RESUMEN
Telcagepant is a calcitonin gene-related peptide (CGRP) receptor antagonist being evaluated for acute migraine treatment. CGRP is a potent vasodilator that is elevated after myocardial infarction, and it delays ischemia during treadmill exercise. We tested the hypothesis that CGRP receptor antagonism does not reduce treadmill exercise time (TET). The effects of supratherapeutic doses of telcagepant on TET were assessed in a double-blind, randomized, placebo-controlled, two-period, crossover study in patients with stable angina and reproducible exercise-induced angina. Patients received telcagepant (600 mg, n = 46; and 900 mg, n = 14) or placebo and performed treadmill exercise at T(max) (2.5 h after the dose). The hypothesis that telcagepant does not reduce TET was supported if the lower bound of the two-sided 90% confidence interval (CI) for the mean treatment difference (telcagepant-placebo) in TET was more than -60 s. There were no significant between-treatment differences in TET (mean treatment difference: -6.90 (90% CI: -17.66, 3.86) seconds), maximum exercise heart rate, or time to 1-mm ST-segment depression using pooled data or with stratification for dose.
Asunto(s)
Angina Estable/tratamiento farmacológico , Azepinas/uso terapéutico , Prueba de Esfuerzo/métodos , Imidazoles/uso terapéutico , Angina Estable/fisiopatología , Antagonistas del Receptor Peptídico Relacionado con el Gen de la Calcitonina , Estudios Cruzados , Método Doble Ciego , Electrocardiografía/métodos , Femenino , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Masculino , Persona de Mediana Edad , Trastornos Migrañosos/tratamiento farmacológico , Vasodilatadores/uso terapéuticoRESUMEN
Estas guías representan una actualización de aquellos publicados en 1996 dirigidas a médicos que están comprometidos en el cuidado preoperatorio, operatorio y postoperatorio de pacientes que van a cirugía no cardiaca. Ellas proveen un marco de referencia para analizar el riesgo cardiaco de cirugia no cardiaca en una variedad de pacientes y situaciones quirúrgicas. El tema principal de estas guías es que la intervención preoperatoria es raramene necesaria simplemente para disminuir el riesgo de la cirugía a menos que dicha intervención sea indicada independiente del contexto preoperatorio.
Asunto(s)
Enfermedades Cardiovasculares , Cirugía General , Cuidados PreoperatoriosRESUMEN
BACKGROUND: This study was a reanalysis of the Bivalirudin Angioplasty Study, which compared bivalirudin with high-dose heparin during coronary angioplasty for unstable angina. METHODS: Differences in rates of death, myocardial infarction, or repeat revascularization were compared at 7, 90, and 180 days after angioplasty with intention-to-treat analysis. RESULTS: The combined end point occurred in 135 of 2161 patients (6.2%) in the bivalirudin group and in 169 of 2151 patients (7.9%) in the heparin group at 7 days (P =.039). Differences persisted between the groups at 90 days (P =.012) and 180 days (P =.153). Bleeding occurred in 76 patients (3.5%) in the bivalirudin group versus 199 (9.3%) in the heparin group (P <.001). CONCLUSIONS: This analysis supports the hypothesis that bivalirudin reduces ischemic complications and bleeding after angioplasty. Further trials are needed to evaluate bivalirudin versus heparin in conjunction with platelet-glycoprotein IIb/IIIa inhibitors and for coronary stenting.
