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Background and objectivesTo investigate the clinical relevance of the timing of heart failure (HF) development on long-term outcome in patients with acute myocardial infarction (AMI).Materials and methodsA total of 1,925 consecutive AMI patients were divided into 4 groups according to the timing of HF development; HF at admission (group I, n = 627), de novo HF during hospitalization (group II, n = 162), de novo HF after discharge (group III, n = 98), no HF (group IV, n = 1,038). Major adverse cardiac events (MACE) defined as the development of death, re-hospitalization, recurrent MI or revascularization were evaluated.ResultsHF was developed in 887 patients (46.1%) after an index AMI. HF was most common at the time of admission for AMI, but the development of de novo HF during hospitalization or after discharge was not uncommon. MACE was developed in 619 out of 1,925 AMI patients (31.7%). MACE was highest in group I, lowest in group IV, and significantly different among groups; 275 out of 627 patients (43.9%) in group I, 64 out of 192 patients (39.5%) in group II, 36 out of 98 patients (36.7%) in group III, and 235 out of 1,038 patients (22.6%) in group IV (P

Women underestimate the risk of cardiovascular disease (CVD). It is essential to assess and raise awareness regarding CVD among women to reduce disease burden and mortality. Therefore, we investigated the awareness regarding CVD among Korean women. We conducted a nationwide survey between December 2020 and January 2021 among a representative sample of Korean women using random-digit-dialing telephonic interviews. We sought information regarding the awareness of CVD risk; recognition of symptoms and signs; and knowledge of the cause and prevention of and appropriate response to CVD. A total of 1,050 women (mean age, 60.2 ± 11.9 years) participated in the study. Approximately 52.0% of participants were unaware of CVD, and only 26% of participants had heard of CVD. Participants considered that compared to other diseases, CVD was not an important health issue for women, and few of them thought that cerebrovascular diseases and CVD were the leading causes of death (10.9% and 7.6%, respectively). After adjustment for possible confounding factors, age >70 years, rural residence, and educational attainment below college were independently associated with a lack of awareness regarding CVD. The awareness regarding CVD being the leading cause of death in women is low, and most women do not consider it an important health issue. Therefore, special attention must be paid to educate the public regarding CVD in women.

Abstract Background With an increasing clinical importance of the treatment of the heart failure (HF) with preserved ejection fraction (HFpEF), it is important to be certain of the diagnosis of HF. We investigated global and regional left ventricular (LV) strains using speckle tracking echocardiography (STE) in patients with HFpEF and compared those parameters with that of patients with hypertension and normal subjects. Methods Peak longitudinal, circumferential and radial strains were assessed globally and regionally for each study groups using STE. Diastolic strain rate was also determined. Results There were 50 patients in HFpEF group, 56 patients in hypertension group and 46 age-matched normal subjects. In patients with HFpEF, global peak longitudinal, circumferential and radial strain and strain rate were reduced compared to both hypertension patients and normal controls (− 15.5 ± 5.3 vs − 17.7 ± 3.1 and − 19.9 ± 2.0; − 9.7 ± 2.2 vs − 19.3 ± 3.1 and − 20.5 ± 3.3; 17.7 ± 8.2 vs 38.4 ± 12.4 and 43.6 ± 11.9, respectively, P

Background Lightwand is a convenient tool that can be used instead of a laryngoscope for intubation. Tracheal intubation causes direct stimulation of the larynx, drastically increasing hemodynamic values including blood pressure and heart rate. This study aims to identify the effect of different doses of esmolol on hemodynamic changes during lightwand intubation. Methods The study subjects included 140 patients who underwent general anesthesia for elective surgery. The patients were randomly divided into four groups (35 patients in each group). The ‘C’ group only received 20 ml of normal saline, while the ‘E0.5’, ‘E1’, and ‘E2’ groups received 20 ml of normal saline containing esmolol—0.5 mg/kg, 1 mg/kg, and 2 mg/kg, respectively, injected 2 min prior to intubation. The patients’ blood pressure, heart rate, and rate-pressure product were measured six times, before and after the intubation. Results The degree of heart rate elevation was suppressed in the E1 and E2 groups compared to the C group, and RPP after intubation significantly decreased in the E2 group compared to the C group. Conclusions Esmolol injection, 1-2 mg/kg, prior to lightwand intubation effectively blunts heart rate elevation, and 2 mg/kg of esmolol injection blunts rate-pressure product elevation.

