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1.
Diabetes Obes Metab ; 13(8): 759-64, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21457426

RESUMEN

AIM: In PROactive, pioglitazone reduced the incidence of death, myocardial infarction and stroke, and significantly improved HbA1c, systolic blood pressure (SBP), triglycerides and high-density lipoprotein (HDL)-cholesterol relative to placebo. As these glycaemic and lipid parameters are major cardiovascular (CV) risk factors, we assessed their separate contribution to the reduced incidence of CV outcomes. METHODS: Patients (n = 5238) with type 2 diabetes and macrovascular disease were randomized to 45 mg pioglitazone or placebo. Relationships among treatment, outcome (time to first event of all-cause mortality, myocardial infarction and stroke) and 10 laboratory measurements and vital signs were investigated using log-linear models. Continuous variable measurements (percent changes from baseline to average of all postbaseline values prior to censoring) were made discrete by categorizing into tertiles. Log-linear models were fitted to multiway tables of discrete data and analysis of deviance used to summarize sources of variation in the data. RESULTS: Although pioglitazone treatment was associated with a decrease in HbA1c and an increase in HDL-cholesterol (HDL-C), only the change from baseline HDL-C predicted the outcome (χ(2) = 28.89, p < 0.0001). No other variables, including HbA1c, triglycerides and systolic blood pressure, showed significant direct associations with outcome. When the analysis was extended to include baseline statin use, this was associated with an improved outcome independently of HDL-C changes. CONCLUSIONS: This post hoc analysis suggests that HDL-C, but probably not HbA1c, is a driver of pioglitazone's favourable influence on CV outcome.


Asunto(s)
Enfermedades Cardiovasculares/tratamiento farmacológico , HDL-Colesterol/sangre , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Hemoglobina Glucada/metabolismo , Tiazolidinedionas/uso terapéutico , Enfermedades Cardiovasculares/sangre , Enfermedades Cardiovasculares/etiología , HDL-Colesterol/efectos de los fármacos , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/complicaciones , Método Doble Ciego , Femenino , Hemoglobina Glucada/efectos de los fármacos , Humanos , Masculino , Pioglitazona , Placebos , Resultado del Tratamiento
2.
Circulation ; 102(2): 149-56, 2000 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-10889124

RESUMEN

BACKGROUND: Although intravenous glycoprotein IIb/IIIa inhibitors are beneficial in patients with acute coronary syndromes, prolonged oral IIb/IIIa inhibition might provide an additional reduction in recurrent events. METHODS AND RESULTS: Investigators at 888 hospitals in 29 countries enrolled 10 288 patients with acute coronary syndromes, which was defined as ischemic pain at rest within 72 hours of randomization, associated with positive cardiac markers, electrocardiographic changes, or prior cardiovascular disease. Patients received aspirin and were randomized to receive, for the duration of the trial, (1) 50 mg of orbofiban twice daily (50/50 group), (2) 50 mg of orbofiban twice daily for 30 days followed by 30 mg of orbofiban twice daily (50/30 group), or (3) a placebo. The primary composite end point was death, myocardial infarction, recurrent ischemia requiring rehospitalization, urgent revascularization, or stroke. The trial was terminated prematurely because of an unexpected increase in 30-day mortality in the 50/30 orbofiban group. Mortality through 10 months was 3.7% for the placebo group versus 5.1% in the 50/30 group (P=0.008) and 4.5% in the 50/50 group (P=0.11). There were no differences in the primary end point (22.9%, 23.1%, and 22.8%, for the placebo, 50/30, and 50/50 groups, respectively). Major or severe bleeding (but not intracranial hemorrhage) was higher with orbofiban; it occurred in 2. 0%, 3.7% (P=0.0004), and 4.5% (P<0.0001) of patients, respectively. Exploratory subgroup analyses found that patients who underwent percutaneous coronary intervention had a lower mortality and a significant reduction in the composite end point (P=0.001) with orbofiban. CONCLUSIONS: -Fixed-dose orbofiban failed to reduce major cardiovascular events and was associated with increased mortality in this broad population of patients with acute coronary syndromes; however, a benefit was observed among patients who underwent percutaneous coronary intervention.


Asunto(s)
Enfermedad Coronaria/tratamiento farmacológico , Infarto del Miocardio/tratamiento farmacológico , Inhibidores de Agregación Plaquetaria/administración & dosificación , Complejo GPIIb-IIIa de Glicoproteína Plaquetaria/antagonistas & inhibidores , Pirrolidinas/administración & dosificación , Administración Oral , Alanina/administración & dosificación , Alanina/efectos adversos , Anticoagulantes/administración & dosificación , Aspirina/administración & dosificación , Enfermedad Coronaria/mortalidad , Método Doble Ciego , Femenino , Estudios de Seguimiento , Heparina/administración & dosificación , Humanos , Hemorragias Intracraneales/inducido químicamente , Hemorragias Intracraneales/mortalidad , Masculino , Persona de Mediana Edad , Infarto del Miocardio/mortalidad , Inhibidores de Agregación Plaquetaria/efectos adversos , Pirrolidinas/efectos adversos , Accidente Cerebrovascular/tratamiento farmacológico , Análisis de Supervivencia , Trombocitopenia/inducido químicamente , Trombocitopenia/mortalidad , Resultado del Tratamiento
3.
Circulation ; 101(22): 2557-67, 2000 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-10840005

