Optimal timing of percutaneous coronary intervention for non-ST elevated myocardial infarction with congestive heart failure.

OBJECTIVES: This study investigated the optimal timing for percutaneous coronary intervention (PCI) in patients with NSTEMI complicated by heart failure (HF). METHODS: In total, 762 patients with NSTEMI and HF in a multicenter, prospective registry in South Korea were classified according to the Killip classification (Killip class 2, n = 414 and Killip class 3, n = 348) and underwent early (within 24 h) and delayed (after 24 h) PCI. The primary outcome was all-cause mortality which was further analyzed with landmark analysis with two months as a cut-off. Secondary outcomes were cardiovascular death, in-hospital cardiogenic shock (CS), readmission due to HF, and acute myocardial infarction during follow-up. RESULTS: Delayed PCI was associated with lower rates of 2-month mortality (6.1 % vs. 15.8 %, p = 0.007) and in-hospital CS (4.3 % vs. 14.1 %, p = 0.003), along with lower risks of 2-month mortality (hazard ratio [HR] = 0.38, 95 % confidence interval [CI] = 0.18-0.83, p = 0.014), in-hospital CS (HR = 0.29, 95 % CI = 0.12-0.71, p = 0.006) in multivariate Cox models of Killip class 3 patients. There was no statistical difference of incidence and risk of all predefined outcomes according to varying timing of PCI in Killip 2 patients. CONCLUSIONS: Based on these results, the timing of PCI in patients with NSTEMI complicated by HF should be determined based on HF severity. Delayed PCI should be considered in patients with NSTEMI and more severe HF.

Timing of fractional flow reserve-guided complete revascularization in patients with ST-segment elevation myocardial infarction with multivessel disease: Rationale and design of the OPTION-STEMI trial.

BACKGROUND: Current guidelines recommend complete revascularization (CR) in hemodynamically stable patients with ST-segment elevation myocardial infarction (STEMI) and multivessel coronary artery disease (MVD). With regard to the timing of percutaneous coronary intervention (PCI) for non-infarct-related artery (non-IRA), recent randomized clinical trials have revealed that immediate CR was non-inferior to staged CR. However, the optimal timing of CR remains uncertain. The OPTION-STEMI trial compared immediate CR and in-hospital staged CR guided by fractional flow reserve (FFR) for intermediate stenosis of the non-IRA. METHODS: The OPTION-STEMI is a multicenter, investigator-initiated, prospective, open-label, non-inferiority randomized clinical trial. The study included patients with at least 1 non-IRA lesion with ≥50% stenosis by visual estimation. Patients fulfilling the inclusion criteria were randomized into 2 groups at a 1:1 ratio: immediate CR (i.e., PCI for the non-IRA performed during primary angioplasty) or in-hospital staged CR. In the in-hospital staged CR group, PCI for non-IRA lesions was performed on another day during the index hospitalization. Non-IRA lesions with 50%-69% stenosis by visual estimation were evaluated by FFR, whereas those with ≥70% stenosis was revascularized without FFR. The primary endpoint was the composite of all-cause death, non-fatal myocardial infarction, and all unplanned revascularization at 1 year after randomization. Enrolment began in December 2019 and was completed in January 2024. The follow-up for the primary endpoint will be completed in January 2025, and primary results will be available in the middle of 2025. CONCLUSIONS: The OPTION-STEMI is a multicenter, non-inferiority, randomized trial that evaluated the timing of in-hospital CR with the aid of FFR in patients with STEMI and MVD. TRIAL REGISTRATION: URL: https://www. CLINICALTRIALS: gov. Unique identifier: NCT04626882; and URL: https://cris.nih.go.kr. Unique identifier: KCT0004457.

A Superparaelectric State in Relaxor Ferroelectric (Sr,Bi)TiO3-Bi(Mg,Ti)O3-Modified BaTiO3 Ceramics to Achieve High Energy Storage Performance.

