Ultrasound-Driven enhancement of Pt/C catalyst stability in oxygen reduction reaction.

Polymer electrolyte membrane fuel cells (PEMFCs) have reached the commercialization phase, representing a promising approach to curbing carbon emissions. However, greater durability of PEMFCs is of paramount importance to ensure their long-term viability and effectiveness, and catalyst development has become a focal point of research. Pt nanoparticles supported on carbon materials (Pt/C) are the primary catalysts used in PEMFCs. Accomplishing both a high dispersion of uniform metal particles on the carbon support and robust adhesion between the metal particles and the carbon support is imperative for superior stability, and will thereby, advance the practical applications of PEMFCs in sustainable energy solutions. Ultrasound-assisted polyol synthesis (UPS) has emerged as a suitable method for synthesizing catalysts with a well-defined metal-support structure, characterized by the high dispersion and uniformity of metal nanoparticles. In this study, we focused on the effect of ultrasound on the synthesis of Pt/C via UPS and the resulting enhanced stability of Pt/C catalysts. Therefore, we compared Pt/C synthesized using a conventional polyol synthesis (Pt/C_P) and Pt/C synthesized via UPS (Pt/C_U) under similar synthesis conditions. The two catalysts had a similar Pt content and the average particle size of the Pt nanoparticles was similar; however, the uniformity and dispersion of Pt nanoparticles in Pt/C_U were better than those of Pt/C_P. Moreover, ex/in-situ analyses performed in a high-temperature environment, in which nanoparticles tend to agglomerate, have revealed that Pt/C_U exhibited a notable improvement in the adhesion of Pt particles to the carbon support compared with that of Pt/C_P. The enhanced adhesion is crucial for maintaining the stability of the catalyst, ultimately contributing to a better durability in practical applications. Ultrasound was applied to the carbon support without the Pt precursor under the same UPS conditions used to synthesize Pt/C_U to identify the reason for the increased adhesion between the Pt particles and the carbon support in Pt/C_U, and we discovered that oxygen functional groups (C-O, C = O, and O-C = O) for anchoring site of Pt particles were generated in the carbon support. Pt/C_U displayed an increase in stability in an electrochemical accelerated stress test (AST) in an acidic electrolyte. The physical and chemical effects of ultrasound on the synthesis of Pt/C via UPS were identified, and we concluded that UPS is suitable for synthesizing carbon supported electrocatalysts with high stability.

Treat-to-target versus high-intensity statin treatment in patients with or without diabetes mellitus: a pre-specified analysis from the LODESTAR trial.

Background: The impact of titrated versus fixed intensity statin therapy in patients with coronary artery disease (CAD) and diabetes mellitus (DM) remains to be elucidated. Methods: This was a pre-specified analysis of patients with and without DM from the LODESTAR trial. Patients with CAD were randomly assigned to receive either a treat-to-target strategy with a target LDL-C level of 50-70 mg/dL or a high-intensity statin treatment. Primary outcome was the 3-year composite of all-cause death, myocardial infarction, stroke, or coronary revascularization. Secondary outcomes were safety endpoints. This trial is registered with ClinicalTrials.gov, NCT02579499. Findings: Between September 9, 2016 and November 27, 2019, 4400 patients with CAD were enrolled in the LODESTAR trial. The median age was 65 years (interquartile range, 59-73 years), 3172 (72%) were male, and 1468 (33%) had DM at baseline. There was no significant difference in the occurrence of the primary outcome between the treat-to-target group and high-intensity statin group among patients with DM (10.5% versus 11.1%, hazard ratio [HR] 0.94, 95% confidence interval [CI] 0.69-1.29, p = 0.70) and those without DM (6.9% versus 7.5%, HR 0.93, 95% CI 0.71-1.21, p = 0.58). Among patients without DM, there was a trend towards a lower risk of new-onset DM in the treat-to-target group (8.4% versus 10.4% in the high-intensity statin group, HR 0.79, 95% CI 0.62-1.01; p = 0.06). Interpretation: In patients with CAD, a treat-to-target LDL-C strategy of 50-70 mg/dL as the goal was comparable to high-intensity statin therapy in terms of 3-year clinical efficacy and safety outcomes regardless of the presence of DM. Funding: Sam Jin Pharmaceutical, Seoul, Korea and Chong Kun Dang Pharmaceutical, Seoul, Korea.

Impact of Atrial Fibrillation on Patients Undergoing Transcatheter Aortic Valve Implantation (TAVI): The K-TAVI Registry.

