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Objective: To assess the association between coronary collateral circulation and ventricular contractile function in patients with non-reperfused acute myocardial infarction., Method: A retrospective and descriptive clinical study was conducted on patients with ST-elevation myocardial infarction (STEMI) at a reference cardiovascular center, from January 2006 to December 2022. Coronary angiographies and echocardiograms were reviewed to evaluate coronary collateral circulation and ventricular function, respectively. Patients were divided into groups based on the presence of collateral circulation. Both groups were compared and mortality during the index hospitalization was analyzed., Results: Out of a total of 14,985 patients with acute coronary syndrome, 8134 (54.3%) had the diagnosis of STEMI. We excluded 12,880, leaving a total of 2105 non-reperfused STEMI patients who underwent coronary angiography, revealing lesions. There were more patients without collateral circulation: 1547 (73.5%) vs. 558 (26.5%) (p = 0.025). Patients without collateral circulation had a higher left ventricular ejection fraction (median of 47% vs. 42%; p < 0.001). Mortality in patients with collateral circulation was higher compared to those without it (11.6% vs. 9.8%; p = 0.225), but statistical significance was not reached., Conclusions: Non-reperfused STEMI patients did not show protection from collateral circulation when assessing left ventricular systolic function. We did not find a difference in mortality compared to the population without development of collateral circulation.

Objective: To analyze the prevalence of no-reflow and the 30-day mortality in a university center in a middle-income country., Method: We analyzed 2463 patients who underwent primary PCI from January 2006 to December 2021. The outcome measure was 30-day mortality., Results: Of a total of 2463 patients, no-reflow phenomenon was found in 413 (16.8%) patients, 30-day mortality was 16.7 vs. 4.29% (p < 0.001). Patients with no-reflow were older 60 (53-69.5) vs. 59 (51-66) (p = 0.001), with a higher delay in onset of symptom to emergency department arrival 270 vs. 247 min (p = 0.001). No-reflow patients also had had fewer previous myocardial infarction, 11.6 vs. 18.4 (p = 0.001) and a Killip class > 1, 37 vs. 26% (p < 0.001). No-reflow patients were more likely to have an anterior myocardial infarction (55.4 vs. 47.8%; p = 0.005) and initial TIMI flow 0 (76 vs. 68%; p < 0.001)., Conclusion: No-reflow occurred in 16.8% of STEMI patients undergoing primary PCI and was more likely with older age, delayed presentation, anterior myocardial infarction and Killip class > 1. No-reflow was associated with a higher mortality at 30-day follow-up., (Copyright: © 2024 Permanyer.)

Background: ST-elevation myocardial infarction (STEMI) systems of care have reduced inter-hospital transfer times and facilitated timely reperfusion goals. Helicopters may be an option when land transportation is not feasible; however, the safety of air transport in patients with acute coronary syndrome (ACS) is a factor to consider., Objetives: The aim of this study was to evaluate the safety of helicopter transport for patients with ACS., Methods: Prospective, observational, and descriptive study including patients diagnosed with ACS within the STEMI network of a metropolitan city transferred by helicopter to a large cardiovascular center to undergo percutaneous coronary intervention. The primary outcome of the study was the incidence of air-travel-related complications defined as IV dislodgement, hypoxia, arrhythmia, angina, anxiety, bleeding, and hypothermia. Secondary outcomes included the individual components of the primary outcome., Results: A total of 106 patients were included in the study; the mean age was 54 years and 84.9% were male. The most frequent diagnosis was STEMI after successful fibrinolysis (51.8%), followed by STEMI with failed fibrinolysis (23.7%) and non-reperfused STEMI (9.4%). Five patients (4.7%) developed at least one complication: IV dislodgement (1.8%) and hypoxemia (1.8%) in two patients and an episode of angina during flight (0.9%). A flight altitude of > 10,000 ft was not associated with complications., Conclusions: The results of this study suggest that helicopter transportation is safe in patients undergoing acute coronary syndrome, despite the altitude of a metropolitan area., (Copyright: © 2024 Permanyer.)

