Acoustic Bubble and Magnetic Actuation-Based Microrobot for Enhanced Multiphase Drug Delivery Efficiency.

This paper proposes an acoustic bubble and magnetic actuation-based microrobot for enhancing multiphase drug delivery efficiency. The proposed device can encapsulate multiphase drugs, including liquids, using the two bubbles embedded within the microtube. Additionally, using the magnetic actuation of the loaded magnetic liquid metal, it can deliver drugs to target cells. This study visualized the flow patterns generated by the oscillating bubble within the tube to validate the drug release principle. In addition, to investigate the effect of the oscillation properties of the inner bubble on drug release, the oscillation amplitude of the inner bubble was measured under various experimental variables using a high-speed camera. Subsequently, we designed a microrobot capable of encapsulating bubbles, drugs, and magnetic liquid metal and fabricated it using microfabrication technology based on ultra-precision 3D printing. As a proof of concept, we demonstrated the transport and drug release of the microrobot encapsulating the drug in a Y-shaped channel simulating a blood vessel. The proposed device is anticipated to enhance the efficiency of drug therapy by minimizing drug side effects, reducing drug administration frequency, and improving the stability of the drug within the body. This paper is expected to be applicable not only to targeted drug delivery but also to various biomedical fields, such as minimally invasive surgery and cell manipulation, by effectively delivering multiphase drugs using the simple structure of a microrobot.

Perception and Experience of Sexual and Gender Minority Korean Youth in School Counseling.

To comprehensively explore the school counseling experience of sexual and gender minority (SGM) youths in South Korea, we interviewed 14 SGM youths about their school counseling experience and the climate of their schools toward SGM. Results showed that a hostile school climate and the accessibility, confidentiality, trustworthiness, and LGBTQ competency of school counselors drove the reluctance of these youths to receive school counseling services. Implications for the role of school counseling services for SGM youths were discussed based on the findings of this work and the suggestions offered by the interviewed SGM youths. Supplementary Information: The online version contains supplementary material available at 10.1007/s10447-022-09490-0.

Electrostatic Stabilization of Nano Liquid Metals in Doped Nonpolar Liquids.

Liquid metals and alloys are attracting renewed attention owing to their potential for application in various advanced technologies. Eutectic gallium-indium (EGaIn) has been focused on in particular because of its integrated advantages of high conductivity, low melting point, and low toxicity. In this study, the colloidal behavior of nano-dispersed EGaIn in nonpolar oils is investigated. Although the nonpolar oil continuous phase is commonly considered to be free of electric charges, electrostatic repulsion appears to be crucial in the colloidal stabilization of the nano-dispersed EGaIn phases, the modulation of which is possible by doping the oil phases with different types of oil-soluble surfactants. The qualitative correlation between the observed colloidal stabilities and the "zero field" particle mobilities inferred from the field-dependent electrophoretic mobilities indicates that the electric charging of EGaIn particles in surfactant-doped nonpolar oils is a static phenomenon that is maintained in equilibrium, rather than a solely field-induced process. A systematic investigation of the charging properties of these unique biphasic particles, consisting of the liquid Ga-In bulk and the solid Ga2 O3 surface that formed spontaneously, reveals the complicated system-dependent nature of the charging mechanisms mediated by ionic and nonionic surfactants in nonpolar media.

Electric Field-Driven Liquid Metal Droplet Generation and Direction Manipulation.

