RESUMEN
BACKGROUND AND PURPOSE: Dual-energy virtual NCCT has the potential to replace conventional NCCT to detect early ischemic changes in acute ischemic stroke. In this study, we evaluated whether virtual NCCT is noninferior compared with standard linearly blended NCCT, a surrogate of conventional NCCT, regarding the detection of early ischemic changes with ASPECTS. MATERIALS AND METHODS: Adult patients who presented with suspected acute ischemic stroke and who underwent dual-energy NCCT and CTA and brain MR imaging within 48 hours were included. Standard linearly blended images were reconstructed to match a conventional NCCT. Virtual NCCT images were reconstructed from CTA. ASPECTS was evaluated on conventional NCCT, virtual NCCT, and DWI, which served as the reference standard. Agreement between CT assessments and the reference standard was evaluated with the Lin concordance correlation coefficient. Noninferiority was assessed with bootstrapped estimates of the differences in ASPECTS between conventional and virtual NCCT with 95% CIs. RESULTS: Of the 193 included patients, 100 patients (52%) had ischemia on DWI. Compared with the reference standard, the ASPECTS concordance correlation coefficient for conventional and virtual NCCT was 0.23 (95% CI, 0.15-0.32) and 0.44 (95% CI, 0.33-0.53), respectively. The difference in the concordance correlation coefficient between virtual and conventional NCCT was 0.20 (95% CI, 0.01-0.39) and did not cross the prespecified noninferiority margin of -0.10. CONCLUSIONS: Dual-energy virtual NCCT is noninferior compared with conventional NCCT for the detection of early ischemic changes with ASPECTS.
Asunto(s)
Isquemia Encefálica , Accidente Cerebrovascular Isquémico , Accidente Cerebrovascular , Adulto , Humanos , Accidente Cerebrovascular/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos , Angiografía Cerebral/métodos , Encéfalo , Isquemia Encefálica/diagnóstico por imagenRESUMEN
OBJECTIVE: The aim of the study was to describe Veterans Healthcare Administration (VHA) system-wide uptake of three HIV protease inhibitors: atazanavir, darunavir and tipranavir. METHODS: This retrospective cohort study evaluated VHA uptake of three target antiretrovirals and lopinavir/ritonavir in each complete 90-day quarter since approval to December 2007 using VHA HIV Clinical Case Registry data. We assessed uptake using number of new prescriptions, number of providers and facilities prescribing target agents, provider type, clinic type, facility size and location within four US regions. RESULTS: Overall, 6551 HIV-infected veterans received target antiretrovirals. Uptake was generally greatest within the first year after Food and Drug Administration (FDA) approval, and then slightly declined and plateaued. Geographically, early adoption of new antiretroviral drugs tended to occur in the Western USA, as evidenced by comparison of uptake patterns of new antiretrovirals to use of all antiretroviral agents. A small percentage of prescribers of all antiretrovirals were responsible for new prescriptions for target medications, particularly for darunavir and tipranavir. Providers at almost 50% of VHA facilities were prescribing these agents within the first year. CONCLUSIONS: Uptake of new antiretrovirals in the VHA generally reflected overall prescribing of all antiretrovirals, suggesting a lack of VHA impediments to new antiretrovirals in the healthcare system. Some regional variation in uptake among the targeted antiretrovirals occurred over time but tended to resolve after the first several months. Providers responsible for early prescribing of the target medications were limited to a fraction of providers who tended to be physicians who practised in infectious disease (ID) clinics at medium-sized facilities.
