Prolonged Delay Time Research Articles

Analysis of head and eye dynamic may explain saccades in dizzy patients with normal VOR gain

ObjectiveCompare the vestibulo-ocular reflex (VOR) gain, compensatory saccades and head and eye coordination during head impulses between patients with dizziness but normal VOR gain and healthy controls. MethodsVideo head impulses test (vHIT; ICS impulse, Otometrics, Denmark) was reviewed in 40 participants (20 patients with dizziness; 20 controls). VOR gain, saccades characteristics (frequency of occurrence, amplitude, latency) and time difference between head and eye velocity was compared. ResultsNo significant difference between groups was observed for VOR gain. However, saccade frequency was greater and time difference between head and eye was prolonged in patients with dizziness. No significant difference was observed for saccade amplitude, nor for saccade latency between groups. ConclusionsThe present study highlights that saccades observed in patients with normal VOR gain could reflect a clinical marker for dizziness in patients with normal VOR gain. We propose that theses saccades are caused by a prolonged time delay between head and eye velocity leading to a gaze position error. SignificanceThe results support previous findings suggesting additional value of saccades and time delay when interpreting vHIT results. This study goes further by proposing time delay as a possible mechanism to explain increased saccade frequency in dizzy patients with normal VOR gain.

Ruptúra voľnej steny myokardu ako komplikácia STEMI

Myocardial free wall rupture is a rare, but serious complication of acute myocardial infarction with high mortality. We present a case of a 64-year-old patient with this devastating complication of an anterior ST segment elevation myocardial infarction (STEMI) with a prolonged time delay. Cardiac surgery was not performed due to prohibitive surgical risk and predicted poor prognosis. We describe our successful therapeutic intervention consisting of immediate pericardial drainage, vasoactive and inotropic support, intraaortic balloon pump placement and continuous veno-venous hemodialysis. This combined therapy led to patient stabilization and after incremental clinical improvement the patient was able to return to a normal life. After several months a long-term mechanical circulatory support was implanted as a bridge to heart transplant.

National and regional variations in timely adherence to recommended measles vaccination scheme in 2-years old in Switzerland, 2005–2019

BackgroundAlthough monitoring of vaccination program performance is usually evaluated by measurement of vaccine coverage, timely uptake is rarely part of this assessment. This study aims to examine the timeliness of the administration of a measles-containing-vaccine (MCV) for 2-year-old children between 2005 and 2019. MethodsWe used data from the Swiss National Vaccination Coverage Survey 2005–2019 for the study. We defined timely vaccinated as a vaccination administered within the recommended age specified in the Swiss National Vaccination Schedule, with an added tolerance period of 30.4 days for both MCV 1 and 2 doses. The median delay time was estimated by Kaplan-Meier survival curve and examined using log-rank test. A Cox hazard ratio was used to identify factors associated with delay. Results81% (95% CI:79–82%) of toddlers were timely vaccinated for MCV1 and 82% (95% CI:81–83%) for MCV2 in survey period 2017–2019. Between 2005 and 2019, the median age of vaccinated children ranged between 12.2 and 12.5 and 18.3–22.0 months for MCV1 and MCV2 with median delay of 44 and 38 days, respectively, at the national level. Children in the French-, Italian- and German-speaking regions were vaccinated earlier between 2005 and 2019 for MCV1 (vaccination coverage range before 10 months of age: 1.7–45.9%, 1.2–35.3% and 1.4–15.0%, respectively). Nationality, linguistic regions, and survey periods were the strongest predictive factors related to prolonged delay time. ConclusionOverall adherence to recommendations has improved over time, as MCV coverage has significantly increased over the years with differences across linguistic regions. Vaccinations were administered earlier and with shorter delay time.

A Diffusive Sveir Epidemic Model with Time Delay and General Incidence.