RESUMEN

BACKGROUND: Appropriate treatment policies should include an accurate estimate of a patient's baseline risk. Risk modeling to date has been underutilized in patients with acute coronary syndromes without persistent ST-segment elevation. METHODS AND RESULTS: We analyzed the relation between baseline characteristics and the 30-day incidence of death and the composite of death or myocardial (re)infarction in 9461 patients with acute coronary syndromes without persistent ST-segment elevation enrolled in the PURSUIT trial [Platelet glycoprotein IIb/IIIa in Unstable angina: Receptor Suppression Using Integrilin (eptifibatide) Therapy]. Variables examined included demographics, history, hemodynamic condition, and symptom duration. Risk models were created with multivariable logistic regression and validated by bootstrapping techniques. There was a 3.6% mortality rate and 11.4% infarction rate by 30 days. More than 20 significant predictors for mortality and for the composite end point were identified. The most important baseline determinants of death were age (adjusted chi(2)=95), heart rate (chi(2)=32), systolic blood pressure (chi(2)=20), ST-segment depression (chi(2)=20), signs of heart failure (chi(2)=18), and cardiac enzymes (chi(2)=15). Determinants of mortality were generally also predictive of death or myocardial (re)infarction. Differences were observed, however, in the relative prognostic importance of predictive variables for mortality alone or the composite end point; for example, sex was a more important determinant of the composite end point (chi(2)=21) than of death alone (chi(2)=10). The accuracy of the prediction of the composite end point was less than that of mortality (C-index 0.67 versus 0.81). CONCLUSIONS: The occurrence of adverse events after presentation with acute coronary syndromes is affected by multiple factors. These factors should be considered in the clinical decision-making process.


Asunto(s)
Electrocardiografía , Infarto del Miocardio/diagnóstico , Infarto del Miocardio/mortalidad , Distribución por Edad , Anciano , Angina de Pecho/diagnóstico , Angina de Pecho/tratamiento farmacológico , Angina de Pecho/mortalidad , Eptifibatida , Femenino , Hospitalización , Humanos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Infarto del Miocardio/tratamiento farmacológico , Péptidos/administración & dosificación , Inhibidores de Agregación Plaquetaria/administración & dosificación , Complejo GPIIb-IIIa de Glicoproteína Plaquetaria/antagonistas & inhibidores , Valor Predictivo de las Pruebas , Pronóstico , Factores de Riesgo , Distribución por Sexo
4.
Circulation ; 101(7): 751-7, 2000 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-10683348

RESUMEN

BACKGROUND: Platelet glycoprotein (GP) IIb/IIIa antagonists prevent the composite end point of death or myocardial infarction (MI) in patients with acute coronary syndromes. There is uncertainty about whether this effect is confined to patients who have percutaneous coronary interventions (PCIs) and whether PCIs further prevent death or MI in patients already treated with GP IIb/IIIa antagonists. METHODS AND RESULTS: PURSUIT patients were treated with the GP IIb/IIIa antagonist eptifibatide or placebo; PCIs were performed according to physician practices. In 2253 of 9641 patients (23.4%), PCI was performed by 30 days. Early (<72 hours) PCI was performed in 1228 (12.7%). In 34 placebo patients (5.5%) and 10 treated with eptifibatide (1.7%) (P=0.001), MI preceded early PCI. In patients censored for PCI across the 30-day period, there was a significant reduction in the primary composite end point in eptifibatide patients (P=0.035). Eptifibatide reduced 30-day events in patients who had early PCI (11.6% versus 16.7%, P=0.01) and in patients who did not (14.6% versus 15.6%, P=0.23). After adjustment for PCI propensity, there was no evidence that eptifibatide treatment effect differed between patients with or without early PCI (P for interaction=0.634). PCI was not associated with a reduction of the primary composite end point but was associated with a reduced (nonspecified) composite of death or Q-wave MI. This association disappeared after adjustment for propensity for early PCI. CONCLUSIONS: Eptifibatide reduced the composite rates of death or MI in PCI patients and those managed conservatively.


Asunto(s)
Angioplastia Coronaria con Balón , Enfermedad Coronaria/terapia , Péptidos/uso terapéutico , Inhibidores de Agregación Plaquetaria/uso terapéutico , Enfermedad Aguda , Anciano , Enfermedad Coronaria/mortalidad , Eptifibatida , Femenino , Humanos , Masculino , Persona de Mediana Edad , Complejo GPIIb-IIIa de Glicoproteína Plaquetaria/antagonistas & inhibidores , Análisis de Supervivencia , Síndrome , Factores de Tiempo , Resultado del Tratamiento
5.
J Am Coll Cardiol ; 25(5): 1063-8, 1995 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-7897117

RESUMEN

OBJECTIVES: This prospective ancillary study was conducted to determine the association between the time from symptom onset to treatment and cardiac rupture in patients with acute myocardial infarction. BACKGROUND: There is strong evidence that the time window for thrombolytic therapy should be extended to at least 12 h; however, many clinicians are concerned that late treatment may cause an excessive occurrence of death from cardiac rupture. Because up to 30% of patients with acute myocardial infarction arrive in the hospital > 6 h from symptom onset, resolving this issue is of paramount clinical importance. METHODS: A total of 5,711 patients with acute myocardial infarction were randomized to receive intravenous recombinant tissue-type plasminogen activator (rt-PA) (100 mg over 3 h) or matching placebo, within 6 and 24 h from symptom onset. Both groups received immediate oral aspirin, and a majority of patients received intravenous heparin during the initial 48 h. RESULTS: By 35 days, 177 patients had died, with the cause of death specified as cardiac rupture (53 patients), electromechanical dissociation (42 patients) or asystole (82 patients). An additional 370 patients had died of other causes. In patients treated within 12 h, the proportion of rupture deaths in the group given rt-PA was higher than that observed in those who received placebo, but the difference was not statistically significant. In patients treated after 12 h, there was no evidence of an increased incidence of rupture with rt-PA, and the proportion of deaths due to rupture in this group was lower than that in patients given placebo. However, there was evidence of a difference between rt-PA and placebo with respect to the time that rupture became clinically manifest (treatment by time to death interaction, p = 0.03). CONCLUSIONS: This study provides unequivocal evidence that late treatment (6 to 24 h after symptom onset) with rt-PA is not associated with an increased risk of cardiac rupture. However, for reasons that are unclear, coronary thrombolysis appears to accelerate rupture events, typically to within 24 h of treatment.


