Very Late Thrombosis of a Drug-Eluting Stent After Discontinuation of Dual Antiplatelet Therapy in a Patient Treated With Both Drug-Eluting and Bare-Metal Stents

Drug-eluting stents (DESs) are the treatment of choice for obstructive coronary artery disease when percutaneous intervention is feasible. However, late stent thrombosis seems to occur more frequently with DESs and is closely associated with the discontinuation of dual antiplatelet therapy. We report a case of very late stent thrombosis after discontinuation of dual antiplatelet therapy. The patient suffered from acute myocardial infarction (MI) and underwent bare metal stent (BMS) implantation in the left anterior descending artery (LAD) five years prior to presentation. Three years after BMS implantation, he presented again with acute MI and had a DES implanted in the right coronary artery (RCA). He ran out of his medication, but failed to refill his prescription. Sixteen days after discontinuing medication, he experienced an episode of chest pain and was taken to the cardiac catheterization laboratory, where he was found to have thrombosis in the DES, but no thrombosis in the BMS. It is possible that DESs are more vulnerable to late thrombosis than are BMSs, supporting the use of prolonged dual antiplatelet therapy in patients treated with DESs. The patient was successfully treated with balloon angioplasty and thrombus aspiration without complications

Effect of typhoons on the Korean national emergency medical service system

Objective While the effect of typhoons on emergency medicine has been evaluated, data are scarce on their effects on the emergency medical service (EMS). This study evaluated the effect of typhoons on EMS patients and performance. Methods The study period was January 2010 to December 2012. Meteorological data regarding typhoons were provided by the Korean Meteorological Administration. EMS data were retrieved from the EMS database of the national emergency management agency. The database includes ambulance run sheets, which contain clinical and operational data. In this case-crossover study, the cases and controls were EMS calls on the day of typhoon warnings and calls one week prior to the typhoon warnings, respectively. Results During the study period, 11 typhoons affected Korea. A total of 14,521 cases were selected for analysis. Overall, there were no obvious differences between the case and control groups. However, there were statistically significant differences in age, place, and time requests. There were fewer patients between 0 and 15 years of age (P=0.01) and more unconscious patients (P=0.01) in the case group. The EMS operational performance, as measured by the times elapsed between call to start, call to field, and call to hospital did not differ significantly. There was also no significant difference in the time from hospital arrival between the cases (28.67, standard deviation 16.37) and controls (28.97, standard deviation 28.91) (P=0.39). Conclusion Typhoons did not significantly affect the EMS system in this study. Further study is necessary to understand the reasons for this finding

Comparison of short-term clinical outcomes between Resolute Onyx zotarolimus-eluting stents and everolimus-eluting stent in patients with acute myocardial infarction: Results from the Korea Acute Myocardial infarction Registry (KAMIR)

Background: There are few studies which compare the efficacy and safety of the Resolute Onyx zotarolimus-eluting stent (O-ZES) and everolimus-eluting stent (EES) in patients with acute myocardial infarction (AMI). Therefore, the present study aimed to compare clinical outcomes of O-ZES and EES in patients with AMI undergoing successful percutaneous coronary intervention (PCI). Methods: From January 2016 to December 2016, the Korea Acute Myocardial Infarction Registry (KAMIR) enrolled 3,364 consecutive patients. Among them, O-ZES was used in 402 patients and EES was used in 1,084 patients. The primary endpoint was target lesion failure (TLF), as defined by composite of cardiac death, target vessel myocardial infarction (TV-MI), and ischemic driven-target lesion revascularization (ID-TLR) at 6 month clinical follow-up. Results: At 6 months, the incidence of TLF was not significantly different between O-ZES and EES group (4.0% vs. 3.9%, adjusted hazard ratio [HR] 1.17, 95% confidential interval [CI] 0.58–2.35, p = 0.665). O-ZES also showed similar results of cardiac death (3.7% vs. 3.4%, adjusted HR 1.25, 95% CI 0.59–2.63, p = 0.560), TV-MI (0.2% vs. 0.6%, adjusted HR 0.56, 95% CI 0.07–4.85, p = 0.600), ID-TLR (0.0% vs. 0.3%, p = 0.524), and definite or probable stent thrombosis (0.2% vs. 0.3%, adjusted HR 0.63, 95% CI 0.06–6.41, p = 0.696) when compared with EES. Conclusions: The present study shows that implantation of O-ZES or EES provided similar clinical outcomes with similar risk at 6-month of TLF and definite/probable ST in patients with AMI undergoing successful PCI

Acute and Subacute Stent Thrombosis in a Patient With Clopidogrel Resistance: A Case Report