Asunto(s)
Antirretrovirales/uso terapéutico , Infecciones por VIH/tratamiento farmacológico , Oligopéptidos/uso terapéutico , Pautas de la Práctica en Medicina/tendencias , Piridinas/uso terapéutico , Pironas/uso terapéutico , Sulfonamidas/uso terapéutico , Instituciones de Atención Ambulatoria/estadística & datos numéricos , Sulfato de Atazanavir , Estudios de Cohortes , Darunavir , Aprobación de Drogas , Prescripciones de Medicamentos/estadística & datos numéricos , Registros Electrónicos de Salud , Femenino , Tamaño de las Instituciones de Salud , Humanos , Masculino , Pautas de la Práctica en Medicina/estadística & datos numéricos , Estudios Retrospectivos , Factores de Tiempo , Estados Unidos , United States Food and Drug Administration , VeteranosRESUMEN
PURPOSE: Previous studies have shown that coronary artery bypass surgery reduces the risk of cardiac complications after noncardiac surgery. Whether coronary angioplasty provides equivalent protection is not known. SUBJECTS AND METHODS: Patients were randomly assigned to undergo cardiac artery bypass surgery or angioplasty as part of the Bypass Angioplasty Revascularization Investigation trial. All subsequent noncardiac surgeries during a mean (+/- SD) follow-up of 7.7 years were recorded among participants in the ancillary Study of Economics and Quality of Life. Rates of mortality and nonfatal myocardial infarction, length of stay, and hospital costs were compared by the original randomized assignment. RESULTS: A total of 501 patients had noncardiac surgery at a median of 29 months after their most recent coronary revascularization procedure. Mortality and nonfatal myocardial infarction within 30 days of the first noncardiac surgery occurred in 4 of the 250 of the surgery-assigned patients and in 4 of the 251 of the angioplasty-assigned patients (P = 1.0). There were no significant differences in the mean length of hospital stay (6.3 +/- 6.7 versus 6.2 +/- 6.8 days; P = 0.47) or hospital cost ($8,920 +/- $11,511 versus $7,785 +/- $7,643; P = 0.33) between the surgery and angioplasty groups. Similar results were obtained when subsequent noncardiac procedures were included in the analysis. CONCLUSION: Rates of myocardial infarction and death after noncardiac surgery are similarly low after contemporary bypass surgery or angioplasty in patients with multivessel coronary artery disease.
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Angioplastia Coronaria con Balón , Puente de Arteria Coronaria , Complicaciones Posoperatorias/prevención & control , Procedimientos Quirúrgicos Operativos/efectos adversos , Anciano , Angina de Pecho/prevención & control , Femenino , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/prevención & control , Recurrencia , Riesgo , Factores de Riesgo , Factores de Tiempo , Resultado del TratamientoRESUMEN
BACKGROUND: Stents are now used in the majority of percutaneous coronary revascularization procedures. It is not clear whether the higher initial cost of stenting is later repaid by reducing costly complications and repeat revascularization procedures, especially for patients with multivessel disease. METHODS: To project the long-term costs of using coronary stents, angioplasty, or bypass surgery to treat patients with multivessel coronary artery disease, we developed a decision model based on the outcomes documented in the Bypass Angioplasty Revascularization Investigation (BARI) randomized trial of coronary artery bypass grafting (CABG) and percutaneous transluminal coronary angioplasty (PTCA). We studied 2 clinical strategies: provisional stenting of suboptimal PTCA results and primary stenting of all angiographically eligible lesions. The cost of CABG was also updated to reflect contemporary practice. RESULTS: Provisional stenting had lower projected costs over a 4-year period than either traditional PTCA (-$1742, or -3.4%) or contemporary CABG (-$832, or -1.7%), mostly because of reductions in emergency CABG after PTCA. In contrast, primary stenting had higher projected costs over a 4-year period than either PTCA (+$333, or +0. 7%) or contemporary CABG (+$1243, or +2.5%), mainly because of the higher initial procedure costs. These results were not substantially altered when we systematically varied the key parameters of the models in 1-way and 2-way sensitivity analyses. CONCLUSIONS: A primary stenting strategy in patients with multivessel disease has higher projected long-term costs than CABG. In contrast, a provisional stenting strategy in multivessel disease has lower projected costs than either PTCA or CABG.
