Recent Innovations, Modifications, and Evolution of ACC/AHA Clinical Practice Guidelines: An Update for Our Constituencies: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines

Since 1980, the American College of Cardiology (ACC) and American Heart Association (AHA) have translated scientific evidence into clinical practice guidelines with recommendations to improve cardiovascular health.¹ These guidelines, based on systematic methods to evaluate and classify evidence, provide a foundation for the delivery of quality cardiovascular care. Practice guidelines provide recommendations applicable to patients with or at risk of developing cardiovascular disease.

Over the past 3 decades,^1–3 there has been a continued evolution of clinical practice guidelines. Beginning in 2017, numerous innovations and modifications to the guidelines were implemented. The purposes of these changes are: 1) to make published guidelines shorter and more “user friendly” (and hence more readable for busy practitioners); 2) to focus guidelines more on actual recommendations and patient management flow diagrams and less on extensive text and background information; 3) to format guidelines in a manner that allows for more facile and seamless updating of the guideline through the incorporation of guideline focused updates; and 4) to format “chunks” of information in a manner that facilitates integration of discrete modules of information into electronic media, fostering easier implementation at the point of care. This communication updates our constituencies and all healthcare providers on these changes that are being implemented.

Modular Knowledge Chunk

The format of clinical practice guidelines has continued to evolve over the past 3 decades. In 2017, the modular knowledge chunk format was introduced. This knowledge chunk format allows guideline information to be grouped into discrete packages (or modules) of information on a disease-specific topic or management issue (eg, treatment of hypertension for secondary stroke prevention). The modular knowledge chunk of information consists of: 1) a table of related recommendations; 2) a brief synopsis; 3) more detailed recommendation-specific supportive text for each recommendation in the section; 4) a flow diagram (when appropriate); 5) an additional informational table (when appropriate); and 6) hyperlinked references specific for that knowledge chunk.

The modular chunk format has numerous advantages over prior formats. In contrast to the prior “knowledge byte” guideline format, this new format bundles all related recommendations together in one table, which enables better conceptualization of when a test treatment or intervention is recommended, when it may be recommended or is considered reasonable, and when it is not recommended. It allows for easier and seamless updating of this information in future guideline focused updates, because future guideline focused updates will update an entire modular knowledge chunk, with all its related recommendations and text. The format allows busy practitioners with limited time to view and read the table of recommendations, a brief text synopsis, and any relevant flow diagrams, while also providing a section titled “recommendation-specific supportive text” for readers interested in a more detailed discussion of the background and rationale for each recommendation.

By bundling related recommendations, text, flow diagrams, and references in what can be transformed into a freestanding entity of information, the modular knowledge chunk may in the future facilitate the ability to search for guideline information on a specific clinical management issue via search engines or smartphone apps.

Several guidelines (high blood pressure, ventricular arrhythmias/sudden cardiac death, adult congenital heart disease) were already in the later stages of writing and review when this modular chunk format was initiated and were retrofitted into this format as best as could be done. Guidelines on bradycardia and cardiac conduction delay⁴ and blood cholesterol management⁵ were the first to be written de novo in this format. Elements of the modular knowledge chunk are shown in Table 1; an example of the general appearance of the modular knowledge chunk is given in Figure 1.

• Download figure
• Download PowerPoint

Standardized Guideline Formats

In conjunction with the implementation of the modular knowledge chunk, standardized guideline formats and a target maximum number of words have been implemented. The intentions of this format are: 1) to make a guideline more recommendation-centric; and 2) to limit text (and thus the overall size of the guideline), making the guideline more relevant and readable for the busy practitioner. Detailed and extensive background information, which can readily be found in book chapters, on websites, or via search engines, is deemphasized. Rather, the focus of the guideline is on the recommendations themselves, presented in the modular knowledge chunk format.