A gallium-based liquid metal got high attention recently, due to the excellent material properties that are useful in various research areas. We report here on electric field-induced liquid metal droplet generation and falling direction manipulation. The well-analyzed electro-hydrodynamic method is a selectable way to control the liquid metal, as the liquid metal is conductive. The electric field-induced liquid metal manipulation can be affected by the flow rate (0.05~0.2 mL/min), voltage (0~7 kV), and distance (15 and 30 mm) between electrodes, which changes the volume of the electric field-induced generated liquid metal droplet and the number of the generated droplets. When the electric field intensity increases or the flow rate increases, the generated droplet volume decreases, and the number of droplets increases. With the highest voltage of 7 kV with 15 mm between electrodes at the 0.2 mL/min flow rate, the lowest volume and the largest number of the generated droplets for 10 s were ~10 nL and 541, respectively. Additionally, we controlled the direction of the generated droplet by changing the electric field. The direction of the liquid metal droplet was controlled with the maximum angle of ~12°. Moreover, we exhibited a short circuit demonstration by controlling the volume or falling direction of the generated liquid metal droplet with an applied electric field.

Electromagnetic three dimensional liquid metal manipulation.

In this paper, we report three-dimensional (3-D) liquid metal manipulation using electromagnets, which can be applied to electrical switching applications. The liquid metal droplet was coated with iron (Fe) particles by chemical reaction with hydrochloric acid (HCl), and thus it became responsive to the magnetic field, becoming a magnetic liquid metal marble. Using electromagnets, the magnetic field was turned on and off on-demand. We investigated an average velocity and the maximum working distance of the horizontal and vertical electromagnetic field-driven manipulation of the magnetic liquid metal marble. Linear (1-D) and plane (2-D) manipulation of the marble was successfully demonstrated and 3-D manipulation was verified for electrical switching.

An Oligoimide Particle as a Pickering Emulsion Stabilizer.

A pyromellitic dianhydride (PMDA) and 4,4'-oxydianiline (ODA)-based oligoimide (PMDA-ODA) was synthesized by a one-step procedure using water as a solvent. The PMDA-ODA particles showed excellent partial wetting properties and were stably dispersed in both water and oil phases. A stable dispersion was not obtained with comparison PMDA-ODA particles that were synthesized by a conventional two-step method using an organic solvent. Both oil-in-water and water-in-oil Pickering emulsions were prepared using the oligoimide particles synthesized in water, and the size of the emulsion droplet was controlled based on the oligoimide particle concentration. The oligoimide particles were tested to prepare Pickering emulsions using various kinds of oils. The oil-in-water Pickering emulsions were successfully applied to prepare microcapsules of the emulsion droplets. Our new Pickering emulsion stabilizer has the advantages of easy synthesis, no need for surface modification, and the capability of stabilizing both oil-in-water and water-in-oil emulsions.

Current Awareness and Use of the Strain Echocardiography in Routine Clinical Practices: Result of a Nationwide Survey in Korea.

BACKGROUND: Because conventional echocardiographic parameters have several limitations, strain echocardiography has often been introduced in clinical practice. However, there are also obstacles in using it in clinical practice. Therefore, we wanted to find the current status of awareness on using strain echocardiography in Korea. METHODS: We conducted a nationwide survey to evaluate current use and awareness of strain echocardiography from the members of the Korean Society of Echocardiography. RESULTS: We gathered total 321 questionnaires from 25 cardiology centers in Korea. All participants were able to perform or interpret echocardiographic examinations. All participating institutions performed strain echocardiography. Most of our study participants (97%) were aware of speckle tracking echocardiography and 185 (58%) performed it for clinical and research purposes. Two-dimensional strain echocardiography was the most commonly used modality and left ventricle (LV) was the most commonly used cardiac chamber (99%) for clinical purposes. Most of the participants (89%) did not think LV strain can replace LV ejection fraction (LVEF) in their clinical practice. The common reasons for not performing routine use of strain echocardiography was diversity of strain measurements and lack of normal reference value. Many participants had a favorable view of the future of strain echocardiography. CONCLUSION: Most of our study participants were aware of strain echocardiography, and all institutions performed strain echocardiography for clinical and research purposes. However, they did not think the LV strain values could replace LVEF. The diversity of strain measurements and lack of normal reference values were common reasons for not using strain echocardiography in clinical practice.

Experimental Realization of Type-II Dirac Fermions in a PdTe_{2} Superconductor.