Dielectric ceramic capacitors are highly regarded for their rapid charge-discharge, high power density, and cyclability in various advanced applications. However, their relatively low energy storage density has prompted intensive research aiming at developing materials with a higher energy density. To enhance energy storage properties, research has focused on modifying ferroelectric materials to induce relaxor ferroelectricity. The present study aims to induce a superparaelectric (SPE) state in relaxor ferroelectrics near room temperature by altering BaTiO3 ferroelectric ceramics using the (Sr,Bi)TiO3-Bi(Mg0.5Ti0.5)O3 system ((1-x)BT-x(SBT-BMT)). X-ray diffraction and Raman spectroscopy analysis demonstrated a shift in the crystal structure from tetragonal to cubic with an increasing x content. Notably, the compositions (except x = 0.1) satisfied the criteria for the SPE state manifestation near room temperature. The x = 0.2 specimen displayed characteristics at the boundary between the relaxor ferroelectric and SPE phases, while x ≥ 0.3 specimens exhibited increased SPE state fractions. Despite reduced maximum polarization, x ≥ 0.3 specimens showcased impressive energy storage capabilities, attributed to the enhanced SPE state, especially for x = 0.3, with impressive characteristics: a recoverable energy density (Wrec) of ~1.12 J/cm3 and efficiency (η) of ~94% at 170 kV/cm applied field. The good stability after the charge-discharge cycles reinforces the significance of the SPE phase in augmenting energy storage in relaxor ferroelectric materials, suggesting potential applications in high-energy density storage devices.

Preliminary Investigation on Efficacy and Safety of Substance P-Coated Stent for Promoting Re-Endothelialization: A Porcine Coronary Artery Restenosis Model.

BACKGROUND: Current polymer-based drug-eluting stents (DESs) have fundamental issues about inflammation and delayed re-endothelializaton of the vessel wall. Substance-P (SP), which plays an important role in inflammation and endothelial cells, has not yet been applied to coronary stents. Therefore, this study compares poly lactic-co-glycolic acid (PLGA)-based everolimus-eluting stents (PLGA-EESs) versus 2-methacryloyloxyethyl phosphorylcholine (MPC)-based SP-eluting stents (MPC-SPs) in in-vitro and in-vivo models. METHODS: The morphology of the stent surface and peptide/drug release kinetics from stents were evaluated. The in-vitro proliferative effect of SP released from MPC-SP is evaluated using human umbilical vein endothelial cell. Finally, the safety and efficacy of the stent are evaluated after inserting it into a pig's coronary artery. RESULTS: Similar to PLGA-EES, MPC-SP had a uniform surface morphology with very thin coating layer thickness (2.074 µm). MPC-SP showed sustained drug release of SP for over 2 weeks. Endothelial cell proliferation was significantly increased in groups treated with SP (n = 3) compared with the control (n = 3) and those with everolimus (n = 3) (SP: 118.9 ± 7.61% vs. everolimus: 64.3 ± 12.37% vs. the control: 100 ± 6.64%, p < 0.05). In the animal study, the percent stenosis was higher in MPC-SP group (n = 7) compared to PLGA-EES group (n = 7) (MPC-SP: 28.6 ± 10.7% vs. PLGA-EES: 16.7 ± 6.3%, p < 0.05). MPC-SP group showed, however, lower inflammation (MPC-SP: 0.3 ± 0.26 vs. PLGA-EES: 1.2 ± 0.48, p < 0.05) and fibrin deposition (MPC-SP: 1.0 ± 0.73 vs. PLGA-EES: 1.5 ± 0.59, p < 0.05) around the stent strut. MPC-SP showed more increased expression of cluster of differentiation 31, suggesting enhanced re-endothelialization. CONCLUSION: Compared to PLGA-EES, MPC-SP demonstrated more decreased inflammation of the vascular wall and enhanced re-endothelialization and stent coverage. Hence, MPC-SP has the potential therapeutic benefits for the treatment of coronary artery disease by solving limitations of currently available DESs.

Nanocrystalline Composite Layer Realized by Simple Sintering Without Surface Treatment, Reducing Hydrophilicity and Increasing Thermal Conductivity.

