Comparison of the Effectiveness of Stress Echocardiography Versus Myocardial Perfusion Imaging in Patients Presenting to the Emergency Department With Low-Risk Chest Pain.

The aim of this study was to compare clinically relevant cardiovascular outcomes and downstream resource utilization associated with stress echocardiography (SE) and myocardial perfusion imaging (MPI) in emergency department patients with low-risk chest pain. This was a retrospective analysis of health insurance claims data for a national sample of privately insured patients over the period January 1 to December 31, 2011. Subjects were selected who presented to the emergency department with a primary or secondary diagnosis of chest pain and underwent either SE or MPI. The primary end points were the percentage of patients in each group who underwent downstream cardiac catheterization, revascularization, repeat noninvasive testing, return emergency department visit with chest pain, and hospitalization for myocardial infarction. The mean length of follow-up was 190 days in both groups. Overall, 48,202 patients or 24,101 propensity-matched pairs were included in the final analysis. Compared with SE, MPI was associated with significantly higher odds of subsequent cardiac catheterization (adjusted odds ratio [AOR] 2.15; 95% confidence interval [CI] 1.99 to 2.33) and revascularization procedures (AOR 1.58; 95% CI 1.36 to 1.85) and repeat emergency department visits (AOR 1.14; 95% CI 1.11 to 1.19). The odds of repeat testing and myocardial infarction did not differ between groups. The average cost of downstream care was significantly higher in the MPI group ($2,193.80 vs $1,631.10, p <0.0001). According to the a priori rules specified for this comparative analysis, SE is more effective than MPI for privately insured patients who present to the emergency department with chest pain. In conclusion, these findings demonstrate the importance of assessing diagnostic tests based on how they affect hard end points because identification of disease, in and of itself, may not confer any clinical advantage.

Noninvasive Testing in Emergency Department Patients with Low-Risk Chest Pain: Does the Evidence Support Current Guidelines?

Patients who present to the emergency department with chest pain but no evidence of ischemia on the electrocardiogram and negative cardiac markers are at very low risk. The newest American Heart Association/American College of Cardiology guidelines give noninvasive cardiac testing a IIa recommendation in this patient population. Here, we will review the existing literature that was cited in the American Heart Association/American College of Cardiology document, as well as several large, contemporary, comparative observational studies which were not included to address the following question: Do the benefits of noninvasive cardiac testing in this patient population outweigh the risks?

Comparative effectiveness of diagnostic testing strategies in emergency department patients with chest pain: an analysis of downstream testing, interventions, and outcomes.

IMPORTANCE: Patients presenting to the emergency department (ED) with chest pain whose evaluation for ischemia demonstrates no abnormalities receive further functional or anatomical studies for coronary artery disease; however, comparative evidence for the various strategies is lacking and multiple testing options exist. OBJECTIVE: To compare chest pain evaluation pathways based on their association with downstream testing, interventions, and outcomes for patients in EDs. DESIGN, SETTING, AND PARTICIPANTS: Retrospective analysis of health insurance claims data for a national sample of privately insured patients from January 1 to December 31, 2011. Individuals with a primary or secondary diagnosis of chest pain in the ED were selected and classified into 1 of 5 testing strategies: no noninvasive testing, exercise electrocardiography, stress echocardiography, myocardial perfusion scintigraphy, or coronary computed tomography angiography. MAIN OUTCOMES AND MEASURES: The proportion of patients in each group who received a cardiac catheterization, coronary revascularization procedure, or future noninvasive test as well as those who were hospitalized for an acute myocardial infarction (MI) during 7 and 190 days of follow-up. RESULTS: In 2011, there were 693 212 ED visits with a primary or secondary diagnosis of chest pain, accounting for 9.2% of all ED encounters. After application of the inclusion and exclusion criteria, 421 774 patients were included in the final analysis; 293 788 individuals did not receive an initial noninvasive test and 127 986 did, representing 1.7% of all ED encounters. Overall, the percentage of patients hospitalized with an MI was very low during both 7 and 190 days of follow-up (0.11% and 0.33%, respectively). Patients who did not undergo initial noninvasive testing were no more likely to experience an MI than were those who did receive testing. Compared with no testing, exercise electrocardiography, myocardial perfusion scintigraphy, and coronary computed tomography angiography were associated with significantly higher odds of cardiac catheterization and revascularization procedures without a concomitant improvement in the odds of experiencing an MI. CONCLUSIONS AND RELEVANCE: Patients with chest pain evaluated in the ED who do not have an MI are at very low risk of experiencing an MI during short- and longer-term follow-up in a cohort of privately insured patients. This low risk does not appear to be affected by the initial testing strategy. Deferral of early noninvasive testing appears to be reasonable.

