Top Things to Know: 2020 AHA/ACC Hypertrophic Cardiomyopathy Guideline
Published: November 20, 2020
- Shared decision making (SDM), a dialogue between patients and their care team, that includes full disclosure of all testing and/or treatment options, discussion of the risks and benefits of those options, and, importantly, engagement of the patient to express their own goals is particularly relevant in the management of conditions such as hypertrophic cardiomyopathy (HCM).
- While the primary cardiology team can initiate an evaluation, treatment, and longitudinal care, referral to multidisciplinary HCM centers, with graduated levels of expertise, can be important to optimizing care for patients with HCM. Challenging treatment decisions where reasonable alternatives exist, where the strength of recommendation is not strong (e.g. any Class 2B decision) or is particularly nuanced, and/or for invasive procedures that are specific to patients with HCM represent crucial opportunities to refer patients to these HCM centers.
- Counseling patients with HCM regarding the potential for genetic transmission of HCM is one of the cornerstones of care. Screening first-degree family members of patients with HCM, using either genetic testing or an imaging/electrocardiographic surveillance protocol, can begin at any age and can be influenced by specifics of the patient/family history and/or family preference. As screening recommendations for family members hinge on the pathogenicity of any detected variants, it is important to reconfirm the reported pathogenicity every 2-3 years.
- Optimal care for patients with HCM requires cardiac imaging to confirm the diagnosis, characterize the pathophysiology for the individual, and identify markers of risk that may inform decisions regarding interventions for left ventricular outflow tract obstruction (LVOTO) and sudden cardiac death (SCD) prevention. Echocardiography continues to be the foundational imaging modality for patients with HCM. Cardiac magnetic resonance imaging (CMR) will also be helpful for many patients, especially those for whom there is diagnostic uncertainty, poor echocardiographic imaging windows, or where uncertainty persists regarding decisions around implantable cardioverter defibrillator (ICD) implantation.
- Assessment of an individual patient’s risk for SCD continues to evolve as new markers emerge (e.g. apical aneurysm, decreased left ventricular (LV) systolic function, and extensive gadolinium enhancement). It is important to account fully for an individual’s risk markers and to communicate with patients regarding the presence of risk markers and magnitude of their individualized risk. This enables the informed patient to participate fully in the decision regarding ICD placement with attention to their own level of risk tolerance and treatment goals.
- The risk factors for SCD in children with HCM carry different weights than that observed in adult patients, they vary with age, and must account for different body size. Coupled with the complexity of placing ICDs in young patients with anticipated growth and a higher risk of device complications, the threshold for ICD implantation in children often differs from adults. These differences are likely best addressed at Primary or Comprehensive HCM centers with particular expertise in children with HCM.
- Septal reduction therapies (surgical septal myectomy and alcohol septal ablation), when performed by dedicated HCM teams at experienced centers, continue to improve in safety and efficacy, such that earlier intervention may be possible in select patients with drug-refractory or severe outflow tract obstruction causing signs of cardiac decompensation. Given the data on the significantly improved outcomes at comprehensive HCM centers, these decisions represent an optimal referral opportunity.
- Patients with HCM and persistent or paroxysmal atrial fibrillation (AF) have sufficiently increased risk of stroke that oral anticoagulation with direct oral anticoagulants (DOACs) (or alternatively warfarin) should be considered the default treatment option independent of the CHA2DS2VASc score {Lip, 2010 #2710}. As rapid AF is often poorly tolerated in patients with HCM, maintenance of sinus rhythm and/or rate control are key pursuits in successful treatment.
- Heart failure symptoms in patients with HCM, in the absence of LVOT obstruction, should be treated similarly to other patients with heart failure symptoms, including consideration of advanced treatment options (e.g. CRT, LVAD, transplantation). It is important to recognize that in patients with HCM, an EF < 50% connotes significantly impaired systolic function and identifies individuals with poor prognosis and who are increased risk for SCD.
- Increasingly, data affirm that the beneficial effects of exercise on general health can be extended to patients with HCM. Healthy recreational exercise (moderate intensity) has not been associated with increased risk of ventricular arrhythmia events in recent studies. Whether an individual patient with HCM wishes to pursue more rigorous exercise/training is dependent on a comprehensive shared discussion between that patient and their expert HCM care team regarding the potential risks of that level of training/participation but with the understanding that exercise-related risk cannot be individualized for a given patient.
Citation
Ommen SR, Mital S, Burke MA, Day SM, Deswal A, Elliott P, Evanovich LL, Hung J, Joglar JA, Kantor P, Kimmelstiel C, Kittleson M, Link MS, Maron MS, Martinez MW, Miyake CY, Schaff HV, Semsarian C, Sorajja P. 2020 AHA/ACC guideline for the diagnosis and treatment of patients with hypertrophic cardiomyopathy: a report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines [published online ahead of print November 20, 2020]. Circulation. doi: 10.1161/CIR.0000000000000937