The surface treatment for a polymer-ceramic composite is additionally performed in advanced material industries. To prepare the composite without a surface treatment, the simplest way to manufacture an advanced ceramic-particle is devised. The method is the formation of a nanocrystalline composite layer through the simple liquid-phase sintering. Using magnesia (MgO) which shows hydrophilicity, a nanocrystalline surface layer is realized by liquid-phase sintering. The amorphous matrix of nanocrystalline composite layer makes MgO hydrophobic and ensures miscibility with polymers, and the nanocrystalline MgO ensures high thermal conductivity. In addition, the liquid phase removes the open pores and makes the surface morphology smooth MgO with smooth surface (MgO-SM). Thermal interface materials (TIM) prepared with MgO-SM and epoxy show a high thermal conductivity of ≈7.5 W m-1 K-1 , which is significantly higher than 4.5 W m-1 K-1 of pure MgO TIM. Consequently, the formation process of a nanocrystalline surface layer utilizing simple liquid-phase sintering is proposed as a fabrication method for a next-generation ceramic-filler. In addition, it is fundamentally identified that the thermal conductivity of MgO depends on the Mg deficiency, and therefore a poly-crystal MgO-SM (produced at a low temperature) has a higher thermal conductivity than a single-crystal MgO (produced at a high temperature).

Significant Gap Between Guidelines and Practice in the Management of LDL Cholesterol: Insight From the Survey of the Korean Society of Myocardial Infarction.

The Guidelines of the 2019 European Society of Cardiology (ESC) and the 5th Society of Lipid and Atherosclerosis (KSoLA) for the Management of Dyslipidemia advocate a more intensive lipid-lowering strategy. However, there is a lack of evidence regarding the current status of lipid management in Korean patients in real-world practice. The Korean Society of Myocardial Infarction conducted a survey among its members of the Korean Society of Cardiology on the new lipid guidelines. Although most participants were aware of the changes in the ESC and the KSoLA guidelines, more than half of them did not agree with lowering the low-density lipoprotein cholesterol levels to < 55 mg/dL, because its safety and efficacy have not yet been proven in Koreans. A substantial disparity exists between lipid management guidelines and current clinical practices, highlighting the necessity for clinical research that specifically targets East Asians and Koreans to bridge this gap.

Early Left Ventricular Unloading or Conventional Approach After Venoarterial Extracorporeal Membrane Oxygenation: The EARLY-UNLOAD Randomized Clinical Trial.

BACKGROUND: Although venoarterial extracorporeal membrane oxygenation (VA-ECMO) is beneficial for the treatment of profound cardiogenic shock, peripheral VA-ECMO cannulation can increase left ventricular afterload, thus compromising myocardial recovery. We investigated whether early routine left ventricular unloading can reduce 30-day mortality compared with the conventional approach in patients with cardiogenic shock undergoing VA-ECMO. METHODS: This randomized clinical trial involved 116 patients with cardiogenic shock undergoing VA-ECMO from March 2021 to September 2022 at Chonnam National University Hospital, Gwangju, South Korea. The patients were randomly assigned to undergo either early routine left ventricular unloading with transseptal left atrial cannulation within 12 hours after randomization (n=58) or the conventional approach, which permitted rescue transseptal left atrial cannulation in case of an increased left ventricular afterload (n=58). The primary outcome was all-cause mortality within 30 days. RESULTS: All 116 randomized patients (mean age, 67.6±13.5 years; 34 [29.3%] women) completed the trial. At 30 days, all-cause death had occurred in 27 (46.6%) patients in the early group and 26 (44.8%) patients in the conventional group (hazard ratio, 1.02 [95% CI, 0.59-1.74]; P=0.942). Crossover to rescue transseptal left atrial cannulation occurred in 29 patients (50%) in the conventional group according to a clear indication. Time to rescue transseptal cannulation in the conventional group was a median of 21.8 (interquartile range, 12.4-52.2) hours after randomization. There were no significant differences in other secondary outcomes between the 2 groups except for a shorter time to disappearance of pulmonary congestion in the early group (median, 3 [interquartile range, 2-6] versus 5 [interquartile range, 3-7] days; P=0.027). CONCLUSIONS: Among patients with cardiogenic shock undergoing VA-ECMO, early routine left ventricular unloading with transseptal left atrial cannulation did not reduce 30-day mortality compared with the conventional strategy, which permitted rescue transseptal left atrial cannulation. These findings should be cautiously interpreted until the results of multicenter trials using other unloading modalities become available. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT04775472.