Clinical efficacy of dofetilide for the treatment of atrial tachyarrhythmias in adults with congenital heart disease.

BACKGROUND: Atrial tachyarrhythmias (AT) including atrial fibrillation (AF), atrial flutter (AFL), and atrial tachycardia represent a clinical challenge in the adult with congenital heart disease (CHD). Dofetilide (D) is a rapidly activating delayed rectifier potassium channel (IKr) blocker effective in pharmacological conversion and maintenance of normal sinus rhythm in patients with AF and AFL. There is limited knowledge regarding the role of D in adults with CHD. METHODS: Safety and efficacy of D was evaluated in a consecutive group of thirteen adult patients (age 40 ± 11; six women) with CHD and refractory AT. RESULTS: Ten patients had persistent (four AFL, one AF, and five atrial tachycardia) and three paroxysmal (one AF and two atrial tachycardia) AT. All patients were symptomatic during tachycardia, 12 patients had previously failed 2 ± 1 antiarrhythmic drugs. Mean systemic ventricular ejection fraction was 55 ± 9%; baseline QRS complex duration was 129 ± 45 ms (>120 ms in six patients). Patients were followed on D for 33 ± 39 months (median 16). Among 10 patients with persistent AT, seven patients (70%) pharmacologically converted to sinus rhythm on D and three patients (30%) required direct current cardioversion. Two patients (15.4%) experienced complete arrhythmia suppression, and seven (53.8%) experienced significant clinical improvement with sporadic recurrences; average time to recurrence was 5.5 ± 3.5 months. One patient developed torsade de pointes during loading, and the drug was discontinued. D was discontinued in five (38.5%) other patients due to recurrence of AT (n = 4) and renal failure (n = 1). Corrected QT interval (QTc) increased from 452 ± 61 to 480 ± 49 ms (P = .04) and corrected JT interval (JTc) from 323 ± 39 to 341 ± 33 ms (P = .09). CONCLUSIONS: D should be considered a pharmacologic alternative when adult patients with CHD develop AT. D does not depress conduction, sinus node, or ventricular function but needs close monitoring for potential ventricular pro-arrhythmia.

Long-term results of the subclavian flap repair for coarctation of the aorta in infants.

BACKGROUND: Coarctation is a congenital narrowing of the aorta that often requires repair during infancy. The subclavian flap aortoplasty was once widely favored for its avoidance of a circumferential suture line and low incidence of recoarctation. The aim of this study is to report the long-term results of the subclavian flap repair for coarctation of the aorta in infants. METHODS: Our operative database was queried for infants with coarctation who underwent subclavian flap aortoplasty from 1966 to 1991. Medical records were reviewed for patient characteristics and outcomes. Survivors were identified for additional phone interview. RESULTS: Fifty-five patients met the inclusion criteria. There were 7 early deaths (in hospital), 11 late deaths, 5 patients lost to follow-up, and 32 known long-term survivors with a mean follow-up of 22.0 years (range 2.4-34.9). Hospital mortality was not associated with patient characteristics but was associated with earlier year of surgery (P = .015). A trend toward decreased overall survival was seen in patients with coarctation with associated cardiac defects (P = .072). Reintervention for recoarctation was required in 3 (6.6%) patients and was not related to the patient characteristics. There were no apparent complications related to subclavian artery sacrifice. CONCLUSIONS: Subclavian flap aortoplasty provides excellent long-term results for the repair of coarctation in infants. The incidence of recoarctation requiring reintervention is low and compares favorably with other techniques. Compromise of growth or function of the left arm was not appreciated. The subclavian flap technique remains a viable surgical option for the repair of coarctation in infants.