Asunto(s)
Angina de Pecho/mortalidad , Angina de Pecho/terapia , Angioplastia Coronaria con Balón/métodos , Heparina/uso terapéutico , Terapia con Hirudina , Hirudinas/análogos & derivados , Fragmentos de Péptidos/uso terapéutico , Proteínas Recombinantes/uso terapéutico , Análisis Actuarial , Adulto , Anciano , Anciano de 80 o más Años , Angina de Pecho/etiología , Angina Inestable/mortalidad , Angina Inestable/terapia , Aspirina/administración & dosificación , Femenino , Estudios de Seguimiento , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/complicaciones , Oportunidad Relativa , Ensayos Clínicos Controlados Aleatorios como Asunto , Tasa de SupervivenciaAsunto(s)
Prueba de Esfuerzo , Ejercicio Físico , Adolescente , Adrenérgicos , Adulto , Arritmias Cardíacas/etiología , Enfermedad Coronaria/prevención & control , Consejo , Ecocardiografía , Electrocardiografía , Femenino , Corazón/diagnóstico por imagen , Corazón/efectos de los fármacos , Corazón/fisiología , Cardiopatías/diagnóstico , Hemodinámica , Humanos , Consentimiento Informado , Masculino , Persona de Mediana Edad , Miocardio/metabolismo , Consumo de Oxígeno , Cooperación del Paciente , Examen Físico , Cintigrafía , VasodilatadoresRESUMEN
OBJECTIVES: We sought to determine if elevated cardiac serum biomarkers after coronary artery bypass graft surgery (CABG) are associated with increased medium-term mortality and to identify patients that may benefit from better postoperative myocardial protection. BACKGROUND: The relationship between the magnitude of cardiac serum protein elevation and subsequent mortality after CABG is not well defined, partly because of the lack of large, prospectively studied patient cohorts in whom postoperative elevations of cardiac serum markers have been correlated to medium- and long-term mortality. METHODS: The GUARD during Ischemia Against Necrosis (GUARDIAN) study enrolled 2,918 patients assigned to the entry category of CABG and considered as high risk for myocardial necrosis. Creatine kinase-myocardial band (CK-MB) isoenzyme measurements were obtained at baseline and at 8, 12, 16 and 24 h after CABG. RESULTS: The unadjusted six-month mortality rates were 3.4%, 5.8%, 7.8% and 20.2% for patients with a postoperative peak CK-MB ratio (peak CK-MB value/upper limits of normal [ULN] for laboratory test) of < 5, > or = 5 to <10, > or =10 to < 20 and > or =20 ULN, respectively (p < 0.0001). The relationship remained statistically significant after adjustment for ejection fraction, congestive heart failure, cerebrovascular disease, peripheral vascular disease, cardiac arrhythmias and the method of cardioplegia delivery. Receiver operating characteristic curve analysis revealed an area under the curve of 0.648 (p < 0.001); the optimal cut-point to predict six-month mortality ranged from 5 to 10 ULN. CONCLUSIONS: Progressive elevation of the CK-MB ratio in clinically high-risk patients is associated with significant elevations of medium-term mortality after CABG. Strategies to afford myocardial protection both during CABG and in the postoperative phase may serve to improve the clinical outcome.
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Puente de Arteria Coronaria/mortalidad , Enfermedad Coronaria/enzimología , Enfermedad Coronaria/mortalidad , Creatina Quinasa/metabolismo , Isoenzimas/metabolismo , Anciano , Forma MB de la Creatina-Quinasa , Electrocardiografía , Femenino , Humanos , Modelos Logísticos , Masculino , Estudios Multicéntricos como Asunto , Infarto del Miocardio/enzimología , Periodo Posoperatorio , Curva ROC , Ensayos Clínicos Controlados Aleatorios como AsuntoRESUMEN
OBJECTIVE: The objective of this study was to evaluate the American College of Cardiology/American Heart Association (ACC/AHA) guidelines for exercise testing (EXT) after successful coronary revascularization (CR) using the Bypass Angioplasty Revascularization Investigation experience. BACKGROUND: The ACC/AHA guidelines state that EXT within three years of successful CR is not useful. METHODS: The 1,678 patients randomized to CR by either angioplasty or bypass surgery were required to take symptom-limited treadmill tests one, three and five years after revascularization. RESULTS: Patients who took the test at each specified time had a much lower subsequent two-year mortality than those who did not (1.9% vs. 9.4%, 3.5% vs. 12.6% and 3.3% vs. 11.0% at one, three and five years, respectively, after CR [p < 0.0001 for each]). Exercise parameters at the one- and three-year test did not improve a multivariable model of survival after including clinical parameters. Exercising to Bruce stage 3 or generating a Duke score >-6 were independently predictive of two-year survival after the five-year test. ST depression on the one-year test was associated with more revascularizations (relative risk = 1.6; p < 0.001). CONCLUSIONS: Patients with stable multivessel coronary disease who took a protocol-mandated exercise test at one, three and five years after revascularization were at low risk for mortality in the two years subsequent to each test. Exercise parameters did not improve prediction of mortality in the two years after the one- and three-year tests. The ACC/AHA guidelines on exercise testing after CR (no value for routine testing in stable patients for three years after revascularization) are supported by these results.