PURPOSE: The incidence and prognostic implications of atrial fibrillation (AF) in patients with severe aortic stenosis (AS) undergoing transcatheter aortic valve implantation (TAVI) are controversial, especially for Korean patients. Furthermore, the pattern of antithrombotic therapy for these patients is unknown. The present study sought to identify the impact of AF on Korean patients undergoing TAVI and demonstrate the status of antithrombotic therapy for these patients. MATERIALS AND METHODS: A total of 660 patients who underwent TAVI for severe AS were recruited from the nationwide K-TAVI registry in Korea. The enrolled patients were stratified into sinus rhythm (SR) and AF groups. The primary endpoint was all-cause death at 1-year. RESULTS: AF was recorded in 135 patients [pre-existing AF 108 (16.4%) and new-onset AF 27 (4.1%)]. The rate of all-cause death at 1 year was significantly higher in patients with AF than in those with SR [16.2% vs. 6.4%, adjusted hazard ratio (HR): 2.207, 95% confidence interval (CI): 1.182-4.120, p=0.013], regardless of the onset timing of AF. The rate of new pacemaker insertion at 1 year was also significantly higher in patients with AF than in those with SR (14.0% vs. 5.5%, adjusted HR: 3.137, 95%CI: 1.621-6.071, p=0.001). Among AF patients, substantial number of patients received the combination of multiple antithrombotic agents (77.8%), and the most common combination was that of aspirin and clopidogrel (38.1%). CONCLUSION: AF was an independent predictor of 1-year mortality and new pacemaker insertion in Korean patients undergoing TAVI.

Treat-to-Target or High-Intensity Statin in Patients With Coronary Artery Disease: A Randomized Clinical Trial.

Importance: In patients with coronary artery disease, some guidelines recommend initial statin treatment with high-intensity statins to achieve at least a 50% reduction in low-density lipoprotein cholesterol (LDL-C). An alternative approach is to begin with moderate-intensity statins and titrate to a specific LDL-C goal. These alternatives have not been compared head-to-head in a clinical trial involving patients with known coronary artery disease. Objective: To assess whether a treat-to-target strategy is noninferior to a strategy of high-intensity statins for long-term clinical outcomes in patients with coronary artery disease. Design, Setting, and Participants: A randomized, multicenter, noninferiority trial in patients with a coronary disease diagnosis treated at 12 centers in South Korea (enrollment: September 9, 2016, through November 27, 2019; final follow-up: October 26, 2022). Interventions: Patients were randomly assigned to receive either the LDL-C target strategy, with an LDL-C level between 50 and 70 mg/dL as the target, or high-intensity statin treatment, which consisted of rosuvastatin, 20 mg, or atorvastatin, 40 mg. Main Outcomes and Measures: Primary end point was a 3-year composite of death, myocardial infarction, stroke, or coronary revascularization with a noninferiority margin of 3.0 percentage points. Results: Among 4400 patients, 4341 patients (98.7%) completed the trial (mean [SD] age, 65.1 [9.9] years; 1228 females [27.9%]). In the treat-to-target group (n = 2200), which had 6449 person-years of follow-up, moderate-intensity and high-intensity dosing were used in 43% and 54%, respectively. The mean (SD) LDL-C level for 3 years was 69.1 (17.8) mg/dL in the treat-to-target group and 68.4 (20.1) mg/dL in the high-intensity statin group (n = 2200) (P = .21, compared with the treat-to-target group). The primary end point occurred in 177 patients (8.1%) in the treat-to-target group and 190 patients (8.7%) in the high-intensity statin group (absolute difference, -0.6 percentage points [upper boundary of the 1-sided 97.5% CI, 1.1 percentage points]; P < .001 for noninferiority). Conclusions and Relevance: Among patients with coronary artery disease, a treat-to-target LDL-C strategy of 50 to 70 mg/dL as the goal was noninferior to a high-intensity statin therapy for the 3-year composite of death, myocardial infarction, stroke, or coronary revascularization. These findings provide additional evidence supporting the suitability of a treat-to-target strategy that may allow a tailored approach with consideration for individual variability in drug response to statin therapy. Trial Registration: ClinicalTrials.gov Identifier: NCT02579499.

Nitrates vs. Other Types of Vasodilators and Clinical Outcomes in Patients with Vasospastic Angina: A Propensity Score-Matched Analysis.

