Prevention of Viridans Group Streptococcal Infective Endocarditis: A Scientific Statement From the American Heart Association.

BACKGROUND: In 2007, the American Heart Association published updated evidence-based guidelines on the recommended use of antibiotic prophylaxis to prevent viridans group streptococcal (VGS) infective endocarditis (IE) in cardiac patients undergoing invasive procedures. The 2007 guidelines significantly scaled back the underlying conditions for which antibiotic prophylaxis was recommended, leaving only 4 categories thought to confer the highest risk of adverse outcome. The purpose of this update is to examine interval evidence of the acceptance and impact of the 2007 recommendations on VGS IE and, if needed, to make revisions based on this evidence. METHODS AND RESULTS: A writing group was formed consisting of experts in prevention and treatment of infective endocarditis including members of the American Dental Association, the Infectious Diseases Society of America, and the American Academy of Pediatrics, in addition to the American Heart Association. MEDLINE database searches were done for English language articles on compliance with the recommendations in the 2007 guidelines and the frequency of and morbidity or mortality from VGS IE after publication of the 2007 guidelines. Overall, there was good general awareness of the 2007 guidelines but variable compliance with recommendations. There was no convincing evidence that VGS IE frequency, morbidity, or mortality has increased since 2007. CONCLUSIONS: On the basis of a review of the available evidence, there are no recommended changes to the 2007 VGS IE prevention guidelines. We continue to recommend VGS IE prophylaxis only for categories of patients at highest risk for adverse outcome while emphasizing the critical role of good oral health and regular access to dental care for all. Randomized controlled studies to determine whether antibiotic prophylaxis is effective against VGS IE are needed to further refine recommendations.

Contemporary Diagnosis and Management of Patients With Myocardial Infarction in the Absence of Obstructive Coronary Artery Disease: A Scientific Statement From the American Heart Association.

Myocardial infarction in the absence of obstructive coronary artery disease is found in ≈5% to 6% of all patients with acute infarction who are referred for coronary angiography. There are a variety of causes that can result in this clinical condition. As such, it is important that patients are appropriately diagnosed and an evaluation to uncover the correct cause is performed so that, when possible, specific therapies to treat the underlying cause can be prescribed. This statement provides a formal and updated definition for the broadly labelled term MINOCA (incorporating the definition of acute myocardial infarction from the newly released "Fourth Universal Definition of Myocardial Infarction") and provides a clinically useful framework and algorithms for the diagnostic evaluation and management of patients with myocardial infarction in the absence of obstructive coronary artery disease.

Chagas Cardiomyopathy: An Update of Current Clinical Knowledge and Management: A Scientific Statement From the American Heart Association.

BACKGROUND: Chagas disease, resulting from the protozoan Trypanosoma cruzi, is an important cause of heart failure, stroke, arrhythmia, and sudden death. Traditionally regarded as a tropical disease found only in Central America and South America, Chagas disease now affects at least 300 000 residents of the United States and is growing in prevalence in other traditionally nonendemic areas. Healthcare providers and health systems outside of Latin America need to be equipped to recognize, diagnose, and treat Chagas disease and to prevent further disease transmission. METHODS AND RESULTS: The American Heart Association and the Inter-American Society of Cardiology commissioned this statement to increase global awareness among providers who may encounter patients with Chagas disease outside of traditionally endemic environments. In this document, we summarize the most updated information on diagnosis, screening, and treatment of T cruzi infection, focusing primarily on its cardiovascular aspects. This document also provides quick reference tables, highlighting salient considerations for a patient with suspected or confirmed Chagas disease. CONCLUSIONS: This statement provides a broad summary of current knowledge and practice in the diagnosis and management of Chagas cardiomyopathy. It is our intent that this document will serve to increase the recognition of Chagas cardiomyopathy in low-prevalence areas and to improve care for patients with Chagas heart disease around the world.

Revision of the Jones Criteria for the diagnosis of acute rheumatic fever in the era of Doppler echocardiography: a scientific statement from the American Heart Association.