So as to decrease the total text (and length) of guidelines, for each aspect of the guideline and each section of the modular chunk, maximum word targets (goals) have been established. Text at the beginning of each major section of the guideline that presents recommendations, the synopsis text for each modular chunk, and recommendation-specific supplemental text all have a target maximum number of 200 words.

The goal for Section 1 of the guideline (methodology, organization of the writing committee, document review and approval, abbreviations and acronyms) and section 2 (general concepts, brief background information, overarching principles) is a maximum of 2000 words and 5 journal-formatted pages for each section. This standardized guideline format is a process-in-evolution that will bring a more standardized layout, and more limited text, to guidelines, although it will still allow guideline writing committee chairs some discretion in how to best construct each specific guideline. The current iteration of this standardized guideline format is shown in Table 2.

Web Guideline Supplement

In accordance with the goal of shortening the length and size of the core guideline document, a web guideline supplement has been created. Tables and figures contained in prior guidelines that provide the reader with additional or supplemental information but are not critical to understanding and executing guideline recommendations have been moved from the primary guideline document to this web guideline supplement. This change reduces the size of the core guideline document, while affording the interested reader access to additional information that may be useful to his or her practice.

The web guideline supplement is a separate PDF file that is hyperlinked to the primary guideline document and downloadable via organizational and journal (Circulation and Journal of the American College of Cardiology) websites. The first implementation of this web guideline supplement was in bradycardia and cardiac conduction delay⁴ and blood cholesterol management⁵ guidelines.

Top 10 Take-Home Messages

It is well recognized that many busy practitioners do not have the time to read a lengthy guideline cover to cover, and that key recommendations and messages in the guideline may thus not be fully appreciated. Therefore, a Top 10 Take-Home Messages list is now being included in all guidelines. This top 10 list may contain information alerting and reminding the reader of new recommendations, important changes to old recommendations (eg, change in the class of recommendation), key overarching principles, and other critical take-home patient management messages of which readers and practitioners should be aware.

This list is at the beginning of the guideline, immediately after the table of contents. The list of top 10 messages serves as a form of abstract, highlighting for the busy practitioner the key take-home messages of the guideline. These top 10 lists could also likely serve as slide presentation bullet points for educational talks on guidelines, be used in articles and websites that summarize guidelines, and be incorporated into electronic media and apps, further disseminating the key practice points of emphasis for a specific topic to practitioners.

Preamble

Guideline writing committees are asked to limit text whenever possible. The task force chair’s preamble should similarly be as concise as possible. Therefore, the task force chair’s preamble at the beginning of each guideline has now been shortened by >50%. This abbreviated preamble contains only the key information that guideline readers should be aware of regarding the guideline process and appropriate use of guidelines. This abbreviated preamble appears in the guidelines for bradycardia and conduction abnormalities⁴ and the blood cholesterol management guidelines⁵ and will be used in subsequent guidelines. The full preamble will be available in each guideline’s web guideline supplement.

Addressing Areas of Perceived Need (“Gaps”) in Our Guidelines

Current ACC/AHA guidelines cover 8 broad topics and consist of >20 guidelines (Table 3). Two areas of perceived need for dedicated guidelines to fill gaps in the portfolio of guidelines are currently being addressed. The first area being addressed is that of chest pain, a condition that requires evaluation in >7 million people each year.⁶ Although the stable ischemic heart disease and non–ST-elevation myocardial infarction guidelines contain small sections on chest pain, the focus of those guidelines is on the downstream management of patients who are already diagnosed with those conditions. Given the importance of this topic and the multidisciplinary approach to evaluation of patients presenting with chest pain, which includes not only cardiologists but also emergency physicians, primary care providers, and radiologists, a dedicated guideline on the evaluation of chest pain, both in the office/clinic setting and in the emergency department, was commissioned. This guideline includes writing committee members from numerous medical stakeholders.