Asunto(s)
Rotura Cardíaca Posinfarto/epidemiología , Terapia Trombolítica/efectos adversos , Activador de Tejido Plasminógeno/uso terapéutico , Anciano , Animales , Aspirina/uso terapéutico , Causas de Muerte , Femenino , Rotura Cardíaca Posinfarto/etiología , Rotura Cardíaca Posinfarto/mortalidad , Heparina/uso terapéutico , Humanos , Incidencia , Modelos Logísticos , Masculino , Infarto del Miocardio/tratamiento farmacológico , Infarto del Miocardio/mortalidad , Estudios Prospectivos , Factores de Riesgo , Factores de Tiempo
6.
J Am Coll Cardiol ; 27(6): 1327-32, 1996 May.
Artículo en Inglés | MEDLINE | ID: mdl-8626939

RESUMEN

OBJECTIVES: We examined the impact of thrombolytic therapy and the prognosis of patients with non-Q wave myocardial infarction in a randomized placebo-controlled trial known as the Late Assessment of Thrombolytic Efficacy (LATE) study. BACKGROUND: Patients with non-Q wave as compared with Q wave myocardial infarction in the era before thrombolytic therapy were traditionally thought to have a higher rate of reinfarction and death between hospital discharge and 1 year such that the overall prognosis for outcome at 1 year was similar in the two groups. METHODS: The study patients began treatment with either recombinant tissue-type plasminogen activator (rt-PA) or matching placebo, 6 to 24 h after the onset of chest pain. Post hoc analysis of mortality and reinfarction was carried out by comparing rt-PA and placebo in various subsets of patients based on the presenting electrocardiogram (ECG) and the evolution of the ECG with respect to the development of Q waves. RESULTS: Among 5,711 participants, 4,759 had a confirmed myocardial infarction, including 1,309 classified as having a non-Q wave infarction at hospital discharge. Irrespective of treatment assignment, all patients with non-Q wave versus Q wave infarction had a lower 1-year mortality rate (13.3% vs. 17.1%, p = 0.001) and a similar 1-year reinfarction rate (8.6% vs. 7.9%, p = 0.7). Of the 4,759 patients with confirmed myocardial infarction, 2,973 presented with ST segment elevation or bundle branch block, 528 with ST depression and 1,258 with neither ST elevation nor depression. No overall benefit from rt-PA versus placebo with respect to mortality rate at 1 year was seen among patients presenting with ST elevation (21.2% vs. 22.4%, p = 0.5 [90% power to detect 20% relative difference]). Patients with ST elevation who were treated with rt-PA versus placebo <3 h after hospital admission had a lower mortality rate at 1 year (15.8% vs. 19.6%, p = 0.028) than did those treated after 3 h (17.6% vs. 13.0%, p = 0.055). Patients presenting initially with ST depression >2 mm had significant benefit from treatment with rt-PA with respect to 1 year mortality rate (20.1% vs. 31.9%, p = 0.006). CONCLUSIONS: Patients with non-Q wave myocardial infarction constitute a heterogeneous group of patients. Although the observations presented here are limited by post hoc analysis, it is apparent that patients classified as having a non-Q wave infarction after thrombolytic therapy have a better prognosis than do those given placebo. Late admission of thrombolytic therapy (after 6 h) may also be beneficial in patients presenting with ST depression >2 mm and confirmed myocardial infarction. These hypotheses require prospective testing in a larger number of patients.


Asunto(s)
Infarto del Miocardio/tratamiento farmacológico , Infarto del Miocardio/mortalidad , Terapia Trombolítica , Activador de Tejido Plasminógeno/uso terapéutico , Electrocardiografía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/fisiopatología , Pronóstico , Proteínas Recombinantes/uso terapéutico , Recurrencia
7.
J Am Coll Cardiol ; 26(5): 1222-9, 1995 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-7594035

RESUMEN

OBJECTIVES: Our purpose was to evaluate the relation between smoking and the outcomes of patients receiving thrombolysis for acute myocardial infarction. BACKGROUND: A paradoxic beneficial effect has been observed in smokers with a myocardial infarction. We analyzed outcomes and baseline characteristics of 11,975 nonsmokers, 11,117 ex-smokers and 17,507 current smokers in a multinational trial of thrombolysis for acute myocardial infarction. METHODS: Patients were randomized to one of four thrombolytic protocols. An angiographic substudy in 2,431 patients evaluated reperfusion, reocclusion and ventricular function. Effects of smoking were evaluated by logistic regression analysis after adjustment for age and gender. A mortality model evaluated the simultaneous effect of baseline characteristics on the prognostic importance of smoking. These processes were performed with data from both the main trial and the angiographic substudy; then angiographic factors (coronary anatomy, patency and ejection fraction) were added to the model. RESULTS: Smokers were significantly younger by a mean of 11 years) and had less comorbidity or severe coronary artery disease than nonsmokers. Nonsmokers had significantly higher hospital and 30-day mortality rates (9.9% and 10.3%, respectively) than smokers (3.7% vs. 4%, respectively, both p < 0.001) and more in-hospital complications. The unadjusted odds ratio for 30-day mortality in nonsmokers was 3.36 (95% confidence interval [CI] 2.08 to 5.41), 1.21 (95% CI 0.71 to 2.08) after adjustment for age and gender and 1.08 (95% CI 0.59 to 1.96) after adjustment for all clinical baseline characteristics. CONCLUSIONS: Smokers receiving thrombolysis for acute myocardial infarction presented 11 years earlier than nonsmokers, which generally accounted for their better outcome. When other differences in clinical and angiographic baseline factors and therapeutic responses were evaluated, no significant difference in mortality was seen between smokers and nonsmokers.