A Dirac fermion in a topological Dirac semimetal is a quadruple-degenerate quasiparticle state with a relativistic linear dispersion. Breaking either time-reversal or inversion symmetry turns this system into a Weyl semimetal that hosts double-degenerate Weyl fermion states with opposite chiralities. These two kinds of quasiparticles, although described by a relativistic Dirac equation, do not necessarily obey Lorentz invariance, allowing the existence of so-called type-II fermions. The recent theoretical discovery of type-II Weyl fermions evokes the prediction of type-II Dirac fermions in PtSe_{2}-type transition metal dichalcogenides, expecting experimental confirmation. Here, we report an experimental realization of type-II Dirac fermions in PdTe_{2} by angle-resolved photoemission spectroscopy combined with ab initio band calculations. Our experimental finding shows the first example that has both superconductivity and type-II Dirac fermions, which turns the topological material research into a new phase.

The changes of individual carotid artery wall layer by aging and carotid intima-media thickness value for high risk.

AIM: It is still unclear which layer (intima or media) is mainly involved in increased carotid intima-media thickness (CIMT) by aging and also unclear regarding CIMT value suggesting high cardiovascular risk, although 75th percentile value of CIMT is known as a high risk in asymptomatic adults. We sought to find the changes of carotid intima thickness (CIT) and carotid media thickness (CMT) by aging and the 75th percentile value of CIMT in asymptomatic Korean adults. METHOD: This is an observational cohort study. Carotid ultrasound findings (n=2204 from 12 hospitals) were prospectively collected. The carotid images were sent to Korea Research Institute of Standards and Science for analysis using specialized software which can measure intima and media wall also. RESULTS: Mean age was 58.1±13.5 years old (52% of men). Pearson's correlation coefficient between age and right CIMT (r=.489, P<.001) and right CMT (r=.482, P<.001) was higher than that between age and right CIT (r=.284, P<.001). Mean right CIMT in male and female was 0.696±0.163 and 0.686±0.167 mm (P=.180), and the 75 percentile value was 0.778 and 0.771 mm, respectively. Mean right CIT was 0.311±0.069 and 0.303±0.064 mm (P=.009), and mean right CMT was 0.391±0.124 and 0.388±0.131 mm (P=.694) in male and female, respectively. Left carotid ultrasound findings showed similar to the right one. CONCLUSION: An increased CIMT by aging was mainly due to increased CMT rather than CIT in asymptomatic adults. The 75th percentile values of right CIMT were 0.778 and 0.771 mm in asymptomatic Korean male and female adults, respectively.

Antioxidative Activity after Rosuvastatin Treatment in Patients with Stable Ischemic Heart Disease and Decreased High Density Lipoprotein Cholesterol.

BACKGROUND AND OBJECTIVES: The clinical significance of statin-induced high-density lipoprotein cholesterol (HDL-C) changes is not well known. We investigated whether rosuvastatin-induced HDL-C changes can influence the anti-oxidative action of high-density lipoprotein particle. SUBJECTS AND METHODS: A total of 240 patients with stable ischemic heart disease were studied. Anti-oxidative property was assessed by paraoxonase 1 (PON1) activity. We compared the lipid profile and PON1 activity at baseline and at 8 weeks after rosuvastatin 10 mg treatment. RESULTS: Rosuvastatin treatment increased the mean HDL-C concentration by 1.9±9.2 mg/dL (6.4±21.4%). HDL-C increased in 138 patients (57.5%), but decreased in 102 patients (42.5%) after statin treatment. PON1 activity increased to 19.1% in all patients. In both, the patients with increased HDL-C and with decreased HDL-C, PON1 activity significantly increased after rosuvastatin treatment (+19.3% in increased HDL-C responder; p=0.018, +18.8% in decreased HDL-C responder; p=0.045 by paired t-test). Baseline PON1 activity modestly correlated with HDL-C levels (r=0.248, p=0.009); however, the PON1 activity evaluated during the course of the treatment did not correlate with HDL-C levels (r=0.153, p=0.075). CONCLUSION: Rosuvastatin treatment improved the anti-oxidative properties as assessed by PON1 activity, regardless of on-treatment HDL-C levels, in patients with stable ischemic heart disease.