BACKGROUND: Acute rheumatic fever remains a serious healthcare concern for the majority of the world's population despite its decline in incidence in Europe and North America. The goal of this statement was to review the historic Jones criteria used to diagnose acute rheumatic fever in the context of the current epidemiology of the disease and to update those criteria to also take into account recent evidence supporting the use of Doppler echocardiography in the diagnosis of carditis as a major manifestation of acute rheumatic fever. METHODS AND RESULTS: To achieve this goal, the American Heart Association's Council on Cardiovascular Disease in the Young and its Rheumatic Fever, Endocarditis, and Kawasaki Disease Committee organized a writing group to comprehensively review and evaluate the impact of population-specific differences in acute rheumatic fever presentation and changes in presentation that can result from the now worldwide availability of nonsteroidal anti-inflammatory drugs. In addition, a methodological assessment of the numerous published studies that support the use of Doppler echocardiography as a means to diagnose cardiac involvement in acute rheumatic fever, even when overt clinical findings are not apparent, was undertaken to determine the evidence basis for defining subclinical carditis and including it as a major criterion of the Jones criteria. This effort has resulted in the first substantial revision to the Jones criteria by the American Heart Association since 1992 and the first application of the Classification of Recommendations and Levels of Evidence categories developed by the American College of Cardiology/American Heart Association to the Jones criteria. CONCLUSIONS: This revision of the Jones criteria now brings them into closer alignment with other international guidelines for the diagnosis of acute rheumatic fever by defining high-risk populations, recognizing variability in clinical presentation in these high-risk populations, and including Doppler echocardiography as a tool to diagnose cardiac involvement.

Infective Endocarditis in Adults: Diagnosis, Antimicrobial Therapy, and Management of Complications: A Scientific Statement for Healthcare Professionals From the American Heart Association.

BACKGROUND: Infective endocarditis is a potentially lethal disease that has undergone major changes in both host and pathogen. The epidemiology of infective endocarditis has become more complex with today's myriad healthcare-associated factors that predispose to infection. Moreover, changes in pathogen prevalence, in particular a more common staphylococcal origin, have affected outcomes, which have not improved despite medical and surgical advances. METHODS AND RESULTS: This statement updates the 2005 iteration, both of which were developed by the American Heart Association under the auspices of the Committee on Rheumatic Fever, Endocarditis, and Kawasaki Disease, Council on Cardiovascular Disease of the Young. It includes an evidence-based system for diagnostic and treatment recommendations used by the American College of Cardiology and the American Heart Association for treatment recommendations. CONCLUSIONS: Infective endocarditis is a complex disease, and patients with this disease generally require management by a team of physicians and allied health providers with a variety of areas of expertise. The recommendations provided in this document are intended to assist in the management of this uncommon but potentially deadly infection. The clinical variability and complexity in infective endocarditis, however, dictate that these recommendations be used to support and not supplant decisions in individual patient management.

Spatial heterogeneity of four-dimensional relative pressure fields in the human left ventricle.

PURPOSE: To assess the spatial heterogeneity of the four-dimensional (4D) relative pressure fields in the healthy human left ventricle (LV) and provide reference data for normal LV relative pressure. METHODS: Twelve healthy subjects underwent a cardiac MRI examination where 4D flow and morphological data were acquired. The latter data were segmented and used to define the borders of the LV for computation of relative pressure fields using the pressure Poisson equation. The LV lumen was divided into 17 pie-shaped segments. RESULTS: In the normal left ventricle, the relative pressure in the apical segments was significantly higher relative to the basal segments (P < 0.0005) along both the anteroseptal and inferolateral sides after the peaks of early (E-wave) and late (A-wave) diastolic filling. The basal anteroseptal segment showed significantly lower median pressure than the opposite basal inferolateral segment during both E-wave (P < 0.0005) and A-wave (P = 0.0024). CONCLUSION: Relative pressure in the left ventricle is heterogeneous. During diastole, the main pressure differences in the LV occur along the basal-apical axis. However, pressure differences were also found in the short axis direction and may reflect important aspects of atrioventricular coupling. Additionally, this study provides reference data on LV pressure dynamics for a group of healthy subjects.