Abstract Background We investigated the usefulness of the left atrial (LA) strain measurement on the prediction of upcoming cancer therapeutics-related cardiac dysfunction (CTRCD) after trastuzumab therapy in patients with breast cancer who did not develop CTRCD after chemotherapy. Methods A total of 72 females with breast cancer who did not develop CTRCD after chemotherapy and underwent additional trastuzumab therapy were divided into CTRCD (n = 13) and no CTRCD group (n = 59). Echocardiographic measurements including left ventricular global longitudinal strain (LVGLS) and peak atrial longitudinal strain (PALS) decline were compared. Results CTRCD was identified in 13 patients (18.1%) after additional trastuzumab therapy. Baseline echocardiographic findings were not different. After the completion of chemotherapy, conventional echocardiographic parameters were not different, but PALS decline (15.0 ± 4.7 vs. 8.9 ± 3.2%, p

Background: Left ventricular diastolic function (LVDF) evaluation using a combination of several echocardiographic parameters is an important predictor of adverse events in patients with acute myocardial infarction (AMI). To date, the clinical impact of each individual LVDF marker is well-known, but the clinical significance of the sum of the abnormal diastolic function markers and the long-term clinical outcome are not well-known. This study aimed to investigate the usefulness of LVDF score in predicting clinical outcomes of patients with AMI.Methods: LVDF scores were measured in a 2,030 patients with AMI who underwent successful percutaneous coronary intervention from 2012 to 2015. Four LVDF parameters (septal e′ ≥ 7 cm/s, septal E/e′ ≤ 15, TR velocity ≤ 2.8 m/s, and LAVI ≤ 34 ml/m2) were used for LVDF scoring. The presence of each abnormal LVDF parameter was scored as 1, and the total LVDF score ranged from 0 to 4. Mortality and hospitalization due to heart failure (HHF) in relation to LVDF score were evaluated. To compare the predictive ability of LVDF scores and left ventricular ejection fraction (LVEF) for mortality and HHF, receiver operating characteristic (ROC) curve and landmark analyses were performed.Results: Over the 3-year clinical follow-up, all-cause mortality occurred in 278 patients (13.7%), while 91 patients (4.5%) developed HHF. All-cause mortality and HHF significantly increased as LVDF scores increased (all-cause mortality–LVDF score 0: 2.3%, score 1: 8.8%, score 2: 16.7%, score 3: 31.8%, and score 4: 44.5%, p < 0.001; HHF–LVDF score 0: 0.6%, score 1: 1.8%, score 2: 6.3%, score 3: 10.3%, and score 4: 18.2%, p < 0.001). In multivariate analysis, a higher LVDF score was associated with significantly higher adjusted hazard ratios for all-cause mortality and HHF. In landmark analysis, LVDF score was a better predictor of long-term mortality than LVEF (area under the ROC curve: 0.739 vs. 0.640, p < 0.001).Conclusion: The present study demonstrated that LVDF score was a significant predictor of mortality and HHF in patients with AMI. LVDF scores are useful for risk stratification of patients with AMI; therefore, careful monitoring and management should be performed for patients with AMI with higher LVDF scores.