Diurnal variation of flow-mediated dilatation in healthy humans.

INTRODUCTION: The measurement of flow-mediated dilatation (FMD) via ultrasound has been established as a reliable non-invasive measurement of endothelial function. However, the guidelines mention nothing regarding diurnal variation of FMD. Thus, we investigated the FMD in healthy people and diurnal variation of FMD. METHODS: Twenty-five apparently healthy persons participated in this study. All participants had no history of cardiovascular diseases, hypertension, or diabetes and used any medication. For each volunteer, the measurements were repeated in the morning and afternoon on two different days. We checked capillary blood glucose, total cholesterol, triglyceride, high-density lipoprotein (HDL), and low-density lipoprotein (LDL)-cholesterol. RESULTS: The average of FMD measurements was 8.45% ± 2.39%. The mean values of systolic and diastolic blood pressure, heart rate, lipid profiles, and glucose levels were similar between the morning and afternoon measurements after 9-h fasting. There was no significant difference of FMD measurements between the morning and afternoon (8.32% ± 2.27% and 8.58% ± 2.56%, p = 0.329). Moreover, there was significant correlation between FMD in the morning and afternoon (r = 0.856, p < 0.001). CONCLUSIONS: Our study shows measurement of FMD was 8.45% in healthy Koreans. Also, there was no significant difference of FMD measurements between the morning and afternoon.

Effect of High Dose Rosuvastatin Loading before Primary Percutaneous Coronary Intervention on Infarct Size in Patients with ST-Segment Elevation Myocardial Infarction.

BACKGROUND AND OBJECTIVES: High dose rosuvastatin loading before percutaneous coronary interventions (PCI) reduces the myocardial damage and the incidence of adverse cardiac events in patients with stable angina and acute coronary syndrome. However, no studies are present yet about rosuvastatin loading in patients with ST-segment elevation myocardial infarction (STEMI) in a primary PCI setting. SUBJECTS AND METHODS: A total of 475 patients who underwent primary PCI for STEMI were studied. The study population was divided into two groups with 208 patients in the statin group=40 mg rosuvastatin loading before primary PCI and 267 patients in the control group=no statin pretreatment. At median 3 days after PCI a single-photon emission computed tomography (SPECT) was performed with technetium 99m tetrofosmin For this study were compared infarct size, corrected Thrombolysis in Myocardial Infarction (TIMI) frame count and the myocardial blush grade (MBG) between the both groups. RESULTS: Baseline clinical and procedural characteristics were similar between the groups. Infarct size, as assessed by SPECT, was significantly smaller (19.0±15.9% vs. 22.9±16.5%, p=0.009) in the statin group than in the control group. Patients of the statin group showed a lower corrected TIMI frame count (28.2±19.3 vs. 32.6±21.4, p=0.020), and higher MBG (2.49±0.76 vs. 2.23±0.96, p=0.001) than the patients of the control group. The multivariate analysis revealed that rosuvastatin loading {odds ratio (OR) 0.61}, pain to balloon time (OR 2.05), anterior myocardial infarction (OR 3.89) and final the MBG (OR 2.93) were independent predictors of a large infarct size. CONCLUSION: A high dose rosuvastatin loading before the primary PCI reduced the infarct size by microvascular myocardial perfusion improvement.

Direct observation of localized spin antiferromagnetic transition in PdCrO2 by angle-resolved photoemission spectroscopy.

