Stent thrombosis in patients with coronary artery disease treated with biodegradable polymer drug-eluting stents: an update meta-analysis

Efficacy and Safety of Sirolimus-Eluting Stent With Biodegradable Polymer Ultimaster™ in Unselected Korean Population: A Multicenter, Prospective, Observational Study From Korean Multicenter Ultimaster Registry

BACKGROUND AND OBJECTIVES

Ultimaster™, a third-generation sirolimus-eluting stent using biodegradable polymer, has been introduced to overcome long term adverse vascular events, such as restenosis or stent thrombosis. In the present study, we aimed to evaluate the 12-month clinical outcomes of Ultimaster™ stents in Korean patients with coronary artery disease.

METHODS

This study is a multicenter, prospective, observational registry across 12 hospitals. To reflect real-world clinical evidence, non-selective subtypes of patients and lesions were included in this study. The study end point was target lesion failure (TLF) (the composite of cardiac death, target vessel myocardial infarction [MI], and target lesion revascularization [TLR]) at 12-month clinical follow up.

RESULTS

A total of 576 patients were enrolled between November 2016 and May 2021. Most of the patients were male (76.5%), with a mean age of 66.0±11.2 years. Among the included patients, 40.1% had diabetes mellitus (DM) and 67.9% had acute coronary syndrome (ACS). At 12 months, the incidence of TLF was 4.1%. The incidence of cardiac death was 1.5%, MI was 1.0%, TLR was 2.7%, and stent thrombosis was 0.6%. In subgroup analysis based on the presence of ACS, DM, hypertension, dyslipidemia, or bifurcation, there were no major differences in the incidence of the primary endpoint.

CONCLUSIONS

The present registry shows that Ultimaster™ stent is safe and effective for routine real-world clinical practice in non-selective Korean patients, having a low rate of adverse events at least up to 12 months.

Propensity-Score Matched Comparison of Midterm Angiographic Outcomes of Sirolimus- Versus Everolimus- and Biolimus-Eluting Stents for De Novo Coronary Stenosis

We conducted propensity-score matched comparisons of midterm angiographic outcomes of sirolimus (SES) versus either everolimus- (EES) or biolimus- (BES) eluting stents after placements for coronary stenosis in a daily practice environment since previous randomized trials did not demonstrate the superiority of EES and BES over SES in terms of midterm angiographic outcomes.The present study was a non-randomized, retrospective, and lesion-based study, recruiting angiographically followed-up lesions within 550 days after successful and elective SES (n = 1793), EES (n = 1303), or BES (n = 324) placement for de novo native coronary stenosis during the period from August 2004 to January 2014 at 6 institutes. The endpoint, as an angiographic surrogate marker of clinical efficacy, was the distribution of in-stent follow-up percent diameter stenosis (%DS) which comprised the percentages of 1) follow-up %DS < 20 and 2) follow-up %DS > 50. Propensityscore matched analyses were conducted to adjust 21 baselines.In 1215 baseline adjusted lesions, the endpoints in the EES group [1) 74.1%, and 2) 4.6%] were significantly different from those in the SES group [57.9%; P < 0.001, 7.2%; P = 0.006, respectively). In 307 baseline adjusted lesions, the endpoints in the BES group [1) 80.5%, 2) 2.0%] were significantly different from those in the SES group [59.3%; P < 0.001, 2) 8.1%; P = 0.001, respectively].The present study is the first to confirm the superiority of midterm angiographic outcomes after the placement of EES and BES over SES for de novo coronary stenosis in a clinical setting.

Administration of Ticagrelor and Double-Dose Clopidogrel Based on Platelet Reactivity Determined by VerifyNow-P2Y12 for Chinese Subjects After Elective PCI