Asunto(s)
Angioplastia Coronaria con Balón/economía , Puente de Arteria Coronaria/economía , Enfermedad Coronaria/economía , Stents , Angioplastia Coronaria con Balón/instrumentación , Angiografía Coronaria , Enfermedad Coronaria/diagnóstico por imagen , Enfermedad Coronaria/cirugía , Análisis Costo-Beneficio , Técnicas de Apoyo para la Decisión , Estudios de Seguimiento , Humanos , Stents/economíaRESUMEN
BACKGROUND: Serial antiarrhythmic drug testing guided by Holter monitoring and electrophysiologic study had similar clinical outcomes in the Electrophysiologic Study versus Electrocardiographic Monitoring (ESVEM) trial, while patients treated with sotalol had improved outcomes. The purpose of this study was to compare long-term cost-effectiveness of these management alternatives. METHODS: Patients in the ESVEM trial were linked to computerized files of either the Health Care Finance Administration or the Department of Veterans Affairs. Total hospital costs and survival time over five year follow-up were measured using actuarial methods, and cost-effectiveness was calculated. RESULTS: Patients randomized to therapy guided by electrophysiologic study had more hospital admissions, higher costs, and a cost-effectiveness ratio of $162,500 per life year added compared with therapy guided by Holter monitoring. Patients randomized to sotalol had fewer hospitalizations, lower costs, and better survival than patients randomized to other drugs, and sotalol was a dominant strategy in the cost-effectiveness analysis. Patients for whom an effective drug was found had fewer hospital admissions, lower costs, and longer survival. These findings were robust in sensitivity analyses and in bootstrap replications. CONCLUSIONS: Serial drug testing guided by electrophysiologic study had an unfavorable cost-effectiveness ratio relative to Holter monitoring, while sotalol was cost-effective relative to other antiarrhythmic drugs.
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Antiarrítmicos/uso terapéutico , Arritmias Cardíacas/tratamiento farmacológico , Anciano , Antiarrítmicos/economía , Arritmias Cardíacas/economía , Arritmias Cardíacas/epidemiología , Análisis Costo-Beneficio , Electrocardiografía Ambulatoria , Electrofisiología , Femenino , Costos de Hospital , Hospitalización , Humanos , Masculino , Persona de Mediana Edad , Ensayos Clínicos Controlados Aleatorios como Asunto , Estudios Retrospectivos , Sotalol/uso terapéutico , Tasa de Supervivencia , Factores de TiempoRESUMEN
PURPOSE: To improve the prediction of individual survival in patients with intracranial astrocytomas through the analysis of volumetric tumor doubling time (VDt) and DNA ploidy. METHODS: A pilot study was retrospectively conducted on a group of 25 patients with intracranial astrocytomas in whom recurrent and/or progressive disease was observed on serial contrast-enhanced CT or MR examinations. VDt was computed using two or more data points from a semilogarithmic plot of tumor volume versus time. Size-adjusted survival was calculated using a method based on VDt and initial tumor volume to decrease the lead time bias attributable to differing tumor sizes at presentation. RESULTS: Slower VDt was associated with significantly longer survival and size-adjusted survival as determined by a univariate Cox proportional hazard analysis. Aneuploidy was a significant indicator of poor survival. Aneuploid and multiclonal astrocytomas had poor size-adjusted survivals compared with diploid astrocytomas. Grade IV astrocytomas had significantly poorer survival and size-adjusted survival compared with lower grades (I to III), which individually were not significantly correlated. However, grade IV histology was not a significant independent predictor of size-adjusted survival in a multivariate Cox model, whereas VDt and DNA ploidy remained significant. VDt also had a significant direct linear correlation to survival and size-adjusted survival. CONCLUSIONS: VDt and DNA ploidy were more sensitive than histologic grading as indicators of individual survival. Initial tumor size needs to be considered when staging and assessing survival in patients with intracranial astrocytomas.