In this paper, we consider a delayed diffusive SVEIR model with general incidence. We first establish the threshold dynamics of this model. Using a Nonstandard Finite Difference (NSFD) scheme, we then give the discretization of the continuous model. Applying Lyapunov functions, global stability of the equilibria are established. Numerical simulations are presented to validate the obtained results. The prolonged time delay can lead to the elimination of the infectiousness.Electronic Supplementary MaterialSupplementary material is available in the online version of this article at 10.1007/s10473-021-0421-9.

Thrombectomy after in-house stroke in the transfer population

BackgroundPatients with large-vessel occlusion (LVO) who initially present to a non-thrombectomy-capable center (“spoke”) have worse outcomes than those presenting directly to a thrombectomy-capable center (“hub”). Furthermore, patients who suffer in-hospital strokes (IHS) suffer worse outcomes than those suffering strokes in the community. Data on patients who suffer IHS at a spoke hospital is lacking. We aim to characterize this particularly vulnerable population, define their outcomes, and compare them to patients who develop IHS at a hub institution. MethodsWe retrospectively reviewed prospectively collected data from patients suffering an IHS at a spoke hospital who were then transferred to the hub hospital for endovascular therapy (EVT). We then compared outcomes of these patients under EVT after developing IHS at the hub institution. ResultsA total of 108 IHS patients met inclusion criteria: 91 (84%) at a spoke facility and 17 (16%) at the hub facility. Baseline characteristics and reason for hospital admission were comparable between the two groups. Time from imaging to IV-tPA administration (17 vs. 70 min, p = 0.01) and time to EVT (120 vs. 247 min, p = 0.001) were significantly shorter in the hub group. More patients had a 90 day-mRS of 0-3 in the hub group than the spoke group (57% vs 22%, p < 0.05). ConclusionPatients undergoing EVT after suffering IHS at a spoke hospital have significantly higher rates of poor outcomes compared to patients who suffer IHS at a hub hospital. Prolonged time delays in the initiation of IV-tPA and EVT represent areas of improvement.

Global dynamics of a latent HIV infection model with general incidence function and multiple delays

In this paper, we propose a latent HIV infection model with general incidence function and multiple delays. We derive the positivity and boundedness of solutions, as well as the existence and local stability of the infection-free and infected equilibria. By constructing Lyapunov functionals, we establish the global stability of the equilibria based on the basic reproduction number. We further study the global dynamics of this model with Holling type-Ⅱ incidence function through numerical simulations. Our results improve and generalize some existing ones. The results show that the prolonged time delay period of the maturation of the newly produced viruses may lead to the elimination of the viruses.

Clinical and Laboratory Parameters Associated with Acute Kidney Injury in Viper Envenomed Cases

Viper species are distributed allover Egypt. Venomous bites by Viperidae snakes are associated with local and systemic manifestations and may be exacerbated by the development of acute kidney injury (AKI). THE AIM of the study was to assess acute renal injury in cases of envenomations by locally prevalent vipers as regards incidence, clinical and laboratory parameters and final outcome. METHODS: The current study was conducted on all patients, of both sex, admitted in Poison Control Center of Ain Shams University hospitals following envenomation by Viperidae snakes during 2014, 2015, and 2016. Diagnosis was based on history of snake bite with suggestive clinical data. Recorded data included patient characteristics (age, gender, delay time), vital data (heart rate, blood pressure), presence of local signs, bleeding manifestations, laboratory parameters (INR, platelet count, hemoglobin level, BUN and serum creatinine), number of antivenom vials used , duration of hospital stay and survival. Cases were sub-grouped to group I with AKI and group II without AKI. RESULTS: A total of 120 cases of venomous bites by Viperidae snakes were recorded during the study period with mortality of 4.2%. Cases were predominantly males with mean age of 35 +/-14.7years. A subset of 5.8% cases developed AKI which statistically was related to older age, longer delay time, increased incidence of bleeding manifestations and tachycardia, higher values of INR, serum creatinine, and blood urea nitrogen, lower platelet count, higher number of used antivenom vials and longer duration of hospital stay. Gender, hypotension, presence of local manifestations and hemoglobin level were insignificant among AKI. Mortality among AKI cases was statistically linked to old age, prolonged delay time, increased incidence of bleeding manifestations, higher INR values, low platelet count and low hemoglobin level and increased number of used antivenom vials and duration of hospital stay. The incidence of tachycardia, hypotension and local manifestations, serum creatinine and blood urea nitrogen levels were not statistically different among non- survivors. CONCLUSION: Acute renal injury may complicate the course of viper envenomations. Venom hemotoxicity is related to morbidity and mortality especially with older age and longer time between bite to antivenom therapy.