We report the first case of the successful measurements of a localized spin antiferromagnetic transition in delafossite-type PdCrO2 by angle-resolved photoemission spectroscopy (ARPES). This demonstrates how to circumvent the shortcomings of ARPES for investigation of magnetism involved with localized spins in limited size of two-dimensional crystals or multi-layer thin films that neutron scattering can hardly study due to lack of bulk compared to surface. Also, our observations give direct evidence for the spin ordering pattern of Cr(3+) ions in PdCrO2 suggested by neutron diffraction and quantum oscillation measurements, and provide a strong constraint that has to be satisfied by a microscopic mechanism for the unconventional anomalous Hall effect recently reported in this system.

Long-Term Predictors of Clinical Events after Off-Label Use of Drug-Eluting Stent beyond 1 Year.

BACKGROUND AND OBJECTIVES: We evaluated the long-term outcomes and predictors of clinical events after off-label use of drug-eluting stents (DES) beyond 1 year after procedure. SUBJECTS AND METHODS: A total of 518 patients who underwent DES implantation for off-label indications and did not have any major adverse cardiac events (MACE) during the first year were analyzed. The occurrence of MACE, including cardiac death, myocardial infarction (MI), stent thrombosis and target vessel revascularization, were evaluated for a median 1179 days (interquartile range 769-1541) after the first year. RESULTS: Major adverse cardiac events occurred in 43 patients (8.3%) including 8 cases (1.5%) of cardiac death, 9 cases (1.7%) of MI, 24 cases (4.6%) of target vessel revascularization, and 11 cases (2.1%) of stent thrombosis. Patients with MACE had a higher serum creatinine level, higher incidence of in-stent restenosis lesion, more overlapping stents, a greater number of stents, and longer stents than did patients without MACE. Multivariate analysis revealed that serum creatinine level >1.5 mg/dL {hazard ratio (HR) 2.3, p=0.019}, stent length >33 mm (HR 2.4, p=0.035), and in-stent restenosis lesions (HR 2.4, p=0.040) were independent risk factors for MACE. Patients with DES length >33 mm had a higher incidence of MACE than those with DES length ≤33 mm (HR 2.7, log rank p=0.002). CONCLUSION: The risk of stent thrombosis and target vessel revascularization persisted in patients undergoing off-label DES implantation beyond 1-year follow-up. A total DES length >33 mm was a significant procedural predictor associated with the incidence of MACE.

Rosuvastatin-induced high-density lipoprotein changes in patients who underwent percutaneous coronary intervention for non-ST-segment elevation acute coronary syndrome.

BACKGROUND: Clinical significance of statin-induced high-density lipoprotein cholesterol (HDL-C) changes is not well known. We investigated the factors affecting rosuvastatin-induced HDL-C changes and their correlation with 12-month major adverse cardiovascular events (MACE) in patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS) and percutaneous coronary intervention (PCI). MATERIALS AND METHODS: We analyzed 556 consecutive NSTE-ACS patients who underwent PCI and received rosuvastatin 10mg before discharge. We measured serum lipids, including total cholesterol, triglycerides (TGs), low-density lipoprotein cholesterol (LDL-C), and HDL-C at baseline and at 4 weeks. The relationship between on-treatment lipid levels, baseline lipid levels, and 12-month MACE was assessed. RESULTS: Rosuvastatin treatment increased the mean HDL-C concentration by 1.1 ± 9.8 mg/dl (4.3 ± 23.0%). HDL-C was increased in 312 patients (56.1%), but decreased in 244 patients (43.9%) after statin treatment. Changes in HDL-C during first month were inversely correlated with baseline HDL-C levels (r=-0.379, p<0.001). The patients with increased HDL-C showed higher baseline TG levels but lower on-treatment TG levels. Changes in TG were correlated with changes in HDL-C (r=-0.212, p<0.001). The incidence of 12-month MACE according to changes in HDL-C was similar between the two groups (11.9% vs. 12.3%, p=0.875). Multivariate analysis revealed that baseline HDL-C level was the only significant predictor of rosuvastatin-induced HDL-C changes. CONCLUSION: Baseline HDL-C concentration was an independent predictor of rosuvastatin-induced HDL-C changes. Statin-induced HDL-C changes did not predict 12-month MACE in patients with NSTE-ACS.