Effects of early, late, and long-term nonselective ß-blockade on left ventricular remodeling, function, and survival in chronic organic mitral regurgitation.

BACKGROUND: Mitral regurgitation (MR) produces sympathetic nervous system activation which is detrimental in other causes of heart failure. However, whether ß-blockade is beneficial in MR has not been determined. METHODS AND RESULTS: Eighty-seven rats with significant organic MR were randomized to the ß-blockade group (n=43) or the control group (n=44). Carvedilol was started in week 2 post MR induction and given for 23 to 35 weeks in the ß-blockade group. Echocardiography was performed at baseline and at weeks 2, 6, 12, 24, 30, and 36 after MR induction. After 23 weeks of ß-blockade, heart rates were significantly reduced by carvedilol (308 ± 25 versus 351 ± 31 beats per minute; P<0.001). Left ventricular end-diastolic (2.2 ± 0.7 versus 1.59 ± 0.6 mL; P<0.001), end-systolic volumes (0.72 ± 0.42 versus 0.40 ± 0.19 mL; P<0.001), and mass index (2.40 ± 0.55 versus 2.06 ± 0.62 g/kg; P<0.001) were significantly higher, and left ventricular fraction shortening (33 ± 7% versus 38 ± 7%; P<0.001) and ejection fraction (69 ± 11% versus 75 ± 7%; P<0.001) were significantly lower in the ß-blockade group than in the control group. Systolic blood pressure was lower in the ß-blockade group than in the control group (114 ± 10 versus 93 ± 12 mm Hg; P<0.005). Survival probability was significantly lower in the early ß-blockade group than in the control group (88% versus 96%; P=0.03). CONCLUSIONS: Early and long-term nonselective ß-blockade was associated with adverse left ventricular remodeling, systolic dysfunction, and a reduction in survival in the experimental rat model of organic MR.

Anaplasma odocoilei sp. nov. (family Anaplasmataceae) from white-tailed deer (Odocoileus virginianus).

Recently, an undescribed Anaplasma sp. (also called Ehrlichia-like sp. or WTD agent) was isolated in ISE6 tick cells from captive white-tailed deer. The goal of the current study was to characterize this organism using a combination of experimental infection, morphologic, serologic, and molecular studies. Each of 6 experimentally inoculated white-tailed deer fawns (Odocoileus virginianus) became chronically infected (100+ days) with the Anaplasma sp. by inoculation of either infected whole blood or culture. None of the deer showed evidence of clinical disease, but 3 of the 6 deer evaluated had multiple episodes of transient thrombocytopenia. Light microscopy of Giemsa-stained, thin blood smears revealed tiny, dark, spherical structures in platelets of acutely infected deer. Anaplasma sp. was detected in platelets of inoculated deer by polymerase chain reaction, transmission electron microscopy, immunohistochemistry, and in situ hybridization. Five of 6 deer developed antibodies reactive to Anaplasma sp. antigen, as detected by indirect fluorescent antibody testing. Phylogenetic analyses of 16S rRNA, groESL, and gltA sequences confirmed the Anaplasma sp. is related to A. platys. Two attempts to transmit the Anaplasma sp. between deer by feeding Amblyomma americanum, a suspected tick vector, were unsuccessful. Based on its biologic, antigenic, and genetic characteristics, this organism is considered a novel species of Anaplasma, and the name Anaplasma odocoilei sp. nov. is proposed with UMUM76(T) (=CSUR-A1) as the type strain.

Cardiac resynchronization therapy: evaluation of ventricular dysynchrony and patient selection.