The second area of perceived need is a comprehensive guideline on the approach to cardiovascular disease prevention. Although there are dedicated guidelines on high blood pressure, blood cholesterol, and secondary prevention, as well as numerous scientific statements, expert consensus documents, and other authoritative publications on aspects of cardiovascular risk reduction and prevention of cardiovascular disease, there is a need for a comprehensive guideline specifically on the approach to cardiovascular disease prevention. Such a guideline was thus commissioned, with the specific charge of being concise enough to be readable in one sitting by busy practitioners. This guideline will consolidate for busy practitioners the key recommendations on assessment of cardiovascular risk, smoking cessation, exercise and physical activity, diet and nutrition, obesity and weight loss, diabetes mellitus management, and aspirin use, as well as the key primary prevention recommendations on high blood pressure and blood cholesterol. This guideline on the prevention of cardiovascular disease, in addition to filling a gap in current guidelines, affirms the AHA’s and the ACC’s commitment to not only treating established cardiovascular disease but preventing it as well.

Abbreviations

To make the guideline document more user friendly, the abbreviation table placed in each guideline has been moved. The table defining the meanings of abbreviations and acronyms used in the guideline, which gave what the abbreviation/acronym meant or stood for, had previously been located at the end of the guideline, in the appendix. This table is now at the beginning of each guideline (in the introduction section).

Other Ongoing Improvements and Refinements of Guidelines

Several additional improvements and refinements of guidelines and of the guideline development process, instituted over the past decade, merit discussion. The first of these are data supplement tables, which summarize the studies and study findings that were considered when Level of Evidence: A or B recommendations were formulated for a specific topic. The data supplement tables include, for key studies relevant to these recommendations, the study aim and design, the study control and intervention groups, and the primary and relevant secondary endpoint findings, both numerically and statistically. These data supplement tables serve 3 purposes.

First and foremost, they facilitate the process by which guideline section authors and the entire guideline writing committee can first thoroughly review the most relevant study data on a specific topic, and then discuss potential recommendations and their designated class of evidence in an optimally informed, evidence-based manner. Second, they allow detailed discussions of study results to be moved from the guideline itself to the data supplement. Guideline text can now simply summarize the data on a topic in broad statements, with more granular details given in the data supplement tables. Third, interested readers can themselves review and scrutinize key aspects and findings of relevant studies. These data supplement tables are published in separate PDF files, are hyperlinked to the guideline itself, and can be downloaded from the websites of both organizations and journals.

The second refinement to the guideline development process was the institution of evidence review committees (ERCs).^1,2 ERCs were established to provide an expert, independent, systematic review and analysis of study data relevant to one or more key patient evaluation or management question. ERCs and systematic reviews are developed by criteria consistent with established methodology practices and are aligned with recommendations promulgated by the Institute of Medicine in 2011.^7,8 All members of the ERC must be free of any relevant relationships with industry and other entities. The first such ERC report, published in 2014, was on the use of perioperative beta blockade in noncardiac surgery.⁹ Subsequent ERC reports have addressed topics including duration of dual antiplatelet therapy in patients with coronary artery disease,¹⁰ pacing as a treatment for reflex-mediated syncope,¹¹ management of patients with asymptomatic preexcitation,¹² targets for blood pressure lowering during antihypertensive therapy,¹³ and the impact of the use of implantable cardioverter-defibrillators for primary prevention in older patients and patients with significant comorbidities,¹⁴ physiologic versus right ventricular pacing among patients with left ventricular ejection fraction >35%,¹⁵ management of secundum atrial septal defects,¹⁶ and the magnitude of benefit of adding a second lipid-modifying agent to statin therapy alone.¹⁷ The criteria for commissioning a formal ERC have evolved over the past decade and now include: 1) absence of a recent authoritative systematic review on the same topic (eg, Cochrane analysis); 2) relevance to a substantial number (eg, at least tens or hundreds of thousands) of patients; and 3) high likelihood that the findings of the systematic review can be translated into actionable recommendations.