Survival analysis for predictive factors of delay vaccination in Iranian children

Background:Today, beside immunization coverage the age appropriate vaccination is another helpful index in public health. Evidences have shown that high immunization coverage rates do not necessarily imply age-appropriate vaccination status. The current study aimed to show the predictive factors of delayed vaccination by survival models.Methods:A historical cohort study conducted on 3610 children aged between 24 and 47 months who was living in the suburbs of five big cities of Iran. Time of delay in vaccination of first dose of mumps-measles-rubella (MMR) was calculated from date of vaccination minus age appropriate time according to vaccine card. Kaplan–Maier and Log rank tests were used for comparison the median of delay time. For controlling of confounding variables, multivariate cox model was used and hazard ratio with 95% confidence interval (95%) was reported.Results:The mean ± standard deviation and median interquartile range of delay time was 38.34 ± 73.1 and 16 (11–31) days in delayed group. The Log rank test showed that city of living, nationality, parents’ education, and birth order are related with prolonged delay time in MMR vaccination (P < 0.05). Nevertheless, child sex, prior living place (rural or city) and parent's job are not related with delay time of vaccination (P > 0.05). Cox regression showed that city of living, mother education, and nationality are the most predictive factors of delay time duration in MMR vaccination.Conclusions:Delay time duration of vaccination increased by faring from capital to the east south. Moreover, concentration of foreign immigrants in big cities and low level of mother education are the most predictors of delayed vaccination. Educational intervention should focus on immigrants and mothers with low education level.

A System of Computer Real Time Optimization Control for Refining Industry

The catalytic cracking unit, of oil refining industry, is a complex process characterized by its prolonged time delay and strong coupling ability. The unit is highly nonlinear and varies with time. Its mathematic model can be obtained online with difficulty, so as the parameters model. We describe the system of A System of Computer Real Time Optimization Control for Oil Refining Indus try ,and it is present that the system rely on coupling method of parameter identification and online simulation and synthesizing evolutionary technology of Multiple optimization strategy. It builds a single input, single output black box mathematic model. It is applied to predict the trend of system outputs, guiding the operations. This system has been adopted in several oil refineries, the benefits are pronounced.

Time to and use of reperfusion Therapy in a health Care Network

Background Time delays to reperfusion therapy in the acute phase of myocardial infarction areassociated with lower treatment efficacy. Shortening these delays requires recognizingthe specific time components in each system of care.ObjectivesThe aim of this study was to analyze the use of reperfusion therapy and the timecomponents of its implementation in a network of public hospitals.MethodsPatients with acute coronary syndromes admitted to the coronary care unit of theHospital El Cruce were included in an observational, prospective study. Patientswith acute myocardial infarction were included for the description of time intervals.ResultsDuring the study period, 327 patients with acute myocardial infarction were hospitalized.Reperfusion therapy was administered to 63.6% of patients (65.9% weretreated with fibrinolytics and 34.1% underwent primary percutaneous intervention).Time to consultation was 60 minutes (interquartile range: 30 to 180 minutes).Door-to-needle time was 75 minutes (45 to 121 minutes). The time from the firstelectrocardiogram to balloon inflation in patients transferred for primary percutaneouscoronary intervention was 240 minutes (154 to 390 minutes) and was longer inpatients transferred from hospitals outside the network (p < 0.016).ConclusionsThe use of reperfusion therapy is suboptimal, with prolonged time delays in thehealth care system. Both aspects have been considered in a network-based myocardialinfarction care protocol and this study constitutes a baseline for the evaluationof future results.