Impact of sex difference on clinical outcomes in acute myocardial infarction patients with single-vessel and multi-vessel disease: based on Korea Acute Myocardial Infarction Registry-National Institute of Health.

Background: Several studies have compared clinical outcomes according to sex in patients with acute myocardial infarction (AMI). However, studies evaluating sex differences in clinical outcomes of single-vessel disease (SVD) and multi-vessel disease (MVD) in Korean patients with AMI are lacking. Therefore, this study aimed to analyze sex differences in the clinical characteristics of patients with AMI with SVD and MVD and to evaluate the impact of sex differences on the clinical outcomes in patients with AMI with SVD and MVD. Methods: A total of 11,002 AMI patients from November 2011 to June 2015 in the Korea AMI Registry, National Institute of Health, were enrolled. The current study was retrospective observational study. Patients were divided into SVD (n=5,644) and MVD (n=5,358) groups, and clinical impact of sex difference were analyzed by propensity score matching analysis and Cox proportional hazard regression model. Results: Women were older and had poor baseline clinical characteristics than men. Propensity score-matched analysis of men and women with SVD and MVD revealed that the adjusted 3-year risk of major adverse cardiac event (MACE) (15.0% vs. 9.4%; hazard ratio, 1.86; 95% confidence interval, 1.10-3.13; P=0.020) was higher in women with SVD aged <65 years. However, the incidence and risk of MACE were similar for men and women with MVD, and those with SVD aged ≥65 years. Conclusions: In the present study of Korean patients with AMI, women were older and exhibited a higher prevalence of comorbidities than men. Women with SVD aged <65 years had a significantly higher risk of MACE.

De-escalation from ticagrelor to clopidogrel in patients with acute myocardial infarction: the TALOS-AMI HBR substudy.

BACKGROUND: The benefits of de-escalation of P2Y12 inhibition after percutaneous coronary intervention (PCI) may differ by high bleeding risk (HBR) status. AIMS: We investigated the efficacy and safety of de-escalation from ticagrelor to clopidogrel after PCI by HBR status. METHODS: This is a non-prespecified post hoc analysis of the TicAgrelor Versus CLOpidogrel in Stabilized Patients with Acute Myocardial Infarction (TALOS-AMI) trial. Net adverse clinical events (a composite of cardiovascular death, myocardial infarction, stroke, or Bleeding Academic Research Consortium [BARC] bleeding type 2, 3, or 5) at 1 year post-PCI were compared between the de-escalation (clopidogrel plus aspirin) and the active control (ticagrelor plus aspirin) groups by HBR status, as defined by the modification of the Academic Research Consortium (ARC) criteria. RESULTS: A total of 2,625 patients in the TALOS-AMI trial were analysed. Of these, 589 (22.4%) met the modified ARC-HBR criteria. The de-escalation group had lower primary endpoint rates than the control group in both HBR (hazard ratio [HR] 0.47, 95% confidence interval [CI]: 0.26-0.84) and non-HBR (HR 0.59, 95% CI: 0.41-0.84) patients. There were no differences in treatment effect for the primary endpoint regardless of HBR status (p for interaction=0.904). BARC bleeding type 3 or 5 was less common in the de-escalation than the control group among HBR patients only (HR 0.24, 95% CI: 0.07-0.84). CONCLUSIONS: In stabilised acute myocardial infarction patients, unguided de-escalation from ticagrelor to clopidogrel was associated with a lower rate of net adverse clinical outcomes irrespective of HBR status. The effect of de-escalation of P2Y12 inhibition on reducing haemorrhagic events was greater in patients with HBR.

Culprit lesion plaque characteristics and angiopoietin like 4 in acute coronary syndrome: A virtual histology-intravascular ultrasound analysis.