Although vasodilators are widely used in patients with vasospastic angina (VA), few studies have compared the long-term prognostic effects of different types of vasodilators. We investigated the long-term effects of vasodilators on clinical outcomes in VA patients according to the type of vasodilator used. Study data were obtained from a prospective multicenter registry that included patients who had symptoms suggestive of VA. Patients were classified into two groups according to use of nitrates (n = 239) or other vasodilators (n = 809) at discharge. The composite clinical events rate, including acute coronary syndrome (ACS), cardiac death, new-onset arrhythmia (including ventricular tachycardia and ventricular fibrillation), and atrioventricular block, was significantly higher in the nitrates group (5.3% vs. 2.2%, p = 0.026) during one year of follow-up. Specifically, the prevalence of ACS was significantly more frequent in the nitrates group (4.3% vs. 1.5%, p = 0.024). After propensity score matching, the adverse effects of nitrates remained. In addition, the use of nitrates at discharge was independently associated with a 2.69-fold increased risk of ACS in VA patients. In conclusion, using nitrates as a vasodilator at discharge can increase the adverse clinical outcomes in VA patients at one year of follow-up. Clinicians need to be aware of the prognostic value and consider prescribing other vasodilators.

Clinical Results of Drug-Coated Balloon Treatment in a Large-Scale Multicenter Korean Registry Study.

BACKGROUND AND OBJECTIVES: The aim of this study was to demonstrate the efficacy and safety of treatment with drug-coated balloon (DCB) in a large real-world population. METHODS: Patients treated with DCBs were included in a multicenter observational registry that enrolled patients from 18 hospitals in Korea between January 2009 and December 2017. The primary outcome was target lesion failure (TLF) defined as a composite of cardiovascular death, target vessel myocardial infarction, and clinically indicated target lesion revascularization at 12 months. RESULTS: The study included 2,509 patients with 2,666 DCB-treated coronary artery lesions (1,688 [63.3%] with in-stent restenosis [ISR] lesions vs. 978 [36.7%] with de novo lesions). The mean age with standard deviation was 65.7±11.3 years; 65.7% of the patients were men. At 12 months, the primary outcome, TLF, occurred in 179 (6.7%), 151 (8.9%), 28 (2.9%) patients among the total, ISR, and de novo lesion populations, respectively. A history of hypertension, diabetes, acute coronary syndrome, previous coronary artery bypass graft, reduced left ventricular ejection fraction, B2C lesion and ISR lesion were independent predictors of 12 months TLF in the overall study population. CONCLUSIONS: This large multicenter DCB registry study revealed the favorable clinical outcome of DCB treatment in real-world practice in patient with ISR lesion as well as small de novo coronary lesion.

Prognostic Impact of Chronic Vasodilator Therapy in Patients With Vasospastic Angina.

Background Chronic vasodilator therapy with long-acting nitrate is frequently used to treat vasospastic angina. However, the clinical benefits of this approach are controversial. We investigated the prognostic impact of vasodilator therapy in patients with vasospastic angina from the multicenter, prospective VA-KOREA (Vasospastic Angina in KOREA) registry. Methods and Results We analyzed data from 1895 patients with positive intracoronary ergonovine provocation test results. The patients were divided into 4 groups: no vasodilator (n=359), nonnitrate vasodilator (n=1187), conventional nitrate (n=209), and a combination of conventional nitrate and other vasodilators (n=140). The primary end point was a composite of cardiac death, acute coronary syndrome, and new-onset arrhythmia at 2 years. Secondary end points were the individual components of the primary end point, all-cause death, and rehospitalization due to recurrent angina. The groups did not differ in terms of the risk of the primary end point. However, the acute coronary syndrome risk was significantly higher in the conventional nitrate (hazard ratio [HR], 2.49; 95% CI, 1.01-6.14; P=0.047) and combination groups (HR, 3.34; 95% CI, 1.15-9.75, P=0.027) compared with the no-vasodilator group, as assessed using the inverse probability of treatment weights. Subgroup analyses revealed prominent adverse effects of nitrate in patients with an intermediate positive ergonovine provocation test result and in those with low Japanese Coronary Spasm Association scores. Conclusions Long-acting nitrate-based chronic vasodilator therapy was associated with an increased 2-year risk of acute coronary syndrome in patients with vasospastic angina, especially in low-risk patients.

Effect of Significant Coronary Artery Stenosis on Prognosis in Patients with Vasospastic Angina: A Propensity Score-Matched Analysis.