Previous studies have identified high on treatment platelet reactivity (HTPR) as a potent factor predicting ischemic events for patients with coronary heart disease. We assessed the efficacy and safety of ticagrelor (90 mg twice-daily) and double-dose of clopidogrel (150 mg once-daily) among Chinese patients for elective percutaneous coronary intervention. We enrolled 40 patients with HTPR from among 317 patients with non-ST-segment elevation acute coronary syndromes after a successful elective percutaneous coronary intervention (PCI). Platelet reactivity was measured by VerifyNow P2Y12 assay. Platelet reactivity was significantly lower for both groups when compared with baseline platelet reactivity after medication adjustment (all P < 0.001). The mean platelet reactivity units (PRU) was significantly lower for the ticagrelor group compared with that of the clopidogrel group over time (all P < 0.001). The differences in the rate of sustained HTPR at different time points between the two groups were significant (2 hours: 0% versus 60%; 8 hours: 5.6% versus 50%; 24 hours: 5.9% versus 43.8%, all P < 0.05). Genetic variation of CYP2C19*2 had no impact on PRU means or rate of HTPR in the ticagrelor group (P > 0.05). During the 30-day follow-up, no MACE occurred in any patient, and the overall risk of bleeding showed no difference between the two groups (35% versus 21%, P = 0.48). Our results suggest that ticagrelor may achieve a more rapid and greater platelet inhibition than double-dose clopidogrel. Further studies are still needed to assess the differences in efficacy and safety between ticagrelor and double-dose clopidogrel administration for Chinese patients post elective PCI.

Current State of Bioabsorbable Polymer-Coated Drug-Eluting Stents

Drug-eluting stents (DES) have been shown to significantly reduce clinical and angiographic restenosis compared to bare metal stents (BMS). The polymer coatings on DES elute antiproliferative drugs to inhibit intimal proliferation and prevent restenosis after stent implantation. Permanent polymers which do not degrade in vivo may increase the likelihood of stent-related delayed arterial healing or polymer hypersensitivity. In turn, these limitations may contribute to an increased risk of late clinical events. Intuitively, a polymer which degrades after completion of drug release, leaving an inert metal scaffold in place, may improve arterial healing by removing a chronic source of inflammation, neoatherosclerosis, and/or late thrombosis. In this way, a biodegradable polymer may reduce late ischemic events. Additionally, improved healing after stent implantation could reduce the requirement for long-term dual antiplatelet therapy and the associated risk of bleeding and cost. This review will focus on bioabsorbable polymer-coated DES currently being evaluated in clinical trials.

Perioperative management of patient with intracoronary stent presenting for noncardiac surgery

As the number of percutaneous coronary interventions increase annually, patients with intracoronary stents (ICS) who present for noncardiac surgery (NCS) are also on the rise. ICS is associated with stent thrombosis (STH) and requires mandatory antiplatelet therapy to prevent major adverse cardiac events. The risks of bleeding and ischemia remain significant and the management of these patients, especially in the initial year of ICS is challenging. The American College of Cardiologists guidelines on the management of patients with ICS recommend dual antiplatelet therapy (DAT) for minimal 14 days after balloon angioplasty, 30 days for bare metal stents, and 365 days for drug-eluting stents. Postponement of elective surgery is advocated during this period, but guidelines concerning emergency NCS are ambiguous. The risk of STH and surgical bleeding needs to be assessed carefully and many factors which are implicated in STH, apart from the type of stent and the duration of DAT, need to be considered when decision to discontinue DAT is made. DAT management should be a multidisciplinary exercise and bridging therapy with shorter acting intravenous antiplatelet drugs should be contemplated whenever possible. Well conducted clinical trials are needed to establish guidelines as regards to the appropriate tests for platelet function monitoring in patients undergoing NCS while on DAT.

Current Practices in the Management of Antithrombotic Therapy During the Periendoscopic Period for Patients With Cardiovascular Disease

The management of antithrombotics during the periendoscopic period is traditionally represented as a doubleedged sword for cardiologists and endoscopists. Appropriate administration prevents thromboembolic events, whereas excessive administration provokes bleeding events. Therefore, cardiologists and endoscopists must consider the risks of bleeding and thromboembolism in individual cases, before deciding whether to continue antithrombotic use. Several guidelines exist concerning antithrombotic management in Asian and Western countries. These guidelines generally classify procedural bleeding risk and thromboembolic risk into high risk and low risk groups and recommend that the two risks be weighed when managing a given patient. Moreover, they generally do not recommend interrupting antithrombotics during the periendoscopic period unless absolutely necessary; however, the details surrounding this point differ among the guidelines after several revisions. In this review, we describe the present state, problems, and future perspectives concerning the management of antithrombotics in patients with cardiovascular disease undergoing gastrointestinal endoscopy.