BACKGROUND: Thin-cap fibroatheroma is a rupture-prone vulnerable plaque that leads to acute coronary syndrome (ACS). However, its underlying mechanisms are not fully understood. Several studies have investigated the clinical association between angiopoietin-like protein 4 (ANGPTL4) and coronary artery disease. Therefore, this study aimed to investigate the correlation of plasma ANGPTL4 in culprit lesion of ACS patients using intravascular ultrasound (IVUS) and virtual-histology IVUS (VH-IVUS). METHODS: Fifty patients newly diagnosed with ACS between March to September 2021 were selected. Blood samples for baseline laboratory tests, including ANGPTL4, were collected before percutaneous coronary intervention (PCI), and all pre- and post-PCI IVUS examinations were performed of the culprit lesions. RESULTS: Linear regression analysis between plasma ANGPTL4 and grayscale IVUS/VH-IVUS parameters revealed that plasma ANGPTL4 was strongly correlated with the necrotic core (NC) of the minimal lumen site (r = -0.666, p = 0.003) and largest NC site (r = -0.687, p < 0.001), and patients with lower plasma ANGPTL4 levels showed a significantly higher proportion of TFCA. CONCLUSION: The present study further demonstrated the protective role of ANGPTL4 in the spectrum of atherosclerotic development in patients with ACS by culprit lesion morphology analysis using IVUS and VH-IVUS.

Early left ventricular unloading after extracorporeal membrane oxygenation: rationale and design of EARLY-UNLOAD trial.

AIMS: The clinical benefits of venoarterial extracorporeal membrane oxygenation (VA-ECMO) for profound cardiogenic shock are well known. However, peripheral VA-ECMO increases the left ventricular afterload, thus compromising myocardial recovery. Recent studies have revealed the benefit of left ventricular unloading using various methods applied at different times. The EARLY-UNLOAD trial compares the clinical outcomes of early left ventricular unloading and conventional approach after VA-ECMO. METHODS AND RESULTS: The EARLY-UNLOAD trial is a single-centre, open-label, randomized trial that recruited 116 patients with cardiogenic shock undergoing VA-ECMO. Patients meeting the inclusion criteria were randomized in a 1:1 ratio to two groups: routine left ventricular unloading via intracardiac echocardiography-guided transseptal left atrial cannulation within 12 h of VA-ECMO initiation or conventional approach that indicates rescue left ventricular unloading if clinical signs of an increased left ventricular afterload are present. The primary endpoint is the cumulative incidence of all-cause death within 30 days, and patients will be followed-up for 12 months. A key secondary endpoint is a composite measure of all-cause death and rescue transseptal left atrial cannulation in the conventional group (suggestive of VA-ECMO treatment failure) within 30 days. The enrolment of patients was finished in September 2022. CONCLUSIONS: The EARLY-UNLOAD trial is the first randomized controlled trial to compare early left ventricular unloading and conventional approach after VA-ECMO using the same unloading modality. The results could impact clinical practice to overcome the haemodynamic issues associated with VA-ECMO.

Incidence, Relevant Patient Factors, and Clinical Outcomes of the Misdiagnosis of ST-Segment-Elevation Myocardial Infarction: Results From the Korea Acute Myocardial Infarction Registry.

Background Data on the incidence, relevant patient factors, and clinical outcomes of the misdiagnosis of ST-segment-elevation myocardial infarction (STEMI) in the modern era of percutaneous coronary intervention are limited. Methods and Results Data from KAMIR (Korea Acute Myocardial Infarction Registry) between November 2011 and June 2020 were analyzed. Out of 28 470 patients with acute myocardial infarction, 11 796 were eventually diagnosed with STEMI following a coronary angiogram. They were classified into 2 groups: patients with an initial working diagnosis of STEMI before starting the initial treatment and patients with an initial working diagnosis of non-STEMI (misdiagnosed group). Out of 11 796 patients with a final diagnosis of STEMI, 165 (1.4%) were misdiagnosed. The door-to-angiography time in the misdiagnosed group was 5 times longer than that in the timely diagnosed group (median 220 [interquartile range {IQR}, 66-1177] versus 43 [IQR, 31-58] minutes; P<0.001). In a multivariable adjustments model, patients with a history of heart failure, atypical chest pain, anemia, or symptom-to-door time ≥4 hours had significantly higher odds, whereas those with systolic blood pressure <100 mm Hg or anterior ST elevation or left bundle-branch block on ECG had lower odds of STEMI misdiagnosis. For patients with culprit lesions in the left anterior descending artery (n=5838), the adjusted 1-year mortality risk for STEMI misdiagnosis was 1.84 (95% CI, 1.01-3.38). Conclusions Misdiagnosis of STEMI is not rare and is associated with a significant delay in coronary angiography, resulting in increased 1-year mortality for patients with culprit lesions in the left anterior descending artery.