Vasospastic angina (VA) is a functional disease of the coronary artery and occurs in an angiographically normal coronary artery. However, it may also occur with coronary artery stenosis. We investigated the effect of coronary artery stenosis on clinical outcomes in VA patients. Study data were obtained from a prospective multicenter registry that included patients who had symptoms of VA. Patients were classified into two groups according to presence of significant coronary artery stenosis. Among 1920 patients with VA, 189 patients were classified in the "significant stenosis" group. The one-year composite clinical events rate was significantly higher in the significant stenosis group than in the "no significant stenosis" group (5.8% vs. 1.4%, respectively; p < 0.001). Additionally, the prevalence of ACS was significantly greater in the "significant stenosis" group (4.8% vs. 0.9%, respectively; p < 0.001). After propensity score matching, the adverse effects of significant stenosis remained. In addition, significant stenosis was independently associated with a 6.67-fold increased risk of ACS in VA patients. In conclusion, significant coronary artery stenosis can increase the adverse clinical outcomes in VA patients at long-term follow-up. Clinicians should manage traditional risk factors associated with atherosclerosis and control vasospasm as well as reduce the burden of atherosclerosis.

Enhancement of Catalytic Activity and Durability of Pt Nanoparticle through Strong Chemical Interaction with Electrically Conductive Support of Magnéli Phase Titanium Oxide.

In this study, we address the catalytic performance of variously sized Pt nanoparticles (NPs) (from 1.7 to 2.9 nm) supported on magnéli phase titanium oxide (MPTO, Ti4O7) along with commercial solid type carbon (VXC-72R) for oxygen reduction reaction (ORR). Key idea is to utilize a robust and electrically conductive MPTO as a support material so that we employed it to improve the catalytic activity and durability through the strong metal-support interaction (SMSI). Furthermore, we increase the specific surface area of MPTO up to 61.6 m2 g-1 to enhance the SMSI effect between Pt NP and MPTO. After the deposition of a range of Pt NPs on the support materials, we investigate the ORR activity and durability using a rotating disk electrode (RDE) technique in acid media. As a result of accelerated stress test (AST) for 30k cycles, regardless of the Pt particle size, we confirmed that Pt/MPTO samples show a lower electrochemical surface area (ECSA) loss (<20%) than that of Pt/C (~40%). That is explained by the increased dissolution potential and binding energy of Pt on MPTO against to carbon, which is supported by the density functional theory (DFT) calculations. Based on these results, we found that conductive metal oxides could be an alternative as a support material for the long-term fuel cell operation.

Smoking may be more harmful to vasospastic angina patients who take antiplatelet agents due to the interaction: Results of Korean prospective multi-center cohort.

BACKGROUND: The interaction between smoking and the use of antiplatelet agents on the prognosis of vasospastic angina (VA) is rarely investigated. METHODS: VA-Korea is a nation-wide multi-center registry with prospective design (n = 1812). The primary endpoint was the composite occurrence of acute coronary syndrome (ACS), symptomatic arrhythmia, and cardiac death. Log-rank test and Cox proportional hazard model were for statistical analysis. Also, we conducted interaction analysis in both additive and multiplicative scales between smoking and antiplatelet agents among VA patients. For additive scale interaction, relative excess risk due to interaction (RERI) was calculated and for multiplicative scale interaction, the ratio of hazard ratio (HR) was calculated. All statistical analysis conducted by Stata Ver 16.1. RESULTS: Patients who were smoking and using antiplatelet agents had the highest incidence rate in the primary composite outcome. The incidence rate was 3.49 per 1,000 person-month (95% CI: 2.30-5.30, log-rank test for primary outcome p = 0.017) and HR of smoking and using antiplatelet agents was 1.66 (95%CI: 0.98-2.81). The adjusted RERI of smoking and using antiplatelet agents was 1.10 (p = 0.009), and the adjusted ratio of HR of smoking and using antiplatelet agents was 3.32 (p = 0.019). The current study observed the interaction between smoking and using antiplatelet agents in both additive and multiplicative scales. CONCLUSIONS: Smoking was associated with higher rates of unfavorable clinical outcomes among VA patients taking antiplatelet agents. This suggested that VA patients, especially those using antiplatelet agents should quit smoking.

Long-Term Left Atrial Function after Device Closure and Surgical Closure in Adult Patients with Atrial Septal Defect.