Very early tissue coverage after drug-eluting stent implantation: an optical coherence tomography study

The aim of this study was to evaluate neointimal coverage in the very early phase after second-generation drug-eluting stent (DES) implantation using optical coherence tomography (OCT). Patients who underwent staged percutaneous coronary intervention within 30 days after DES implantation were enrolled. OCT was performed to observe DES previously implanted. The median time interval from implantation to OCT examination was 21.5 days. A total of 10,625 struts of 54 stents (52 everolimus-eluting stents and 2 zotarolimus-eluting stents) in 42 lesions were analyzed. Strut tissue coverage was observed in 71.1 ± 19.2 % of the struts, malapposed struts in 2.56 ± 3.37 %, strut tissue coverage at the side branch orifice in 10.6 ± 17.2 %, and struts with protrusion in 0.95 ± 3.46 %. Mean tissue thickness on the covered struts was 39.8 ± 14.2 µm. The percentage of stent coverage was significantly lower in the overlapping segments than in the non-overlapping segments (48.4 ± 17.5 % vs. 74.4 ± 20.2 %, P < 0.05). Most of the stent struts were covered by tissue within 30 days after second-generation DES implantation. However, the percentage of strut coverage was lower in the overlapping segments than in the non-overlapping segments, suggesting that very early interruption of dual antiplatelet therapy might result in increased risk of stent thrombosis, even in second-generation DES.

The effect of targeted temperature management on coagulation parameters and bleeding events after out-of-hospital cardiac arrest of presumed cardiac cause

AIMS

Targeted temperature management (TTM) is part of the standard treatment of comatose patients after out-of-hospital cardiac arrest (OHCA) to attenuate neurological injury. In other clinical settings, hypothermia promotes coagulopathy leading to an increase in bleeding and thrombosis tendency. Thus, concern has been raised as to whether TTM can be applied safely, as acute myocardial infarction requiring primary percutaneous coronary intervention (PCI) with the need of effective antiplatelet therapy is frequent following OHCA. This study investigated the influence of TTM at 33 or 36°C on various laboratory and coagulation parameters.

METHODS AND RESULTS

In this single-center predefined substudy of the TTM trial, 171 patients were randomized to TTM at either 33 or 36°C in the postresuscitation phase. The two subgroups were compared regarding standard laboratory coagulation parameters, thrombelastography (TEG), bleeding, and stent thrombosis events. Platelet counts were lower in the TTM33-group compared to TTM36 (p=0.009), but neither standard coagulation nor TEG-parameters showed any difference between the groups. TEG revealed a normocoagulable state in the majority of patients, while approximately 20% of the population presented as hypercoagulable. Adverse events included 38 bleeding events, one stent thrombosis, and one reinfarction, with no significant difference between the groups.

CONCLUSIONS

There was no evidence supporting the assumption that TTM at 33°C was associated with impaired hemostasis or increased the frequency of adverse bleeding and thrombotic events compared to TTM at 36°C. We found that TTM at either temperature can safely be applied in the postresuscitation phase after acute myocardial infarction and primary PCI.

Early Phase Arterial Reaction Following Drug-Eluting and Bare-Metal Stent Implantation in Patients With ST-Segment Elevation Myocardial Infarction

The early phase arterial reaction after implantation of second-generation drug-eluting stents (2nd DES) and baremetal stents (BMS) in patients with ST-segment elevation myocardial infarction (STEMI) remains unclear.The MECHANISM pilot study is a multi-center prospective registry that enrolled 24 STEMI patients (from 11 centers) who had undergone implantation of everolimus-eluting (n = 6), biolimus A9-eluting (n = 6) or zotarolimus-eluting stents (n = 6), or BMS (n = 6). Scheduled optical coherence tomography (OCT) was performed 2 weeks after implantation, and images were independently analyzed at a core laboratory in a blinded fashion. Intra-stent thrombus was quantitatively analyzed in terms of the maximal area and the percentage of cross-sections with thrombus (the numbers of cross-section with thrombus × 100 divided by total number of cross-sections within the stented segment). More than 90% of struts were already covered 2 weeks after the index procedure, regardless of the stent type. There were no differences in stent diameter, minimal lumen diameter, minimal lumen area, neointimal thickness, or the frequencies of malapposed and uncovered struts among the 4 groups. The quantity of intra-stent thrombus also did not differ among the 4 groups.The results of this pilot study suggest that the 2-week vascular responses seem to be similar among 2nd DES and BMS in STEMI patients. Considering the possible advantage of 2nd DES in the prevention of restenosis, 2nd DES are a feasible option for the treatment of patients with STEMI.

Development of a novel drug-eluting stent consisting of an abluminal and luminal coating layer dual therapy system

The aim of this study was to develop a dual drug-coated stent using a bi-directional coating system.