Cardiac resynchronization therapy (CRT) is an established treatment modality for systolic heart failure. Aimed to produce simultaneous biventricular stimulation and correct the lack of ventricular synchrony in selected patients with congestive heart failure, CRT has shown to improve mortality and reduce hospital admissions when compared to medical treatment. At present, the indication criteria for the implantation of a CRT device include an ejection fraction of less than 35%, heart failure symptoms consistent with NYHA functional class III-IV and a QRS complex duration equal or longer than 120 milliseconds. It has been reported that 30% of patients who meet those criteria still may not derive clinical benefit from CRT. Due to the existing diversity of imagin modalities and resources for their process and analysis, a great expectation in terms of more accurate diagnosis of ventricular dyssynchrony has been raised. Reilable identification of dyssynchrony could allow us to better predict the favorable response of an individual patient to CRT and therefore offer this procedure to those individuals most likely to benefit. We review the available techniques for the study of ventricular dyssynchrony for CRT patient selection and the results of its application in clinical trials. Despite tremendous progress in the imaging technology available for the assessment and diagnosis of ventricular dyssynchrony, an ideal method has not been identified and the duration of QRS complex in the surface ECG remains the accepted criteria of dyssynchrony in the selection of patients for CRT.

Cardiac resynchronization therapy: evaluation of ventricular dysynchrony and patient selection / Terapia de resincronización cardiaca: evaluación de la disincronía ventricular y selección de pacientes

Cardiac resynchronization therapy (CRT) is an established treatment modality for systolic heart failure. Aimed to produce simultaneous biventricular stimulation and correct the lack of ventricular synchrony in selected patients with congestive heart failure, CRT has shown to improve mortality and reduce hospital admissions when compared to medical treatment. At present, the indication criteria for the implantation of a CRT device include an ejection fraction of less than 35%, heart failure symptoms consistent with NYHA functional class III-IV and a QRS complex duration equal or longer than 120 milliseconds. It has been reported that 30% of patients who meet those criteria still may not derive clinical benefit from CRT. Due to the existing diversity of imaging modalities and resources for their process and analysis, a great expectation in terms of more accurate diagnosis of ventricular dyssynchrony has been raised. Reliable identification of dyssynchrony could allow us to better predict the favorable response of an individual patient to CRT and therefore offer this procedure to those individuals most likely to benefit. We review the available techniques for the study of ventricular dyssynchrony for CRT patient selection and the results of its application in clinical trials. Despite tremendous progress in the imaging technology available for the assessment and diagnosis of ventricular dyssynchrony, an ideal method has not been identified and the duration of the QRS complex in the surface ECG remains the accepted criteria of dyssynchrony in the selection of patients for CRT.

La terapia de resincronización cardiaca es una modalidad de tratamiento bien establecida para la insuficiencia sistólica cardiaca. Dirigida a producir una estimulación biventricular simultánea y a corregir la falta de sincronía ventricular en pacientes seleccionados con insuficiencia cardiaca congestiva, la terapia de resincronización cardiaca ha mostrado ser capaz de mejorar los índices de mortalidad y reducir las admisiones hospitalarias cuando se compara con el tratamiento médico. Actualmente, los criterios para la implantación de un dispositivo de terapia de resincronización cardiaca incluyen una fracción de eyección menor a 35%, síntomas de insuficiencia cardiaca consistentes con la clase funcional NYHA III-IV, y una duración del complejo QRS igual o mayor de 120 milisegundos. Se ha reportado que 30% de los pacientes que cumplen con estos criterios pueden inclusive no obtener beneficio clínico de la terapia de resincronización cardiaca. Debido a la diversidad existente de los estudios de imagenología y de los recursos para su proceso y análisis, ha surgido una gran expectativa en términos de un diagnóstico más exacto de la asincronía ventricular. La identificación confiable de la asincronía nos podría permitir predecir mejor la respuesta favorable de un paciente en particular a la terapia de resincronización cardiaca y así ofrecer este procedimiento a aquellos pacientes con mayores probabilidades de beneficiarse de dicha terapia. Hacemos una revisión de las técnicas disponibles para el estudio de la asincronía ventricular para la selección de pacientes para esta terapia y los resultados de su aplicación en pruebas clínicas. A pesar de los grandes progresos alcanzados en la tecnología de imágenes disponibles para la evaluación y diagnóstico de la asincronía ventricular, no se ha identificado un método ideal y la duración del complejo QRS en el ECG de superficie sigue siendo el criterio aceptado de asincronía en la selección de pacientes para terapia de resincronización cardiaca.