Turbulent kinetic energy in normal and myopathic left ventricles.

PURPOSE: To assess turbulent kinetic energy (TKE) within the left ventricle (LV) of healthy subjects using novel 4D flow magnetic resonance imaging (MRI) methods and to compare TKE values to those from a limited group of patients with a spectrum of dilated cardiomyopathy (DCM). MATERIALS AND METHODS: 4D flow and morphological MRI data were acquired in 11 healthy subjects and 9 patients with different degrees of diastolic dysfunction. TKELV was calculated within the LV at each diastolic timeframe. At peak early (E) and late (A) diastolic filling, the TKELV was compared to transmitral peak velocity, LV diameter, and mitral annular diameter. RESULTS: In the majority of subjects, TKELV peaks were observed at E and A. Peak TKELV at E was not different between the groups (P = 0.33), and correlated with mitral annular dimensions (r(2) = 0.32, P = 0.01). Peak TKELV at A was higher in DCM patients compared to healthy subjects (3.0 ± 1.8 vs. 1.5 ± 0.8 mJ, P = 0.02), and correlated with LV diameter and transmitral velocity (r(2) = 0.36, P = 0.01 and r(2) = 0.47, P < 0.01, respectively). CONCLUSION: In LVs of healthy subjects, TKE values are low. Values are highest during early diastole, and diminish with increasing LV size. In a heterogeneous group of DCM patients, late diastolic TKE values are higher than in healthy subjects.

4D flow cardiovascular magnetic resonance consensus statement.

Pulsatile blood flow through the cavities of the heart and great vessels is time-varying and multidirectional. Access to all regions, phases and directions of cardiovascular flows has formerly been limited. Four-dimensional (4D) flow cardiovascular magnetic resonance (CMR) has enabled more comprehensive access to such flows, with typical spatial resolution of 1.5×1.5×1.5 - 3×3×3 mm(3), typical temporal resolution of 30-40 ms, and acquisition times in the order of 5 to 25 min. This consensus paper is the work of physicists, physicians and biomedical engineers, active in the development and implementation of 4D Flow CMR, who have repeatedly met to share experience and ideas. The paper aims to assist understanding of acquisition and analysis methods, and their potential clinical applications with a focus on the heart and greater vessels. We describe that 4D Flow CMR can be clinically advantageous because placement of a single acquisition volume is straightforward and enables flow through any plane across it to be calculated retrospectively and with good accuracy. We also specify research and development goals that have yet to be satisfactorily achieved. Derived flow parameters, generally needing further development or validation for clinical use, include measurements of wall shear stress, pressure difference, turbulent kinetic energy, and intracardiac flow components. The dependence of measurement accuracy on acquisition parameters is considered, as are the uses of different visualization strategies for appropriate representation of time-varying multidirectional flow fields. Finally, we offer suggestions for more consistent, user-friendly implementation of 4D Flow CMR acquisition and data handling with a view to multicenter studies and more widespread adoption of the approach in routine clinical investigations.

Periodontal disease and atherosclerotic vascular disease: does the evidence support an independent association?: a scientific statement from the American Heart Association.

A link between oral health and cardiovascular disease has been proposed for more than a century. Recently, concern about possible links between periodontal disease (PD) and atherosclerotic vascular disease (ASVD) has intensified and is driving an active field of investigation into possible association and causality. The 2 disorders share several common risk factors, including cigarette smoking, age, and diabetes mellitus. Patients and providers are increasingly presented with claims that PD treatment strategies offer ASVD protection; these claims are often endorsed by professional and industrial stakeholders. The focus of this review is to assess whether available data support an independent association between ASVD and PD and whether PD treatment might modify ASVD risks or outcomes. It also presents mechanistic details of both PD and ASVD relevant to this topic. The correlation of PD with ASVD outcomes and surrogate markers is discussed, as well as the correlation of response to PD therapy with ASVD event rates. Methodological issues that complicate studies of this association are outlined, with an emphasis on the terms and metrics that would be applicable in future studies. Observational studies to date support an association between PD and ASVD independent of known confounders. They do not, however, support a causative relationship. Although periodontal interventions result in a reduction in systemic inflammation and endothelial dysfunction in short-term studies, there is no evidence that they prevent ASVD or modify its outcomes.

