The top 10 takeaways from the 2017 AHA/ACC/HRS guidelines

Sana Al-Khatib
Sana Al-Khatib chaired the AHA/ACC/HRS guidelines for ventricular arrhythmias and prevention of sudden cardiac death

In October 2017, the American Heart Association/American College of Cardiology/Heart Rhythm Society (AHA/ACC/HRS) released a guideline document on the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death (SCD): a guideline document for healthcare professionals. Sana Al-Khatib (professor of Medicine and electrophysiologist, Duke University, Durham, USA), who chaired this guideline, now provides the top 10 takeaways.

This document provides up-to-date and evidence-based recommendations on managing adults with ventricular arrhythmias and those who are at risk for SCD, including diseases and syndromes associated with a risk of SCD from ventricular arrhythmias. While this guideline may be used to inform health policy decisions, its intent is to educate healthcare providers and help them enhance the quality of health care delivered to patients. The guideline includes indications for implantable cardioverter defibrillators (ICDs) for the primary and secondary prevention of SCD. Those recommendations require that a patient will have a meaningful survival of >1 year with a reasonable quality of life and functional status. The document also covers indications for catheter ablation and emphasises the importance of a high level of expertise in catheter ablation of ventricular arrhythmias in achieving optimal patient outcomes.


Before offering patients with heart failure with reduced ejection fraction (HFrEF, left ventricular ejection fraction [LVEF] ≤ 35%) an ICD, it is imperative to treat them with evidence-based medications that can reduce the risk of SCD. While prior guidelines mentioned this point in the ICD recommendations, the current guideline emphasises this point even more by devoting a whole recommendation on the use of evidence-based medications. The guideline states that treatment with a beta-blocker, a mineralocorticoid receptor antagonist, and either an angiotensin-converting enzyme inhibitor, an angiotensin-receptor blocker, an angiotensin-receptor blocker, or an angiotensin receptor-neprilysin inhibitor is recommended to reduce SCD and all-cause mortality (Class I).


The guideline highlights the fact that in patients with ischaemic heart disease and sustained monomorphic ventricular tachycardia (VT), coronary revascularisation alone is not enough to prevent recurrent VT. This should encourage clinicians to consider antiarrhythmic interventions (like medications or catheter ablation) to reduce the risk of recurrent VT in such patients.


The guideline recommends (Class I) implanting a primary prevention ICD in patients with non-ischaemic cardiomyopathy (LVEF ≤ 35%), class II or III heart failure symptoms who are on guideline-directed medical therapy and who are expected to have a meaningful survival of >1 year. The DANISH Study to Assess the Efficacy of ICDs in Patients with Non Ischaemic Systolic Heart Failure on Mortality (DANISH) had called into question the role of primary prevention ICDs in patients with non-ischaemic cardiomyopathy. After long deliberations, the guideline writing committee made a decision to keep this recommendation Class I in light of the nuances of the DANISH trial in which 58% of patients in each arm of the trial ended up with a cardiac resynchronisation therapy device. The deliberations were also informed by the results of meta-analyses generally showing a significant 25% relative risk reduction in the risk of mortality with an ICD.


Different types of defibrillators (implantable through the vein or under the skin vs. a wearable defibrillator) are reviewed. The guideline provides recommendations on various types of defibrillators in different patient populations including patients with a left ventricular assist device and heart transplantation. The document highlights the need for more research on ICDs in these patient groups and on subcutaneous ICDs and wearable defibrillators.


There has been substantial progress in technologies that facilitate treatment of heart rhythm disorders with catheter ablation. The guideline provides updated recommendations on catheter ablation of ventricular arrhythmias from the most benign (premature ventricular contractions) to the most ominous (ventricular fibrillation).


The importance of shared decision making is underscored. In patients with ventricular arrhythmias or who are at increased risk for SCD, clinicians are required to adopt a shared decision-making approach in which treatment decisions are based not only on the best available evidence, but also on the patients’ health goals, comorbidities, values, and preferences. This is further clarified by requiring that patients considering implantation of a new ICD or replacement of an existing ICD should be informed of their individual risk of SCD and non-sudden death from cardiac and non-cardiac conditions and the effectiveness and safety of the ICD.


The guideline provides recommendations on terminal care highlighting the following: “In patients with refractory heart failure symptoms, refractory sustained life-threatening arrhythmias, or nearing the end of life from other illness, clinicians should discuss defibrillator shock deactivation and consider the patients’ goals and preferences.”


There has been substantial progress in understanding how mutations in genes cause SCD. The guideline provides important information on genetic testing and counseling that should help patients engage in discussions surrounding these aspects of care with their health care providers. In addition, the guideline emphasises that identification of a genetic abnormality associated with SCD in one member of a family, should prompt evaluation of their relatives.


In patients younger than 40 years of age with unexplained SCD or recurrent exertional syncope, who do not have ischaemic or other structural heart disease, the guideline recommends (Class I) further evaluation for genetic arrhythmia syndromes.


This guideline document is the first to provide value statements that cover cost-effectiveness of ICDs in the primary and secondary prevention of SCD in patients with ischaemic heart disease. More cost-effectiveness data are needed on ICDs in other patient populations.


Sana Al-Khatib is a professor of Medicine at Duke University Medical Center, Durham, USA. She was chair of the writing committee for the 2017 AHA/ACC/HRS Guideline for management of patients with ventricular arrhythmias and the prevention of sudden cardiac death.


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