HCM has become a treatable disease, in contrast to its reputation many years ago. First, it is important to emphasize that most patients with HCM have normal—or even extended—longevity, without the need for major interventions. Even in highly selected HCM Centers such patients comprise more than one half of the clinical population.
Drug treatments and medications
Many HCM patients successfully control their symptoms for years—even decades—solely with medication. Some of our most commonly prescribed HCM medications include:
- Beta blockers (controls symptoms)
- Calcium channel blockers (controls symptoms)
- Disopyramide (controls symptoms in some obstructive HCM patients)
- Antiarrhythmic drugs (manages atrial fibrillation)
- Anticoagulants (manages atrial fibrillation)
Surgical treatment options
When drug treatments are ineffective or further treatment is required, effective options are available:
- Implantable cardioverter defibrillators (ICDs) to prevent sudden cardiac death in high risk patients. An ICD is a sophisticated device permanently inserted under the skin, capable of sensing potentially lethal arrhythmias and automatically terminating them by shocking to return a normal rhythm. Only a very small percentage of HCM patients are at increased risk for these arrhythmias. The ICD device has become smaller and easier to implant. The newer subcutaneous ICDs sit adjacent to the left rib cage with leads just under the skin and require no wires.
- Surgical septal myectomy for patients who experience significant limitation during physical activity and are unresponsive to medical drug treatment. This operation may be performed along with the Maze procedure to lessen the chances of recurrent atrial fibrillation.
- Alcohol septal ablation for patients who are generally not ideal candidates for the myectomy operation. This procedure takes place in the catheterization laboratory without general anesthesia, and mimics the beneficial effects of surgery.
- Ablation for recurrent atrial fibrillation performed in the catheterization laboratory to lessen the likelihood for additional episodes.
- Heart transplant for the occasional patients without obstruction who experience severe symptoms and are unresponsive to drug treatment—in order to restore normal activity and quality of life.
Heart failure with obstructive HCM is permanently reversible
Many patients experience shortness of breath with exertion—due in 90% to blood flow obstruction—that significantly compromise their quality of life (referred to as “heart failure”). When such patients no longer benefit symptomatically from drug treatments—such as beta-blockers, verapamil and disopyramide—they can be candidates for procedures that will relieve both their obstruction and symptoms.
Obstruction in HCM is mechanical in nature and produces elevated pressures in the heart chamber. The septal myectomy operation is the preferred method for relieving this problem and is associated with low surgical risk (0.5%) when performed in experienced HCM referral centers—lower than with virtually any other open-heart procedure.
The myectomy surgeon removes—through an incision in the aorta—a small amount of muscle from the top part of the ventricular septum (the muscular partition between the left and right ventricular cavities). This is a key area which opens up ejection of blood from the left side of the heart and has the effect of reducing pressures in the heart to normal.
It is important to emphasize myectomy dramatically improves or eliminates symptoms and reverses heart failure in 90-95% of patients, and this correction is essentially permanent. The average hospital stay for this procedure is 5 days, after which most patients return home for a recovery period of a few weeks.
Dr. Hassan Rastegar at Tufts Medical Center has safely and effectively operated on 550 patients with highly symptomatic HCM with obstruction.
Alcohol Septal Ablation - the alternative to myectomy
If you have significant symptoms due to obstruction and have not benefited from drugs and if you do not qualify for, or choose, the myectomy operation, alcohol septal ablation is a reasonable and effective alternative for some older patients.
Dr. Carey Kimmelstiel has safely and effectively performed more than 100 such interventional alcohol septal ablation procedures which is performed in the cardiac catheterization laboratory at Tufts MC without general anesthesia and mimics the myectomy by relieving obstruction and symptoms.
Heart failure in nonobstructive HCM is treatable
About one-third of all HCM patients referred to Centers such at Tufts Medical Center do not have the ability to generate obstruction to blood flow out of the left side of the heart either at rest or with exercise (as on the treadmill with stress echocardiogram).
Of these patients, the vast majority (about 90%) will develop either no, or only mild, symptoms limiting their physical activity. Such mild symptoms can be controlled with the drugs used in HCM. However, a small fraction of patients will experience unrelenting severe symptoms that become unacceptable for quality of life, even with all available medications. This progression of HCM is often due to extensive irreversible scarring of the heart as part of the disease process. It is only these patients, among all HCM patients, who become candidates for reversal of heart failure symptoms with a heart transplant.
At Tufts Medical Center, with Dr. David DeNofrio and the Heart Failure and Cardiac Transplant Program team, survival with a heart transplant is exceptional: >90% at 5-10 years and with the longest survivor currently at 12 years to date.
Atrial fibrillation in HCM is treatable and stroke is preventable
Atrial fibrillation is the most common arrhythmia (i.e. irregular heart rhythm) in HCM, affecting 20% of patients. Some patients experience atrial fibrillation but are not even aware of it. The importance of this arrhythmia to patients is two-fold—the impact it has on their quality of life should episodes happen too frequently and the risk of stroke arising should clots form, break off, and travel to the brain.
However, treatment options are now available to reduce the occurrence of atrial fibrillation—anti-arrhythmia drugs as well as radio-frequency ablation to target the pathways responsible for the arrhythmia. Stroke and stroke death are preventable with aggressive use of anticoagulant medications. Deaths related to atrial fibrillation in patients with HCM are virtually non-existent when these drugs are used properly.