Objective: The objective of the study is to identify clinical and angiographic characteristics of patients with ST-segment elevation myocardial infarction (STEMI) but without clinical manifestations of COVID-19 infection during the pandemic, compared with patients 1 year before the pandemic., Methods: Observational study that included 138 consecutive patients hospitalized with STEMI who underwent primary percutaneous coronary intervention (PCI) without COVID-19 infection during the 2020 pandemic. A group of 175 STEMI patients treated with PCI in the year before the pandemic served as the control group., Results: During the periods analyzed, compared with the control group, patients admitted during the pandemic without clinical manifestations of COVID-19 did not have significant differences in demographic characteristics, comorbidities, or delayed time and location of the acute myocardial infarction. Furthermore, there were no differences between the two groups concerning levels of CK-MB and NT-proBNP, or in inflammation markers and left ventricular ejection fraction. In patients without COVID-19 during the pandemic compared with control, we found a higher intracoronary thrombus burden (thrombus grade 5; 78.3% vs. 62.9%, respectively. p = 0.002). Accordingly, the use of glycoprotein IIB/IIIa inhibitors (37.7% vs. 26.3%, p = 0.03) was higher in these patients., Conclusions: This study demonstrates an increased thrombus burden in STEMI patients without clinical manifestation of COVID-19 during the pandemic compared with the same time period in the previous year.

Introduction: Coronary Ectasia (CE) is a pathological remodeling with a low worldwide prevalence. It is defined as a diffuse dilatation greater than 1.5 times the diameter of the adjacent segments of the same or different coronary arteries., Objective: To document the clinical and angiographic characteristics, and medical treatment at the discharge of patients diagnosed with coronary ectasia who attended the National Institute of Cardiology (INC)., Methods: Cross-sectional study with a non-experimental descriptive design, with a non-probabilistic convenience sampling., Results: Of 69 patients who attended the INC with a diagnosis of CD, most were men, with a mean age of 56 + 11 years, the most common coronary risk factor in patients with CE was smoking 58% (40); it was associated mostly with an acute myocardial infarction ST-segment elevation (STEMI) 65.2% (45), of frequent location in the lower face 40% (18), correlated with the most affected artery is the Right Coronary Artery (CD) 69.6% (48), followed by the circumflex (Cx) 56.5% (39). A mean LVEF of 47 + 9.72 was evident within the ventricular function. As well as the preferential use of dual antiplatelet therapy with anticoagulant (DAP + OAC) in 58% (40) at the discharge of each patient from the INC., Conclusion: CE is a not uncommon pathological remodeling in INC. This study showed that STEMI is the most typical manifestation of CE, diagnostic coronary angiography identified a type 3 Markis, so a low rate of mortality and recurrence of cardiovascular events would be expected, and despite the lack of consensus on the ideal therapy, at the INC individualized treatment is preferred, recommending lifestyle changes, and using triple therapy (DAP + OAC) as a medical treatment only at the time of patient discharge., (Copyright: © 2023 Permanyer.)

Objective: The objective of the study was to analyze the differences between survivors and non-survivors with non-reperfused ST-segment elevation myocardial infarction (STEMI) and to identify the predictors of in-hospital mortality., Methods: A retrospective cohort study included non-reperfused STEMI patients from October 2005 to August 2020. Patients were classified into survivors and non-survivors. We compared patient characteristics, treatments, and outcomes among the groups and identified factors associated with in-hospital mortality., Results: We included 2442 patients with non-reperfused STEMI and we found a mortality of 12.7% versus 7.2% in reperfused STEMI. The main reason for non-reperfusion was delayed presentation (96.1%). Non-survivors were older, more often women, and had diabetes, hypertension, or atrial fibrillation. The left main coronary disease was more frequent in non-survivors as well as three-vessel disease. Non-survivors developed more in-hospital heart failure, reinfarction, atrioventricular block, bleeding, stroke, and death. The main predictors for in-hospital mortality were renal dysfunction (HR 3.41), systolic blood pressure < 100 mmHg (HR 2.26), and left ventricle ejection fraction < 40% (HR 1.97)., Conclusion: Mortality and adverse outcomes occur more frequently in non-reperfused STEMI. Non-survivors tend to be older, with more comorbidities, and have more adverse in-hospital outcomes., (Copyright: © 2023 Permanyer.)