A System of Multistep Self-Learning Forecast and its Application on Oil Refining Industry

The catalytic cracking unit of oil refining industry, is a complex process characterized by its prolonged time delay and strong coupling ability.This system adopts the method of modern control theory, artificial intelligence combined effectively production techniques, researchs the problem of the multistep self-learning experience forecast online by computers and its applications in oil refinery. The system guides and optimizes the operations of the production process based on its memory, comparisons and analysis. The system is very effective to increase yield; It has been applied and popularized in 20 large-scale or middle-scale oil refining corporations.

The patient’s interpretation of myocardial infarction symptoms and its role in the decision process to seek treatment: the MONICA/KORA Myocardial Infarction Registry

The patients' misinterpretation of symptoms of an evolving acute myocardial infarction (AMI) is a major cause for prolonged pre-hospital delays. The objective of this study was to identify factors associated with an attribution of the symptoms to the heart and to investigate the association between symptom misinterpretation and time until first medical contact (delay time). The study population comprised 1,684 men and 559 women, aged 25-74 years, hospitalized with a first-time AMI recruited from a population-based AMI Registry. A total of 50.3 % of the patients attributed their experienced symptoms to the heart. Logistic regression modeling revealed that symptoms like chest pain, pain in the left upper extremity, and fear of death facilitated a correct attribution to the heart, whereas symptoms like vomiting or pain in the right upper extremity made a correct labeling difficult. Female sex, low educational status, migration background, and current smoking were associated with a higher risk of misinterpretation of symptoms. A family history of AMI or a history of angina pectoris, hypertension, and hyperlipidemia were shown to facilitate a correct interpretation of symptoms. Variables associated with a misinterpretation of symptoms did not significantly differ between men and women. People with misinterpretation of symptoms had a 1.59-fold risk (95 % confidence interval 1.33-1.90) to have a delay time of at least 2 h, compared with persons who correctly attributed their symptoms. Symptom misinterpretation is common among patients with AMI, significantly related to symptoms, sociodemographic characteristics and individual risk factors, and associated with a prolonged delay time.

Abstract 5730: Dosimetric properties of a new thermobrachytherapy seed with ferromagnetic core for treatment of solid tumors

Abstract Studies of the curative effects of hyperthermia and radiation therapy on treatment of cancer show a strong evidence of a synergistic enhancement when both radiation and hyperthermia modalities are applied simultaneously. Varieties of tissue heating approaches developed up to date still fail to overcome such essential limitations as an inadequate temperature control, temperature non-uniformity, and prolonged time delay between hyperthermia and radiation treatments. We propose a new self-regulating Thermobrachytherapy seed, which serves as a source of both radiation and heat for concurrent administration of brachytherapy and hyperthermia. The proposed seed is based on the BEST Seed Model 2301-I125, where tungsten marker core and the air gap are replaced with a ferromagnetic material. The ferromagnetic core produces heat when subjected to alternating electro-magnetic (EM) field and effectively shuts off after reaching the Curie temperature (TC) of the ferromagnetic material thus realizing the temperature self-regulation. We present the Monte Carlo study of dose rate constant and the other TG-43 radiation characteristic factors for the proposed seed. For the thermal characteristics, we studied a model consisting of 16 seeds placed in the central region of a cylindrical water phantom using a finite-element partial differential equation solver package “COMSOL Multiphysics”. The modeling result shows that temperature of the thermoseed surface rises rapidly and stays constant around TC of the ferromagnetic material. The amount of heat produced by the ferromagnetic core is sufficient to raise the temperature of the surrounding volume to the therapeutic range. The volume of the therapeutic temperature range increases with increase of frequency or magnetic field strength. These studies demonstrate that an optimal isothermal distribution can be achieved on a target volume to match with the radiation isodose distribution for the seed configuration by tuning frequency and intensity of the alternating magnetic field. The proposed combination seed model has a high potential for implementation of concurrent brachytherapy and hyperthermia. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5730. doi:1538-7445.AM2012-5730

