Lipid-Lowering Efficacy of Combination Therapy With Moderate-Intensity Statin and Ezetimibe Versus High-Intensity Statin Monotherapy: A Randomized, Open-Label, Non-Inferiority Trial From Korea.

Objective: This phase IV, multicenter, randomized controlled, open-label, and parallel clinical trial aimed to compare the efficacy and safety of ezetimibe and moderate intensity rosuvastatin combination therapy to that of high intensity rosuvastatin monotherapy in patients with atherosclerotic cardiovascular disease (ASCVD). Methods: This study enrolled patients with ASCVD and after a four-week screening period, patients were randomly assigned to receive either rosuvastatin and ezetimibe (RE 10/10 group) or high-intensity rosuvastatin (R20 group) only in a 1:1 ratio. The primary outcome was the difference in the percent change in the mean low-density lipoprotein cholesterol (LDL-C) level from baseline to 12 weeks between two groups after treatment. Results: The study found that after 12 and 24 weeks of treatment, the RE10/10 group had a greater reduction in LDL-C level compared to the R20 group (-22.9±2.6% vs. -15.6 ± 2.5% [p=0.041] and -24.2±2.5% vs. -12.9±2.4% [p=0.001] at 12 and 24 weeks, respectively). Moreover, a greater number of patients achieved the target LDL-C level of ≤70 mg/dL after the treatment period in the combination group (74.6% vs. 59.9% [p=0.012] and 76.2% vs. 50.8% [p<0.001] at 12 and 24 weeks, respectively). Importantly, there were no significant differences in the occurrence of overall adverse events and adverse drug reactions between two groups. Conclusion: Moderate-intensity rosuvastatin and ezetimibe combination therapy had better efficacy in lowering LDL-C levels without increasing adverse effects in patients with ASCVD than high-intensity rosuvastatin monotherapy. Trial Registration: ClinicalTrials.gov Identifier: NCT03494270.

Numerical study to identify the effect of fluid presence on the mechanical behavior of the stents during coronary stent expansion.

In this study, structural analysis and one-way fluid-structure interaction (FSI) analysis were performed to identify the effect of fluid presence on the mechanical behavior of the stents during stent expansion. An idealized vessel model with stenosis was used for simulation, and stents made of metal and polymer were assumed, respectively. The bilinear model was applied to the stents, and the Mooney-Rivlin model was applied to the arterial wall and plaque. The blood used in the FSI analysis was assumed to be a non-Newtonian fluid. As a result of all numerical simulations, the von Mises stress, the first principal stress and the displacement were calculated as the mechanical behaviors. Through the comparison of the results of the structural analysis with those of the one-way FSI analysis, our results indicated the fluid had no significant influence on the expansion of the metal stent. However, it was found that the expansion of the polymer stent affected by the presence of fluid. These findings meant the one-way FSI technique was suggested to achieve an accurate analysis when targeting a polymer stent for numerical simulation.

Numerical study to evaluate the effect of a surface-based sensor on arterial tonometry.

Arterial tonometry is a widely used non-invasive blood pressure measurement method. In contrast to the cuff-based method, it is possible to obtain a continuous pressure profile with respect to systolic and diastolic pressures using this method. However, due to a requirement of arterial tonometry-that a sensor needs to be placed directly above a blood vessel-placement error is inevitable if the measurement device is only capable of measuring local regions. This study assumed that the plate sensor is flexible, thus reducing the placement error. We investigated the pressure distribution along the wrist surface rather than the local region through the contact simulation between the flexible plate sensor and the wrist. As a result, we concluded that there is a unique pressure distribution for any specific wrist, regardless of the length and position of the plate, and that it is possible to measure the blood pressure using the response at the wrist surface to the pressure inside the radial artery.

Finite element modeling for predicting the contact pressure between a foam mattress and the human body in a supine position.