Asunto(s)
Antifibrinolíticos/uso terapéutico , Infarto del Miocardio/tratamiento farmacológico , Fumar , Adulto , Anciano , Angiografía Coronaria , Femenino , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/mortalidad , Infarto del Miocardio/fisiopatología , Análisis de Supervivencia , Resultado del Tratamiento
8.
J Am Coll Cardiol ; 30(1): 171-9, 1997 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-9207639

RESUMEN

OBJECTIVES: This study was undertaken to define and better understand the characteristics and outcomes of patients with diabetes treated for acute myocardial infarction with contemporary thrombolysis. BACKGROUND: Although thrombolysis has substantially improved survival of patients with myocardial infarction, diabetes mellitus remains an independent predictor for a poor prognosis. METHODS: We characterized the contemporary relation between diabetes and outcome after myocardial infarction treated with thrombolytic agents from a large international cohort. Of 41,021 patients randomized to receive accelerated tissue-type plasminogen activator (t-PA), streptokinase or a combination of both agents in the Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries study, there were 5,944 patients with diabetes and 34,888 patients without diabetes. RESULTS: Patients with diabetes were older and more likely to be female, to present with anterior wall infarction, to receive thrombolysis later and to have triple-vessel coronary artery disease. Mortality at 30 days was highest among diabetic patients treated with insulin (12.5%) compared with non-insulin-treated diabetic (9.7%) and nondiabetic (6.2%) patients (p < 0.001). Mortality was lowest among those with diabetes receiving accelerated t-PA, which is consistent with the results of the overall patient cohort. Although stroke occurred more frequently among diabetic (1.9%) than nondiabetic patients (1.4%, p < 0.001), there was no significant difference in the rates of intracranial hemorrhage. Cardiac failure, shock, atrioventricular block and atrial flutter/ fibrillation were more common among diabetic patients. The proportion of patients undergoing revascularization was similar between patients with and without diabetes, although diabetic patients were more likely to undergo coronary artery bypass graft surgery (10.4% vs. 8.3%). Diabetes remained an independent predictor for mortality at 1-year follow-up (14.5% vs. 8.9%, p < 0.001). CONCLUSIONS: Diabetes, alone and in association with its comorbidities, portends a substantially worse 30-day and 1-year prognosis for patients with myocardial infarction.


Asunto(s)
Complicaciones de la Diabetes , Infarto del Miocardio/complicaciones , Infarto del Miocardio/tratamiento farmacológico , Activadores Plasminogénicos/uso terapéutico , Estreptoquinasa/uso terapéutico , Terapia Trombolítica , Activador de Tejido Plasminógeno/uso terapéutico , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/mortalidad , Oportunidad Relativa , Valor Predictivo de las Pruebas , Pronóstico , Estudios Prospectivos , Resultado del Tratamiento
9.
J Am Coll Cardiol ; 37(2): 492-8, 2001 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11216968

RESUMEN

OBJECTIVES: We aimed to evaluate the benefits of the glycoprotein (GP) IIb/IIIa antagonist, eptifibatide, after patients with acute coronary syndromes (ACS) were admitted to hospitals that approach revascularization for ACS through early transfer to tertiary referral centers. BACKGROUND: Across a variety of hospital settings, GP IIb/IIIa inhibition, after patients were admitted to the hospital for non-ST segment elevation ACS, is associated with a reduction in death or myocardial infarction (MI) before and during a percutaneous coronary intervention. METHODS: The outcomes of 429 patients from 153 sites in the Platelet glycoprotein IIb/IIIa in unstable angina: Receptor Suppression Using Integrilin Therapy (PURSUIT) trial, who were transferred during study drug infusion ("transfer patients"), were compared with those of 1,987 patients who either remained in the hospital at those sites or were transferred after study drug termination ("nontransfer patients"). RESULTS: The baseline characteristics of transfer and nontransfer patients were similar. Patients receiving eptifibatide were transferred less frequently than those receiving placebo (16% vs. 20%, p = 0.014). Transfer patients underwent more procedures and experienced a greater 30-day incidence of death or MI, as compared with nontransfer patients (21% vs. 12%, p = 0.001). Eptifibatide was associated with a reduction in death or MI through 30 days, independent of transfer status (2.5% absolute reduction), as well as for those transferred (5.5% absolute reduction). CONCLUSIONS: For patients with ACS admitted to community hospitals, eptifibatide is associated with a reduced need for transfer and improved clinical outcomes.