Objective: The aim of the study was to assess whether a recent SARS-CoV-2 infection could by itself be a risk or prognostic factor for ST-segment elevation myocardial infarction (STEMI)., Method: An observational study in unvaccinated patients with STEMI confirmed by cardiac catheterization was conducted. A recent or concurrent SARS-CoV-2 infection was identified by the presence of serum IgG against the nucleocapsid protein, or a positive polymerase chain reaction test on nasopharyngeal swabs. Baseline cardiovascular risk factors, clinical STEMI severity, main catheterization findings, and occurrence of major adverse cardiovascular events (MACE) during hospitalization were compared between study subgroups., Results: Of a total of 89 patients recruited, 14 (16%) had a recent SARS-CoV-2 infection. Patients with STEMI and recent SARS-CoV-2 infection had a markedly lower frequency of high blood pressure (20% versus 55%; P = 0.03) as well as a tendency to have fewer comorbidities. Regarding the clinical presentation, there were no differences in the severity of the STEMI. Furthermore, the main findings during cardiac catheterization including the atherosclerotic burden and the number of vessels affected, as well as the occurrence of MACE during follow-up, were not significantly different between the groups., Conclusions: A recent SARS-CoV-2 infection appears to facilitate the triggering of STEMI, as these patients have fewer traditional cardiovascular risk factors than their uninfected counterparts. However, this does not seem to affect the clinical presentation or the in-hospital course of STEMI patients.

Considerando la alta incidencia de las enfermedades cardiovasculares (ECV) en México y el mundo, la presente revisión proporciona un panorama general sobre la relación entre el desarrollo de periodontitis y la patogenia de estas enfermedades, describiendo aspectos sobre la alteración de la microbiota oral y los mecanismos asociados con el establecimiento de la respuesta inmunitaria local y sistémica en los pacientes con ECV. Además, proporciona las bases para considerar el análisis de la microbiota de la cavidad oral como un blanco terapéutico potencialmente útil en la regulación de la respuesta inmunitaria, lo que permitiría conseguir mejores pronósticos en pacientes con ECV., Considering the high incidence of cardiovascular disease (CVD) worldwide, the present review provides a general panorama of the relation between the pathogenesis of these diseases and the development of periodontitis. Specific associations are described between an altered oral microbiota (and associated mechanisms) and the local and systemic immune response in patients with CVD. Additionally, the basis is established for considering an imbalance in the microbiota of the oral cavity as a potentially useful therapeutic target for the regulation of the immune response, which could possibly allow for better therapeutic outcomes in the case of patients with CVD., (Copyright: © 2022 Permanyer.)

Reperfusion therapy is a measure of care in patients with ST-elevation myocardial infarction (STEMI), which should be performed once we have the diagnosis. Percutaneous coronary intervention is considered the gold standard, however in patients with SARS-CoV-2 infection, the reperfusion strategy is more focused on fibrinolytic therapy due to the shorter time required to perform and less exposure. This pandemic represents a contact problem in health personnel, since cases are increasing worldwide, so it is important to know the measures that must be followed to avoid coronavirus disease (COVID-19)., (Copyright: © 2020 Permanyer.)

Mexico has been positioned as the country with the highest mortality attributed to myocardial infarction among the members of the Organization for Economic Cooperation and Development. This rate responds to multiple factors, including a low rate of reperfusion therapy and the absence of a coordinated system of care. Primary angioplasty is the reperfusion method recommended by the guidelines, but requires multiple conditions that are not reached at all times. Early pharmacological reperfusion of the culprit coronary artery and early coronary angiography (pharmacoinvasive strategy) can be the solution to the logistical problem that primary angioplasty rises. Several studies have demonstrated pharmacoinvasive strategy as effective and safe as primary angioplasty ST-elevation myocardial infarction, which is postulated as the choice to follow in communities where access to PPCI is limited. The Mexico City Government together with the National Institute of Cardiology have developed a pharmaco-invasive reperfusion treatment program to ensure effective and timely reperfusion in STEMI. The model comprises a network of care at all three levels of health, including a system for early pharmacological reperfusion in primary care centers, a digital telemedicine system, an inter-hospital transport network to ensure primary angioplasty or early percutaneous coronary intervention after fibrinolysis and a training program with certification of the health care personal. This program intends to reduce morbidity and mortality associated with myocardial infarction., (Copyright © 2016 Instituto Nacional de Cardiología Ignacio Chávez. Publicado por Masson Doyma México S.A. All rights reserved.)