Assessment of transmitral and left atrial appendage flow rate from cardiac 4D-CT.

BACKGROUND: Cardiac time-resolved CT (4D-CT) acquisitions provide high quality anatomical images of the heart. However, some cardiac diseases require assessment of blood flow in the heart. Diastolic dysfunction, for instance, is diagnosed by measuring the flow through the mitral valve (MV), while in atrial fibrillation, the flow through the left atrial appendage (LAA) indicates the risk for thrombus formation. Accurate validated techniques to extract this information from 4D-CT have been lacking, however. METHODS: To measure the flow rate though the MV and the LAA from 4D-CT, we developed a motion tracking algorithm that performs a nonrigid deformation of the surface separating the blood pool from the myocardium. To improve the tracking of the LAA, this region was deformed separately from the left atrium and left ventricle. We compared the CT based flow with 4D flow and short axis MRI data from the same individual in 9 patients. RESULTS: For the mitral valve flow, good agreement was found for the time span between the early and late diastolic peak flow (bias: <0.1 s). The ventricular stroke volume is similar compared to short-axis MRI (bias 3 ml). There are larger differences in the diastolic peak flow rates, with a larger bias for the early flow rate than the late flow rate. The peak LAA outflow rate measured with both modalities matches well (bias: -6 ml/s). CONCLUSIONS: Overall, the developed algorithm provides accurate tracking of dynamic cardiac geometries resulting in similar flow rates at the MV and LAA compared to 4D flow MRI.

Assessing the blood flow inside the heart is important in diagnosis and treatment of various cardiovascular diseases, such as atrial fibrillation or heart failure. We developed a method to accurately track the motion of the heart walls over the course of a heartbeat in three-dimensional Computed Tomography (CT) images. Based on the motion, we calculated the amount of blood passing through the mitral valve and the left atrial appendage orifice, which are markers used in the diagnostic of heart failure and assessment of stroke risk in atrial fibrillation. The results agreed well with measurements from 4D flow MRI, an imaging technique that measures blood velocities. Our method could broaden the use of CT and make additional exams redundant. It can even be used to calculate the blood flow inside the heart.

Update on cardiovascular implantable electronic device infections and their management: a scientific statement from the American Heart Association.

Despite improvements in cardiovascular implantable electronic device (CIED) design, application of timely infection control practices, and administration of antibiotic prophylaxis at the time of device placement, CIED infections continue to occur and can be life-threatening. This has prompted the study of all aspects of CIED infections. Recognizing the recent advances in our understanding of the epidemiology, risk factors, microbiology, management, and prevention of CIED infections, the American Heart Association commissioned this scientific statement to educate clinicians about CIED infections, provide explicit recommendations for the care of patients with suspected or established CIED infections, and highlight areas of needed research.

Quantification of presystolic blood flow organization and energetics in the human left ventricle.

Intracardiac blood flow patterns are potentially important to cardiac pumping efficiency. However, these complex flow patterns remain incompletely characterized both in health and disease. We hypothesized that normal left ventricular (LV) blood flow patterns would preferentially optimize a portion of the end-diastolic volume (LVEDV) for effective and rapid systolic ejection by virtue of location near and motion towards the LV outflow tract (LVOT). Three-dimensional cine velocity and morphological data were acquired in 12 healthy persons and 1 patient with dilated cardiomyopathy using MRI. A previously validated method was used for analysis in which the LVEDV was separated into four functional flow components based on the blood's locations at the beginning and end of the cardiac cycle. Each component's volume, kinetic energy (KE), site, direction, and linear momentum relative to the LVOT were calculated. Of the four components, the LV inflow that passes directly to outflow in a single cardiac cycle (Direct Flow) had the largest volume. At the time of isovolumic contraction, Direct Flow had the greatest amount of KE and the most favorable combination of distance, angle, and linear momentum relative to the LVOT. Atrial contraction boosted the late diastolic KE of the ejected components. We conclude that normal diastolic LV flow creates favorable conditions for ensuing ejection, defined by proximity and energetics, for the Direct Flow, and that atrial contraction augments the end-diastolic KE of the ejection volume. The correlation of Direct Flow characteristics with ejection efficiency might be a relevant investigative target in cardiac failure.