In this paper, we generated finite element (FE) models to predict the contact pressure between a foam mattress and the human body in a supine position. Twenty-year-old males were used for three-dimensional scanning to produce the FE human models, which was composed of skin and muscle tissue. A linear elastic isotropic material model was used for the skin, and the Mooney-Rivlin model was used for the muscle tissue because it can effectively represent the nonlinear behavior of muscle. The contact pressure between the human model and the mattress was predicted by numerical simulation. The human models were validated by comparing the body pressure distribution obtained from the same human subject when he was lying on two different mattress types. The experimental results showed that the slope of the lower part of the mattress caused a decrease in the contact pressure at the heels, and the effect of bone structure was most pronounced in the scapula. After inserting a simple structure to function as the scapula, the contact pressure predicted by the FE human models was consistent with the experimental body pressure distribution for all body parts. These results suggest that the models proposed in this paper will be useful to researchers and designers of products related to the prevention of pressure ulcers.

Numerical study to indicate the vulnerability of plaques using an idealized 2D plaque model based on plaque classification in the human coronary artery.

Atherosclerosis is one of the leading causes of death in the world. In this study, an idealized 2D plaque model based on plaque classification in the coronary artery is developed. When creating the idealized 2D model for each plaque type (fibrocalcic, FC; fibrofatty, FT; calcified fibroatheroma, CaFA; fibroatheroma, FA; calcified thin-cap fibroatheroma, CaTCFA; thin-cap fibroatheroma, TCFA), the cap thickness and stenosis by diameter were set as variables. In order to establish the correlation between each plaque type and plaque rupture, a numerical simulation was performed and the stress and stress gradient were reviewed to analyze the mechanical behavior. Results show that both the TCFA and CaTCFA plaque types, which have the smallest cap thicknesses of the different types of plaque, showed relatively high stress values in the thin membrane when compared with the FT type. The FT type is considered to be relatively stable since it does not have necrotic core or a thin membrane. With a stenosis rate of 50% and a cap thickness of 60 µm, the TCFA and CaTCFA types showed approximately 11 and 110% higher stress values, respectively, and 679 and 1568% higher negative stress gradient values, respectively. In other words, the plaque types with thin caps, which have weak load-bearing capacities, showed high stress values and high negative stress gradients in the radial direction. It is understood that this result could indicate the possibility of plaque rupture.

Evaluation of the Efficacy and Safety of the Lercanidipine/Valsartan Combination in Korean Patients With Essential Hypertension Not Adequately Controlled With Lercanidipine Monotherapy: A Randomized, Multicenter, Parallel Design, Phase III Clinical Trial.

PURPOSE: The objective of this study was to evaluate the efficacy and safety of the lercanidipine/valsartan combination compared with lercanidipine monotherapy in patients with hypertension. METHODS: Part 1 of this study was the randomized, multicenter, double-blind, parallel group, Phase III, 8-week clinical trial to compare superiority of lercanidipine 10 mg/valsartan 80 mg (L10/V80) and lercanidipine 10 mg/valsartan 160 mg (L10/V160) combinations with lercanidipine 10 mg (L10) monotherapy. At screening, hypertensive patients, whose diastolic blood pressure (DBP) was >90 mm Hg after 4 weeks with L10, were randomized to 3 groups of L10, L10/V80, and L10/V160. The primary end point was the change in the mean sitting DBP from baseline (week 0) after 8 weeks of therapy. Patients who were randomly assigned to L10/V160 and whose mean DBP was still ≥ 90 mm Hg in part 1 were enrolled to the up-titration extension study with lercanidipine 20 mg/valsartan 160 mg (L20/V160) (part 2). FINDINGS: Of 772 patients screened, 497 were randomized to 3 groups (166 in the L10 group, 168 in the L10/V80 group, and 163 in the L10/V160 group). Mean (SD) age was 55 (9.9) years, and male patients comprised 69%. The mean (SD) baseline systolic blood pressure (SBP)/DBP were 148.4 (15.1)/94.3 (9.5) mm Hg. No significant differences were found between groups in baseline characteristics except the percentages of previous history of antihypertensive medication. The primary end points, the changes of mean (SD) DBP at week 8 from the baseline were -2.0 (8.8) mm Hg in the L10 group, -6.7 (8.5) mm Hg in L10/V80 group, and -8.1 (8.4) mm Hg in L10/V160 group. The adjusted mean difference between the combination groups and the L10 monotherapy group was -4.6 mm Hg (95% CI, -6.5 to -2.6; P < 0.001) in the L10/V80 group and -5.9 mm Hg (95% CI, -7.9 to -4.0, P < 0.001) in the L10/V160 group, which had significantly greater efficacy in BP lowering. A total of 74 patients were enrolled in the part 2 extension study. Changes of mean (SD) DBP and SBP from week 8 to week 12 and week 16 were -5.6 (7.9)/-8.0 (12.0) mm Hg and -5.5 (7.0)/-8.5 (11.3) mm Hg, respectively. For evaluation of the safety profile, the frequencies of adverse events between groups were also not significantly different. The most frequently reported adverse events were headache (6 cases, 20.7%) in the L10 group, dizziness (8 cases, 16.3%) in L10/V80 group, and nasopharyngitis (3 cases, 9.4%) in L10/V160 group, and the incidences of adverse events were not different between groups. IMPLICATIONS: Treatment of L10/V80 or L10/V160 combination therapy resulted in significantly greater BP lowering compared with L10 monotherapy. Moreover, the L20/V160 high dose combination had additional BP lowering effect compared with nonresponders with the L10/V160 combination. ClinicalTrials.gov: NCT01928628.

