Indications for Sleeve Gastrectomy-Is It Worth Waiting for Comorbidities to Develop?

(1) Background and Objectives: Morbid obesity significantly increases the prevalence of comorbidities, such as heart disease, restrictive lung disease, stroke, diabetes mellitus and more. (2) Methods: Patients undergoing gastric sleeve surgery were divided into three groups with BMI between 30-34.9 kg/m2 (Group I), 35-39.9 kg/m2 (Group II), and over 40 kg/m2 (Group III). Preoperative examinations included cardiac ultrasound, respiratory function and laboratory tests, and preoperative comorbidities were also recorded. Following a one-year follow-up, we compared the rate of weight loss in the three groups at six months and one year following surgery, specifically, the effect of surgery on preoperative comorbidities at one year. (3) Results: The weight loss surgeries performed were successful in all three groups. Preoperative laboratory examinations, an echocardiogram and respiratory function results showed no clinically significant difference, except moderate elevations in blood lipid levels. Hypertension was the most common comorbidity. (4) Conclusions: In our patient population, hypertension and diabetes were the only comorbidities with a high prevalence. It can be explained by the relatively younger age among the patients (mean age 44.5 years) and the fact that they had not yet developed the pathological consequences of severe obesity. Consequently, while performing the surgery at a relatively younger age, it seems far more likely that the patient will return to a more active and productive life and enjoy a better quality of life. Additionally, the perioperative risk is lower, and the burden upon health systems and health expenditure is reduced by preventing comorbidities, in particular, multimorbidity. On this basis, it may be advisable to direct patients who do not exhaust the classical indications for bariatric surgery toward the surgical solution at a younger age. Our results suggest it is not worth waiting for comorbidities, especially multimorbidity, to appear.

Hydrothermal alteration and Cu-Ni-PGE mobilization in the charnockitic rocks of the footwall of the South Kawishiwi intrusion, Duluth Complex, USA.

In the Neoarchean (~ 2.7 Ga) contact metamorphosed charnockitic footwall of the Mesoproterosoic (1.1 Ga) South Kawishiwi intrusion of the Duluth Complex, the primary metamorphic mineral assemblage and Cu-Ni-PGE sulfide mineralization is overprinted by an actinolite + chlorite + cummingtonite + prehnite + pumpellyite + quartz + calcite hydrothermal mineral assemblage along 2-3 cm thick veins. In calcite, hosted by the hydrothermal alteration zones and in a single recrystallized quartz porphyroblast, four different fluid inclusion assemblages are documented; the composition of these fluid inclusions provide p-T conditions of the fluid flow, and helps to define the origin of the fluids and evaluate their role in the remobilization and reprecipitation of the primary metamorphic sulfide assemblage. Pure CO2 fluid inclusions were found as early inclusions in recrystallized quartz porphyroblast. These inclusions may have been trapped during the recrystallization of the quartz during the contact metamorphism of the footwall charnockite in the footwall of the SKI. The estimated trapping pressure (1.6-2.0 kbar) and temperature (810-920 °C) conditions correspond to estimates based on felsic veins in the basal zones of the South Kawishiwi intrusion. Fluid inclusion assemblages with CO2-H2O-NaCl and CH4-N2-H2O-NaCl compositions found in this study along healed microfractures in the recrystallized quartz porphyroblast establish the heterogeneous state of the fluids during entrapment. The estimated trapping pressure and temperature conditions (240-650 bar and 120-150 °C for CO2-H2O-NaCl inclusions and 315-360 bar and 145-165 °C for CH4-N2-H2O-NaCl inclusions) are significantly lower than the p-T conditions (> 700 °C and 1.6-2 kbar) during the contact metamorphism, indicating that this fluid flow might not be related to the cooling of the Duluth Complex and its contact aureole. The presence of chalcopyrite inclusions in these fluid inclusions and in the trails of these fluid inclusion assemblages confirms that at least on local scale these fluids played a role in base metal remobilization. No evidences have been observed for PGE remobilization and transport in the samples. The source of the carbonic phase in the carbonic assemblages (CO2; CH4) could be the graphite, present in the metasedimentary hornfelsed inclusions in the basal zones of the South Kawishiwi intrusion. The hydrothermal veins in the charnockite can be characterized by an actinolite + cummingtonite + chlorite + prehnite + pumpellyite + calcite (I-II) + quartz mineral assemblage. Chlorite thermometry yields temperatures around 276-308 °C during the earliest phase of the fluid flow. In the late calcite (II) phase, high salinity (21.6-28.8 NaCl + CaCl2 equiv. wt.%), low temperature (90-160 °C), primary aqueous inclusions were found. Chalcopyrite (± sphalerite ± millerite), replacing and intersecting the early hydrothermal phases, are associated to the late calcite (II) phase. The composition of the formational fluids in the Canadian Shield is comparable with the composition of the studied fluid inclusions. This suggests that the composition of the fluids did not change in the past 2 Ga and base metal remobilization by formational fluids could have taken place any time after the formation of the South Kawishiwi intrusion. Sulfur isotope studies carried out on the primary metamorphic (δ34S = 7.4-8.9‰) and the hydrothermal sulfide mineral assemblage (δ34S = 5.5-5.7‰) proves, that during the hydrothermal fluid flow the primary metamorphic ores were remobilized.