Renin-Angiotensin-Aldosterone System Inhibitions and Cardiovascular Outcomes in Acute Myocardial Infarction With Renal Impairment.

OBJECTIVE: To compare the clinical outcomes of patients with acute myocardial infarction with renal impairment (AMI-RI) treated with either angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) in real-world clinical settings. PATIENTS AND METHODS: A total of 4790 consecutive patients with AMI-RI between November 1, 2011, and December 31, 2015, were subdivided into ACEI (n=2845) and ARB (n=1945) treatment groups. The primary end points were major adverse cardiac and cerebrovascular events, including all-cause mortality, nonfatal myocardial infarction, any revascularization, cerebrovascular accident, rehospitalization, and stent thrombosis. Propensity score matching (PSM) was used to adjust for group differences. RESULTS: The ARB group had a significantly higher incidence of major adverse cardiac and cerebrovascular events (at 3-year follow-up) than the ACEI group according to the unadjusted analysis (3-year hazard ratio [HR], 1.60; 95% CI, 1.43 to 1.78) and the PSM-adjusted analysis (3-year HR, 1.34; 95% CI, 1.15 to 1.56). However, any revascularization (3-year HR, 1.21; 95% CI, 0.95 to 1.54) and rehospitalization (3-year HR, 1.21; 95% CI, 0.88 to 1.67) were not significantly different between groups in the PSM-adjusted analysis. Compared with the ARB group, the ACEI group had lower rates of all-cause mortality at estimated glomerular filtration rates of at least 15 or less than 90 mL/min/1.73 m2 in the unadjusted data and at least 60 or less than 90 mL/min/1.73 m2 in the PSM-adjusted analysis. CONCLUSION: Treatment with ACEIs seemed to be more beneficial than treatment with ARBs for patients with AMI-RI; further prospective studies are required to confirm these results.

Baseline Lipoprotein(a) Levels and Long-Term Cardiovascular Outcomes After Acute Myocardial Infarction.

BACKGROUND: Lipoprotein(a) is a known independent risk factor for atherosclerotic cardiovascular disease. However, the prognostic impact of the baseline lipoprotein(a) levels on long-term clinical outcomes among patients with acute myocardial infarction remain unclear. METHODS: We analyzed 1,908 patients with acute myocardial infarction from November 2011 to October 2015 from a single center in Korea. They were divided into 3 groups according to their baseline lipoprotein(a) levels: groups I (< 30 mg/dL, n = 1,388), II (30-49 mg/dL, n = 263), and III (≥50 mg/dL, n = 257). Three-point major adverse cardiovascular events (a composite of nonfatal myocardial infarction, nonfatal stroke, and cardiac death) at 3 years were compared among the 3 groups. RESULTS: The patients were followed for 1094.0 (interquartile range, 1,033.8-1,095.0) days, during which a total of 326 (17.1%) three-point major adverse cardiovascular events occurred. Group III had higher rates of three-point major adverse cardiovascular events compared with Group I (23.0% vs. 15.7%; log-rank P = 0.009). In the subgroup analysis, group III had higher rates of three-point major adverse cardiovascular events compared with group I in patients with non-ST-segment elevation myocardial infarction (27.0% vs. 17.1%; log-rank P = 0.006), but not in patients with ST-segment elevation myocardial infarction (14.4% vs. 13.3%; log-rank P = 0.597). However, in multivariable Cox time-to-event models, baseline lipoprotein(a) levels were not associated with an increased incidence of three-point major adverse cardiovascular events, regardless of the type of acute myocardial infarction. Sensitivity analyses in diverse subgroups showed similar findings to those of the main analysis. CONCLUSION: Baseline lipoprotein(a) levels in Korean patients with acute myocardial infarction were not independently associated with increased major adverse cardiovascular events at 3 years.