Differential regulation of p53 function by the N-terminal ΔNp53 and Δ113p53 isoforms in zebrafish embryos.

BACKGROUND: The p53 protein family coordinates stress responses of cells and organisms. Alternative promoter usage and/or splicing of p53 mRNA gives rise to at least nine mammalian p53 proteins with distinct N- and C-termini which are differentially expressed in normal and malignant cells. The human N-terminal p53 variants contain either the full-length (FL), or a truncated (ΔN/Δ40) or no transactivation domain (Δ133) altogether. The functional consequences of coexpression of the different p53 isoforms are poorly defined. Here we investigated functional aspects of the zebrafish ΔNp53 ortholog in the context of FLp53 and the zebrafish Δ133p53 ortholog (Δ113p53) coexpressed in the developing embryo. RESULTS: We cloned the zebrafish ΔNp53 isoform and determined that ionizing radiation increased expression of steady-state ΔNp53 and Δ113p53 mRNA levels in zebrafish embryos. Ectopic ΔNp53 expression by mRNA injection caused hypoplasia and malformation of the head, eyes and somites, yet partially counteracted lethal effects caused by concomitant expression of FLp53. FLp53 expression was required for developmental aberrations caused by ΔNp53 and for ΔNp53-dependent expression of the cyclin-dependent kinase inhibitor 1A (CDKN1A, p21, Cip1, WAF1). Knockdown of p21 expression markedly reduced the severity of developmental malformations associated with ΔNp53 overexpression. By contrast, forced Δ113p53 expression had little effect on ΔNp53-dependent embryonal phenotypes. These functional attributes were shared between zebrafish and human ΔNp53 orthologs ectopically expressed in zebrafish embryos. All 3 zebrafish isoforms could be coimmunoprecipitated with each other after transfection into Saos2 cells. CONCLUSIONS: Both alternative N-terminal p53 isoforms were expressed in developing zebrafish in response to cell stress and antagonized lethal effects of FLp53 to different degrees. However, in contrast to Δ113p53, forced ΔNp53 expression itself led to developmental defects which depended, in part, on p21 transactivation. In contrast to FLp53, the developmental abnormalities caused by ΔNp53 were not counteracted by concomitant expression of Δ113p53.

Impact of mitral regurgitation on left ventricular anatomic and molecular remodeling and systolic function: implication for outcome.

The aim of the study was to assess the impact of mitral regurgitation (MR) on left ventricular (LV) anatomic and molecular remodeling and function and to determine whether early LV remodeling and function predict long-term outcome in experimental organic MR. A new rodent model of chronic MR was created. Twenty-eight rats had surgically induced MR, twelve rats had a sham operation, and twelve rats had no operation. LV diameters, volume, and mass and LV ejection fraction (LVEF) and LV fractional shortening (LVFS) were assessed using echocardiography in the early stage of MR (6 and 12 wk after induction of MR). LV hemodynamics was assessed invasively. Cardiac alpha- and beta-myosin heavy chains and sarco(endo)plasmic reticulum Ca(2+)-ATPase 2 (SERCA2) were measured to assess molecular remodeling and contractility. Cox's proportional hazard ratios (HR) were used to identify outcome predictors. Early LV dilation was demonstrated in rats with MR when LVEF and LVFS were still normal. LV remodeling was associated with an increase in LV end-diastolic pressure and decrease in maximal change in pressure over time. Shifting of alpha- to beta-myosin and reduced SERCA2 were observed in rats with MR. Cox's proportional hazard analysis showed that LV end-diastolic diameters (HR, 1.2-2.4; P = 0.007) and LV end-diastolic volume (HR, 1.1-1.4; P = 0.005) at 6 wk and LV mass index (HR, 1.1-2.0; P = 0.004) at 12 wk after induction of MR were significantly associated with 1-yr mortality. However, LVEF (HR, 0.7-6.8 for the 6 wk, P > 0.05; and HR, 0.4-3.2 for the 12 wk, P > 0.05) and LVFS (HR, 0.4-1.4 for the 6 wk; and 0.4-3.1 for the 12 wk, P > 0.05) did not predict late death. Chronic MR leads to LV anatomic and cellular remodeling and impaired contractility. The time course of LV remodeling and function changes in the rat model of MR is similar to humans. Prediction of outcome may be achieved by assessments of early LV remodeling.