Investigation of the effectiveness of prehospital amputation devices on cadavers.

Amputations take place in the operating rooms. At dangerous sites, circumstances may necessitate on-site amputation to save lives. Currently, there are no evidence-based guidelines for the execution of the amputation or the instruments to be chosen. Furthermore, there are no widely accepted criteria for the standardized characterization of amputation devices. The present study examined the effectiveness of commercially available cutting tools and instruments used by rescue services as possible on-site amputation tools. Five different tools (Holmatro type hydraulic cutter, with two cutting attachments, reciprocating saw, hacksaw, Gigli saw) were used to carry out amputations on designated locations on cadavers (brachial, antebrachial, femoral, and crural regions). During the experiment, the time required for amputation and the number of necessary cutting attempts to detach limbs were recorded. The proximal cut surfaces were analyzed with the help of post-amputation CT scan-based 3D models. An Amputation Index (AI) was determined for each device in each examined region based on the cut surface quality. An Amputation Score (AS) was calculated using the time required for cutting, the number of cutting attempts, and the AI. With the help of AS, the usability of the used devices was determined. According to our scoring system, the reciprocating saw proved the most effective tool. Based on our results, we recommend the consideration and further investigation of the reciprocating saw as a possible on-site amputation device, as well as the introduction of the Amputation Score as an objective and quantitative indicator in the future characterization of on-site amputation devices.

Predictability of cortico-cortical connections in the mammalian brain.

Despite a five order of magnitude range in size, the brains of mammals share many anatomical and functional characteristics that translate into cortical network commonalities. Here we develop a machine learning framework to quantify the degree of predictability of the weighted interareal cortical matrix. Partial network connectivity data were obtained with retrograde tract-tracing experiments generated with a consistent methodology, supplemented by projection length measurements in a nonhuman primate (macaque) and a rodent (mouse). We show that there is a significant level of predictability embedded in the interareal cortical networks of both species. At the binary level, links are predictable with an area under the ROC curve of at least 0.8 for the macaque. Weighted medium and strong links are predictable with an 85%-90% accuracy (mouse) and 70%-80% (macaque), whereas weak links are not predictable in either species. These observations reinforce earlier observations that the formation and evolution of the cortical network at the mesoscale is, to a large extent, rule based. Using the methodology presented here, we performed imputations on all area pairs, generating samples for the complete interareal network in both species. These are necessary for comparative studies of the connectome with minimal bias, both within and across species.

Validation of a novel, low-fidelity virtual reality simulator and an artificial intelligence assessment approach for peg transfer laparoscopic training.