Asunto(s)
Enfermedad Coronaria/tratamiento farmacológico , Infarto del Miocardio/tratamiento farmacológico , Transferencia de Pacientes , Péptidos/uso terapéutico , Inhibidores de Agregación Plaquetaria/uso terapéutico , Anciano , Enfermedad Coronaria/mortalidad , Eptifibatida , Femenino , Hospitales Comunitarios , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/mortalidad , Revascularización Miocárdica , Péptidos/efectos adversos , Inhibidores de Agregación Plaquetaria/efectos adversos , Derivación y Consulta , Tasa de Supervivencia
10.
Cardiovasc Res ; 19(3): 177-80, 1985 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-3986859

RESUMEN

To evaluate the possible role of prostaglandins in exercise-induced changes in blood pressure and limb blood flow we have compared the effects of aspirin and indomethacin in a double-blind placebo controlled study in a group of normal volunteers. Nine men undertook treadmill exercise after pretreatment with placebo, aspirin and indomethacin. Indomethacin caused a greater increase in systolic blood pressure during exercise than aspirin (p less than 0.05) and a smaller fall in diastolic pressure than either placebo or aspirin (p less than 0.02 and p less than 0.01). Compared with placebo both aspirin and indomethacin attenuated to a similar degree the increase in calf blood flow (p less than 0.05 and p less than 0.03) and the changes in forearm blood flow following exercise. These results suggest that although aspirin and indomethacin both inhibit prostaglandin production they have different effects on exercise-induced changes in blood pressure. They have, however, similar effects on limb blood flow.


Asunto(s)
Aspirina/farmacología , Presión Sanguínea/efectos de los fármacos , Extremidades/irrigación sanguínea , Indometacina/farmacología , Esfuerzo Físico , Adulto , Método Doble Ciego , Antebrazo/irrigación sanguínea , Humanos , Pierna/irrigación sanguínea , Masculino , Flujo Sanguíneo Regional/efectos de los fármacos , Factores de Tiempo
11.
Thromb Haemost ; 82(4): 1307-11, 1999 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-10544919

RESUMEN

We have used a whole blood single-platelet counting assay (WB-SPC) that is sensitive to microaggregation for monitoring GPIIb/IIIa antagonists and have compared this with other methodologies. In vitro effects of the GPIIb/IIIa antagonist fradafiban on ADP-induced platelet aggregation were determined using WBSPC and PRP turbidimetry, comparing citrate and hirudin anticoagulation. Fradafiban was a more potent inhibitor of aggregation assessed by PRP turbidimetry compared to WBSPC. Citrate showed only a trend towards enhancing fradafiban potency (p = 0.087). Citrated blood from 8 patients with unstable angina, randomised to receive oral lefradafiban (the oral prodrug of fradafiban) or placebo, was studied before and during treatment using WBSPC, PRP turbidimetry, impedance aggregometry and Rapid Platelet Function Assay (RPFA, Accumetrics). RPFA, PRP turbidimetry and WBSPC measurements correlated well. Impedance aggregometry responses were oversensitive to GPIIb/IIIa blockade. WBSPC was most discriminating at high levels of inhibition and offered a rapid means of monitoring GPIIb/IIIa antagonist effect within the therapeutic range of inhibition.


Asunto(s)
Bioensayo , Inhibidores de Agregación Plaquetaria/farmacología , Agregación Plaquetaria/efectos de los fármacos , Complejo GPIIb-IIIa de Glicoproteína Plaquetaria/antagonistas & inhibidores , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Humanos , Persona de Mediana Edad , Sensibilidad y Especificidad
12.
Thromb Haemost ; 85(3): 401-7, 2001 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-11307804

RESUMEN

Platelet aggregation is the central process in the pathophysiology of acute coronary syndromes. ADP contributes to thrombosis by activating platelets, and AR-C69931MX is a specific antagonist of this process acting at the P2T receptor. At 5 hospitals, 39 patients with unstable angina or non-Q wave myocardial infarction, who were receiving aspirin and heparin, were administered intravenous AR-C69931MX with stepped dose increments over 3 h to a plateau of either 2 microg/kg/min for 21 h (Part 1; n = 12) or up to 69 h (Part 2; n = 13) or 4 microg/kg/min for up to 69 h (Part 3: n = 14). Safety parameters, platelet aggregation (PA) induced by ADP 3 micromol/L (impedance aggregometry), bleeding time (BT) and plasma concentrations of AR-C69931XX were assessed. AR-C69931MX was well tolerated. 33 patients completed the study. There were no deaths at 30 days and no serious adverse events attributed to AR-C69931MX. Trivial bleeding (56%) was common. At 24 h, mean inhibition of PA was 96.0 +/- 8.6, 94.9 +/- 14.4 and 98.7 +/- 2.1% and BT was 9.5 +/- 8.4, 14.0 +/- 9.7 and 16.0 +/- 11.1 min for Parts 1, 2 and 3 respectively. At 1 h post-infusion, mean inhibition of PA was 36.2 +/- 39.2, 20.7 +/- 25.9 and 40.7 +/- 36.7% respectively. 90% patients had a plasma half-life for AR-C69931XX of <9 min. In conclusion, AR-C69931MX is a potent, short-acting platelet ADP receptor antagonist suitable for further studies as an antithrombotic agent.