BACKGROUND: Studies comparing left atrial (LA) function after surgical closure or percutaneous closure in patients with an atrial septal defect (ASD) are lacking. METHODS: Between 1 and 3 years after ASD treatment, we retrospectively analyzed the medical records and transthoracic echocardiographic images of patients who had been diagnosed with an ASD after 20 years of age and who had undergone surgical closure (ASD-S) or percutaneous device closure (ASD-D). We measured LA peak systolic, early diastolic, and late diastolic strain values using 2-dimensional (2D) speckle tracking echocardiography (STE) and calculated reservoir, conduit, and contraction strain. RESULTS: The reservoir strain value of the ASD-D groups was 25.2% ± 7.4%, which was lower compared to the control group (33.6% ± 5.5%) (p = 0.004). The LA conduit strain and the LA contraction values of the ASD-D group were also lower compared to the control group (-13.8% ± 5.8% vs. -20.4% ± 4.7%, p = 0.034; -11.3% ± 4.2% vs. -13.2% ± 2.5%, p = 0.037, respectively). The reservoir, conduit, and contraction strains of the ASD-S group were 27.8% ± 8.8%, -15.3% ± 6.4%, and -12.5% ± 5.8%, respectively, and were not different from those of the control group or the ASD-D group. CONCLUSIONS: The 2D STE is a suitable method for evaluating LA function after ASD closure. Our results demonstrate that 1 year after device closure, the LA reservoir, conduit and contraction function were reduced in ASD-D group compared to healthy controls, while there was no difference between the ASD-S and ASD-D groups.

Quaternary Ammonium-Bearing Perfluorinated Polymers for Anion Exchange Membrane Applications.

Perfluorinated polymers are widely used in polymer electrolyte membranes because of their excellent ion conductivity, which are attributed to the well-defined morphologies resulting from their extremely hydrophobic main-chains and flexible hydrophilic side-chains. Perfluorinated polymers containing quaternary ammonium groups were prepared from Nafion- and Aquivion-based sulfonyl fluoride precursors by the Menshutkin reaction to give anion exchange membranes. Perfluorinated polymers tend to exhibit poor solubility in organic solvents; however, clear polymer dispersions and transparent membranes were successfully prepared using N-methyl-2-pyrrolidone at high temperatures and pressures. Both perfluorinated polymer-based membranes exhibited distinct hydrophilic-hydrophobic phase-separated morphologies, resulting in high ion conductivity despite their low ion exchange capacities and limited water uptake properties. Moreover, it was found that the capacitive deionization performances and stabilities of the perfluorinated polymer membranes were superior to those of the commercial Fumatech membrane.

Community-Based Pre-Hospital Electrocardiogram Transmission Program for Reducing Systemic Time Delay in Acute ST-Segment Elevation Myocardial Infarction.

BACKGROUND AND OBJECTIVES: In acute ST-segment elevation myocardial infarction (STEMI), on-site transmission of electrocardiogram (ECG) has been shown to reduce systemic time delay to reperfusion and improve outcomes. However, it has not been adopted in community-based emergency transport system in Korea. METHODS: Busan Regional Cardio-cerebrovascular Center and Busan Metropolitan City Fire and Safety Headquarters (BMFSH) jointly developed and conducted a pre-hospital ECG transmission program. Seven tertiary hospitals and 22 safety stations of BMFSH participated. Systemic time delay to reperfusion of STEMI patients in the program was compared with that of 95 patients transported by 119 emergency medical system (EMS) before the program was implemented. RESULTS: During the study period, 289 ECG transmissions were made by 119 EMS personnel, executed within 5 minutes in 88.1% of cases. Of these, 42 ECGs were interpreted as ST-segment elevation. Final diagnosis of STEMI was made in 20 patients who underwent primary percutaneous coronary intervention. With the program, systemic time delay to reperfusion was significantly reduced (median [interquartile range; IQR], 76.0 [62.2-98.7] vs. 90.0 [75.0-112.0], p<0.01). Significant reduction of door-to-balloon time was also observed (median [IQR], 45.0 [34.0-69.5] vs. 58.0 [51.0-68.0], p=0.03). The proportion of patients with systemic time delay shorter than 90 minutes rose (51.6% vs. 75.0%, p=0.08) with pre-hospital ECG transmission. CONCLUSIONS: We developed and implemented a community-based pre-hospital ECG transmission program for expeditious triage of STEMI patients. Significant reductions of systemic time delay and door-to-balloon time were observed. The expanded use of pre-hospital ECG transmission should be encouraged to realize the full potential of this program.

