Complication Of Stent Implantation Research Articles

Factors associated with early, late, and very late stent thrombosis among patients with acute coronary syndrome undergoing coronary stent placement: analysis from the ATLAS ACS 2-TIMI 51 trial.

Stent thrombosis (ST) is an uncommon but serious complication of stent implantation. This study aimed to explore factors associated with early, late, and very late ST to help guide risk assessment and clinical decision-making on ST. The analysis included patients who received stent placement for the index acute coronary syndrome (ACS). Cumulative incidence of ST was assessed at 30 days (early ST), 31-360 days (late ST), 361-720 days (very late ST), and up to 720 days. Cox proportional hazards models were used to assess associations between ST and various factors, including patient characteristics [i.e., age, sex, ACS presentation, history of hypertension, smoking, diabetes, prior myocardial infarction (MI), heart failure, prior ischemic stroke, and cancer], laboratory tests [i.e., positive cardiac biomarker, hemoglobin, platelet count, white blood cell (WBC) count], and treatment [i.e., drug-eluting stent (DES) vs. bare-metal stent (BMS) and anticoagulant with rivaroxaban vs. placebo]. Among the 8,741 stented patients, 155 ST events (2.25%) occurred by Day 720. The cumulative incidences of early, late, and very late ST were 0.80%, 0.81%, and 0.77%, respectively. After multivariable adjustment, age ≥ 75 [hazard ratio (HR) = 2.13 (95% confidence interval, CI: 1.26-3.60)], a history of prior MI [HR = 1.81 (95% CI: 1.22-2.68)], low hemoglobin level [HR = 2.34 (95% CI: 1.59-3.44)], and high WBC count [HR = 1.58 (95% CI: 1.02-2.46)] were associated with a greater risk of overall ST, whereas DES [HR = 0.56 (95% CI: 0.38-0.83)] and rivaroxaban therapy [HR = 0.63 (95% CI: 0.44-0.88)] were associated with a lower risk of overall ST up to 720 days. Low hemoglobin level and high WBC count were associated with early ST (low hemoglobin: HR = 2.35 [95% CI: 1.34-4.12]; high WBC count: HR = 2.11 [95% CI: 1.17-3.81]). Low hemoglobin level and prior MI were associated with a greater risk of late ST (low hemoglobin: HR = 2.32 [95% CI: 1.26-4.27]; prior MI: HR = 2.98 [95% CI: 1.67-5.31]), whereas DES was associated with a lower risk of late ST [HR = 0.33 (95% CI: 0.16-0.67)]. Age ≥75 years was associated with very late ST. The study identified positive and negative associations with early, late, and very late ST. These variables may be useful in constructing risk assessment models for ST. http://www.clinicaltrials.gov, identifier NCT00809965.

Zein nanospheres assisting inorganic and organic drug combination to overcome stent implantation-induced thrombosis and infection

The complication of stent implantation is the biggest obstacle to the success of its clinical application. In this study, we developed a combination way of 3D printing and the coating technique for preparation of functional polyurethane stents against stent implantation-induced thrombosis and postoperative infection. SEM, XPS, static water contact angle, and XRD demonstrated that the functional polyurethane stent had a 37 μm-thickness membrane composed of zein nanospheres (250–350 nm). Meanwhile, ZnO nanoparticles were encapsulated in zein nanospheres while heparin was adsorbed on the surface, causing 97.1 ± 6.4 % release of heparin in 120 min (first-order kinetic model) and 62.7 ± 5.6 % release of Zn2+ in 9 days (Korsmeyer-Peppas model). The mechanical analysis revealed that the functional polyurethane stents had about 8.61 MPa and 2.5 MPa tensile strength and bending strength, respectively. The in vitro biological analysis showed that the functional polyurethane stents had good EA.hy926 cells compatibility (97.9 ± 3.8 %), anti-coagulation response (comparable plasma protein, platelet adhesion and suppressed clotting) and sustained antibacterial activities by comparison with the bare polyurethane stent. The preliminary evaluation by rabbit ex vivo carotid artery intervention experiment demonstrated that the functional polyurethane stents could maintain blood circulation under the continuous stresses of blood flow. Meanwhile, the detailed data from the simulated implant infection experiment in vivo showed the functional polyurethane stents could effectively reduce microbial infection by 3–6 times lower and improve fibrosis and macrophage infiltration.