Quantitative assessment of pulmonary insufficiency by Doppler echocardiography in patients with adult congenital heart disease.

We determined the utility of continuous wave (CW) Doppler for quantification of pulmonary insufficiency (PI) confirmed by pulmonary angiography in patients with postoperative adult congenital heart disease. A total of 41 patients with PI were divided into two groups on the basis of PI severity by pulmonary angiography: group A (n = 27) with severe PI and group B (n = 14) with mild or moderate PI. Nine patients in group A had pulmonic valve replacement and reverted to mild PI after surgery. Their pre- and postoperative data were compared. All underwent a two-dimensional/Doppler study with interrogation of the PI jet for jet width by color Doppler and peak flow velocity, deceleration time (DT), pressure half-time (PHT), diastolic period (DP), and PI flow time (FT) by CW Doppler. The no-flow time (NFT), NFT/FT ratio, and NFT/DP fraction were calculated. Group A had a larger right ventricle (4.1 +/- 0.9 vs. 3.5 +/- 0.6 cm, P = .033), higher PI peak velocity (2.1 +/- 0.5 vs. 1.7 +/- 0.5 m/s, P = .04), shorter DT (261 +/- 61 vs. 317 +/- 83 ms, P = .018) and PHT (76 +/- 29 vs. 132 +/- 53, P < .0001), longer NFT (146 +/- 66 vs. 40 +/- 42 ms, P < .0001), and higher ratios of NFT/FT (46% +/- 27% vs. 13% +/- 14%, P < .0001) and NFT/DP (29% +/- 13% vs. 10% +/- 9%, P < .0001). The PHT and DT lengthened, and the NFT shortened in patients who underwent pulmonic valve replacement (all P < .05). By binary logistic regression, NFT and PHT were the best predictors for severe PI. An NFT of 80 ms had 84% sensitivity and 93% specificity, and a PHT of 100 ms had 93% sensitivity and 93% specificity for identifying angiographically severe PI. CW Doppler accurately distinguishes severe from lesser degrees of PI in patients with postoperative adult congenital heart disease.

A preliminary investigation of Ehrlichia species in ticks, humans, dogs, and capybaras from Brazil.

A molecular epidemiologic investigation in two Brazilian states (Rondônia and São Paulo) was undertaken to determine if Ehrlichia species responsible for human and animal ehrlichioses in North America could be found in Brazilian vectors, potential natural mammalian reservoirs and febrile human patients with a tick bite history. Samples, including 376 ticks comprising 9 Amblyomma species, 29 capybara (Hydrochaeris hydrochaeris) spleens, 5 canine blood, and 75 human blood samples from febrile patients with history of tick bites were tested by a real-time PCR assay targeting a fragment of the Ehrlichia dsb gene. Ehrlichia DNA was not detected in any tick, capybara or human samples. In contrast, 4 out of 5 dogs contained Ehrlichia canis DNA in their blood, which were sequenced, representing the first report of E. canis infecting dogs in the Amazon region of Brazil. Further studies are needed to evaluate the presence of other agents of human and animal ehrlichioses in Brazil.