Over the past decade, the focus of guidelines has changed from procedure-centric to condition-centric. Thus, procedures such as pacemakers and defibrillators, which were previously addressed in a guideline on device-based therapies,¹⁸ are now addressed in guidelines on bradycardia and cardiac conduction delays,⁴ ventricular arrhythmias and sudden cardiac death,¹⁹ and syncope.²⁰ Similarly, indications for cardiac resynchronization therapy are covered in the guideline on heart failure.²¹ By being disease- or condition-centric, the focus is now on the indications for such interventions, and how these interventions fit within the overall management of the specific condition, rather than on the devices themselves and nuances of device implantation (such as pacing or defibrillation thresholds). Current guidelines on percutaneous coronary intervention²² and coronary artery bypass grafting,²³ which contain sections on topics such as bifurcation stenting and bypass graft anastomotic techniques, will be consolidated into one guideline on myocardial revascularization. The consolidated guideline will focus on coronary artery disease–related conditions and clinical settings in which revascularization is indicated, and where one revascularization procedure may or may not be preferred. This new guideline on revascularization will have its kickoff meeting in March 2019.

Continuing Challenges and Future Directions

Physicians and all healthcare providers face increasing demands on their time, because in addition to the long hours devoted to actual direct patient care, there are increasing administrative and clerical demands (eg, electronic health records, coding), as well as time required for continuing educational and academic activities. These requirements and activities in aggregate often leave little time for reading lengthy guidelines. Thus, there is an increasing need to format guidelines and deliver practice-relevant information and guidance in actually readable, searchable, and electronically accessible formats. The modular chunk format and standardized guideline format are in their early stages, and the Task Force will continuously evaluate how recommendations and information are presented and made available to busy practitioners. At the organizational level, the AHA and ACC continue to develop and refine electronic platforms and applications to facilitate ready access to and dissemination of guidelines and guideline recommendations.

The formatting, development, and presentation of guidelines is a continuing process in evolution. It is hoped and believed that these recent innovations and modifications will serve to improve guidelines and their dissemination to point-of-care practitioners devoted to improving cardiovascular health. As always, we will continue to highly value our constituencies’ and practitioners’ feedback.

ACC and AHA Guideline Organizational and Joint Staff Leadership

Thomas S.D. Getchius, AHA/ACC Director, Guideline Strategy and Operations

Katherine A. Sheehan, PhD, Immediate Past AHA/ACC Director, Guideline Strategy and Operations

Mariell Jessup, MD, FAHA, AHA Chief Science and Medicine Officer

Rose Marie Robertson, MD, FAHA, AHA Deputy Chief Science and Medicine Officer

William J. Oetgen, MD, MBA, FACC, ACC Executive Vice President, Science, Education, Quality, and Publishing

Gayle R. Whitman, PhD, RN, FAHA, FAAN, AHA Senior Vice President, Office of Science Operations

MaryAnne Elma, MPH, ACC Senior Director, Science, Education, Quality, and Publishing

Abdul R. Abdullah, MD, AHA/ACC Senior Manager, Guideline Science

Heather Goodell, AHA Vice President Scientific Publishing, Office of Science Operations

Radhika Rajgopal Singh, PhD, AHA Director, Science and Medicine, Office of Science Operations

Morgane Cibotti-Sun, MPH, ACC Associate, Guidelines and QI Solutions

Acknowledgments

The innovations and modifications discussed in this communication have evolved as a joint and collaborative effort of the ACC/AHA Task Force on Clinical Practice Guidelines leadership and members, organizational science and executive leadership, and joint staff leadership. Past members of the Task Force who were also involved in recent guideline innovations include Biykem Bozkurt, MD, PhD, FACC, FAHA; Lesley H. Curtis, PhD, FAHA; Samuel Gidding, MD, FAHA; Laura Mauri, MD, MSc, FAHA; Susan J. Pressler, PhD, RN, FAHA; and Barbara Riegel, PhD, RN, FAHA.

Footnotes