The variables of die temperature, pressure, time, lamination method, and forming count are applied to fabricate thermosoftening CFRP (CFRTP) with compression molding method. The mechanical properties of CFRTP are compared with those of thermosetting CFRP (CFRTS). The first lamination method is that one hotmelt is inserted into carbon fiber (five carbon fibers and four hotmelts). The optimal lamination conditions are the die temperature of 220°C, pressure of 6 MPa, and pressurization time for 10 min. The tensile strength of CFRTP of this lamination method is 400 MPa. For higher tensile strength value, the second lamination method was applied. CFRTP prepreg was prepared with one hotmelt and one carbon fiber by applying die temperature at optimal lamination conditions. Five CFRTP prepregs were laminated under the same conditions. When the CFRTP sheet was three formings, the tensile strength of 494 MPa could be obtained. CFRTS are prepared by laminating the epoxy prepregs at 140°C with the compressive pressure of 0.5 MPa for 30 min. CFRTP sheet has the lower tensile strength than CFRTS sheet by 223 MPa, but the flexural strength was higher by 61 MPa and by 1.0 J/cm 2 for Charpy impact test.

Background Nonhyperemic pressure ratios (NHPRs) such as instantaneous wave‐free ratio, resting full‐cycle ratio, or diastolic pressure ratio have emerged as invasive physiologic indices precluding the need for hyperemic agents. The current study sought to evaluate the long‐term prognostic implications of NHPRs compared with fractional flow reserve (FFR). Methods and Results NHPRs were calculated from resting pressure tracings by an independent core laboratory in 1024 vessels (435 patients). The association between NHPRs and the risk of 5‐year vessel‐oriented composite outcomes (VOCO, a composite of cardiac death, vessel‐related myocardial infarction, and ischemia‐driven revascularization) were analyzed among 864 deferred vessels. Lesions with positive NHPRs (instantaneous wave free ratio, resting full‐cycle ratio, and diastolic pressure ratio ≤0.89) or FFR (≤0.80) showed significantly higher risk of VOCO at 5 years than those with negative NHPRs or FFR, respectively. Discriminant ability for 5‐year VOCO was not different among NHPRs and FFR (C‐index: 0.623–0.641, P for comparison=0.215). In comparison of VOCO among the groups with deferred concordant negative (NHPRs−/FFR−), deferred discordant (NHPRs+/FFR− or NHPRs−/FFR+), and revascularized vessels, the cumulative incidence of VOCO were 7.5%, 14.4%, and 14.8% (log‐rank P

Abstract Human coronary artery tree is a physiological transport system for oxygen and vital materials through a hierarchical vascular network to match the energy demands of myocardium, which has the highest oxygen extraction ratio among body organs and heavily depends on the blood flow for its energy supply. Therefore, it would be reasonable to expect that the key design principle of this arterial network is to minimize energy expenditure, which can be described by allometric scaling law. We enrolled patients who underwent coronary computed tomography angiography without obstructive lesion. The cumulative arterial length (L), volume (V), and diameter (D) in relation to the artery‐specific myocardial mass (M) were assessed. Flow rate (Q) was computed using quantitative flow ratio (QFR) measurement in patients who underwent invasive angiography. A total of 638 arteries from 43 patients (mean age 61 years, male gender 65%) were analyzed. A significant power‐law relationship was found among L–M, V–M, D–M, V–L, D–L, and V–D, and also among Q–M, Q–L, Q–V, and Q–D in 106 arteries interrogated with QFR (p

Background Sex‐specific differences may influence prognosis after deferred revascularization following fractional flow reserve (FFR) measurement. This study sought to investigate the sex differences in long‐term prognosis of patients with deferred revascularization following FFR assessment. Methods and Results A total of 879 patients (879 vessels) with deferred revascularization with FFR >0.75 who underwent FFR and coronary flow reserve measurements were enrolled from 3 countries (Korea, Japan, and Spain). Long‐term outcomes were assessed in 649 men and 230 women by the patient‐oriented composite outcome (POCO, a composite of any death, any myocardial infarction, and any revascularization). We applied inverse‐probability weighting based on propensity scores to account for differences at baseline between women and men (age, hyperlipidemia, diabetes mellitus, diameter stenosis, lesion length, multivessel disease, FFR, coronary flow reserve. The median follow‐up duration was 1855 days (745–1855 days). Median FFR values were 0.88 (0.83–0.93) in men and 0.89 (0.85–0.94) in women, respectively. The occurrences of POCO were significantly high in men compared with that in women (10.5% versus 4.2%, P=0.007). Kaplan–Meier analysis revealed that women had a significantly lower risk of POCO (χ2=7.2, P=0.007). Multivariate COX proportional hazards regression analysis revealed that age, male, diabetes mellitus, diameter stenosis, lesion length, and coronary flow reserve were independent predictors of POCO. After applying IPW, the hazard ratio of males for POCO was 2.07 (95% CI, 1.07–4.04, P=0.032). Conclusions This large multinational study reveals that long‐term outcome differs between women and men in favor of women after FFR‐guided revascularization deferral. Clinical Trial Registration URL: http://www.ClinicalTrials.gov. Unique identifier: NCT02186093.

