Improving coronary heart disease risk assessment in asymptomatic people: Role of traditional risk factors and noninvasive cardiovascular tests

At least 25% of coronary patients have sudden death or nonfatal myocardial infarction without prior symptoms.1 Therefore, the search for coronary patients with subclinical disease who could potentially benefit from intensive primary prevention efforts is critically important. The American Heart Association’s (AHA) Prevention V Conference, “Beyond Secondary Prevention: Identifying the High Risk Patient for Primary Prevention,” addressed ways to identify more patients who are asymptomatic and clinically free of coronary heart disease (CHD) but at sufficiently high risk for a future coronary event to justify more intensive risk reduction efforts.2 In this report, we amplify on key findings and recommendations of the AHA Prevention V conference, highlight new research since the conference, and propose an approach to the use of office-based testing and additional noninvasive procedures in selected patients to better define their coronary event risk. The recommendations are concordant with the recently released approach to risk assessment and management from the third report of the Adult Treatment Panel of the National Cholesterol Education Program (ATP-III).

Prevention Conference V: Beyond secondary prevention: Identifying the high-risk patient for primary prevention: Executive summary

"This conference, “Beyond Secondary Prevention: Identifying the High-Risk Patient for Primary Prevention,” which was the fifth in a series of prevention conferences sponsored by the American Heart Association (AHA), was held October 26–28, 1998, in San Francisco, Calif. The need for this conference was precipitated by the remarkable advances in medical therapies for the prevention of coronary heart disease (CHD). The AHA has already set forth guidelines for aggressive medical therapy in patients with established CHD (secondary prevention). The major issue under consideration at this conference was the development of strategies to identify high-risk patients without established CHD who are candidates for aggressive medical therapies for primary prevention. Therefore, a central theme for the conference was the emphasis on establishing a prognosis for high-risk patients without clinical evidence of CHD. Three writing groups were established to report on the following areas: (1) medical office assessment, (2) tests for silent and inducible ischemia, and (3) noninvasive tests of atherosclerotic burden. Each working group reviewed research on existing risk-assessment strategies relevant to the prediction of risk in patients without clinical evidence of CHD. The key findings of each working group are presented in this Executive Summary of the conference. The full conference report with references is available online at http://circ.ahajournals.org/ in the January 4, 2000, issue of Circulation. The recommended strategies will assist in expanding preventive therapies, including lipid lowering, blood pressure control, smoking cessation, diet, and exercise, to patients at high risk for developing CHD. The following briefly summarizes the major conclusions of the conference.

Integrating quality into the cycle of therapeutic development

The quality of healthcare, particularly as reflected in current practice versus the available evidence, has become a major focus of national health policy discussions. Key components needed to provide quality care include: 1) development of quality indicators and performance measures from specific practice guidelines, 2) better ways to disseminate such guidelines and measures, and 3) development of support tools to promote standardized practice. Although rational decision-making and development of practice guidelines have relied upon results of randomized trials and outcomes studies, not all questions can be answered by randomized trials, and many treatment decisions necessarily reflect physiology, intuition, and experience when treating individuals. Debate about the role of "evidence-based medicine" also has raised questions about the value of applying trial results in practice, and some skepticism has arisen about whether advocated measures of clinical effectiveness, the basic definition of quality, truly reflect a worthwhile approach to improving medical practice. We provide a perspective on this issue by describing a model that integrates quantitative measurements of quality and performance into the development cycle of existing and future therapeutics. Such a model would serve as a basic approach to cardiovascular medicine that is necessary, but not sufficient, to those wishing to provide the best care for their patients

Myocardial blood flow in man: effects of coronary collateral circulation and coronary artery bypass surgery

A B S T R A C T The effects of coronary artery bypass graft (CAB) and coronary collaterals (CC) even with CAB occluded. Vessels with greater than 80% stenosis or total occlusion by angiography had significant pressure gradients with marked reduction of postobstructive MBF. No significant difference in postobstructive MBF was found when vessels with CC (21±4 ml/min per 100 g) were compared to those without CC (17+4 ml/min per 100 g) (P > 0.4). These studies demonstrate that (a) mean MBF increased 268% after CAB, (b) heterogeneous MBF persisted after CAB, (c) CC were not associated with significant increases in MUBF, and (d) vessels with less than 80% stenosis had less than 20 mm Hg gradient with minimal effect on resting MBF