Asunto(s)
Adenosina Monofosfato/administración & dosificación , Enfermedad Coronaria/tratamiento farmacológico , Proteínas de la Membrana , Antagonistas del Receptor Purinérgico P2 , Enfermedad Aguda , Adenosina Monofosfato/análogos & derivados , Adenosina Monofosfato/farmacocinética , Adenosina Monofosfato/normas , Adulto , Anciano , Angina Inestable/complicaciones , Angina Inestable/tratamiento farmacológico , Aspirina/administración & dosificación , Pruebas de Coagulación Sanguínea , Seguridad de Productos para el Consumidor , Enfermedad Coronaria/complicaciones , Relación Dosis-Respuesta a Droga , Quimioterapia Combinada , Electrocardiografía , Femenino , Heparina/administración & dosificación , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/complicaciones , Infarto del Miocardio/tratamiento farmacológico , Inhibidores de Agregación Plaquetaria/administración & dosificación , Inhibidores de Agregación Plaquetaria/farmacocinética , Inhibidores de Agregación Plaquetaria/normas , Receptores Purinérgicos P2Y12
13.
Thromb Haemost ; 74(5): 1310-5, 1995 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-8607115

RESUMEN

Ticlopidine is thought to be a selective inhibitor of ADP-induced platelet function. Here we have investigated the effects of ticlopidine on platelet function in whole blood induced by ADP and by other platelet agonists. Whole blood was used because it was considered that ADP derived from red cells might act synergistically with other platelet agonists to enhance platelet responses, and that ticlopidine might interfere with this process. Measurements were performed using blood from 16 healthy volunteers before ticlopidine administration, after taking ticlopidine 250 mg daily for 10 days, after taking ticlopidine 250 mg twice daily for a further 10 days, and after 14 days off treatment. Ticlopidine proved to be a very effective inhibitor of the platelet aggregation induced by ADP; it was most effective in enhancing the reversibility of the aggregation response. The drug modestly but significantly reduced streptokinase, adrenaline, collagen, sodium arachidonate, PAF and U46619 - induced platelet aggregation. The drug significantly reduced the extent of the release reaction (14C-5HT release) induced by ADP, streptokinase, PAF, ristocetin and sodium arachidonate, and also reduced the extent of the synergistic 14C-5HT release induced by combinations of ADP and PAF, ADP and adrenaline and PAF and adrenaline. The various inhibitory effects of ticlopidine were evident after treatment with 250 mg daily but were more pronounced after 250 mg twice daily. All values had returned to normal after 14 days off treatment. Ticlopidine had no effect on serum thromboxane B2 production nor on several parameters of coagulation and fibrinolysis. We conclude that ticlopidine is an effective inhibitor of ADP-induced platelet aggregation and also the platelet aggregation and 14C-5HT release induced in whole blood by a number of platelet agonists and combinations of agonists. These latter effects are probably mainly via a selective effect on ADP. The inhibitory effects of the drug are dose-related.


Asunto(s)
Inhibidores de Agregación Plaquetaria/administración & dosificación , Agregación Plaquetaria/efectos de los fármacos , Ticlopidina/administración & dosificación , Ácido 15-Hidroxi-11 alfa,9 alfa-(epoximetano)prosta-5,13-dienoico , Adenosina Difosfato/farmacología , Adulto , Células Cultivadas , Humanos , Masculino , Persona de Mediana Edad , Endoperóxidos de Prostaglandinas Sintéticos/farmacología , Tromboxano A2/análogos & derivados , Tromboxano A2/farmacología
14.
Am J Cardiol ; 78(12A): 20-3, 1996 Dec 19.
Artículo en Inglés | MEDLINE | ID: mdl-8990407

RESUMEN

Numerous controlled clinical trials have documented the efficacy of thrombolytic agents in reducing the risk of mortality after myocardial infarction (MI). As a result, it is no longer ethical to test a new thrombolytic regimen against placebo. Rather, promising new therapies must be compared with proven treatments. This has been the direction taken in trials of reteplase, a new recombinant plasminogen activator. Initial studies of double-bolus reteplase demonstrated its superior ability to produce. TIMI grade 2 or 3 flow at 90 minutes when compared with accelerated alteplase. A subsequent randomized, double-blind, 9-country study, the International Joint Efficacy Comparison of Thrombolytics (INJECT) trial was designed to determine whether the efficacy of reteplase is at least equivalent to that of streptokinase. The 2 treatments were associated with similar frequencies of inhospital cardiac events, bleeding, and strokes. Likewise, no significant difference was apparent between the reteplase and streptokinase groups with regard to 35-day mortality (the primary endpoint), the combined endpoint of 35-day mortality plus continuing disability from inhospital stroke, or 6-month mortality. Unadjusted data from the 3 countries that contributed the majority of patients seemed to indicate a survival benefit, irrespective of treatment allocation, among patients who underwent interventional procedures. However, no such benefit was apparent when the data were adjusted for differences in the baseline characteristics of the patients enrolled in the different countries. Rather, intervention within the first 3 days post-MI was found to place patients at a substantially higher risk of 35-day mortality. Further insights into the relative efficacy of reteplase should emerge from the ongoing third Global Utilization of Strategies to Open Occluded Coronary Arteries (GUSTO-III) trial.


Asunto(s)
Fibrinolíticos/uso terapéutico , Ensayos Clínicos Controlados Aleatorios como Asunto , Terapia Trombolítica , Trastornos Cerebrovasculares/inducido químicamente , Circulación Coronaria , Método Doble Ciego , Fibrinolíticos/administración & dosificación , Fibrinolíticos/efectos adversos , Hemorragia/inducido químicamente , Humanos , Estudios Multicéntricos como Asunto , Infarto del Miocardio/tratamiento farmacológico , Placebos , Activadores Plasminogénicos/administración & dosificación , Activadores Plasminogénicos/efectos adversos , Activadores Plasminogénicos/uso terapéutico , Proteínas Recombinantes/administración & dosificación , Proteínas Recombinantes/efectos adversos , Proteínas Recombinantes/uso terapéutico , Estreptoquinasa/administración & dosificación , Estreptoquinasa/efectos adversos , Estreptoquinasa/uso terapéutico , Tasa de Supervivencia , Factores de Tiempo , Activador de Tejido Plasminógeno/administración & dosificación , Activador de Tejido Plasminógeno/efectos adversos , Activador de Tejido Plasminógeno/uso terapéutico , Resultado del Tratamiento , Grado de Desobstrucción Vascular
15.
Am J Cardiol ; 87(5): 636-9, A10, 2001 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-11230853

RESUMEN

We observed in a study of 7,651 patients with acute coronary syndromes that a white blood cell (WBC) count of > 10,000 was associated with increased 30-day and 10-month mortality (6.2% vs 3.2% to 3.6% for WBC count < 10,000; p < 0.000). With its simplicity and widespread availability, WBC count could serve as a simple, inexpensive, new tool for risk stratification in acute coronary syndromes.