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Astrocitoma/patología , Neoplasias Encefálicas/patología , División Celular/fisiología , ADN de Neoplasias/análisis , Glioblastoma/patología , Ploidias , Adolescente , Adulto , Anciano , Astrocitoma/mortalidad , Encéfalo/patología , Neoplasias Encefálicas/mortalidad , Niño , Preescolar , Femenino , Glioblastoma/mortalidad , Humanos , Lactante , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Proyectos Piloto , Pronóstico , Modelos de Riesgos Proporcionales , Estudios Retrospectivos , Tasa de Supervivencia , Tomografía Computarizada por Rayos XRESUMEN
The US Department of Veterans Affairs (VA) cares for many human immunodeficiency virus/hepatitis C virus (HIV/HCV)-coinfected patients. VA treatment recommendations indicate that all HIV/HCV-coinfected patients undergo evaluation for HCV treatment and list pretreatment assessment tests. We compared clinical practice with these recommendations. We identified 377 HIV/HCV-coinfected veterans who began HCV therapy with pegylated interferon and ribavirin and 4135 HIV/HCV-coinfected veterans who did not but were in VA care at the same facilities during the same period. We compared laboratory and clinical characteristics of the two groups and estimated multivariate logistic regression models of receipt of HCV treatment. Overall, patients had high rates of receipt of tests necessary for HCV pretreatment assessment. Patients starting HCV treatment had higher alanine aminotransferase (ALT), lower creatinine, higher CD4 counts and lower HIV viral loads than patients not starting HCV treatment. In the multivariate model, positive predictors of starting HCV treatment included being non-Hispanic whites, having higher ALTs, lower creatinines, higher HCV viral loads, higher CD4 counts, undetectable HIV viral loads and receiving HIV antiretrovirals. A history of chronic mental illness and a history of hard drug use were negative predictors. Most HIV/HCV-coinfected patients received the necessary HCV pretreatment assessments, although rates of screening for hepatitis A and B immunity can be improved. Having well-controlled HIV disease is by far the most important modifiable factor affecting the receipt of HCV treatment. More research is needed to determine if the observed racial differences in starting HCV treatment reflect biological differences, provider behaviour or patient preference.
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Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/virología , VIH , Hepacivirus , Hepatitis C/tratamiento farmacológico , Hepatitis C/virología , Veteranos , Estudios de Cohortes , Femenino , Infecciones por VIH/diagnóstico , Hepatitis C/diagnóstico , Humanos , Interferón alfa-2 , Interferón-alfa/uso terapéutico , Masculino , Persona de Mediana Edad , Polietilenglicoles/uso terapéutico , Proteínas Recombinantes , Ribavirina/uso terapéutico , Estados Unidos , United States Department of Veterans AffairsRESUMEN
BACKGROUND: Accelerated coronary artery disease is a major cause of late morbidity and mortality among heart-transplant recipients. Because calcium-channel blockers can suppress diet-induced atherosclerosis in laboratory animals, we assessed the efficacy of diltiazem in preventing coronary artery disease in transplanted hearts. METHODS: Consecutive eligible cardiac-transplant recipients were randomly assigned to receive diltiazem (n = 52) or no calcium-channel blocker (n = 54). Coronary angiograms obtained early after cardiac transplantation and annually thereafter were used for the visual assessment of the extent of coronary artery disease. The average diameters of identical coronary artery segments were measured on the angiograms obtained at base line and at the first and second follow-up examinations. RESULTS: In the 57 patients who had all three angiograms, the average coronary artery diameter (+/- SD) 0.27 decreased in the group that received no calcium-channel blocker from 2.41 +/- 0.27 mm at base line to 2.19 +/- 0.28 mm at one year, and to 2.22 +/- 0.26 mm at two years (P < 0.001 for both years). The average diameter in the diltiazem group changed little from the base-line value of 2.32 +/- 0.22 mm (2.32 +/- 0.27 mm at one year and 2.36 +/- 0.22 mm at two years). The average change in the diameter of the segment differed significantly between the two treatment groups (P < 0.001), and the estimated effect of treatment changed only negligibly after adjustment for other relevant clinical variables. New angiographic evidence of coronary artery disease developed in 14 patients not given calcium-channel blockers, as compared with 5 diltiazem-treated patients (P = 0.082). Coronary stenoses greater than 50 percent of the luminal diameter developed in seven patients not given calcium-channel blockers, as compared with two patients given diltiazem; death due to coronary artery disease or retransplantation occurred in five patients in the group that did not receive calcium-channel blockers and none of those who received diltiazem. CONCLUSIONS: Our preliminary results suggest that diltiazem can prevent the usual reduction in the diameter of the coronary artery in cardiac-transplant recipients, but further follow-up will be required to determine whether diltiazem can decrease the long-term incidence of symptomatic coronary artery disease.