In casting steel for offshore construction, integral casted structures are superior to welded structures in terms of preventing fatigue cracks in the stress raisers. In this study, mold design and casting analysis were conducted for integral carrier housing. Casting simulation was used for predicting molten metal flow and solidification during carrier housing casting, as well as the hot spots and porosity of the designed runner, risers, riser laggings, and the chiller. These predictions were used for deriving the final carrier housing casting plan, and a prototype was fabricated accordingly. A chemical composition analysis was conducted using a specimen sampled from a section of the prototype; the analytically obtained chemical composition agreed with the chemical composition of the existing carrier housing. Tensile and Charpy impact tests were conducted for determining the mechanical material properties. Carrier housing product after normalizing (920 °C/4.5 h, air-cooling) has 371 MPa of yield strength, 582 MPa of tensile strength, 33.4% of elongation as well as 64 J (0 °C) of impact energy.

Hybrid composites in which a CR980 metal plate was bonded on carbon-fiber-reinforced plastic (CFRP) were prepared. Hybrid composites were two types of CFRP/CR980 hybrid composites and CR980/CFRP hybrid composites. The properties of the hybrid composites according to surface roughness on CR980 plate and the laminating number of CFRP prepregs were analyzed. The spring-back or spring-go angles were also measured through the V-bending test of hybrid composites. In addition, a three-point bending test for the hybrid composites was conducted to measure the flexural strength. Spring-back occurred in the CFRP/CR980 hybrid composites, while spring-go was observed in the CR980/CFRP hybrid composites. Voids were not found at the bonding area of the CFRP and CR980. As the roughness at the bonding area increased, the flexural strength slightly increased. The higher the laminating number of the CFRP prepregs, the lower the deformation value. CFRP/CR980 was deformed more easily than CR980/CFRP.

Inconel 625 alloys are widely applied for high-corrosion resistance and as high-efficiency materials in aeronautical, aerospace, chemical, nuclear, petrochemical, and marine industries. Although Inconel 625 alloys are excellent materials, they cannot be formed at room temperature owing to difficulties in processing. To improve the formability of Inconel 625, it is necessary to investigate its formability at a high-temperature range and its strain rate variation. In this study, high-temperature deformation behavior after forming was investigated. A high-temperature compression test was performed with a Gleeble 3500 testing machine at various temperatures (approximately 900−1200 °C) and strain rates (10 and 30 s−1) to obtain the high-temperature deformation characteristics of Inconel 625. Furthermore, high-temperature tensile tests were performed to measure elongations and reductions in the area of the Inconel 625 alloy. The tests focused on obtaining the flow stress data and optimal hot forging conditions under various strain rates and temperatures. The results of this research are expected to contribute to hot forming processes and to formability in hot extrusion and pilger processes.

This study involves performing direct and indirect hot press forming on ultra-high-strength steel (UHSS) boron steel sheets to determine formability. The indirect hot press process is performed as a cold deep drawing process, while the direct hot press process is performed as a hot deep drawing process. The initial blank temperature and the blank holding force are set as parameters to evaluate the performance of the direct and indirect deep drawing processes. The values of punch load and forming depth curve were obtained in the experiment. In addition, the hardness and microstructure of the boron steel sheets are examined to evaluate the mechanical properties of the material. The forming depth, maximum punch load, thickness, and thinning rate according to blank holding force were examined. The result shows that a larger blank holding force has a more significant effect on the variation of the thickness and thinning rate of the samples during the drawing process. Furthermore, the thinning rate of the deep drawing part in with and without fracture boundary was respectively examined.