Effect of Operator Volume on In-Hospital Outcomes Following Primary Percutaneous Coronary Intervention for ST-Elevation Myocardial Infarction: Based on the 2014 Cohort of Korean Percutaneous Coronary Intervention (K-PCI) Registry.

BACKGROUND AND OBJECTIVES: The relationship between operator volume and outcomes of percutaneous coronary intervention (PCI) in patients with ST-elevation myocardial infarction (STEMI) has not been fully investigated. We aimed to investigate the relationship between operator PCI volume and in-hospital outcomes after primary PCI for STEMI. METHODS: Among the total of 44,967 consecutive cases of PCI enrolled in the Korean nationwide, retrospective registry (K-PCI registry), 8,282 patients treated with PCI for STEMI by 373 operators were analyzed. PCI volumes above the 75th percentile (>30 cases/year), between the 75th and 25th percentile (10-30 cases/year), and below the 25th percentile (<10 cases/year) were defined as high, moderate, and low-volume operators, respectively. In-hospital outcomes including mortality, non-fatal myocardial infarction (MI), stent thrombosis, stroke, and urgent repeat PCI were analyzed. RESULTS: The average number of primary PCI cases performed by 373 operators was 22.2 in a year. In-hospital mortality after PCI for STEMI was 571 cases (6.9%). In-hospital outcomes by operator volume showed no significant differences in the death rate, cardiac death, non-fatal MI, and stent thrombosis. However, the rate of urgent repeat PCI tended to be lower in the high-volume operator (0.6%) than in the moderate-(0.7%)/low-(1.5%) volume operator groups (p=0.095). The adjusted odds ratios for adverse in-hospital outcomes were similar in the 3 groups. Multivariate analysis also showed that operator volume was not a predictor for adverse in-hospital outcomes. CONCLUSIONS: In-hospital outcomes after primary PCI for STEMI were not associated with operator volume in the K-PCI registry.

Clopidogrel plus Aspirin Use is Associated with Worse Long-Term Outcomes, but Aspirin Use Alone is Safe in Patients with Vasospastic Angina: Results from the VA-Korea Registry, A Prospective Multi-Center Cohort.

Anti-platelet agents are commonly used in vasospastic angina (VA) patients with comorbidity like coronary artery disease. However, long-term clinical outcomes in the use of aspirin, clopidogrel or the two agents together have rarely been investigated in VA patients. In a prospective study, we enrolled 2960 patients who received coronary angiography and ergonovine provocation test at 11 university hospitals in Korea. Among them, 1838 patients were diagnosed either with definite (n = 680) or intermediate (n = 1212) VA, using the criteria of chest pain, ECG changes and ergonovine provocation test results. They were analyzed according to their use of aspirin, clopidogrel or both, or no anti-platelet agent at all. The primary outcome was time to composite events of death from any cause, acute coronary syndrome (ACS) and symptomatic arrhythmia during a 3-year follow-up. A primary composite outcome was significantly more common in the aspirin plus clopidogrel group, at 10.8% (14/130), as compared with the non-antiplatelet group, at 4.4% (44/1011), (hazard ratio [HR] 2.41, 95% confidence interval [CI], 1.32-4.40, p = 0.004). With regard to the person-time event rate, similar results were shown, with the highest rate in the aspirin plus clopidogrel user at 4.72/1000 person months (95% CI, 2.79-7.96, log-rank test for primary outcome p = 0.016). The person-time event of the ACS rate was also highest in that group, at 2.81 (95% CI, 1.46-5.40, log-rank test for ACS p = 0.116). Kaplan-Meier survival analysis demonstrated poor prognosis in primary outcomes and ACS in aspirin plus clopidogrel users (log-rank test, p = 0.005 and p = 0.0392, respectively). Cox-proportional hazard regression analysis, adjusting for age, sex, history of coronary heart disease, hypertension, diabetes, presence or not of definite spasm, use of calcium channel blocker, demonstrated that the use of aspirin plus clopidogrel is an independent risk for the primary outcome (HR 2.01, CI: 1.07-3.81, p = 0.031). The aspirin-alone group had a similar primary and individual event rate compared to the no-antiplatelet agent group (HR 0.96, CI, 0.59-1.55, p = 0.872). Smokers using aspirin plus clopidogrel had poorer outcomes than non-smokers, with HR 6.36 (CI 2.31-17.54, p = 0.045 for interaction). In conclusion, among VA patients, aspirin plus clopidogrel use is associated with a poor clinical outcome at 3 years, especially in ACS. Aspirin alone appears to be safe for use in those patients.

