Top Things to Know: 2024 Guideline for the Management of Hypertrophic Cardiomyopathy (HCM)
Published: May 08, 2024
- Shared decision-making is essential to provide the best clinical care. This involves thoughtful dialogue among patients, families, and their care team in which health care professionals present all available testing and treatment options, discuss the risks, benefits, and applicability of those options to the individual patient, and ensure the patient expresses their personal preferences and goals to develop their treatment plan.
- Although the primary cardiology team can initiate evaluation, treatment, and longitudinal care, referral to multidisciplinary hypertrophic cardiomyopathy (HCM) centers with appropriate expertise can be important to optimizing care for patients with HCM. Challenging treatment decisions—where reasonable alternatives exist, where the strength of recommendation is weak (e.g., any decision relying on a Class of Recommendation 2b) or is particularly nuanced (e.g., interpretation of genetic testing; primary prevention implantable cardioverter-defibrillator decision-making), and for HCM-specific invasive procedures—may critically benefit from involving specialized HCM centers.
- Careful ascertainment of family history, counseling patients with HCM about the potential for genetic transmission of HCM, and options for genetic testing are cornerstones of care. Screening first-degree family members of patients with HCM, using genetic testing, serial imaging, or electrocardiographic surveillance as appropriate, can begin at any age and can be influenced by specifics of the patient and family history and family preference. Because screening recommendations for family members hinge on the pathogenicity of any detected variants, the reported pathogenicity should be reconfirmed every 2 to 3 years, and input from specialized HCM centers with genetics expertise may be valuable.
- Assessing a patient’s risk for sudden cardiac death is an essential component of management. Integrating the presence or absence of established risk markers with tools to estimate individual risk scores will facilitate the patient’s ability to participate in decision-making regarding implantable cardioverter-defibrillator placement. These discussions should incorporate a patient’s personal level of risk tolerance and their specific treatment goals.
- The risk factors for sudden cardiac death in children with HCM carry different weights and components than those used in adult patients. Pediatric risk stratification also varies with age and must account for various body sizes. Coupled with the complexity of placing implantable cardioverter-defibrillators in young patients with anticipated growth and a higher risk of device complications, the threshold for implantable cardioverter-defibrillator implantation in children often differs from adults. These differences are best addressed at comprehensive HCM centers with expertise in caring for children with HCM. New risk calculators, specific to children and adolescents, have been validated and can help young patients and their families contextualize their estimated risk of sudden cardiac death.
- Cardiac myosin inhibitors are now available to treat patients with symptomatic obstructive HCM. This new class of medication inhibits actin-myosin interaction, thus decreasing cardiac contractility and reducing left ventricular outflow tract obstruction. Mavacamten is currently the only agent approved by the US Food and Drug Administration. These agents can be beneficial for patients with obstructive HCM who do not derive adequate symptomatic relief from first-line drug therapy.
- Invasive septal reduction therapies (surgical septal myectomy and alcohol septal ablation), when performed by experienced HCM teams at dedicated centers, can provide safe and effective symptomatic relief for patients with drug-refractory or severe outflow tract obstruction. Given the data on the significantly improved outcomes at comprehensive HCM centers, these decisions represent an optimal opportunity for referral.
- Patients with HCM and persistent or paroxysmal atrial fibrillation have a sufficiently increased risk of stroke such that oral anticoagulation with direct-acting oral anticoagulants (or warfarin) should be considered the default treatment option irrespective of the CHA2DS2-VASc score. New tools to stratify risk for incident atrial fibrillation have been developed and may assist in determining the frequency of screening patients with ambulatory telemetry. Because rapid atrial fibrillation is often poorly tolerated in patients with HCM, maintenance of sinus rhythm and rate control are key treatment goals.
- Exercise stress testing is particularly helpful in determining overall exercise tolerance and for latent exercise-provoked left ventricular outflow tract obstruction. Because children may not readily describe symptoms, routine exercise testing can be particularly important for young patients.
- Increasingly, data affirm that the beneficial effects of exercise on general health are extended to patients with HCM. Healthy recreational exercise (light [<3 metabolic equivalents], moderate [3–6 metabolic equivalents], and vigorous [>6 metabolic equivalents] intensity levels) have not been associated with an increased risk of ventricular arrhythmia events in short-term studies. If patients pursue rigorous exercise training for performance or competition, it is crucial to engage in a comprehensive discussion and seek input from expert HCM professionals regarding the potential risks and benefits, to develop an individualized training plan, and to establish a regular schedule for reevaluation.
Citation
Ommen SR, Ho CY, Asif IM, Balaji S, Burke MA, Day SM, Dearani JA, Epps-Anderson KC, Evanovich L, Ferrari VA, Joglar JA, Khan SS, Kim JJ, Kittleson MM, Krittanawong C, Martinez MW, Mital S, Naidu SS, Saberi S, Semsarian C, Times S, Waldman CB. 2024 AHA/ACC/AMSSM/HRS/PACES/SCMR guideline for the management of hypertrophiccardiomyopathy: a report of the American Heart Association/American College of Cardiology Joint Committee onClinical Practice Guidelines. Circulation. Published online May 8, 2024. doi: 10.1161/CIR.0000000000001250