For carbon nanotube (CNT)/Al composites, compaction forming is conducted for densification processing, and then sintering and secondary processes are conducted. This general process has problems such as the complexity of the processing procedures, and high manufacturing costs. This study presents a hot extrusion process without sintering for fabrication of CNTs/Al6061 composites. Before hot extrusion, preforms are fabricated by the compaction process for the mixture of Al6061 power and CNTs. Several hot extrusion experiments were performed under six types of CNT content; three extrusion ratios and three extrusion temperatures. The formability increased as the extrusion temperature increased for low CNT content. At 620 °C, the forming of all materials except for 10 vol % CNTs/Al6061 was possible at extrusion ratios R = 4, R = 8, and R = 16. As CNT content increases, extrusion pressure almost linearly increases. As the extrusion ratio increases, the extrusion pressure increases. The amount of CNT content increases as Vickers hardness increases. The Vicker’s hardness of 1 vol % CNTs/Al6061 billet is about 100 HV while that of 10 vol % CNTs/Al6061 billet is about 230 HV. There are no significant differences of compression stress according to extrusion ratio as observed in terms of pure Al6061, 1 vol % CNT/Al6061, and 3 vol % CNTs/Al6061.

Purpose: The regions where patients diagnosed with prostate cancer by biopsy receive prostatectomy are divided into national hub and regional hubs, and to confirm the change in the role of regional hubs compared to national hub. Materials and Methods: Data from July 2013 to June 2017 encompassing 218,155 patients aged ≥18 years diagnosed with prostate cancer were analyzed using the Health Insurance Review & Assessment Service database. The degree of patient outflow was assessed by dividing the regional diagnosis-to-surgery ratio with the national ratio for each year. Based on this ratio, national and regional hubs were determined. Results: Seoul consistently maintained a patient influx with a ratio above 1.6. Busan and Gyeonggi consistently exceeded 0.9, while Ulsan and Daegu steadily increased, exceeding 1.0 between 2015 and 2016. Jeonnam province also consistently maintained the ratio above 0.7. Jeju, Daejeon, Gangwon, and Incheon remained below 0.5, indicative of substantial patient outflows, whereas Gwangju and Gyeongbuk had the highest patient outflows with ratios below 0.15. Therefore, Seoul was designated as a national hub, whereas Busan, Gyeonggi, Ulsan, Daegu, and Jeonnam were classified as regional hubs. Jeju, Daejeon, Gangwon, and Incheon were the dominant outflow areas, while Gwangju and Gyeongbuk were the highest outflow areas. Conclusions: Seoul, as the national hub for prostate cancer surgery, operated on 1.76 times more patients than any other region during 2013–2017. Busan, Gyeonggi, Ulsan, Daegu, and Jeonnam functioned as regional hubs, but approximately 10%–20% of patients sought treatment at national hubs.

In this paper, aluminium-based (Al6061) composites with 1, 3, 5, 7, and 10 vol % of multi-walled carbon nanotubes (MWCNTs) are investigated. The composites are fabricated by high-energy ball milling, cold-compacting at room temperature under compacting pressures of 400–1600 MPa, and sintering at 620 °C in an argon gas atmosphere. Thereafter, the hardness and microstructure of MWCNTs/Al6061 composites are examined. Further, to improve the relative density and hardness level of the complex material, open-die forging is performed after cold-compacting under 1 GPa pressure at room temperature and sintering at 620 °C. The open-die forging parameters include 1, 3, 5, 7, and 10 vol % MWCNTs/Al6061, and Al6061. The experimental results show that the mechanical properties of the composites are significantly superior to that of the Al6061 alloy after undergoing cold-compacting, sintering, and open-die forging.