Simulators are widely used in medical education, but objective and automatic assessment is not feasible with low-fidelity simulators, which can be solved with artificial intelligence (AI) and virtual reality (VR) solutions. The effectiveness of a custom-made VR simulator and an AI-based evaluator of a laparoscopic peg transfer exercise was investigated. Sixty medical students were involved in a single-blinded randomised controlled study to compare the VR simulator with the traditional box trainer. A total of 240 peg transfer exercises from the Fundamentals of Laparoscopic Surgery programme were analysed. The experts and AI-based software used the same criteria for evaluation. The algorithm detected pitfalls and measured exercise duration. Skill improvement showed no significant difference between the VR and control groups. The AI-based evaluator exhibited 95% agreement with the manual assessment. The average difference between the exercise durations measured by the two evaluation methods was 2.61 s. The duration of the algorithmic assessment was 59.47 s faster than the manual assessment. The VR simulator was an effective alternative practice compared with the training box simulator. The AI-based evaluation produced similar results compared with the manual assessment, and it could significantly reduce the evaluation time. AI and VR could improve the effectiveness of basic laparoscopic training.

Probability of the emergence of helical precipitation patterns in the wake of reaction-diffusion fronts.

Helical and helicoidal precipitation patterns emerging in the wake of reaction-diffusion fronts are studied. In our experiments, these chiral structures arise with well-defined probabilities P(H) controlled by conditions such as, e.g., the initial concentration of the reagents. We develop a model which describes the observed experimental trends. The results suggest that P(H) is determined by a delicate interplay among the time and length scales related to the front and to the unstable precipitation modes and, furthermore, that the noise amplitude also plays a quantifiable role.

Evaluation of arterial stiffness for predicting future cardiovascular events in patients with ST segment elevation and non-ST segment elevation myocardial infarction.

BACKGROUND: Arterial stiffness parameters in patients who experienced MACE after acute MI have not been studied sufficiently. We investigated arterial stiffness parameters in patients with ST segment elevation (STEMI) and non-ST segment elevation myocardial infarction (NSTEMI). METHODS: Ninety-four patients with acute MI (45 STEMI and 49 NSTEMI) were included in the study. Arterial stiffness was assessed noninvasively by using TensioMed Arteriograph. RESULTS: Arterial stiffness parameters were found to be higher in NSTEMI group but did not achieve statistical significance apart from pulse pressure (P = 0.007). There was no significant difference at MACE rates between two groups. Pulse pressure and heart rate were also significantly higher in MACE observed group. Aortic pulse wave velocity (PWV), aortic augmentation index (AI), systolic area index (SAI), heart rate, and pulse pressure were higher; ejection fraction, the return time (RT), diastolic reflex area (DRA), and diastolic area index (DAI) were significantly lower in patients with major cardiovascular events. However, PWV, heart rate, and ejection fraction were independent indicators at development of MACE. CONCLUSIONS: Parameters of arterial stiffness and MACE rates were similar in patients with STEMI and NSTEMI in one year followup. The independent prognostic indicator aortic PWV may be an easy and reliable method for determining the risk of future events in patients hospitalized with acute MI.

Nonlinear heart rate variability measures under electromagnetic fields produced by GSM cellular phones.

This study was designed to assess the nonlinear dynamics of heart rate variability (HRV) during exposure to low-intensity EMFs. Twenty-six healthy young volunteers were subjected to a rest-to-stand protocol to evaluate autonomic nervous system in quiet condition (rest, vagal prevalence) and after a sympathetic activation (stand). The procedure was conducted twice in a double-blind design: once with a genuine EMFs exposure (GSM cellular phone at 900 MHz, 2 W) and once with a sham exposure (at least 24 h apart). During each session, three-lead electrocardiograms were recorded and RR series extracted off-line. The RR series were analyzed by nonlinear deterministic techniques in every phase of the protocol and during the different exposures. The analysis of the data shows there was no statistically significant effect due to GSM exposure on the nonlinear dynamics of HRV.