Effectiveness and Safety of Zotarolimus-Eluting Stent (Resolute™ Integrity) in Patients with Diffuse Long Coronary Artery Disease.

BACKGROUND AND OBJECTIVES: Diffuse long coronary artery disease (DLCAD) still has unfavorable clinical outcomes after successful percutaneous coronary intervention (PCI). Therefore, we aimed to evaluate the effectiveness and safety of Resolute™ zotarolimus-eluting stent (R-ZES; Resolute™ Integrity) for patients with DLCAD. METHODS: From December 2011 to December 2014, 1,011 patients who underwent PCI using R-ZES for CAD with longer than 25 mm lesion were prospectively enrolled from 21 hospitals in Korea. We assessed the clinical outcome of major adverse cardiac events (MACE) defined as the composite of cardiac death, non-fatal myocardial infarction (MI), and clinically-driven target vessel revascularization at 12 months. RESULTS: Mean age was 63.8±10.8 years, 701 (69.3%) patients were male, 572 (87.0%) patients had hypertension, 339 (33.8%) patients had diabetes, 549 (54.3%) patients diagnosed with acute MI and 545 (53.9%) patients had multi-vessel disease (MVD). A total of 1,697 stents were implanted into a total of 1,472 lesions. The mean diameter was 3.07±0.38 mm and the length was 28.27±6.97 mm. Multiple overlapping stents were performed in 205 (13.8%) lesions. A 12-month clinical follow-up was available in 1,004 patients (99.3%). The incidences of MACE and definite stent thrombosis at 12-month were 3.0% and 0.3% respectively. On multivariate Cox-regression analysis, multiple overlapping stents implantation, previous congestive heart failure, MVD, and age ≥75 years were independent predictors of one-year MACE. CONCLUSIONS: Our study shows that R-ZES has an excellent 1-year clinical outcome in Korean patients with DLCAD.

Impact of multi-vessel vasospastic angina on cardiovascular outcome.

BACKGROUND AND AIMS: Since clinical characteristics and prognosis of patients with multi-vessel vasospastic angina (VSA) are not clear, we investigated the nature and prognosis of multi-vessel VSA in Koreans. METHODS: Among 2960 patients enrolled in the VA-KOREA (Vasospastic Angina in Korea) registry, 104 definite multi-vessel VSA patients, 163 single vessel VSA patients and 737 non-VSA patients were identified using the intracoronary ergonovine provocation test. RESULTS: Multi-vessel VSA and single vessel VSA groups showed similar baseline characteristics and medical treatment on discharge, but different from the non-VSA group. The primary composite endpoint (cardiac death, acute coronary syndrome, and symptomatic new onset arrhythmia) over a 36-month follow-up period was significantly higher in the multi-vessel VSA group than in the single vessel VSA and non-VSA groups (8.7% vs. 1.8% and 1.1%, each log-rank p < 0.05, respectively). The rate of death and acute coronary syndrome of the multi-vessel VSA group was higher than in the single vessel VSA and non-VSA groups (5.8% vs. 1.2% and 0.9%, each log-rank p < 0.05, respectively). In addition, multi-vessel VSA was an independent predictor of the primary composite endpoint at 36 months (HR 8.5, 95% CI [2.6-27.2], p < 0.0001). CONCLUSIONS: Patients with multi-vessel VSA had worse clinical outcomes than single vessel VSA and non-VSA groups, suggesting that the existence of multi-vessel VSA itself is highly prognostic.

Evaluation of the flexural mechanical properties of various thermoplastic denture base polymers.

This study evaluated the flexural mechanical properties of various thermoplastic denture base polymers (six polyamides, four acrylic resins, polyester, polypropylene, and polycarbonate) by three different testing conditions; specimens were tested in water bath at 37°C (Wet/Water, by ISO 20795-1), or in ambient air (Wet/Air) after being immersed in distilled water for 50 h, or after desiccation for 7 days (Dry/Air). The mean ultimate flexural strength (UFS) and flexural modulus (FM) for most products ranged from 27 to 61 MPa and from 611 to 1,783 MPa respectively, which failed to meet the minimum requirements of the international standard, except for polycarbonate (89 and 2,245 MPa). The mean UFS and FM values were ranked Dry/Air>Wet/Air>Wet/Water (p<0.05). In conclusion, the flexural mechanical properties of denture base polymers varied with the products and were significantly affected by the testing medium (air or water) and specimen conditions (wet or dry).