Abstract 9153: Predictive and Protective Factors of Early, Late, and Very Late Stent Thrombosis in Acute Coronary Syndrome Patients Undergoing Coronary Stent Implantation: Findings from the Atlas Acs 2-timi 51 Trial

Introduction: Stent thrombosis (ST) is an uncommon but serious complication of stent implantation. The aim of this analysis was to explore predictive and protective factors of early, late, and very late ST. Methods: This was a post-hoc analysis of the ATLAS ACS 2-TIMI 51 trial, which included acute coronary syndrome patients who received stent placement. Incidence of ST was assessed by Kaplan-Meier estimates at 30 days, 31 to 360 days, 361 to 720 days, and up to 720 days, with day 1 defined as the day of stent implantation. Multivariable associations with ST were explored by fitting Cox proportional hazards models. The covariates included patient characteristics, baseline laboratory tests (i.e., cardiac biomarkers, hemoglobin, platelet count, white blood cell [WBC]), and ST treatment (i.e., drug-eluting stent [DES] vs. bare-metal stent and anticoagulant with rivaroxaban vs. placebo). Results: Among 8,741 stented patients, a total of 155 ST events (2.25%) occurred by day 720. The cumulative incidence of early, late, and very late ST was 0.80%, 0.81%, and 0.77%, respectively. After multivariable adjustment, age ≥75 years (HR=2.13 [95% CI: 1.26-3.60]), a history of prior myocardial infarction (MI) (HR=1.81 [95% CI: 1.22-2.68]), low hemoglobin (HR=2.34 [95% CI: 1.59-3.44]), high WBC (HR=1.58 [95% CI: 1.02-2.46]), DES (HR=0.56 [95% CI: 0.38-0.83]), and rivaroxaban (HR=0.63 [95% CI: 0.44-0.88]) were associated with overall ST. Low hemoglobin (HR=2.35 [95% CI: 1.34-4.12]) and high WBC (HR=2.11 [95% CI: 1.17-3.81]) were predictive of early ST. Low hemoglobin (HR=2.32 [95% CI: 1.26-4.27]), prior MI (HR=2.98 [95% CI: 1.67-5.31]), and DES (HR=0.33 [95% CI: 0.16-0.67]) were associated with late ST. Age ≥75 years was predictive of very late ST (HR=3.71 [95% CI: 1.12-12.3]). Conclusions: The study identified factors with positive and negative associations with early, late, and very late ST that may be useful in constructing risk assessment models for ST.

Primary percutaneous coronary intervention for acute coronary syndrome due to stent thrombosis

Stent thrombosis (ST) is complication of stent implantation and there are very few scientific data about the effectiveness and long-term outcomes of primary percutaneous coronary intervention (PPCI) in patients (pts) with acute coronary syndrome (ACS) due to ST. We sought to investigate efficacy of PPCI and prognosis of pts with ST presenting as ACS in single high-volume center. In 6534 consecutive pts treated with PPCI for ACS in our center, from 2006-2013., we identified 145 (2.2%) pts with ACS caused by ST. Study population consisted predominately of male pts 97 (66.9%), with mean age of 60.6 (34-93) years. Median time of ST occurrence was 6 days after stenting (range 0-4015), with acute ST in 23 (15.8%) pts, subacute in 77 (53.2%), late in 13 (8.9%) and very-late ST in 32 (22.1%) pts. Most ST occurred in stents implanted during previous PPCI for ST-segment elevation myocardial infarction (STEMI) 112 (77.2%) pts, with 33 (22.8%) pts having previous drug eluting stent, 102 (70.3%) bare-metal stent implantation, while for 10 (6.9%) pts type of previous stent was unknown. ST presented clinically as a new STEMI in 130 (89.6%) pts, in 15 (10.4%) as non-STEMI, and LAD was the predominant culprit artery in 76 pts (52.4%). Thrombus aspiration was performed in 24 (16.5%), balloon angioplasty (BA) only in 60 (41.4%) and additional stenting after BA was performed in 67 (46.2%), with overall procedure successes in 135 (93.1%) pts. GP IIb/IIIa were used in 77 (53.1%) pts and 4 (2.7%) pts received bailout intracoronary administration of thrombolytic. Distribution of In-hospital and long-term MACE, with mean duration of FU of 25.8 months (range 1-76 months), available for 96.5% of pts is presented (Table 1.): View this table: Table 1. In-hospital and long-term MACE Stent thrombosis occurs most frequently in stents previously implanted during primary PCI procedures and presents mainly as new STEMI. Patients with ST have a high rate of MACE during in-hospital stay, as well as during long-term follow-up.