Assessment of cardiovascular risk by use of multiple-risk-factor assessment equations: A statement for healthcare professionals from the American Heart Association and the American College of Cardiology

The past decade has witnessed major strides in the prevention of coronary heart disease (CHD) through modification of its causes. The most dramatic advance has been the demonstration that aggressive medical therapy will substantially reduce the likelihood of recurrent major coronary syndromes in patients with established CHD (secondary prevention). The American Heart Association (AHA) and the American College of Cardiology (ACC) have published joint recommendations for medical intervention in patients with CHD and other forms of atherosclerotic disease.1 A similar potential exists for risk reduction in patients without established CHD (primary prevention). However, the risk status of persons without CHD varies greatly, and this variability mandates a range in the intensity of interventions. Effective primary prevention thus requires an assessment of risk to categorize patients for selection of appropriate interventions. The present statement is being published jointly by the AHA and ACC to outline current issues and approaches to global risk assessment for primary prevention. The approaches described in this statement can be used for guidance at several levels of primary prevention; however, the statement does not attempt to specifically link risk assessment to treatment guidelines for particular risk factors. Nonetheless, it provides critical background information that can be used in the development of new treatment guidelines

Assessment of cardiovascular risk by use of multiple-risk-factor assessment equations: A statement for healthcare professionals from the American Heart Association and the American College of Cardiology

The past decade has witnessed major strides in the prevention of coronary heart disease (CHD) through modification of its causes. The most dramatic advance has been the demonstration that aggressive medical therapy will substantially reduce the likelihood of recurrent major coronary syndromes in patients with established CHD (secondary prevention). The American Heart Association (AHA) and the American College of Cardiology (ACC) have published joint recommendations for medical intervention in patients with CHD and other forms of atherosclerotic disease 1. A similar potential exists for risk reduction in patients without established CHD (primary prevention). However, the risk status of persons without CHD varies greatly, and this variability mandates a range in the intensity of interventions. Effective primary prevention thus requires an assessment of risk to categorize patients for selection of appropriate interventions. The present statement is being published jointly by the AHA and ACC to outline current issues and approaches to global risk assessment for primary prevention. The approaches described in this statement can be used for guidance at several levels of primary prevention; however, the statement does not attempt to specifically link risk assessment to treatment guidelines for particular risk factors. Nonetheless, it provides critical background information that can be used in the development of new treatment guidelines

Scientific evidence underlying the ACC/AHA clinical practice guidelines

Context The joint cardiovascular practice guidelines of the American College of Cardiology (ACC) and the American Heart Association (AHA) have become important documents for guiding cardiology practice and establishing benchmarks for quality of care. Objective To describe the evolution of recommendations in ACC/AHA cardiovascular guidelines and the distribution of recommendations across classes of recommendations and levels of evidence. Data Sources and Study Selection Data from all ACC/AHA practice guidelines issued from 1984 to September 2008 were abstracted by personnel in the ACC Science and Quality Division. Fifty-three guidelines on 22 topics, including a total of 7196 recommendations, were abstracted. Data Extraction The number of recommendations and the distribution of classes of recommendation (I, II, and III) and levels of evidence (A, B, and C) were determined. The subset of guidelines that were current as of September 2008 was evaluated to describe changes in recommendations between the first and current versions as well as patterns in levels of evidence used in the current versions. Results Among guidelines with at least 1 revision or update by September 2008, the number of recommendations increased from 1330 to 1973 (+48%) from the first to the current version, with the largest increase observed in use of class II recommendations. Considering the 16 current guidelines reporting levels of evidence, only 314 recommendations of 2711 total are classified as level of evidence A (median, 11%), whereas 1246 (median, 48%) are level of evidence C. Level of evidence significantly varies across categories of guidelines (disease, intervention, or diagnostic) and across individual guidelines. Recommendations with level of evidence A are mostly concentrated in class I, but only 245 of 1305 class I recommendations have level of evidence A (median, 19%)

Clinical Management of Metabolic Syndrome: Report of the American Heart Association/National Heart, Lung, and Blood Institute/American Diabetes Association Conference on Scientific Issues Related to Management