Efficacy and safety of morning versus evening dose of controlled-release simvastatin tablets in patients with hyperlipidemia: a randomized, double-blind, multicenter phase III trial.

BACKGROUND: Flexibility in the recommended dosing time for a statin may improve patient compliance. OBJECTIVE: This study was designed to compare the efficacy and tolerability of morning and evening doses of controlled-release simvastatin in Korean adults with dyslipidemia. It was carried out as a requirement to obtain authorization from the Korean regulatory agency to market the product. METHODS: In this prospective, randomized, double-blind, multicenter, placebo-controlled Phase III study, we randomly assigned 132 patients with hypercholesterolemia to a morning-dose group or an evening-dose group. Patients in the morning-dose group received 20 mg controlled-release simvastatin in the morning and a placebo in the evening, and those in the evening-dose group received a placebo in the morning and 20 mg controlled-release simvastatin in the evening. RESULTS: After 8 weeks of the treatment, the difference in the mean change of LDL-C between the morning-dose and evening-dose groups was -2.78% (95% confidence interval, -7.65 to 2.10). The changes in total cholesterol, triglycerides, HDL-C, apolipoprotein A1, apolipoprotein B, and lipoprotein (a) after treatment did not differ between groups. Also, the achievement rates of the target LDL-C goal suggested by the dyslipidemia treatment guideline of the Korean Society of Lipidology and Atherosclerosis were not different. No serious adverse event was observed in either group. Mild and moderate adverse events were observed similarly in both groups. CONCLUSIONS: Although controlled-release simvastatin significantly reduces LDL-C levels with good tolerability in Korean adults with dyslipidemia, the time of administration does not affect its efficacy.

Construction of healthy arteries using computed tomography and virtual histology intravascular ultrasound.

Vessel geometry for numerical analysis is generally obtained by computed tomography (CT) or magnetic resonance imaging (MRI) and intravascular ultrasound (IVUS). Most medical imaging is obtained from patients for hemodynamic analysis due to the properties of vascular disease and the difficulties in angiography. To predict the site where plaque occurs and understand the progression of the lesion, however, it is necessary to take into consideration not only the diseased artery, but also the blood flow characteristics of healthy artery. In order to simulate healthy vessels prior to lesion formation, we performed CT and virtual histology intravascular ultrasound (VH-IVUS) on three actual patients and this data was used to develop criteria for healthy vessel construction, a method that virtually removes all intravascular plaque. The lumen of a vessel generated by CT and the lumen from VH-IVUS were compared, and the cross-sectional areas of plaque components (fibrous, fibrofatty, dense calcium, and necrotic) and the lumen from VH-IVUS were analyzed. Geometric differences in the healthy vessel and diseased vessel were analyzed, and flow characteristics of the healthy vessel and diseased vessel were compared through computational fluid dynamics simulation. Low average wall shear stress (AWSS) was distributed in the site where plaque was removed from the healthy vessel, and a high oscillatory shear index (OSI) was observed in the region proximal to the site where plaque previously existed. Low AWSS and high OSI are widely accepted indicators of plaque formation or the direction of plaque progression. A numerical model that effectively predicts lesion forming sites was also generated based on the healthy vessel construction method presented in this study.