4-D blood flow in the human right ventricle.

Right ventricular (RV) function is a powerful prognostic indicator in many forms of heart disease, but its assessment remains challenging and inexact. RV dysfunction may alter the normal patterns of RV blood flow, but those patterns have been incompletely characterized. We hypothesized that, based on anatomic differences, the proportions and energetics of RV flow components would differ from those identified in the left ventricle (LV) and that the portion of the RV inflow passing directly to outflow (Direct Flow) would be prepared for effective systolic ejection as a result of preserved kinetic energy (KE) compared with other RV flow components. Three-dimensional, time-resolved phase-contrast velocity, and balanced steady-state free-precession morphological data were acquired in 10 healthy subjects using MRI. A previously validated method was used to separate the RV and LV end-diastolic volumes into four flow components and measure their volume and KE over the cardiac cycle. The RV Direct Flow: 1) followed a smoothly curving route that did not extend into the apical region of the ventricle; 2) had a larger volume and possessed a larger presystolic KE (0.4 ± 0.3 mJ) than the other flow components (P < 0.001 and P < 0.01, respectively); and 3) represented a larger part of the end-diastolic blood volume compared with the LV Direct Flow (P < 0.01). These findings suggest that diastolic flow patterns distinct to the normal RV create favorable conditions for ensuing systolic ejection of the Direct Flow component. These flow-specific aspects of RV diastolic-systolic coupling provide novel perspectives on RV physiology and may add to the understanding of RV pathophysiology.

Hemodynamic aspects of mitral regurgitation assessed by generalized phase-contrast MRI.

PURPOSE: To investigate the utility of MRI measurement of left atrial (LA) flow patterns and turbulent kinetic energy (TKE) in patients with clinically significant mitral regurgitation. MATERIALS AND METHODS: Three-dimensional cine phase-contrast MRI (PC-MRI) data were acquired in five patients with posterior mitral leaflet prolapse and two normal volunteers. LA flow patterns were assessed using particle trace visualization. Specifically, vortices were recognized by closed streamlines. LA flow distortion was assessed by estimation of TKE. In addition, the regurgitant volume was measured. RESULTS: Four of the mitral regurgitation patients had eccentric regurgitant jets directed toward the septum; one patient had a central jet. The dominant systolic vortex was located in proximity to the regurgitant jet. The LA flow was highly disturbed with elevated values of TKE; peak LA TKE ranged from 13 to 37 mJ and occurred consistently at late systole. The average LA TKE per cardiac cycle was significantly related to the regurgitant volume (TKE = 0.573 + 0.179·RegVol, R(2) = 0.983). CONCLUSION: MRI permits investigations of atrial flow patterns and TKE in significant mitral regurgitation. The degree of LA flow distortion, as measured by the average LA TKE over one cardiac cycle, appears to reflect the severity of regurgitation.

Out-of-pocket expenditure for administration of benzathine penicillin G injections for secondary prophylaxis in patients with rheumatic heart disease: A registry-based data from a tertiary care center in Northern India.