Arterial stiffness and pulse wave reflection in young adult heterozygous sickle cell carriers.

OBJECTIVE: Pulse wave velocity (PWV) and aortic augmentation index (AI) are indicators of arterial stiffness. Pulse wave reflection and arterial stiffness are related to cardiovascular events and sickle cell disease. However, the effect of these parameters on the heterozygous sickle cell trait (HbAS) is unknown. The aim of this study is to evaluate the arterial stiffness and wave reflection in young adult heterozygous sickle cell carriers. MATERIALS AND METHODS: We enrolled 40 volunteers (20 HbAS cases, 20 hemoglobin AA [HbAA] cases) aged between 18 and 40 years. AI and PWV values were measured by arteriography. RESULTS: Aortic blood pressure, aortic AI, and brachial AI values were significantly higher in HbAS cases compared to the control group (HbAA) (p=0.033, 0.011, and 0.011, respectively). A statistically significant positive correlation was found between aortic pulse wave velocity and mean arterial pressure, age, aortic AI, brachial AI, weight, and low-density lipoprotein levels (p=0.000, 0.017, 0.000, 0.000, 0.034, and 0.05, respectively) in the whole study population. Aortic AI and age were also significantly correlated (p=0.026). In addition, a positive correlation between aortic PWV and systolic blood pressure and a positive correlation between aortic AI and mean arterial pressure (p=0.027 and 0.009, respectively) were found in HbAS individuals. Our study reveals that mean arterial pressure and heart rate are independent determinants for the aortic AI. Mean arterial pressure and age are independent determinants for aortic PWV. CONCLUSION: Arterial stiffness measurement is an easy, cheap, and reliable method in the early diagnosis of cardiovascular disease in heterozygous sickle cell carriers. These results may depend on the amount of hemoglobin S in red blood cells. Further studies are required to investigate the blood pressure changes and its effects on arterial stiffness in order to explain the vascular aging mechanism in the HbAS trait population. CONFLICT OF INTEREST: None declared.

[Efficacy of laparoscopic sleeve gastrectomy on morbidly obese patients]. / Kórosan elhízott betegeken végzett laparoszkópos csogyomorképzés eredményességének vizsgálata.

INTRODUCTION: Obesity is a modern-day epidemic that places a significant and growing burden on the health systems of societies and their financial resources. OBJECTIVE: Our prospective, descriptive clinical study aimed to investigate the effect of laparoscopic gastric sleeve surgery in morbidly obese patients through a one-year follow-up. METHOD: In our study, we included 151 patients who underwent laparoscopic gastric sleeve surgery. We performed cardiac ultrasound, respiratory function and laboratory tests for pre-operative examination, possible co-morbidities were assessed, and the parameters of morbid obesity were also recorded, before surgery, half a year and one year after. RESULTS: Patients' body mass index decreased by 26.9% in the first six months and by 35.4% overall at one year, and body fat percentage decreased by 26.2% and 35%, respectively, over the same time intervals. The average age of patients was 41 years. Pre-operative cardiac ultrasound, respiratory function and laboratory tests showed no significant pathological abnormalities and a low rate of co-morbidities were associated with obesity (hypertension 51.7%, type two diabetes mellitus 13.8%). DISCUSSION: Based on the one-year follow-up data, the surgery was effective in weight loss, but long-term results can be expected at the five-year assessment, as there is a risk of repeated weight gain. Based on our study, in the case of failure of conservative treatment, it is recommended to perform the surgery at a young age, achieving the appropriate weight loss before the appearance or further aggravation of co-morbidities. Thus, the perioperative risk (and the probability of the subsequent development or further deterioration of co-morbidities) will decrease; conversely, the number of years spent in a better quality of life will increase. CONCLUSION: Laparoscopic sleeve gastrectomy is an effective weight loss procedure in the short term. If conservative treatment is ineffective, it is worthwhile to steer the patient towards invasive procedures as soon as possible to reduce the perioperative risk and the number of years spent in poor quality of life. Orv Hetil. 2023; 164(44): 1749-1754.