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Angioplastia Coronaria con Balón , Puente de Arteria Coronaria , Enfermedad Coronaria/epidemiología , Prueba de Esfuerzo , Enfermedad Coronaria/mortalidad , Angiopatías Diabéticas/epidemiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Guías de Práctica Clínica como Asunto , Pronóstico , Medición de RiesgoRESUMEN
CONTEXT: Patients experience the highest rate of death and recurrent ischemic events during the early period after an acute coronary syndrome, but it is not known whether early initiation of treatment with a statin can reduce the occurrence of these early events. OBJECTIVE: To determine whether treatment with atorvastatin, 80 mg/d, initiated 24 to 96 hours after an acute coronary syndrome, reduces death and nonfatal ischemic events. DESIGN AND SETTING: A randomized, double-blind trial conducted from May 1997 to September 1999, with follow-up through 16 weeks at 122 clinical centers in Europe, North America, South Africa, and Australasia. PATIENTS: A total of 3086 adults aged 18 years or older with unstable angina or non-Q-wave acute myocardial infarction. INTERVENTIONS: Patients were stratified by center and randomly assigned to receive treatment with atorvastatin (80 mg/d) or matching placebo between 24 and 96 hours after hospital admission. MAIN OUTCOME MEASURES: Primary end point event defined as death, nonfatal acute myocardial infarction, cardiac arrest with resuscitation, or recurrent symptomatic myocardial ischemia with objective evidence and requiring emergency rehospitalization. RESULTS: A primary end point event occurred in 228 patients (14.8%) in the atorvastatin group and 269 patients (17.4%) in the placebo group (relative risk [RR], 0.84; 95% confidence interval [CI], 0.70-1.00; P =.048). There were no significant differences in risk of death, nonfatal myocardial infarction, or cardiac arrest between the atorvastatin group and the placebo group, although the atorvastatin group had a lower risk of symptomatic ischemia with objective evidence and requiring emergency rehospitalization (6.2% vs 8.4%; RR, 0.74; 95% CI, 0.57-0.95; P =.02). Likewise, there were no significant differences between the atorvastatin group and the placebo group in the incidence of secondary outcomes of coronary revascularization procedures, worsening heart failure, or worsening angina, although there were fewer strokes in the atorvastatin group than in the placebo group (12 vs 24 events; P =.045). In the atorvastatin group, mean low-density lipoprotein cholesterol level declined from 124 mg/dL (3.2 mmol/L) to 72 mg/dL (1.9 mmol/L). Abnormal liver transaminases (>3 times upper limit of normal) were more common in the atorvastatin group than in the placebo group (2.5% vs 0.6%; P<.001). CONCLUSION: For patients with acute coronary syndrome, lipid-lowering therapy with atorvastatin, 80 mg/d, reduces recurrent ischemic events in the first 16 weeks, mostly recurrent symptomatic ischemia requiring rehospitalization.
Asunto(s)
Angina Inestable/tratamiento farmacológico , Anticolesterolemiantes/uso terapéutico , Ácidos Heptanoicos/uso terapéutico , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Infarto del Miocardio/tratamiento farmacológico , Pirroles/uso terapéutico , Anciano , Angina Inestable/sangre , Atorvastatina , Método Doble Ciego , Femenino , Humanos , Lípidos/sangre , Masculino , Persona de Mediana Edad , Infarto del Miocardio/sangre , Modelos de Riesgos Proporcionales , Recurrencia , Análisis de SupervivenciaRESUMEN
An academic 12-lead electrocardiogram (ECG) core laboratory aims to provide the highest possible quality ECG recording, measurement, and storage to aid clinicians in research into important cardiovascular outcomes and to maximize the credibility of scientific results based solely, or in part, on ECG data. This position paper presents a guide for the structure and function of an academic ECG core laboratory. The key functional aspects are: 1) Data collection, 2) Staff composition, 3) Diagnostic measurement and definition standards, 4) Data management, 5) Academic considerations, 6) Economic consideration, and 7) Accreditation. An ECG Core Laboratory has the responsibility for rapid and accurate analysis and responsible management of the electrocardiographic data in multicenter clinical trials. Academic Laboratories, in addition, provide leadership in research protocol generation and production of research manuscripts for submission to the appropriate peer-review journals.