Introduction: Patients with ST elevation acute myocardial infarction (STEMI) comprise a heterogeneous population with respect to the risk for adverse events. Primary percutaneous coronary intervention (PCI) has shown to be better, mainly in high-risk patients., Objective: The purpose of this study was to determine if the Thrombolysis in Myocardial Infarction (TIMI) risk score for STEMI applied to patients undergo primary PCI identifies a group of patients at high risk for adverse events., Methods: We identified patients with STEMI without cardiogenic shock on admission, who were treated with primary PCI. The TIMI and CADILLAC (Controlled Abciximab and Device Investigation to Lower Late Angioplasty Complications) risk scores were calculated to determine their predictive value for in hospital mortality. Patients were divided into two groups according to their TIMI risk score, low risk being 0-4 points and high risk .5 points, and the frequency of adverse events was analyzed., Results: We analyzed 572 patients with STEMI. The c-statistics predictive value of the TIMI risk score for mortality was 0.80 (p=0.0001) and the CADILLAC risk score was 0.83, (p=0.0001). Thirty-two percent of patients classified as high risk (TIMI .5) had a higher incidence of adverse events than the low-risk group: mortality 14.8% vs. 2.1%, (p=0.0001); heart failure 15.3% vs. 4.1%, (p=0.0001); development of cardiogenic shock 10.9% vs. 1.5%, (p=0.0001); ventricular arrhythmias 14.8% vs. 5.9%, (p=0.001); and no-reflow phenomenon 22.4% vs. 13.6%, (p=0.01)., Conclusions: The TIMI risk score for STEMI prior to primary PCI can predict in hospital mortality and identifies a group of high-risk patients who might develop adverse events.

Objective: To evaluate the agreement between de ECG leads with ST elevation and the myocardial segments that present myocardial edema in the MRI study, in patients with acute myocardial infarction., Methods: There were included 91 patients with a first ST elevation myocardial infarction (STEMI) with reperfusion therapy during the first 12 hours of onset symptoms, in whom a Cardiovascular Magnetic Resonance (CMR) was done (mean 3 day after the ischemic event). Among the ECG leads (thoracic circle), there were identified those with ST higher elevation. In the CMR there were evaluated the myocardial segments with edema (T2-weighted sequence with hyperintensity)., Results: The ECG leads with the best sensibility in the detection of injury, corresponding to cellular edema, were: basal anterior and anteroseptal: V2; basal inferoseptal LIII and aVF; basal inferior and inferolateral: LIII; basal anterolateral V7-V9; mid anterior and anteroseptal:V2 and V3; mid inferoseptal, inferior and inferolateral: LIII and aVF; mid anterolateral V2 and V8; apical anterior and septal: V2-V4; apical inferior and lateral: LII, LIII and aVF; apex: V2-V4., Conclusions: The surface ECG leads with higher ST elevation corresponded to the myocardial segments with more important edema (defined as someone with hyperintensity in the T2- weighted MRI sequence).

Objective: Compare in-hospital outcome in patients with ST-elevation myocardial infarction with right versus left bundle branch block., Methods: RENASICA II, a national Mexican registry enrolled 8098 patients with final diagnosis of acute coronary syndrome secondary to ischemic heart disease. In 4555 STEMI patients, 545 had bundle branch block, 318 (58.3%) with right and 225 patients with left (41.6%). Both groups were compared in terms of in-hospital outcome through major cardiovascular adverse events; (cardiovascular death, recurrent ischemia and reinfarction). Multivariable analysis was performed to identify in-hospital mortality risk among right and left bundle branch block patients., Results: There were not statistical differences in both groups regarding baseline characteristics, time of ischemia, myocardial infarction location, ventricular dysfunction and reperfusion strategies. In-hospital outcome in bundle branch block group was characterized by a high incidence of major cardiovascular adverse events with a trend to higher mortality in patients with right bundle branch block (OR 1.70, CI 1.19 - 2.42, p < 0.003), compared to left bundle branch block patients., Conclusion: In this sub-study right bundle branch block accompanying ST-elevation myocardial infarction of any location at emergency room presentation was an independent predictor of high in-hospital mortality.