Validation of 3D printed MAYO tubes and stethoscope in simulated medical environment - Tools fabricated with additive manufacturing for emergency care.

Emergency and disaster medical care often face resource or equipment shortages. 3D printing technology has been proven to be effective in cases with insufficient supply chains. MAYO tubes and stethoscopes are essential components of ABCDE patient examinations; however, 3D-printed variants have not been fully tested. These 3D-printed instruments were substituted and validated in a simulated pre-hospital environment. In total, 26 participants were included in this study. Fifteen clinicians or paramedics with at least 3 years of professional experience and 10 medical students. One student was excluded because he had relevant experience with emergency care. As basic tasks, the placement of MAYO tubes and auscultation with stethoscopes were performed using medical simulators. 3D printed instruments were compared with conventional clinical devices by measuring the time required for the intervention, success rate, and user satisfaction. In the study FFF (Fused Filament Fabrication (FFF), SLS (Selective Laser Sintering (SLS), and SLA (stereolithography) 3D printing were used in this study. The times required for implementation and auscultation were examined for each instrument. There was no significant difference between the MAYO tube (p = 0.798) and the stethoscope (p = 0.676). In the case of stethoscopy, the study investigated the correct diagnosis, and no significant difference was found (p = 0.239), although an interesting trend was observed. Regarding the MAYO tube, the study found no significant difference in correct position formation (p = 0.163). The experience levels of the groups did not influence these factors. However, significant differences in user satisfaction were found in both cases in favour of the conventional versions (p < 0.001). Overall, the results of this study suggest that 3D-printed devices could be suitable replacements for clinic-based devices in emergency situations. The 3D-printed devices did not perform inferiorly at any of the indicated points compared to their classical counterparts. However, the practical applicability of the devices used in this study requires further investigation.

Asymmetry underlies stability in power grids.

Behavioral homogeneity is often critical for the functioning of network systems of interacting entities. In power grids, whose stable operation requires generator frequencies to be synchronized-and thus homogeneous-across the network, previous work suggests that the stability of synchronous states can be improved by making the generators homogeneous. Here, we show that a substantial additional improvement is possible by instead making the generators suitably heterogeneous. We develop a general method for attributing this counterintuitive effect to converse symmetry breaking, a recently established phenomenon in which the system must be asymmetric to maintain a stable symmetric state. These findings constitute the first demonstration of converse symmetry breaking in real-world systems, and our method promises to enable identification of this phenomenon in other networks whose functions rely on behavioral homogeneity.

Manufacturing a First Upper Molar Dental Forceps Using Continuous Fiber Reinforcement (CFR) Additive Manufacturing Technology with Carbon-Reinforced Polyamide.

3D printing is an emerging and disruptive technology, supporting the field of medicine over the past decades. In the recent years, the use of additive manufacturing (AM) has had a strong impact on everyday dental applications. Despite remarkable previous results from interdisciplinary research teams, there is no evidence or recommendation about the proper fabrication of handheld medical devices using desktop 3D printers. The aim of this study was to critically examine and compare the mechanical behavior of materials printed with FFF (fused filament fabrication) and CFR (continuous fiber reinforcement) additive manufacturing technologies, and to create and evaluate a massive and practically usable right upper molar forceps. Flexural and torsion fatigue tests, as well as Shore D measurements, were performed. The tensile strength was also measured in the case of the composite material. The flexural tests revealed the measured force values to have a linear correlation with the bending between the 10 mm (17.06 N at 5000th cycle) and 30 mm (37.99 N at 5000th cycle) deflection range. The findings were supported by scanning electron microscopy (SEM) images. Based on the results of the mechanical and structural tests, a dental forceps was designed, 3D printed using CFR technology, and validated by five dentists using a Likert scale. In addition, the vertical force of extraction was measured using a unique molar tooth model, where the reference test was carried out using a standard metal right upper molar forceps. Surprisingly, the tests revealed there to be no significant differences between the standard (84.80 N ± 16.96 N) and 3D-printed devices (70.30 N ± 4.41 N) in terms of extraction force in the tested range. The results also highlighted that desktop CFR technology is potentially suitable for the production of handheld medical devices that have to withstand high forces and perform load-bearing functions.