The correlation between early complications of percutaneous coronary intervention and high sensitive C-reactive protein.

Increased incidence of cardiovascular diseases, especially coronary artery disease (CAD), during recent decades shows this disease entity to be the leading cause of death in the world. On the other hand many successes were achieved in the treatment of these diseases with new technology, which has its own side effects and threats for the patient. Among these new strategies is percutaneous coronary intervention (PCI), especially with stent implantation. Although coronary stents are effective in the treatment of dissection and prevention of restenosis, many side effects and even death have been observed, from 5-10% per year. Some studies showed that there is a relation between high sensitivity C-reactive protein (hs-CRP), as a laboratory marker for early detection of thrombosis and/or restenosis, and early complications of percutaneous coronary intervention. The aim of this study is to evaluate hs-CRP level in patients after PCI and to investigate if this can be a prognostic value for detection of early complication. This is a descriptive, analytical study done in Shahid Chamran Hospital (Isfahan, Iran) in 2011-2012. 87 patients who had undergone PCI were studied. Their hs-CRP level was measured before and after the study. Moreover, early stent complications were detected during the first 24 hours after insertion. The data was recorded in a researcher-constructed checklist and analyzed by SPSS for Windows 20. The mean ± SD of hs-CRP level in patients with and without complication were 1.36 ± 0.97 and 3.09 ± 1.8, respectively. According to Student's t-test, the hs-CRP level in patients with early complications was higher than patients without early complications of stent implantation; the difference was statistically significant (P < 0.001). The hs-CRP serum concentrations of patients with, and without early stent complications were significantly different. According to the control diseases center (CDC) guideline, patients with a high level of hs-CRP need special care and attention.

Statins and stent thrombosis

Thrombosis is a rare but serious complication of stent implantation in atherosclerotic arteries, affecting both bare-metal and drug-eluting stents. Diagnostic criteria for stent thrombosis have recently been updated with the time and probability of the event being considered as crucial parameters. To be considered as "definite", the diagnosis of stent thrombosis has to be confirmed by angiography or histology. This statement position has clearly rendered more difficult the clinical assessment of stent thrombosis in randomised clinical trials. Considering these limitations, stent thrombosis represents a dramatic complication for both patients and cardiologists. In coronary plaques, thrombosis is often associated with death, acute coronary syndromes and arrhythmias. For these reasons, the pharmacological improvement of this outcome represents a "hot-topic" field for research. Among several medications, statins have been shown to potentially reduce the incidence of coronary stent thrombosis in humans. However, randomised clinical trials focussing on "definite" diagnosis are still needed to confirm these promising results. In addition, the use of statins in patients implanted with stents in other arteries is largely unexplored. Finally, statin-eluting stents (only tested in pigs) have to be evaluated in other animal models and human beings. Therefore, a clear recommendation on the use of statins to prevent stent thrombosis is not available and caution should be used. The "pleiotropic" anti-atherosclerotic properties of statins might represent a crucial investigation field to pathophysiologically clarify the role of statins in stent complications.

Stent implantation through a self-expanding stent.

Jailing of a side-branch is a known complication of stent implantation, and makes access to the side-branch difficult, especially if the stent is of the self-expanding type. Although plain balloon angioplasty is feasible for the jailed side-branches, the use of newer devices (a stent, Rotablation or atherectomy) has not been described. We describe a novel way of treating a side-branch jailed by a self-expanding stent by using stent implantation through the strut of a self-expanding stent.