Asunto(s)
Electrocardiografía/normas , Laboratorios de Hospital/normas , Acreditación , Humanos , Proyectos de InvestigaciónAsunto(s)
Angiografía Coronaria , Electrocardiografía , Infarto del Miocardio/terapia , Revascularización Miocárdica , Terapia Trombolítica , Anciano , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/diagnóstico , Infarto del Miocardio/mortalidad , Evaluación de Procesos y Resultados en Atención de Salud , Ensayos Clínicos Controlados Aleatorios como Asunto , Recurrencia , Análisis de SupervivenciaRESUMEN
There are few data comparing the relative frequency of new electrocardiographic (ECG) abnormalities after coronary artery bypass grafting (CABG) compared with percutaneous transluminal coronary angioplasty (PTCA) and their association with long-term cardiac mortality. The study population consisted of 3,373 patients who were either randomized or eligible to be randomized to CABG or PTCA in the BARI trial. The frequency of new postprocedural ECG abnormalities was significantly greater after a CABG procedure than after PTCA. The incidence of new postprocedural major Q waves, ST-segment elevation, and T-wave abnormalities were significantly more frequent after CABG. After PTCA (n = 1,869), the 5-year cardiac mortality rates associated with the new development of major Q waves, ST-segment elevation, ST-segment depression, T-wave abnormalities, or no abnormality was 18.1%, 8.5%, 8.9%, 6.0%, and 5.4%, respectively. After CABG (n = 1,427), 5-year cardiac mortality rates were 8.0%, 4.2%, 3.8%, 2.8%, and 3.7%, respectively. The adjusted relative risk of 5-year cardiac mortality for new Q-wave abnormalities was 2.6 after CABG (p <0.04) and 4.6 after PTCA (p <0.01). Thus, patients who undergo CABG have more postinitial procedural ECG abnormalities than patients who undergo PTCA. Cardiac mortality is significantly increased by the new development of postprocedural Minnesota code Q-wave abnormalities regardless of whether patients undergo CABG or PTCA.
Asunto(s)
Angioplastia Coronaria con Balón , Puente de Arteria Coronaria , Enfermedad Coronaria/mortalidad , Enfermedad Coronaria/terapia , Angiopatías Diabéticas/mortalidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Ensayos Clínicos Controlados Aleatorios como AsuntoRESUMEN
BACKGROUND: The internal thoracic artery (ITA) bypass to the left anterior descending coronary artery is of proven benefit in multigraft coronary artery bypass. Total ITA grafts, if reoperation is averted by avoiding saphenous vein grafts (SVGs), are attractive. The safety of the total ITA graft operation (all-ITA) is a concern. METHODS: A randomized trial of multiple-ITA bypass graftings with the use of bilateral sequential ITA without SVGs was performed. Control patients received 1 ITA plus SVG. Inclusion criteria were those used in the Coronary Artery Surgery Study, extended to age 76 years, and any angina class, except emergent. One hundred sixty-two patients were randomized (81 patients per group) from January 1, 1990, to December 31, 1994. RESULTS: Baseline traits were similar as were cross-clamp times, pump times, and number of arteries bypassed (average, 4.3 arteries). Patients who received multiple ITA grafts had no myocardial infarctions, per reference laboratory. One patient died, and 2 patients returned for bleeding. The ITA-SVG group had similar results. The all-ITA group experienced successful completion in 93% of cases. Complications did not differ from control patients. CONCLUSIONS: Early and 5-year outcomes were not different between the all-ITA group and the ITA with SVGs group. We believe experienced surgeons can safely extend the ITA to multibypass coronary artery bypass without use of SVG to achieve an all-ITA operation.