Asunto(s)
Angina Inestable/mortalidad , Recuento de Leucocitos , Infarto del Miocardio/mortalidad , Anciano , Alanina/administración & dosificación , Angina Inestable/tratamiento farmacológico , Angina Inestable/inmunología , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/tratamiento farmacológico , Infarto del Miocardio/inmunología , Inhibidores de Agregación Plaquetaria/administración & dosificación , Pirrolidinas/administración & dosificación , Factores de Riesgo , Tasa de Supervivencia
16.
Am J Cardiol ; 84(11): 1281-6, 1999 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-10614791

RESUMEN

Troponin T has been used successfully to risk stratify patients with acute coronary syndromes, but the utility of this approach using a rapid bedside assay in patients undergoing thrombolysis for ST-segment elevation acute myocardial infarction has not been assessed in a large population. We assessed whether a point-of-care, qualitative troponin T test at enrollment could independently risk-stratify patients randomized to receive alteplase or reteplase in the GUSTO-III trial. Complete troponin T data were available for 12,666 patients (84%) enrolled at 550 hospitals. The primary end point was mortality at 30 days, and the predictive ability of an elevated baseline troponin T level was analyzed (after adjustment for baseline characteristics) with multiple logistic regression. Patients with an elevated troponin T result at enrollment (8.9%) had significantly higher mortality at 30 days (unadjusted 15.7% vs 6.2% for negative patients; p = 0.001), which persisted even after adjustment for age, heart rate, location of infarction, Killip class, and systolic blood pressure. In a multivariable regression model, a positive troponin T result added independently to the prediction of 30-day mortality (chi-square 46, p = 0.001). A positive result with qualitative troponin T testing on admission is an independent marker of higher 30-day mortality. Troponin T testing could be a valuable addition to the evaluation strategy for patients with acute myocardial infarction.


Asunto(s)
Electrocardiografía , Infarto del Miocardio/sangre , Sistemas de Atención de Punto , Troponina T/sangre , Anciano , Aspirina/uso terapéutico , Biomarcadores/sangre , Causas de Muerte , Quimioterapia Combinada , Femenino , Fibrinolíticos/uso terapéutico , Heparina/uso terapéutico , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/tratamiento farmacológico , Infarto del Miocardio/mortalidad , Pronóstico , Estudios Prospectivos , Proteínas Recombinantes/uso terapéutico , Medición de Riesgo , Factores de Riesgo , Tasa de Supervivencia , Terapia Trombolítica , Activador de Tejido Plasminógeno/uso terapéutico , Estados Unidos/epidemiología
17.
Am J Cardiol ; 83(8): 1147-51, 1999 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-10215274

RESUMEN

Aspirin is beneficial in the prevention and treatment of cardiovascular events, but patients who have events while taking aspirin may have worse outcomes than those not on aspirin. We investigated the association between prior aspirin use and clinical outcomes in 9,461 patients with non-ST-elevation acute coronary syndromes enrolled in the Platelet IIb/IIIa in Unstable angina: Receptor Suppression Using Integrilin Therapy (PURSUIT) trial, before and after adjustment for baseline factors. We also examined whether eptifibatide has a differential treatment effect in prior aspirin users. Prior aspirin users were less likely to have an enrollment myocardial infarction (MI) (vs unstable angina) (43.9% vs 48.8%, p = 0.001) but more likely to have death or MI at 30 days (16.1% vs 13.0%, p = 0.001) and at 6 months (19.9% vs 15.9%, p = 0.001). After adjustment, prior aspirin users remained less likely to have an enrollment MI (odds ratio 0.88, 95% confidence interval 0.79 to 0.97) and more likely to have death or MI at 30 days (odds ratio 1.16, 95% confidence interval 1.00 to 1.33) but not at 6 months (odds ratio 1.14, 95% confidence interval 0.98 to 1.33). In a multivariable model, eptifibatide did not have a different treatment effect in prior aspirin users compared with nonusers (p = 0.534). Prior aspirin users had fewer enrollment MIs but worse long-term outcomes than nonusers. We found no evidence for a different treatment effect of eptifibatide in prior aspirin users.


Asunto(s)
Angina Inestable/prevención & control , Aspirina/uso terapéutico , Electrocardiografía , Inhibidores de Agregación Plaquetaria/uso terapéutico , Enfermedad Aguda , Anciano , Angina Inestable/mortalidad , Angina Inestable/fisiopatología , Electrocardiografía/efectos de los fármacos , Eptifibatida , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Oportunidad Relativa , Péptidos/uso terapéutico , Pronóstico , Seguridad , Tasa de Supervivencia , Síndrome
18.
Chest ; 95(5 Suppl): 270S-275S, 1989 May.
Artículo en Inglés | MEDLINE | ID: mdl-2495910

