; early ST (EST, within 30 days): N = 17, late ST (LST, between 31 and 365 days): N = 7, and very late ST (VLST, >1 year): N = 24. Eosinophil fraction in the aspirated thrombi was significantly higher in patients with VLST (8.2±5.7%) as compared with those with EST (4.3±3.0%) and LST (5.5±3.8%) (P = 0.03). Eosinophil fraction in the aspirated thrombi was significantly higher in 12 VLST patients with angiographic peri-stent contrast staining (PSS) and/or incomplete stent apposition (ISA) by intravascular ultrasound than in 12 VLST patients without PSS or ISA (10.6±6.1% versus 5.8±4.1%, P = 0.03). Evidences for fragments of atherosclerotic plaques in the aspirated thrombi were observed only in 3 (13%) out of 24 patients with DES VLST.

CONCLUSIONS

Eosinophil fraction in the aspirated thrombi was significantly higher in patients with DES VLST as compared with those with EST and LST. Evidences for fragments of atherosclerotic plaques were relatively uncommon in patients with DES VLST.

Learning from the Cardiologists and Developing Eluting Stents Targeting the Mtor Pathway for Pulmonary Application; A Future Concept for Tracheal Stenosis

Tracheal stenosis due to either benign or malignant disease is a situation that the pulmonary physicians and thoracic surgeons have to cope in their everyday clinical practice. In the case where tracheal stenosis is caused due to malignancy mini-interventional interventions with laser, apc, cryoprobe, balloon dilation or with combination of more than one equipment and technique can be used. On the other hand, in the case of a benign disease such as; tracheomalacia the clinician can immediately upon diagnosis proceed to the stent placement. In both situations however; it has been observed that the stents induce formation of granuloma tissue in both or one end of the stent. Therefore a frequent evaluation of the patient is necessary, taking also into account the nature of the primary disease. Evaluation methodologies identifying different types and extent of the trachea stenosis have been previously published. However; we still do not have an effective adjuvant therapy to prevent granuloma tissue formation or prolong already treated granuloma lesions. There have been proposed many mechanisms which induce the abnormal growth of the local tissue, such as; local pressure, local stress, inflammation and vascular endothelial growth factor overexpression. Immunomodulatory agents inhibiting the mTOR pathway are capable of inhibiting the inflammatory cascade locally. In the current mini-review we will try to present the current knowledge of drug eluting stents inhibiting the mTOR pathway and propose a future application of these stents as a local anti-proliferative treatment.