The Number of Endothelial Progenitor Cells is Decreased in Patients With Non-Dipper Hypertension.

BACKGROUND AND OBJECTIVES: Circulating endothelial progenitor cells (EPCs) play a key role in the maintenance of endothelial homeostasis and promote vascular repair. A reduced number of EPCs and the functional activity have been associated with several cardiovascular risk factors. However, the relationship between the number of EPCs and circadian rhythm of the blood pressure (BP) remains unclear. The purpose of the present study was to evaluate the relationship between the circadian rhythm of the BP and EPCs in patients with essential hypertension. SUBJECTS AND METHODS: A total of 45 patients with essential hypertension who were newly identified by outpatient BP measurements, underwent 24-hour ambulatory BP monitoring. Among the 45 patients with essential hypertension, 20 were classified as dippers (12 men and 8 women; mean age 48±14 years) and 25 as non-dippers (14 men and 11 women; mean age 52±18 years). The EPC count was isolated from the peripheral bloodstream and quantified by flow cytometry. RESULTS: The baseline clinical characteristics were similar between the dipper and non-dipper hypertensive patients. The circulating EPCs were statistically reduced in the non-dipper patients as compared to the dippers (104±60 vs. 66±47 EPCs per 106 mononuclear cells, p=0.027). The circulating EPC level correlated positively with the circadian changes in the systolic and diastolic BP (r=0.435, p=0.003, and r=0.310, p=0.038, respectively). CONCLUSION: The present study demonstrated that the EPC count was reduced in the peripheral bloodstream in non-dipper hypertensive patients.

Evaluation of the dose-response relationship of amlodipine and losartan combination in patients with essential hypertension: an 8-week, randomized, double-blind, factorial, phase II, multicenter study.

BACKGROUND: Despite recommendations for more intensive treatment and the availability of several effective treatments, hypertension remains uncontrolled in many patients. OBJECTIVE: The aim of this study was to determine the dose-response relationship and assess the efficacy and safety of amlodipine or losartan monotherapy and amlodipine camsylate/losartan combination therapy in patients with essential hypertension. METHODS: This was an 8-week, randomized, double-blind, factorial design, phase II, multicenter study conducted in outpatient hospital clinics among adult patients aged 18-75 years with essential hypertension. At screening, patients received placebo for 2-4 weeks. Eligible patients (n=320) were randomized to one of eight treatment groups: amlodipine 5 mg or 10 mg, losartan 50 mg or 100 mg, amlodipine camsylate/losartan 5 mg/50 mg, 5 mg/100 mg, 10 mg/50 mg, or 10 mg/100 mg. MAIN OUTCOME MEASURES: The assumption of strict superiority was estimated using the mean change in sitting diastolic blood pressure (DBP) at 8 weeks. Safety was monitored through physical examinations, vital signs, laboratory test results, ECG, and adverse events. RESULTS: The reduction in DBP at 8 weeks was significantly greater in patients treated with the combination therapies compared with the respective monotherapies for all specified comparisons except amlodipine camsylate/losartan 10 mg/100 mg versus amlodipine 10 mg. The incidence of adverse events in the group of patients treated with the amlodipine camsylate/losartan 10 mg/50 mg combination tended to be higher than for any other group (27.9%, 12/43); however, the effect was not statistically significant. CONCLUSION: Combination amlodipine camsylate/losartan (5 mg/50 mg, 5 mg/100 mg and 10 mg/50 mg) resulted in significantly greater BP lowering compared with amlodipine or losartan monotherapy, and was determined to be generally safe and tolerable in patients with essential hypertension. CLINICAL TRIAL REGISTRATION: Registered at clinicaltrials.gov: NCT00942344.

Coronary artery responsiveness to ergonovine provocation in patients without vasospatic angina: a quantitative coronary angiography analysis.