Background: The objectives of the present investigation were to validate the prognostic role of a proposed Clinical Classification [CC], to evaluate the TIMI risk score [RS] and to establish whether the TIMI-RS should incorporate points for patients with acute right ventricular infarction [TIMI-RS-RVI]., Methods and Results: A total of 523 RVI patients were classified on clinical and functional basis as: A, without right ventricular failure [RVF], B with RVF and C with cardiogenic shock. The CC was evaluated prospectively among 98 patients with RVI and retrospectively in 425 RVI patients. The TIMI-RS was evaluated prospectively among 622 patients with STEMI [anterior:277, inferior:247, RVI:98], and retrospectively in 425 RVI patients. The CC established differences among the 3-RVI Classes for in-hospital mortality [prospectively and retrospectively; p<0.01, p<0.001, respectively] that were maintained at 8 years [p < 0.001]. Patients with anterior and inferior STEMI, but not those with RVI revealed an association between outcome and TIMI-RS [p<0.001]. Testing for TIMI-RS-RVI did not result a good prognostic tool [ROC=0.9; excellent discrimination, but with a very poor "clinical calibration"]., Conclusions: The proposed CC allowed prediction of mortality at short- and long-term in the setting of acute RVI. The role of the TIMI-RS should be reevaluated prospectively as a prognostic tool in the scenario of RVI patients.

After prolonged periods of ischemia and energy depletion, the ischemic myocardial cell can be jeopardized by specific causes within the reperfusion period. These causes can be viewed as unwanted aspects of the recovery process itself limiting its efficiency. Three potential initial causes of immediate reperfusion injury, aside from oxygen radicals, have been experimentally investigated in detail, and are briefly discussed: 1. re-energization; 2. rapid normalization of tissue pH; and 3. rapid normalization of tissue osmolality. These potential causes are not entirely independent. Understanding of the basic causes has opened novel perspectives for specific interference with these serious pathomechanisms. The experimental results obtained in the last years encourage the development of therapeutic approaches to reduce infarct size by specific measures applied during the early phase of reperfusion. In the clinical setting, reperfusion therapy for acute myocardial infarction (AMI) has shown to reduce mortality, yet it may also have deleterious effects, including myocardial necrosis and no-reflow. Almost two decades ago, great hope arose from the description of ischemic preconditioning. Unfortunately, ischemic preconditioning is not feasible in the clinical practice because the coronary artery is already occluded at the time of hospital admission of the AMI patient. Recently, in the dog model, a phenomenon called "postconditioning" has been described. It has been reported previouly that reperfusion injury can be significantly reduced by modifying the conditions and the composition of the initial reperfusate. Whereas preconditioning is triggered by brief episodes of ischemia-reperfusion performed just before a prolonged coronary artery occlusion, postconditioning is induced by a comparable sequence of reversible ischemia-reperfusion, but it is applied "just after the prolonged" ischemic insult. Protection afforded by postconditioning is as potent as that provided by preconditioning. Unlike preconditioning, the experimental design of postconditioning allows direct application in the clinical practice, especially during PTCA. It has been reported very recently, that postconditioning patients with ST segment elevation AMI, during coronary angioplasty protects the human heart in this clinical scenario. Obtaining such a beneficial effect by a simple manipulation of reperfusion is of major potential clinical interest. Now more than ever, mechanistic and pharmacological research in the field of reperfusion injury appears to be necessary and clinically relevant.

The classical pathophysiologic concept of the acute coronary syndromes is the coronary artery thrombosis as a consequence of rupture or vulnerable atherosclerotic plaques. Actually, it is also been considered that systemic inflammatory phenomenon play a central role in the plaque instability associated to the atherothrombotic activity of the tissue factor (TF). The thrombotic phenomenon is controlled by tissue factor, stimulating the way of the protease's active receptors (PAR) and cause a negative cycle between inflammation and coagulation.

Kawasaki's disease is by now the first cause of pediatric acquired cardiopathies in many countries, even more than rheumatic fever. Probably the most common complication of this disease is coronary affection, which often causes stenosis. Treatment of the acute and chronic coronary events in children is based on the knowledge acquired from the disease in adults. The increasing experience in pediatric patients with this pathology has led to better ways of handling and treating this disease.