Dosimetric and thermal properties of a newly developed thermobrachytherapy seed with ferromagnetic core for treatment of solid tumors

Studies of the curative effects of hyperthermia and radiation therapy on treatment of cancer show a strong evidence of a synergistic enhancement when both radiation and hyperthermia modalities are applied simultaneously. Varieties of tissue heating approaches developed up to date still fail to overcome such essential limitations as an inadequate temperature control, temperature nonuniformity, and prolonged time delay between hyperthermia and radiation treatments. The authors propose a new self-regulating thermobrachytherapy seed, which serves as a source of both radiation and heat for concurrent administration of brachytherapy and hyperthermia. The proposed seed is based on the BEST Medical, Inc., Seed Model 2301-I(125), where tungsten marker core and the air gap are replaced with a ferromagnetic material. The ferromagnetic core produces heat when subjected to alternating electromagnetic (EM) field and effectively shuts off after reaching the Curie temperature (T(C)) of the ferromagnetic material thus realizing the temperature self-regulation. The authors present a Monte Carlo study of the dose rate constant and other TG-43 factors for the proposed seed. For the thermal characteristics, the authors studied a model consisting of 16 seeds placed in the central region of a cylindrical water phantom using a finite-element partial differential equation solver package "COMSOL Multiphysics." The modification of the internal structure of the seed slightly changes dose rate and other TG-43 factors characterizing radiation distribution. The thermal modeling results show that the temperature of the thermoseed surface rises rapidly and stays constant around T(C) of the ferromagnetic material. The amount of heat produced by the ferromagnetic core is sufficient to raise the temperature of the surrounding phantom to the therapeutic range. The phantom volume reaching the therapeutic temperature range increases with increase in frequency or magnetic field strength. An isothermal distribution matching with the radiation isodose distribution can be achieved within a target volume by tuning frequency and intensity of the alternating magnetic field. The proposed combination seed model has a potential for implementation of concurrent brachytherapy and hyperthermia.

Inequalities in the early treatment of women and men with acute chest pain?

PurposeThe aim of this study was to identify sex differences in the early chain of care for patients with chest pain. DesignThis is a retrospective study performed at 3 centers including all patients admitted to the emergency department because of chest pain, during a 3-month period in 2008, in the municipality of Göteborg. Chest pain or discomfort in the chest was the only inclusion criterion. There were no exclusion criteria. Data SourcesData were retrospectively collected from ambulance and medical records and electrocardiogram (ECG), echocardiography, and laboratory databases. Main FindingsA total of 2588 visits (1248 women and 1340 men) made by 2393 patients were included.When adjusting for baseline variables, female sex was significantly associated with a prolonged delay time (defined as above median) between (a) admission to hospital and admission to a hospital ward (odds ratio [OR], 1.59; 95% confidence interval [CI], 1.25-2.03), (b) first physical contact and first dose of aspirin (OR, 2.22; 95% CI, 1.30-3.82), and (c) admission to hospital and coronary angiography (OR, 2.50; 95% CI, 1.29-5.13).Delay time to the first ECG recording did not differ significantly between women and men. Principal ConclusionsAmong patients hospitalized due to chest pain, when adjusting for differences at baseline, female sex was associated with a prolonged delay time until admission to a hospital ward, to administration of aspirin, and to performing a coronary angiography. There was no difference in delay to the first ECG recording.