Fluids as primary carriers of sulphur and copper in magmatic assimilation.

Magmas readily react with their wall-rocks forming metamorphic contact aureoles. Sulphur and possibly metal mobilization within these contact aureoles is essential in the formation of economic magmatic sulphide deposits. We performed heating and partial melting experiments on a black shale sample from the Paleoproterozoic Virginia Formation, which is the main source of sulphur for the world-class Cu-Ni sulphide deposits of the 1.1 Ga Duluth Complex, Minnesota. These experiments show that an autochthonous devolatilization fluid effectively mobilizes carbon, sulphur, and copper in the black shale within subsolidus conditions (≤ 700 °C). Further mobilization occurs when the black shale melts and droplets of Cu-rich sulphide melt and pyrrhotite form at ∼1000 °C. The sulphide droplets attach to bubbles of devolatilization fluid, which promotes buoyancy-driven transportation in silicate melt. Our study shows that devolatilization fluids can supply large proportions of sulphur and copper in mafic-ultramafic layered intrusion-hosted Cu-Ni sulphide deposits.

[Thirty-five-year angiographic follow-up of the first coronary bypass surgery by internal mammary artery in Hungary]. / A Magyarországon végzett elso arteria mammaria interna graftolás harmincöt éves coronarographiás utánkövetése.

Coronary artery bypass grafting (CABG) plays an important role in the treatment of symptomatic coronary artery disease. During the fifty years since the first operation, a great amount of clinical observations confirm that the internal mammary artery (IMA) can be used for the bypass grafting by the most favorable outcome. IMA's histological structure and physiological properties make it resistant to atherosclerosis. In our article, we remember the first CABG operation in Hungary using IMA graft and we also confirm the favorable properties of IMA by the results of the 35-year follow-up, with the longest reported coronary angiography in the literature after IMA grafting. On the basis of this case, we can speculate that the prostacyclin secretion of the mammary graft can prevent the run-off tract of the left anterior descending (LAD) artery from the atherosclerotic progression. Large-scale study is warranted to compare the long-term prognosis of the run-off tract after grafting versus stenting of the LAD. Orv Hetil. 2020; 161(9): 354-358.

Effects of UMTS cellular phones on human hearing: results of the European project EMFnEAR.

Abstract The European project EMFnEAR was undertaken to assess potential changes in human auditory function after a short-term exposure to radiofrequency (RF) radiation produced by UMTS (Universal Mobile Telecommunication System) mobile phones. Participants were healthy young adults with no hearing or ear disorders. Auditory function was assessed immediately before and after exposure to radiofrequency radiation, and only the exposed ear was tested. Tests for the assessment of auditory function were hearing threshold level (HTL), distortion product otoacoustic emissions (DPOAE), contralateral suppression of transiently evoked otoacoustic emission (CAS effect on TEOAE), and auditory evoked potentials (AEP). The exposure consisted of speech at a typical conversational level delivered via an earphone to one ear, plus genuine or sham RF-radiation exposure produced by a commercial phone controlled by a personal computer. Results from 134 participants did not show any consistent pattern of effects on the auditory system after a 20-min UMTS exposure at the maximum output of the phone with 69 mW/kg SAR in the cochlea region in a double blind comparison of genuine and sham exposure. An isolated effect on the hearing threshold at high frequencies was identified, but this was statistically nonsignificant after correction for multiple comparisons. It is concluded that UMTS short-term exposure at the maximum output of consumer mobile phones does not cause measurable immediate effects on the human auditory system.

