Treatment options for HCM
General Clinical Practice Update: Canadian Cardiovascular Society Clinical Practice Update on Contemporary Management of the Patient with Hypertrophic Cardiomyopathy.
Crean AM, et al. Can J Cardiol 2024.1
The identification of left ventricular outflow tract (LVOT) obstruction is fundamental to HCM management.1
oHCM:
- Management of symptomatic obstruction is step-wise and includes lifestyle changes, pharmacologic therapy, and invasive procedures.1
HCM:
- Symptomatic nonobstructive HCM might be challenging to effectively treat.1
I. Nonobstructive HCM1
Symptomatic nonobstructive HCM might be challenging to effectively treat.
- Use of beta blockers and/or nondihydropyridine calcium channel blockers can be attempted.
- Diuretics can be used if filling pressure is elevated.
II. Management of symptomatic obstruction in patients with HCM1
(Note that mavacamten and alcohol septal ablation are not approved for use in pediatric HCM.)
Symptomatic obstructive HCM
First-line therapy
Non-vasodilating beta-blocker (e.g., metoprolol)
or
Non-dihydropyridine calcium-channel blocker (verapamil or diltiazem)
Avoidance of vasodilators unless required for comorbidities
Avoidance of hypovolemia
Persistent symptomatic obstruction
Second-line therapies to consider:
Choice depends on patient preference, access/expertise, comorbidities, HCM subtype and response to prior therapies
Drug therapy
(generally attempted prior to invasive therapy)
Cardiac myosin inhibitors (mavacamten)
PROS
- RCT showing significant improvement of symptoms, exercise capacity, QoL, imaging markers and biomarkers
- Once-daily use
- Non-invasive
CONS
- Shorter experience
- Risk of systolic dysfunction requiring need for echocardiography every 1-3 months
- Cost
- Pediatric trials pending
Disopyramide
PROS
- Long experience
- Antiarrhythmic effect can be useful for atrial fibrillation
- Non-invasive
CONS
- Recurrent shortage in recent years
- Anticholinergic side effects
- Only short-acting available in Canada: taken 3 times a day
- QT prolongation
- Efficacy based on observational data
Invasive septal reduction therapy
(generally reserved when medical therapy fails)
Alcohol septal ablation
PROS
- Less invasive than surgery, preferred in older patients with comorbidities
- Sustained efficacy for LVOT obstruction
CONS
- Access to local high-volume centre
- Risk of AV block requiring pacemaker implantation (≤10%)
- Feasibility depends on septal morphology and coronary anatomy
- Not used in pediatric population
Surgical myectomy (+/- mitral intervention)
PROS
- Likely most effective and durable therapy for obstructive HCM
- Useful for diverse septal morphologies
- Concomitant correction of mitral valve anomalies contributing to obstruction/symptoms
CONS
- Access to local high-volume centre
- Invasive therapy
- Risk of AV block requiring pacemaker implantation (≤5%)
AV=atrioventricular; HCM=hypertrophic cardiomyopathy; LVOT=left ventricular outflow tract; QoL=quality of life; RCT=randomized controlled trial
Source: Canadian Cardiovascular Society Clinical Practice Update on Contemporary Management of the Patient with Hypertrophic Cardiomyopathy (2024).1
Footnotes
Management of symptomatic obstruction in patients with hypertrophic cardiomyopathy (HCM).
Note that mavacamten and alcohol septal ablation are not approved for use in pediatric HCM.
Reference
- Crean AM, et al. General Clinical Practice Update: Canadian Cardiovascular Society Clinical Practice Update on Contemporary Management of the Patient with Hypertrophic Cardiomyopathy. Can J Cardiol 2024;40(9):1503-23.