Hemodynamic monitoring has been used extensively during the last decades for risk stratification and guiding treatment of patients with cardiovascular destabilization, especially in the scenario of acute heart failure and cardiac shock. Every cardiac pump has its own maximum performance, which denotes its pumping capability. The heart is a muscular mechanical pump with an ability to generate both flow (cardiac output) and pressure. The product of flow output and systemic arterial pressure is the rate of useful work done, "or the cardiac power" (CP). Cardiac pumping capability can be defined as the cardiac power output achieved by the heart during maximal stimulation, and cardiac reserve is the increase in power output as the cardiac performance is increased from the resting to the maximally stimulated state (CPR). Resting CP for a hemodynamically stable average sized adult is approximately 1 W. However, during stress or exercise, CPR can be recruited to increase the heart's pumping ability up to 6 W. In acute heart failure, the patient becomes hemodynamically unstable, and most of the cardiac pumping potential is recruited in order to sustain life. Hence, cardiac power measurements in patients with acute heart failure or with cardiogenic shock at rest represent most of the recruitable reserve available during the acute event, and their measurement reflects the severity of the patient's condition. It has been found that a cutoff value for CP of 0.53 W accurately predict in-hospital mortality for cardiogenic shock patients. Others investigators observed cutoff for increased mortality of CP < 1 W, data that were obtained at doses of maximal pharmacologic support yielding the individual maximal CP. In our experience, the cutoff value for CP that accurately predicts in-hospital mortality for cardiogenic shock patients is 0.7 W, but its impact on short-term prognosis is clearer if the patient achieves a CP equal or higher than 1 W after an optimal myocardial revascularization with interventional cardiac procedures. According to the data collected from the literature, CP deserves a place in the evaluation of the patient with cardiogenic shock due to an acute myocardial infarction, but a more profound analysis of this parameter an further evaluation are required in order to better understand its prognostic meaning in this acute cardiac syndrome.

Treatment for ST- elevation acute coronary syndromes (acute myocardial infarction: AMI) has advanced rapidly in the last decade with major improvements in early fibrinolytic therapy (FT), primary percutaneous interventions (PCI) with the aid of platelet glycoprotein IIb/IIIa inhibitors. Recent interest has shifted from infarct related artery (IRA) patency to microvascular perfusion in the evaluation of patients with AMI. It is well known that establishing epicardial patency after AMI (TIMI 3 E) is not synonymous with tissue-level perfusion (TIMI 4M). Microvascular dysfunction due to the roles of platelet and inflammatory mediators in the no-reflow phenomenon occurs in a substantial proportion of patients despite thrombolytic therapy or PCI procedures. Techniques are now available that measure real tissue-level perfusion and also therapy is directed to optimize myocardial perfusion in patients with AMI. Despite advances, contemporary FT strategies with the combination of platelet glycoprotein IIb/IIIa inhibitors restore normal coronary flow (TIMI 3) in the IRA in only 50-75% and PCI achieves TIMI 3 flow rates in 90-95%, but only with modest reductions in mortality, but with significant reductions in rethrombosis of the IRA or stents, reinfarctions and in some patients with benefits in ventricular dysfunction. Therefore moving beyond the importance of TIMI 3 flow, the TIMI 4 flow, or improving tissue-level perfusion in the setting of AMI seems to be the paradigm for the treatment of ST-elevation acute coronary syndromes.

Unlabelled: In this prospective, randomized and controlled study, we compare complications in 2 groups of patients: group 1, enoxaparin 0.8 mg/kg, subcutaneous every 12 hours during 5 days, and group 2, intravenous unfractionated heparin during 5 days, by infusion treated to activate partial tromboplastin time 1.5-2 the upper limit of normal. Blood samples were obtained at 4, 12, 24 hours and at day 5 of treatment, to measure anti-Xa levels, and also, evaluated end points at 30 days, between groups. Univariate and multivariate logistic regression analyses were performed with clinical and angiographic variables between groups, with p < 0.05., Results: 203 consecutive patients, average age of 60.5 +/- 11.2 years, and 80% men, were included. There were no differences in clinical and angiographic characteristics. All patients with enoxaparin had therapeutic levels of anti-Xa, of 0.5 to 0.67 U/mL. There was increasing risk of total bleeding in group 2 (18.7%) than in group 1 (5.6%), with RR = 1.72 (95% CI 1.29, 2.29), p = .003. Also, there was 33.3% of MACE in group 2, and only 17.8% in group 1, with RR = 1.88 (CI 95% 1.29, 2.29), p = .011., Conclusions: 1) Low doses of enoxaparine achieve therapeutic levels, since the first 4 hours of treatment. 2) A significant reduction of total bleeding occurred with the low doses of enoxaparin, with the same efficacy to reduce MACE during follow-up.

This article reviews the usefulness of heparins in the management of patients with acute coronary syndromes. Low molecular weight heparins have a series of advantages over unfractionated heparins, and evidences show that they are more effective than placebo and equal to unfractionated heparin in diminishing the incidence of acute myocardial infarction or death. Evidences that the effectiveness of the low molecular weight heparins are superior is limited to enoxaparin and the most benefited group is the stratified one as high risk.