RESUMEN

Intravenous rtPA (total dose, 100 mg over 3 h) was compared with placebo in a prospective, randomized, double-blind trial in 5,011 patients with suspected AMI of less than 5 h duration. No ECG or enzymatic confirmation of the diagnosis was required for study entry. At 1 month 9.8% of patients given placebo had died compared with 7.2% of those who received rtPA (2.6% actual reduction, 26% relative reduction, with 95% confidence intervals of 11-39%). The majority of deaths occurred in patients who had an in-hospital diagnosis of MI (72% in both groups), with a 1-month infarct mortality of 13.1% in the placebo limb and 9.4% in the rtPA limb (relative reduction 28%, 95% CI, 14-41%). Approximately 18% of patients in both groups had a normal ECG on entry to the trial, and at 1 month the fatality was 1.6% in the rtPA group and 3.0% in the placebo group. Treatment with rtPA did not reduce the number of patients with normal ECGs from developing MI (28% rtPA vs 24% placebo). Treatment with rtPA was associated with significantly more bleeding episodes, the vast majority of which were clinically minor. The risk of all strokes in the rtPA group was similar to that in the placebo group (1.1% vs 1.0%). Treatment with rtPA was unaccompanied by either allergic or hypotensive episodes, and, among rtPA treated patients, there was no increase in clinically important ventricular dysrhythmias. Neither age nor time from onset of symptoms reduced the benefit from rtPA.


Asunto(s)
Infarto del Miocardio/tratamiento farmacológico , Activador de Tejido Plasminógeno/uso terapéutico , Anciano , Método Doble Ciego , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Multicéntricos como Asunto , Infarto del Miocardio/mortalidad , Placebos , Estudios Prospectivos , Distribución Aleatoria , Proteínas Recombinantes/uso terapéutico , Países Escandinavos y Nórdicos , Reino Unido
19.
Heart ; 81(6): 598-602, 1999 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10336917

RESUMEN

OBJECTIVE: To assess the medium to long term outcome of patients ineligible for thrombolysis compared to those enrolled in a clinical trial of thrombolysis and patients receiving non-trial thrombolysis. DESIGN: Cohort study based on the Nottingham heart attack register. SETTING: Two district general hospitals serving a defined urban/rural population. SUBJECTS: All patients admitted with a confirmed acute myocardial infarction during 1992 categorised as either participants of a thrombolytic trial (group A, n = 140), receiving non-trial thrombolysis (group B, n = 329), or deemed ineligible for lytic treatment (group C, n = 431). MAIN OUTCOME MEASURES: Background characteristics, inhospital treatment, patterns of follow up, referrals to cardiologists, revascularisation rates, and short and long term survival. RESULTS: Clinical trial recruits were younger by almost 10 years, were less likely to have a previous history of myocardial infarction, and more likely to be in Killip class 1 on admission than those ineligible for thrombolysis. Cardiology follow up was mandatory for all surviving trial participants but 22% of patients in group B and 31% of patients in group C received no follow up, and during four years less than 50% ever saw a cardiologist. Revascularisation was performed in 17.2% of patients in group A, 13.6% of patients in group B, and 7.5% of patients in group C. Cumulative mortality at a median of four years was 24.3% in group A, 36.8% in B, and 59.6% in group C. Adjusting for age, sex, previous myocardial infarction, type of infarction, and Killip class in a logistic regression model the odds ratios (OR) of death at four years for groups B and C were 1.60 (95% confidence intervals (CI) 0.97 to 2.63, p = 0.065) and 2.64 (95% CI 1.61 to 4. 32, p < 0.001), respectively, when compared to group A (OR 1). CONCLUSIONS: Patients enrolled into thrombolytic trials are at low risk. Patients deemed ineligible for thrombolysis are high risk, receive less surveillance, are less likely to be revascularised or receive trial proven treatments, have a poor long term outcome not entirely explained by increased age or severity of infarction, and deserve further evaluation.


Asunto(s)
Ensayos Clínicos como Asunto , Infarto del Miocardio/tratamiento farmacológico , Selección de Paciente , Terapia Trombolítica , Cuidados Posteriores , Anciano , Estudios de Cohortes , Contraindicaciones , Inglaterra , Femenino , Mortalidad Hospitalaria , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/mortalidad , Readmisión del Paciente , Derivación y Consulta , Tasa de Supervivencia , Terapia Trombolítica/mortalidad , Resultado del Tratamiento
20.
J Hum Hypertens ; 2(2): 127-32, 1988 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-2977406

RESUMEN

The therapeutic usefulness of adding once-daily amlodipine (10 mg) for four weeks in moderate-severe hypertensive patients uncontrolled on low dose captopril (25 mg twice daily) alone was studied in 29 patients in a double-blind, placebo-controlled two-way crossover comparison. Once daily amlodipine was shown to be an effective antihypertensive drug when combined with captopril. The amlodipine minus placebo differences in mean changes from captopril baseline values were: -18/-12 mmHg and -20/-12 mmHg for supine and standing systolic/diastolic pressures (P less than 0.001 for all four pressure variables). The combination was well tolerated, and no patient discontinued therapy. Five patients experienced ankle oedema and four patients reported flushing while receiving amlodipine/captopril.


Asunto(s)
Bloqueadores de los Canales de Calcio/uso terapéutico , Captopril/administración & dosificación , Hipertensión/tratamiento farmacológico , Nifedipino/análogos & derivados , Adolescente , Adulto , Anciano , Amlodipino , Bloqueadores de los Canales de Calcio/efectos adversos , Captopril/efectos adversos , Captopril/uso terapéutico , Método Doble Ciego , Quimioterapia Combinada , Femenino , Humanos , Masculino , Persona de Mediana Edad , Nifedipino/administración & dosificación , Nifedipino/efectos adversos , Nifedipino/uso terapéutico , Distribución Aleatoria
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