Comparative Performance of Cell Life Span and Cell Transit Models for Describing Erythropoietic Drug Effects

Prolonged time delay in response to drug action is a common feature of hematological responses to pharmacotherapy such as erythropoiesis. The objective of this study was to compare the performance of two competing modeling approaches for delayed drug effects, mechanistic cell life span models, and semi-mechanistic cell transit models. The comparison was performed with an experimental dataset from multiple dose administrations of an erythropoietin mimetic to Cynomolgus monkeys. Comparative performance measures include visual predictive checks, goodness-of-fit plots, model estimation time, estimation status, and estimation error. The analysis revealed that both models resulted in a similarly good description of the erythropoietic drug effect, with precision and bias of the model-based predictions of red blood cell counts of less than 11%. The cell transit model needed slightly longer time to converge compared to the cell life span model. The system and drug effect parameters were similar in both models indicating that the models can be interchangeably used to describe the current data. Thus, model selection would be dependent on the purpose of the modeling exercise, the available data, and the time allocated for model development.

MO‐G‐BRA‐04: Advantages of Implementation of a Self‐Regulating Thermobrachy Seed for Solid Tumors

Introduction: The recently proposed thermobrachy seed combines a sealed radioactive source with a ferromagnetic core serving as a source for self‐ regulating hyperthermia when placed in an alternating electromagnetic field. This seed has the potential to address some shortcomings of other methods suggested for delivery of radiotherapy and hyperthermia, such as, as an inadequate temperature control due to complex invasive thermometry and feedback loops, temperature non‐uniformity, and prolonged time delay between hyperthermia and radiation treatments. Materials and Method: The thermobrachy seed consists of Ni‐Cu ferromagnetic alloy core coated with carbon containing I‐125 source and encapsulated in titanium capsule. The external dimension of the seed is the same as the BEST Model 2301 I125. In our modeling study, seeds are located in the central region of cylindrical water phantom. An alternating magnetic field was applied using an externally wrapped current carrying coil. The temperature distribution within the phantom due to the induction heating of the ferromagnetic seed was obtained using a finite element analysis method. This distribution was compared to radiation dose distribution from treatment planning system. Results: The thermoseed surface temperature rises rapidly and stays constant around the Curie temperature of the ferromagnetic material used. The temperature self‐regulation eliminates the need for invasive thermometry and simplifies the treatment procedure. The phantom volume reaching the therapeutic temperature range increases with increase of frequency or magnetic field strength. The temperature coverage over the target volume can be optimized by changing the magnetic field variables (intensity and frequency). Furthermore the tuning of the variables allows us achieving isothermal surfaces exactly similar to the radiation isodoses. Conclusion: The result shows that one can obtain the optimal isothermal distribution on the target volume to match with the prescribed radiation isodose distribution for the seed configuration by changing frequency and intensity of the alternating applied magnetic field.

TU-D-BRB-05: Three-Dimentional Dosimetric and Thermal Properties of a Newly Developed Ferromagnetic Core Thermobrachytherapy Seed for Treatment of Solid Tumors

Purpose: Studies of the curative effects of hyperthermia and radiation therapy on treatment of cancer show a strong evidence of a synergistic enhancement when two modalities are applied simultaneously. Varieties of tissue heating approaches developed up to date still fail to overcome such essential limitations as an inadequate temperature control, temperature non‐uniformity, and prolonged time delay between hyperthermia and radiation treatments. We propose a new self‐regulating Thermobrachytherapy seed, which serves as a source of both radiation and heat for concurrent administration of brachytherapy and hyperthermia. Methods: The proposed seed is based on the BEST Model 2301‐I125, where tungsten marker is replaced with a ferromagnetic material. The ferromagnetic core produces heat when subjected to alternating electro‐magnetic (EM) field and effectively shuts off after reaching its Curie temperature thus realizing the temperature self‐regulation. We studied a model consisting 32 seeds, placed in the central region of a cylindrical water phantom. The temperature distribution thorough the volume surrounding the seeds was modeled using a finite‐element partial differential equation solver package “COMSOL Multiphysics” for different EM field parameters. Results:Temperature of the thermoseed surface rises rapidly and stays constant around Curie temperature of the ferromagnetic material (Cu‐Ni alloy) used. The amount of heat produced by the ferromagnetic core is sufficient for raising the temperature of the surrounding volume to the therapeutic range. The volume of the therapeutictemperature range increases with increase of frequency or magnetic field. The temperature distribution is tunable based on the number of seeds used, their locations, magnetic field strength, and its frequency. Conclusion: The amount of heat produced by the seeds is sufficient for achieving the therapeutictemperature range in the surrounding volume when the appropriate frequency and magnetic field is applied. Our study demonstrates feasibility of the proposed combinational seed for clinical implementation of concurrent brachytherapy and hyperthermia.