Drug-eluting stents (DES) are considered the treatment of choice for most patients with obstructive coronary artery disease when percutaneous intervention (PCI) is feasible. However, stent thrombosis seems to occur more frequently with DES and occasionally is associated with resistance to anti-platelet drugs. We have experienced a case of recurrent stent thrombosis in a patient with clopidogrel resistance. A 63-year-old female patient suffered from acute myocardial infarction and underwent successful PCI of the left anterior descending coronary artery (LAD) with two DESs. She was found to be hyporesponsive to clopidogrel and was treated with triple anti-platelet therapy (aspirin 100 mg, clopidogrel 75 mg, and cilostazol 200 mg daily). Three days after discharge, she developed chest pain and was again taken to the cardiac catheterization laboratory, where coronary angiography (CAG) showed total occlusion of the mid-LAD where the stent had been placed. After intravenous administration of a glycoprotein IIb/IIIa inhibitor, balloon angioplasty was performed, resulting in Thrombolysis In Myocardial Infarction (TIMI) III antegrade flow. The next day, however, she complained of severe chest pain, and the electrocardiogram showed marked ST-segment elevation in V1-V6, I, and aVL with complete right bundle branch block. Emergent CAG revealed total occlusion of the proximal LAD due to stent thrombosis. She was successfully treated with balloon angioplasty and was discharged with triple anti-platelet therapy

Differentially Expressed Potassium Channels Are Associated with Function of Human Effector Memory CD8+T cells

The voltage-gated potassium channel, Kv1.3, and the Ca2+-activated potassium channel, KCa3.1, regulate membrane potentials in T cells, thereby controlling T cell activation and cytokine production. However, little is known about the expression and function of potassium channels in human effector memory ( EM) CD8+ T cells that can be further divided into functionally distinct subsets based on the expression of the interleukin ( IL)-7 receptor alpha ( IL-7R alpha) chain. Herein, we investigated the functional expression and roles of Kv1.3 and KCa3.1 in EM CD8+ T cells that express high or low levels of the IL-7 receptor alpha chain ( IL-7R alpha(high) and IL-7R alpha(low), respectively). In contrast to the significant activity of Kv1.3 and KCa3.1 in IL-7Rahigh EM CD8+ T cells, IL-7Ralow EM CD8+ T cells showed lower expression of Kv1.3 and insignificant expression of KCa3.1. Kv1.3 was involved in the modulation of cell proliferation and IL-2 production, whereas KCa3.1 affected the motility of EM CD8+ T cells. The lower motility of IL-7Ralow EM CD8+ T cells was demonstrated using transendothelial migration and motility assays with intercellular adhesion molecule 1-and/or chemokine stromal cell-derived factor-1 alpha-coated surfaces. Consistent with the lower migration property, IL-7Ralow EM CD8+ T cells were found less frequently in human skin. Stimulating IL-7Ralow EM CD8+ T cells with IL-2 or IL-15 increased their motility and recovery of KCa3.1 activity. Our findings demonstrate that Kv1.3 and KCa3.1 are differentially involved in the functions of EM CD8+ T cells. The weak expression of potassium channels in IL-7Ralow EM CD8+ T cells can be revived by stimulation with IL-2 or IL-15, which restores the associated functions. This study suggests that IL-7Rahigh EM CD8+ T cells with functional potassium channels may serve as a reservoir for effector CD8+ T cells during peripheral inflammation.112Ysciescopu

Very Late Stent Thrombosis due to Neointimal Rupture After Paclitaxel-Eluting Stent Implantation

We report our experience of very late stent thrombosis (VLST) in a young male patient who underwent implantation of two paclitaxel-eluting stents (PES) six years ago. The patient was compliant with standard dual antiplatelet therapy, but he presented with acute myocardial infarction which was associated with VLST. Intravascular ultrasound showed neointimal rupture with thrombus within the PES implanted in the right coronary artery. The lesion was successfully treated with balloon angioplasty without complications, however he was found to be hyporesponsive to clopidogrel when tested for adenosine diphosphate-induced platelet aggregation. The patient was discharged after uneventful recovery with triple anti-platelet therapy using aspirin, clopidogrel and cilostazol. To the best of our knowledge, a time interval of 2,223 days is the longest reported time interval between PES deployment and VLST occurrence. VLST may indeed occur in clinically stable patients, as multiple factors can influence the pathological mechanisms of VLST

Congenital Hemidiaphragmatic Agenesis Presenting as Reversible Mesenteroaxial Gastric Volvulus and Diaphragmatic Hernia: A Case Report

A 70-yr-old woman complained of left sided chest pain and non-bilious vomiting for four days after taking a gastric bloating agent for an upper gastrointestinal study. The chest radiography revealed gastric air-fluid levels and bowel loops in the left thoracic cavity. An emergency thoracotomy was performed. The abdominal organs (stomach, spleen, splenic flexure of the colon) were in the left thorax and the entire left hemidiaphragm was absent. There were no diaphragmatic remnants visible for reconstruction of the left diaphragm. We provided warm saline irrigation and performed a left lower lobe adhesiotomy. Thirteen days after surgery, the chest radiography showed improvement in the herniation but mild haziness remained at the left lower lung field. Here we present the oldest case of congenital diaphragmatic agenesis presenting with transient gastric volvulus and diaphragmatic hernia