Even patients without vasospastic angina show vasoconstriction after intracoronary ergonovine administration. We evaluated the determinants of coronary artery responsiveness to ergonovine in such patients.In 165 patients with no provoked electrocardiographic changes or ischemic chest pain during an intracoronary ergonovine test, total cholesterol, triglycerides (TG), high density lipoprotein cholesterol (HDL), and low density lipoprotein cholesterol (LDL) were correlated with the arterial luminal diameters before and after ergonovine infusion and after nitroglycerin injection by quantitative coronary angiography analysis.The mean and maximal basal tone (ie, percent change between baseline luminal diameter and diameter after nitroglycerin) were 7.0 ± 9.9% and 27.9 ± 10.8%, respectively. The mean and maximal responsiveness to ergonovine (ie, percent change between minimal diameter during ergonovine infusion and diameter after nitroglycerin) were 30.3 ± 13.6% and 52.7 ± 16.0%, respectively. The TG level (r = 0.191, P = 0.016) and TG/HDL ratio (r = 0.182, P = 0.021) were positively correlated with the basal tone, whereas LDL level (r = 0.155, P = 0.048) and LDL/HDL ratio (r = 0.172, P = 0.030) were positively correlated with the responsiveness to ergonovine. By multivariate analysis, LDL level, LDL/HDL ratio, and smoking were independent predictors of more than 50% responsiveness to ergonovine.Serum lipid profile and smoking influence the basal tone and responsiveness to ergonovine of coronary artery in patients without vaospastic angina.

Left ventricular thrombus associated with takotsubo cardiomyopathy: a cardioembolic cause of cerebral infarction.

Takotsubo cardiomyopathy, also called stress-induced cardiomyopathy, usually occurs in patients with severe emotional or physiologic stress. The prognosis is favorable, and the wall motion abnormlities normalize within weeks. However, stress-induced cardiomyopathy is rarely assosicated with left ventricular thrombus and thromboembolic complications. Here, we report a case of stress-induced cardiomyopathy with left ventricular thrombus that embolized to cause cerebral infarction.

Effect of previous statin therapy in patients with acute coronary syndrome and percutaneous coronary intervention.

BACKGROUND AND OBJECTIVES: Statin therapy after percutaneous coronary intervention (PCI) has been associated with reduced major adverse cardiovascular events (MACE). However, it has been less clear as to whether statin therapy before acute coronary syndrome (ACS) is beneficial. We studied the effect of previous statin therapy, initiated ≥1 month before PCI, on the outcome of patients with ACS who had undergone early invasive strategies. SUBJECTS AND METHODS: We stratified 479 consecutive patients with ACS who had undergone PCI, according to preprocedural statin administration as follows: previous statin-treated patients (statin group, n=237) and statin-naive patients (control group, n=242). The incidence of periprocedural myocardial infarction (MI) and in-hospital MACE was assessed. RESULTS: The incidence of Braunwald class III angina and MI presentation were significantly lower in the statin group than in the control group. Angiographic and procedural characteristics were similar between the two groups; however, slow/no reflow phenomenon occurred more frequently in the control group. After PCI, the incidence of periprocedural MI was higher in the control group than in the statin group (6.6% vs. 2.1%, p=0.016). Multivariate analysis revealed that no prior use of statin {odds ratio (OR)=2.8; 95% confidence interval (CI)=1.1-7.2; p=0.038), procedural complication (OR=4.0; 95% CI=1.5-10.5; p=0.004), stent overlap (OR=4.7; 95% CI=1.3-16.4; p=0.015), and old age (OR=3.2; 95% CI=1.2-8.0; p=0.016) were independent predictors for in-hospital MACE. CONCLUSION: Previous statin therapy before ACS was associated with milder clinical presentation and lower incidence of in-hospital MACE after early invasive strategies. The beneficial outcome is attributable to a significant reduction in periprocedural MI after PCI.