The impact of a dose of the angiotensin receptor blocker valsartan on post-myocardial infarction ventricular remodelling.

AIMS: Although clinical guidelines advocate the use of the highest tolerated dose of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers after acute myocardial infarction (MI), the optimal dosing or the risk-benefit profile of different doses have not been fully identified. METHODS AND RESULTS: In this multicentre trial, 495 Korean patients with acute ST segment elevation MI and subnormal left ventricular (LV) ejection fraction (<50%) were randomly allocated (2:1) to receive maximal tolerated dose of valsartan (titrated up to 320 mg/day, n = 333) or low-dose valsartan (80 mg/day, n = 162) treatment. The primary objective was to assess the changes in echocardiographic parameters of LV remodelling from baseline to 12 months after discharge. After treatment, end-diastolic LV volume (LVEDV) decreased significantly in the low-dose group, but the difference in LVEDV changes was insignificant between the maximal-tolerated-dose and low-dose groups. End-systolic LV volume decreased significantly in both groups, to a similar degree between groups. LV ejection fraction rose significantly in both study groups, to a similar degree. Changes in plasma levels of neurohormones were also comparable between the two groups. Drug-related adverse effects occurred more frequently in the maximal-tolerated-dose group than in the low-dose group (7.96 vs. 0.69%, P < 0.001). CONCLUSIONS: In the present study, treatment with the maximal tolerated dose of valsartan did not exhibit a superior effect on post-MI LV remodelling compared with low-dose treatment and was associated with a greater frequency of adverse effect in Korean patients. Further study with a sufficient number of cases and statistical power is warranted to verify the findings of the present study.

Efficacy and Tolerability of Telmisartan/Amlodipine + Hydrochlorothiazide Versus Telmisartan/Amlodipine Combination Therapy for Essential Hypertension Uncontrolled With Telmisartan/Amlodipine: The Phase III, Multicenter, Randomized, Double-blind TAHYTI Study.

PURPOSE: This 8-week study in Korea aimed to evaluate the efficacy and tolerability of a telmisartan/amlodipine + hydrochlorothiazide (TAH) combination versus telmisartan/amlodipine (TA) combination in patients with essential hypertension that did not respond appropriately to 4-week treatment with TA. METHODS: All patients who met the inclusion criteria received TA (40/5 mg) during a 4-week run-in period (period 1). Patients who met the criteria for essential hypertension (mean sitting systolic blood pressure [MSSBP], ≥140 and <200 mm Hg, or ≥130 and<200 mm Hg in those with diabetes mellitus or chronic kidney disease) after period 1 were randomly assigned to receive TA 40/5 mg + hydrochlorothiazide 12.5 mg (test group) or TA only (control group). The test and control drugs were administered in each group for 2 weeks (period 2). Patients who completed period 2 underwent 6-week treatment (period 3) with a TAH and TA dose twice that in period 2. The primary end point was the change in MSSBP at week 8 of treatment. Secondary end points were the change in MSSBP at week 2 and MS diastolic BP, BP control rate, and BP response rate at weeks 2 and 8. Treatment tolerability was assessed based on adverse events (AEs), laboratory evaluations (chemistry, hematology, and urinalysis), 12-lead ECG, and physical examination including vital sign measurements. FINDINGS: We randomized 310 patients to the treatment groups. The mean (SD) ages of the TAH and TA groups were 62.0 (10.8) and 63.4 (10.4) years, respectively. The least squares mean change in MSSBP was significantly greater in the TAH group than in the TA group after 8 weeks (-18.7 vs -12.2 mm Hg; P < 0.001). Similar results were obtained on changes in MSSBP after 2 weeks and changes in sitting diastolic BP, BP control rate, and BP response rate at weeks 2 and 8 compared with the respective baseline values. The prevalences of treatment-emergent AEs (29.0% vs 16.3%; P = 0.008) and adverse drug reactions (20.0% vs 10.5%; P = 0.020) were significantly greater in the TAH group than in the TA group. Most treatment-emergent AEs were mild or moderate; none were severe. The most frequently reported AEs were dizziness and headache. IMPLICATION: TAH triple therapy was more effective than was TA double therapy in reducing BP in these patients in Korea with essential hypertension that did not adequately respond to TA. ClinicalTrials.gov identifier: NCT02738632.