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Puente de Arteria Coronaria/métodos , Puente de Arteria Coronaria/estadística & datos numéricos , Enfermedad Coronaria/mortalidad , Enfermedad Coronaria/cirugía , Arterias Mamarias/cirugía , Anciano , Circulación Coronaria , Enfermedad Coronaria/diagnóstico , Electrocardiografía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Morbilidad , Complicaciones Posoperatorias/mortalidad , Arteria Radial , Vena Safena , Análisis de Supervivencia , Resultado del TratamientoAsunto(s)
Instituciones Cardiológicas , Enfermedad Coronaria/diagnóstico , Pruebas de Función Cardíaca/efectos adversos , Admisión del Paciente , Alta del Paciente , Algoritmos , Angina Inestable/fisiopatología , Electrocardiografía , Femenino , Humanos , Masculino , Infarto del Miocardio/diagnóstico , Valor Predictivo de las Pruebas , Pronóstico , Estándares de Referencia , Medición de Riesgo , Seguridad , TriajeRESUMEN
BACKGROUND: The impact of percutaneous transluminal coronary angioplasty (PTCA) and coronary artery bypass grafting (CABG) on long-term mortality rates in the presence of various demographic, clinical, and angiographic factors is uncertain in the population of patients suitable for both procedures. METHODS AND RESULTS: In the Bypass Angioplasty Revascularization Investigation (BARI) randomized trial and registry, 3610 patients who were eligible to receive PTCA and CABG were revascularized between 1989 and 1992. Multivariate Cox models were used to identify factors associated with 5-year mortality and cardiac mortality, with particular attention to factors that interact with treatment. Diabetic patients receiving insulin had higher mortality and cardiac mortality rates with PTCA compared with CABG (relative risk [RR] 1.78 and 2.63, respectively, P<0.001), and patients with ST elevation had higher cardiac mortality rates with CABG than with PTCA (RR 4.08, P<0.001). Factors most strongly associated with high overall mortality rates were insulin-treated diabetes, congestive heart failure, kidney failure, and older age. Black race was also associated with higher mortality rates (RR 1.49, P=0.019). CONCLUSIONS: A set of variables was identified that could be used to help select a revascularization procedure and to evaluate risk of long-term mortality in the population of patients considering revascularization.
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Angioplastia Coronaria con Balón/mortalidad , Puente de Arteria Coronaria/mortalidad , Isquemia Miocárdica , Causas de Muerte , Diabetes Mellitus Tipo 2/mortalidad , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Isquemia Miocárdica/mortalidad , Isquemia Miocárdica/cirugía , Isquemia Miocárdica/terapia , Valor Predictivo de las Pruebas , Sistema de Registros , Análisis de SupervivenciaRESUMEN
This article examines specific electrocardiographic (ECG) and electrophysiological features of ventricular repolarization in rats and mice, and the role of depolarization-activated potassium currents in mediating the unique features of ECG recordings in these rodents. This article describes the currents that underlie ventricular repolarization in these rodents, identifies terminology that appropriately describes the unique features of murine ECG recordings, and correlates these unique findings with selected human ECG ventricular repolarization abnormalities. The absence of a distinct isoelectric interval between the QRS complex and the T wave, accompanied by a relatively short QT interval, are common features of ECG recordings in mice and rats, but not in ECGs in guinea pigs. The murine ECG morphology is apparently attributable to the presence of large outward K+ currents that dominate the early phase of ventricular repolarization. In rats and mice, the predominant current underlying the early phase of repolarization appears to be the rapidly activating and inactivating 4-aminopyridine-sensitive transient outward current (ie, I(to)). Importantly, the density of I(to) in rats and mice is high, whereas this current is not evident in the ventricular myocytes of guinea pigs. The high density of I(to) appears to underlie the prominent J wave or downsloping ST-segment elevation seen in rats and mice, whereas the ST-segment is isoelectric in guinea pigs. The unusual J wave and ST-segment pattern in murine ECGs, however, does bear some resemblance to ECG features observed in humans with Brugada syndrome, and with hypothermia and ischemia. These patterns in rats and mice might, therefore, serve as an experimental model for the idiopathic J wave.