Delay to reperfusion in patients with acute myocardial infarction presenting to acute care hospitals: an international perspective

To examine the extent of delay from initial hospital presentation to fibrinolytic therapy or primary percutaneous coronary intervention (PCI), characteristics associated with prolonged delay, and changes in delay patterns over time in patients with ST-segment elevation myocardial infarction (STEMI). We analysed data from 5170 patients with STEMI enrolled in the Global Registry of Acute Coronary Events from 2003 to 2007. The median elapsed time from first hospital presentation to initiation of fibrinolysis was 30 min (interquartile range 18-60) and to primary PCI was 86 min (interquartile range 53-135). Over the years under study, there were no significant changes in delay times to treatment with either strategy. Geographic region was the strongest predictor of delay to initiation of fibrinolysis >30 min. Patient's transfer status and geographic location were strongly associated with delay to primary PCI. Patients treated in Europe were least likely to experience delay to fibrinolysis or primary PCI. These data suggest no improvements in delay times from hospital presentation to initiation of fibrinolysis or primary PCI during our study period. Geographic location and patient transfer were the strongest predictors of prolonged delay time, suggesting that improvements in modifiable healthcare system factors can shorten delay to reperfusion therapy even further.

023 Impact of time on thrombus composition in STEMI patients treated with Primary PCI

To identify factors associated with change in thrombus pattern in STEMI patients undergoing primary PCI. Thrombi (n=45) were obtained using the Export thromboaspiration device in consecutive STEMI early presenters (<12hours from symptoms onset) undergoing primary PCI. Ten different areas of each thrombus were randomly scanned using a Scanning Electronic Microscope (4nm resolution). High definition pictures (Magnification 3000X) were analysed in a blinded way by a semi-quantitative and a visual approach to evaluate fibrin and platelet content (in %). The primary endpoint was fibrin and platelet content according to time delay from symptom onset (SO). All patients were enrolled in the web-based registry (e-PARIS). Mean age was 59+/-14 years, 25 (83%) were male, 16 (53%) were smoker, 12 (40%) had hypertension, 12(40%) dyslipidemia and 7(23%) were diabetic. 4 patients (13.3%) had pre-hospital cardiac arrest and 25 patients (83%) had a single vessel disease. All Patients received aspirin, clopidogrel, enoxaparin or UHF and 25 (83%) received abciximab. Thrombi were composed by 55.9±18% of fibrin (mean±SD), 16.8±18% of platelets, 11.5±9% of red cells, 5.2±8.4% of cholesterol crystal, 1.3±2.0% of white cells, and 2.8±3.7% mixed cell-fibrin. Median time delay from SO to PCI was (182 min +/- 235 IQR). There was a stepwise decrease in platelet content with respect to prolonged time delay from SO to PCI ranging from 25.6±25% in the first tertile down to 8.7±7% in the third tertile (p=0.09) (fig.). On the other hand, there was a stepwise increase in fibrin content ranging from 47.8±24% up to 67.3±9% (p=0.04). Analysis of other determinants of clot composition and relation with myocardial TIMI Blush Grade is pending. Platelet and fibrin content within the occlusive thrombus of early STEMI presenters is a fast evolving process. Time delay from symptom onset is a key determinant of thrombus composition. Thrombus content in STEMI according ischemic time