Asunto(s)
Enfermedad Coronaria/prevención & control , Diltiazem/uso terapéutico , Trasplante de Corazón , Adulto , Cineangiografía , Angiografía Coronaria , Enfermedad Coronaria/diagnóstico por imagen , Enfermedad Coronaria/cirugía , Femenino , Estudios de Seguimiento , Humanos , Terapia de Inmunosupresión , Masculino , Persona de Mediana Edad , Recurrencia , Análisis de Regresión , Estudios RetrospectivosRESUMEN
BACKGROUND: After the occlusion of an internal carotid artery the principal source of collateral flow is through the arteries of the circle of Willis, but the size and patency of these arteries are quite variable. Study of the anatomy of the collateral pathways in patients with internal-carotid-artery occlusion with or without infarction in the watershed area of the deep white matter may identify patterns that afford protection from ischemic infarction. METHODS: Using conventional magnetic resonance imaging and three-dimensional phase-contrast magnetic resonance angiography, we evaluated 29 consecutive patients (32 hemispheres at risk) with angiographically proved occlusion of the internal carotid artery. Four collateral pathways to the occluded vessel were evaluated: the proximal segment of the anterior cerebral artery, the posterior communicating artery, the ophthalmic artery, and leptomeningeal collateral vessels from the posterior cerebral artery. RESULTS: Only features of the ipsilateral posterior communicating artery were related to the risk of watershed infarction. The presence of posterior communicating arteries measuring at least 1 mm in diameter was associated with the absence of watershed infarction (13 hemispheres, no infarcts; P < 0.001). Conversely, there were 4 watershed infarcts in the 6 hemispheres with posterior communicating arteries measuring less than 1 mm in diameter and 10 infarcts in the 13 hemispheres with no detectable flow in the ipsilateral posterior communicating artery. CONCLUSIONS: A small (< 1 mm in diameter) or absent ipsilateral posterior communicating artery is a risk factor for ischemic cerebral infarction in patients with internal-carotid-artery occlusion.
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Isquemia Encefálica/etiología , Estenosis Carotídea/complicaciones , Infarto Cerebral/etiología , Círculo Arterial Cerebral/patología , Isquemia Encefálica/patología , Arteria Carótida Interna/patología , Estenosis Carotídea/patología , Infarto Cerebral/patología , Circulación Colateral , Intervalos de Confianza , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Oportunidad Relativa , Factores de Riesgo , Grado de Desobstrucción VascularRESUMEN
BACKGROUND: Medical costs vary substantially among patients. Understanding the baseline factors that predict subsequent cost may allow better selection of therapy for individual patients. Understanding the postprocedure events that increase cost should help to improve efficiency and effectiveness of coronary revascularization. METHODS: Data on 4-year costs were collected from patients randomly assigned to coronary angioplasty or bypass surgery as part of the BARI (Bypass Angioplasty Revascularization Investigation) trial. Regression models first examined factors known at the time of randomization that prospectively predicted initial procedure cost and long-term cost. Subsequent models tested the value of postrandomization events as explanatory variables for cost. RESULTS: The independent baseline predictors of higher initial percutaneous transluminal coronary angioplasty cost included 3-vessel disease (+12%) and acute presentations (+22%), whereas the independent predictors of higher initial coronary artery bypass grafting cost included the number of comorbid conditions (+5% per condition) and female sex (+7%). The independent baseline predictors of 4-year cost included heart failure (+26%), diabetes (+22%), comorbidity (+10%), and angioplasty assignment in patients with 2-vessel disease (-15%). Postrandomization models showed higher initial and long-term costs were strongly correlated with the number of repeat revascularization procedures (+30% to +128%) and the occurrence of clinical complications (+8% to +131%). CONCLUSIONS: Two-vessel disease identifies patients likely to have lower costs after angioplasty, whereas heart failure, comorbid conditions, and diabetes identify patients likely to accrue higher costs after either angioplasty or bypass surgery. Long-term costs can be potentially reduced by interventions that decrease procedural complications or reduce the need for repeat revascularization.