Preclinical Evaluation of an Everolimus-Eluting Bioresorbable Vascular Scaffold Via a Long-Term Rabbit Iliac Artery Model.

BACKGROUND: Biodegradable poly (l-lactic acid) (PLLA), a bio safe polymer with a large elastic modulus, is widely used in biodegradable medical devices. However, because of its poor mechanical properties, a PLLA strut must be made twice as thick as a metal strut for adequate blood vessel support. Therefore, the mechanical properties of a drug-eluting metal-based stents (MBS) and a bioresorbable vascular scaffolds (BVS) were evaluated and their safety and efficacy were examined via a long-term rabbit iliac artery model. METHODS: The surface morphologies of the MBSs and BVSs were investigated via optical and scanning electron microscopy. An everolimus-eluting (EE) BVS or an EE-MBS was implanted into rabbit iliac arteries at a 1.1:1 stent-to-artery ratio. Twelve months afterward, stented iliac arteries from each group were analyzed via X-ray angiography, optical coherence tomography (OCT), and histopathologic evaluation. RESULTS: Surface morphology analysis of the EE coating on the MBS confirmed that it was uniform and very thin (4.7 µm). Comparison of the mechanical properties of the EE-MBS and EE-BVS showed that the latter outperformed the former in all aspects (radial force (2.75 vs. 0.162 N/mm), foreshortening (0.24% vs. 1.9%), flexibility (0.52 vs. 0.19 N), and recoil (3.2% vs. 6.3%). At all time points, the percent area restenosis was increased in the EE-BVS group compared to the EE-MBS group. The OCT and histopathological analyses indicate no significant changes in strut thickness. CONCLUSION: BVSs with thinner struts and shorter resorption times should be developed. A comparable long-term safety/efficacy evaluation after complete absorption of BVSs should be conducted.

A novel polymer-free everolimus-eluting stent with a nitrogen-doped titanium dioxide film inhibits restenosis and thrombosis in a swine coronary model.

BACKGROUND: Short-term outcomes regarding the safety and efficacy of a polymer-free everolimus-eluting stent (EES) with a nitrogen-doped titanium dioxide (N-TiO2) film in a swine coronary model have been reported. However, the long-term results of the use of this type of stent have not yet been evaluated or compared to those of other polymer-free coronary stents. Therefore, this study aimed to determine the mid- to long-term safety and efficacy of a polymer-free EES with an N-TiO2 film in a swine coronary model. METHODS: Polymer-free EES with N-TiO2 films (n = 30) and polymer-free sirolimus-eluting stents (SES; n = 30) were implanted in 30 pigs. Quantitative coronary analysis and optical coherence tomography were conducted immediately and at 1 (quantitative coronary analysis only), 3, and 6 months after stenting. Histopathologic examinations were performed at 1, 3, and 6 months after stenting. RESULTS: The polymer-free EES group had a lower percentage of neointimal growth than the polymer-free SES group at 3 months (22.5% ± 11.4% vs. 32.1% ± 12.3%; p < 0.001). The polymer-free EES group had a lower fibrin score than the polymer-free SES group at 1 month (1.9 ± 0.45 vs. 2.5 ± 0.54; p = 0.001). The re-endothelialization rates were similar between groups. The polymer-free EES group had a lower percentage of the area of stenosis than the polymer-free SES group throughout the follow-up period. CONCLUSIONS: The novel polymer-free EES with an N-TiO2 film has superior safety and efficacy than the polymer-free SES at the 6-month follow-up in a swine model.

Autonomous Resonance-Tuning Mechanism for Environmental Adaptive Energy Harvesting.