State observation and sensor selection for nonlinear networks.

A large variety of dynamical systems, such as chemical and biomolecular systems, can be seen as networks of nonlinear entities. Prediction, control, and identification of such nonlinear networks require knowledge of the state of the system. However, network states are usually unknown, and only a fraction of the state variables are directly measurable. The observability problem concerns reconstructing the network state from this limited information. Here, we propose a general optimization-based approach for observing the states of nonlinear networks and for optimally selecting the observed variables. Our results reveal several fundamental limitations in network observability, such as the trade-off between the fraction of observed variables and the observation length on one side, and the estimation error on the other side. We also show that, owing to the crucial role played by the dynamics, purely graph-theoretic observability approaches cannot provide conclusions about one's practical ability to estimate the states. We demonstrate the effectiveness of our methods by finding the key components in biological and combustion reaction networks from which we determine the full system state. Our results can lead to the design of novel sensing principles that can greatly advance prediction and control of the dynamics of such networks.

A continuous-time MaxSAT solver with high analog performance.

Many real-life optimization problems can be formulated in Boolean logic as MaxSAT, a class of problems where the task is finding Boolean assignments to variables satisfying the maximum number of logical constraints. Since MaxSAT is NP-hard, no algorithm is known to efficiently solve these problems. Here we present a continuous-time analog solver for MaxSAT and show that the scaling of the escape rate, an invariant of the solver's dynamics, can predict the maximum number of satisfiable constraints, often well before finding the optimal assignment. Simulating the solver, we illustrate its performance on MaxSAT competition problems, then apply it to two-color Ramsey number R(m, m) problems. Although it finds colorings without monochromatic 5-cliques of complete graphs on N ≤ 42 vertices, the best coloring for N = 43 has two monochromatic 5-cliques, supporting the conjecture that R(5, 5) = 43. This approach shows the potential of continuous-time analog dynamical systems as algorithms for discrete optimization.

A randomized comparison of a sirolimus-eluting stent with a standard stent for coronary revascularization.

BACKGROUND: The need for repeated treatment of restenosis of a treated vessel remains the main limitation of percutaneous coronary revascularization. Because sirolimus (rapamycin) inhibits the proliferation of lymphocytes and smooth-muscle cells, we compared a sirolimus-eluting stent with a standard uncoated stent in patients with angina pectoris. METHODS: We performed a randomized, double-blind trial to compare the two types of stents for revascularization of single, primary lesions in native coronary arteries. The trial included 238 patients at 19 medical centers. The primary end point was in-stent late luminal loss (the difference between the minimal luminal diameter immediately after the procedure and the diameter at six months). Secondary end points included the percentage of in-stent stenosis of the luminal diameter and the rate of restenosis (luminal narrowing of 50 percent or more). We also analyzed a composite clinical end point consisting of death, myocardial infarction, and percutaneous or surgical revascularization at 1, 6, and 12 months. RESULTS: At six months, the degree of neointimal proliferation, manifested as the mean (+/-SD) late luminal loss, was significantly lower in the sirolimus-stent group (-0.01+/-0.33 mm) than in the standard-stent group (0.80+/-0.53 mm, P<0.001). None of the patients in the sirolimus-stent group, as compared with 26.6 percent of those in the standard-stent group, had restenosis of 50 percent or more of the luminal diameter (P<0.001). There were no episodes of stent thrombosis. During a follow-up period of up to one year, the overall rate of major cardiac events was 5.8 percent in the sirolimus-stent group and 28.8 percent in the standard-stent group (P<0.001). The difference was due entirely to a higher rate of revascularization of the target vessel in the standard-stent group. CONCLUSIONS: As compared with a standard coronary stent, a sirolimus-eluting stent shows considerable promise for the prevention of neointimal proliferation, restenosis, and associated clinical events.