"The National Cholesterol Education Program’s Adult Treatment Panel III report (ATP III)1 identified the metabolic syndrome as a multiplex risk factor for cardiovascular disease (CVD) that is deserving of more clinical attention. Subsequently, the National Heart, Lung, and Blood Institute (NHLBI), in collaboration with the American Heart Association (AHA), convened a conference to examine scientific issues related to definition of the metabolic syndrome.2 The present report summarizes a second conference devoted to clinical management of the metabolic syndrome, which was sponsored by the AHA in partnership with the NHLBI and cosponsored by the American Diabetes Association (ADA). This latter conference considered the following issues: (1) pathogenesis and presentation of the metabolic syndrome, (2) management of underlying risk factors, (3) management of metabolic risk factors, and (4) unresolved issues and research challenges. The conference on definition2 confirmed CVD as a major clinical outcome of metabolic syndrome and identified 6 major components of the syndrome: abdominal obesity, atherogenic dyslipidemia, elevated blood pressure, insulin resistance ± glucose intolerance, a proinflammatory state, and a prothrombotic state. The follow-up conference on management was structured around therapies for these components. Clinical recognition of the metabolic syndrome is generally based on finding several well-recognized signs in clinical practice: abdominal obesity, elevated triglycerides, reduced HDL cholesterol, raised blood pressure, and elevated plasma glucose. In addition, research shows that other components not routinely measured commonly aggregate with the major components: elevated apolipoprotein B, small LDL particles, insulin resistance and hyperinsulinemia, impaired glucose tolerance (IGT), elevated C-reactive protein (CRP), and variation in coagulation factors (eg, plasminogen activator inhibitor [PAI]-1 and fibrinogen). The conference on definition2 also emphasized that risk for type 2 diabetes is higher in persons with metabolic syndrome and that diabetes is a major risk factor for CVD. It also examined various criteria for a clinical diagnosis of the metabolic syndrome. The diagnostic scheme developed by ATP III is shown in the Table. Clinical criteria proposed by the World Health Organization3 and American Association of Clinical Endocrinologists4 also were reviewed. These latter criteria overlap with those of ATP III but differ by requiring direct evidence of insulin resistance for diagnosis. Both the World Health Organization and the American Association of Clinical Endocrinologists recommend an oral glucose tolerance test (OGTT) in patients without an elevated fasting glucose. In other words, in the absence of impaired fasting glucose (IFG), IGT detected by OGTT is considered as one metabolic risk factor defining the metabolic syndrome. ATP III does not recommend OGTT in such persons, even through IGT is a high-risk condition for type 2 diabetes (independent of IFG) and correlates with increased risk for CVD. ATP III, however, held that the information gained by OGTT does not outweigh its costs and inconvenience in routine practice. The present conference on management moved from the issue of definition of the metabolic syndrome to the wide issues of clinical management.

Definition of metabolic syndrome: report of the National Heart, Lung, and Blood Institute/American Heart Association conference on scientific issues related to definition

The National Cholesterol Education Program’s Adult Treatment Panel III report (ATP III)1 identified the metabolic syndrome as a multiplex risk factor for cardiovascular disease (CVD) that is deserving of more clinical attention. The cardiovascular community has responded with heightened awareness and interest. ATP III criteria for metabolic syndrome differ somewhat from those of other organizations. Consequently, the National Heart, Lung, and Blood Institute, in collaboration with the American Heart Association, convened a conference to examine scientific issues related to definition of the metabolic syndrome. The scientific evidence related to definition was reviewed and considered from several perspectives: (1) major clinical outcomes, (2) metabolic components, (3) pathogenesis, (4) clinical criteria for diagnosis, (5) risk for clinical outcomes, and (6) therapeutic interventions

Definition of Metabolic Syndrome: Report of the National Heart, Lung, and Blood Institute/American Heart Association Conference on Scientific Issues Related to Definition

The National Cholesterol Education Program’s Adult Treatment Panel III report (ATP III)1 identified the metabolic syndrome as a multiplex risk factor for cardiovascular disease (CVD) that is deserving of more clinical attention. The cardiovascular community has responded with heightened awareness and interest. ATP III criteria for metabolic syndrome differ somewhat from those of other organizations. Consequently, the National Heart, Lung, and Blood Institute, in collaboration with the American Heart Association, convened a conference to examine scientific issues related to definition of the metabolic syndrome. The scientific evidence related to definition was reviewed and considered from several perspectives: (1) major clinical outcomes, (2) metabolic components, (3) pathogenesis, (4) clinical criteria for diagnosis, (5) risk for clinical outcomes, and (6) therapeutic interventions