An innovative autonomous resonance-tuning (ART) energy harvester is reported that utilizes adaptive clamping systems driven by intrinsic mechanical mechanisms without outsourcing additional energy. The adaptive clamping system modulates the natural frequency of the harvester's main beam (MB) by adjusting the clamping position of the MB. The pulling force induced by the resonance vibration of the tuning beam (TB) provides the driving force for operating the adaptive clamp. The ART mechanism is possible by matching the natural frequencies of the TB and clamped MB. Detailed evaluations are conducted on the optimization of the adaptive clamp tolerance and TB design to increase the pulling force. The energy harvester exhibits an ultrawide resonance bandwidth of over 30 Hz in the commonly accessible low vibration frequency range (<100 Hz) owing to the ART function. The practical feasibility is demonstrated by evaluating the ART performance under both frequency and acceleration-variant conditions and powering a location tracking sensor.

Long-term clinical outcomes in patients with acute myocardial infarction complicated by cardiogenic shock according to the application and initiation time of extracorporeal membrane oxygenation in South Korea.

BACKGROUND: Limited data are available regarding the proper application time and long-term outcomes of extracorporeal membrane oxygenation (ECMO) in patients with cardiogenic shock. This cohort study appraised the clinical outcomes according to ECMO application without or before cardiopulmonary resuscitation (CPR) in patients with acute myocardial infarction (AMI) combined with cardiogenic shock. METHODS: Between 2011 and 2015, a total of 13,104 patients with AMI were enrolled in a nationwide AMI registry. Eligible patients with cardiogenic shock, who underwent percutaneous coronary intervention, with a 3-year clinical follow-up, were analyzed. The 949 included patients were divided into two groups: no ECMO (n = 845) and ECMO application (n = 104). The ECMO group was further divided into ECMO without or before CPR (n = 11) and ECMO after CPR (n = 93). RESULTS: Significant differences were noted in major adverse cardiac events (MACEs) between the no ECMO and ECMO application groups during the 3-year follow-up (41.5% vs. 80.8%; p < 0.001). However, the ECMO without or before CPR group showed similar outcomes to the no ECMO group in 3-year MACEs (63.6% vs. 41.5%; p = 0.055). MACEs during 3 years of follow-up were significantly lower in the ECMO without or before CPR group than in the ECMO after CPR group (63.6% vs. 82.8%; p = 0.005). CONCLUSIONS: A significantly lower risk of major cardiac events in ECMO without or before CPR suggests that early application of ECMO can be a reasonable strategy to improve outcomes in patients with AMI complicated by cardiogenic shock.

Comparison of long-term clinical outcomes among zotarolimus-, everolimus-, and biolimus-eluting stents in acute myocardial infarction patients with renal impairment.

BACKGROUND: It is important to determine the best drug-eluting stent (DES) for acute myocardial infarction (AMI) in patients with renal impairment. In this studythe outcomes of everolimus-eluting stents (EESs), zotarolimus-eluting stents (ZESs) and biolimus-eluting stents (BESs) were evaluated. METHODS: From the Korea Acute Myocardial Infarction-National Institutes of Health registry, a total of 1,470 AMI patients with renal impairment undergoing percutaneous coronary intervention (PCI) were enrolled (816 with EES, 345 with ZES, and 309 with BES). Renal impairment was defined as creatinine clearance < 60 mL/min/1.73 m² estimated by the Cockcroft-Gault method. Major adverse cardiac and cerebrovascular events were determined as the composite of all-cause death, non-fatal myocardial infarction (MI), cerebrovascular accident, any revascularization, rehospitalization and stent thrombosis. All clinical outcomes were analyzed. RESULTS: The baseline characteristics of the patients revealed no significant difference between the three groups, except for Killip classification > 2, beta-blockers, lesion type, vascular approach, staged PCI, left main coronary artery (LMCA) complex lesions, LMCA PCI, and the number and length of implanted stents. In the Kaplan-Meier analysis, similar clinical outcomes were derived from the unadjusted data between the three DES groups. However, after the inverse probability of treatment weighting, a statistically significant difference was found in non-fatal MI, which implied a higher incidence of non-fatal MI in the ZES group than in the other two DES groups. CONCLUSIONS: In AMI patients with renal impairment, there was no significant difference between the three stent groups in terms of long-term clinical outcomes, except for non-fatal MI.