Asunto(s)
Electrocardiografía , Ratones/fisiología , Ratas/fisiología , Función Ventricular , Potenciales de Acción , Animales , Electrofisiología , Cobayas , Humanos , Canales de Potasio/fisiologíaRESUMEN
BACKGROUND: Acute myocardial infarction in patients with diabetes is associated with high mortality. We studied whether previous revascularization by coronary-artery bypass grafting (CABG), as compared with percutaneous transluminal coronary angioplasty (PTCA), influences the prognosis in such patients. METHODS: We classified all patients eligible for the Bypass Angioplasty Revascularization Investigation who underwent coronary revascularization within three months after entry into the study according to whether they had diabetes and whether they had undergone CABG, either initially or after PTCA. The protective effect of CABG with regard to mortality in the presence and in the absence of subsequent spontaneous Q-wave myocardial infarction was estimated with the use of Cox regression models. RESULTS: Among the 641 patients with diabetes and the 2962 without diabetes, the cumulative five-year rates of death were 20 percent and 8 percent, respectively (P<0.001), and the five-year rates of spontaneous Q-wave myocardial infarction were 8 percent and 4 percent (P<0.001). CABG greatly reduced the risk of death after spontaneous Q-wave myocardial infarction in the patients with diabetes (relative risk, 0.09; 95 percent confidence interval, 0.03 to 0.29). Among patients with diabetes who had undergone CABG but did not have spontaneous Q-wave myocardial infarctions, the corresponding relative risk of death was 0.65 (95 percent confidence interval, 0.45 to 0.94). Among the patients without diabetes, no protective effect of CABG was evident. CONCLUSIONS: Among patients with diabetes, previous coronary bypass surgery, as compared with coronary angioplasty, has a highly favorable influence on prognosis after acute myocardial infarction and a smaller beneficial effect among patients who do not have infarction. These findings should influence the type of coronary revascularization procedure selected for patients with diabetes who have multivessel coronary artery disease.
Asunto(s)
Puente de Arteria Coronaria , Enfermedad Coronaria/cirugía , Complicaciones de la Diabetes , Infarto del Miocardio/mortalidad , Anciano , Angioplastia Coronaria con Balón , Enfermedad Coronaria/complicaciones , Enfermedad Coronaria/terapia , Electrocardiografía , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/etiología , Pronóstico , Modelos de Riesgos Proporcionales , Ensayos Clínicos Controlados Aleatorios como Asunto , Análisis de SupervivenciaRESUMEN
BACKGROUND: The transmembrane sodium/hydrogen exchanger maintains myocardial cell pH integrity during myocardial ischemia but paradoxically may precipitate cell necrosis. The development of cariporide, a potent and specific inhibitor of the exchanger, prompted this investigation of the potential of the drug to prevent myocardial cell necrosis. METHODS AND RESULTS: A total of 11 590 patients with unstable angina or non-ST-elevation myocardial infarction (MI) or undergoing high-risk percutaneous or surgical revascularization were randomized to receive placebo or 1 of 3 doses of cariporide for the period of risk. The trial failed to document benefit of cariporide over placebo on the primary end point of death or MI assessed after 36 days. Doses of 20 and 80 mg every 8 hours had no effect, whereas a dose of 120 mg was associated with a 10% risk reduction (98% CI 5.5% to 23.4%, P=0.12). With this dose, benefit was limited to patients undergoing bypass surgery (risk reduction 25%, 95% CI 3.1% to 41.5%, P=0.03) and was maintained after 6 months. No effect was seen on mortality. The rate of Q-wave MI was reduced by 32% across all entry diagnostic groups (2.6% versus 1.8%, P=0.03), but the rate of non-Q-wave MI was reduced only in patients undergoing surgery (7.1% versus 3.8%, P=0.005). There were no increases in clinically serious adverse events. CONCLUSIONS: No significant benefit of cariporide could be demonstrated across a wide range of clinical situations of risk. The trial documented safety of the drug and suggested that a high degree of inhibition of the exchanger could prevent cell necrosis in settings of ischemia-reperfusion.