Diagnosis and Treatment of Patients with Hypertrophic Cardiomyopathy

Publication Date: December 1, 2020

Key Points

Key Points

  • Shared decision-making, a dialogue between patients and their care team that includes full disclosure of all testing and 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).
  • Although the primary cardiology team can initiate 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 weak (e.g., any Class 2b decision) or is particularly nuanced, and 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 family preference. As screening recommendations for family members hinge on the pathogenicity of any detected variants, the reported pathogenicity should be reconfirmed every 2 to 3 years.
  • Optimal care for patients with HCM requires cardiac imaging to confirm the diagnosis, characterize the pathophysiology for the individual, and identify risk markers 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. Cardiovascular magnetic resonance (CMR) imaging will also be helpful in many patients, especially those in whom there is diagnostic uncertainty, poor echocardiographic imaging windows, or where uncertainty persists regarding decisions around implantable cardioverter-defibrillator (ICD) placement.
  • 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). In addition to a full accounting of an individual’s risk markers, communication with patients regarding not just the presence of risk markers but also the magnitude of their individualized risk is key. This enables the informed patient to fully participate in the decision-making regarding ICD placement, which incorporates their own level of risk tolerance and treatment goals.
  • The risk factors for SCD in children with HCM carry different weights than those observed in adult patients; they vary with age and must account for different body sizes. 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 best addressed at primary or comprehensive HCM centers with expertise in children with HCM.
  • Septal reduction therapies (surgical septal myectomy and alcohol septal ablation), when performed by experienced HCM teams at dedicated 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 (AF2) have a sufficiently increased risk of stroke such that oral anticoagulation with direct oral anticoagulants (DOACs) (or alternatively warfarin) should be considered the default treatment option independent of the CHADSVASc score. As rapid 2AF is often poorly tolerated in patients with HCM, maintenance of sinus rhythm and rate control are key pursuits in successful treatment.
  • Heart failure (HF) symptoms in patients with HCM, in the absence of LVOTO, should be treated similarly to other patients with HF symptoms, including consideration of advanced treatment options (e.g., cardiac resynchronization therapy [CRT], LV assist device [LVAD], transplantation). In patients with HCM, an ejection fraction (EF) <50% connotes significantly impaired systolic function and identifies individuals with poor prognosis and who are at 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.

Treatment

Treatm...

...red Decision-Making...

...ts with HCM or at risk for HCM, shared...


...idisciplinary HCM Centers...

...n patients with HCM in whom septal reductio...

...ts with HCM, consultation with or refer...


Table 1. Suggested Competencies of Comprehensive and Primary HCM Centers

.... Suggested Competencies of Comprehen...

Table 2. Example Targets for Invasive Septal Reduction Therapies Outcomes

...le 2. Example Targets for Invasive Septal Reducti...

Clinical Diagnosis

...linical Diagnosis...

...Initial Evaluation and Follow-upIn patients...


Table 3. Clinical Features in Patients with “HCM Phenocopies (Mimics)"

.... Clinical Features in Patients with “HCM P...

Figure 1. Recommended Evaluation and Testing for HCM

...re 1. Recommended Evaluation and Test...

Echocardiography

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...patients with HCM with no change in clinical statu...

...hildren573


...patients with HCM who experience a change in cl...


...ith HCM and resting LVOT gradient...


...mptomatic patients with HCM who do not...


...r patients with HCM undergoing surgical septal...


...ents with HCM undergoing alcohol s...


...ients with HCM who have undergone SRT, TTE withi...


...ing: In first-degree relatives of...


...g: In individuals who are genotype-positive o...


...h HCM, TEE can be useful if TTE is in...


For patients with HCM in whom the di...


...asymptomatic patients with HCM who do not have...