BACKGROUND: Costs can be a major barrier to medication adherence in low and middle-income countries and are an important target for policy-level interventions. The use of benzathine penicillin G (BPG) for secondary prevention of rheumatic heart disease (RHD) averts substantial morbidity and mortality, yet the total out-of-pocket costs for patients receiving this intervention are unknown. OBJECTIVE: To estimate the total out-of-pocket costs for obtaining BPG prophylaxis among RHD patients in India. METHODS: We prospectively collected self-reported drug-, transportation-, and provider-related costs for secondary prophylaxis among RHD patients presenting for follow-up to a tertiary care centre in New Delhi, India. Monthly costs were estimated by adjusting unit costs by frequency of drug administration. RESULTS: The cost data provided by 420 patients [mean age (±SD) 11.6 (±2.9) years] was analysed. Majority of the patients were male (65.2%), hailed from rural areas (87.1%), and belonged to lower socioeconomic strata (73.3%). The median monthly total out-of-pocket costs (IQR) for obtaining BPG injections was Indian rupee (INR) 62.5 (42.5-117.0). The median costs for procuring the drug (IQR) was INR 34.0(30.0-39.0). Whereas median costs (IQR) for health care provider and transportation was INR 16.0 [0-32.0]) and INR 11 [0-31.0] respectively. When expressed as mean (SD), the costs for transportation constituted 50% of the total costs, whereas the mean cost for drug procurement and drug administration constituted 30% and 22% of the total costs respectively. CONCLUSION: RHD patients receiving BPG prophylaxis incur substantial out-of-pocket costs, with transportation costs constituting nearly half of the total expenditures. National investments in RHD control must be strategically directed at improving health care access and drug supply in order to lower the total costs of secondary prophylaxis and improve adherence rates.

Adapted from: Prevention of Viridans Group Streptococcal Infective Endocarditis: A Scientific Statement From the American Heart Association.

BACKGROUND: In 2007, the American Heart Association published updated evidence-based guidelines on the recommended use of antibiotic prophylaxis to prevent viridans group streptococcal (VGS) infective endocarditis (IE) in cardiac patients undergoing invasive procedures. The 2007 guidelines significantly scaled back the underlying conditions for which antibiotic prophylaxis was recommended, leaving only 4 categories thought to confer the highest risk of adverse outcome. The purpose of this update is to examine interval evidence of the acceptance and impact of the 2007 recommendations on VGS IE and, if needed, to make revisions based on this evidence. METHODS AND RESULTS: A writing group was formed consisting of experts in prevention and treatment of infective endocarditis including members of the American Dental Association, the Infectious Diseases Society of America, and the American Academy of Pediatrics, in addition to the American Heart Association. MEDLINE database searches were done for English language articles on compliance with the recommendations in the 2007 guidelines and the frequency of and morbidity or mortality from VGS IE after publication of the 2007 guidelines. Overall, there was good general awareness of the 2007 guidelines but variable compliance with recommendations. There was no convincing evidence that VGS IE frequency, morbidity, or mortality has increased since 2007. CONCLUSIONS: On the basis of a review of the available evidence, there are no recommended changes to the 2007 VGS IE prevention guidelines. We continue to recommend VGS IE prophylaxis only for categories of patients at highest risk for adverse outcome while emphasizing the critical role of good oral health and regular access to dental care for all. Randomized controlled studies to determine whether antibiotic prophylaxis is effective against VGS IE are needed to further refine recommendations.

In vitro assessment of flow patterns and turbulence intensity in prosthetic heart valves using generalized phase-contrast MRI.

PURPOSE: To assess in vitro the three-dimensional mean velocity field and the extent and degree of turbulence intensity (TI) in different prosthetic heart valves using a generalization of phase-contrast MRI (PC-MRI). MATERIALS AND METHODS: Four 27-mm aortic valves (Björk-Shiley Monostrut tilting-disc, St. Jude Medical Standard bileaflet, Medtronic Mosaic stented and Freestyle stentless porcine valve) were tested under steady inflow conditions in a Plexiglas phantom. Three-dimensional PC-MRI data were acquired to measure the mean velocity field and the turbulent kinetic energy (TKE), a direction-independent measure of TI. RESULTS: Velocity and TI estimates could be obtained up- and downstream of the valves, except where metallic structure in the valves caused signal void. Distinct differences in the location, extent, and peak values of velocity and TI were observed between the valves tested. The maximum values of TKE varied between the different valves: tilting disc, 100 J/m(3); bileaflet, 115 J/m(3); stented, 200 J/m(3); stentless, 145 J/m(3). CONCLUSION: The TI downstream from a prosthetic heart valve is dependent on the specific valve design. Generalized PC-MRI can be used to quantify velocity and TI downstream from prosthetic heart valves, which may allow assessment of these aspects of prosthetic valvular function in postoperative patients.