Septal Reduction Therapy

It is critical to understand the mechanism that causes obstruction to evaluate your options.  We suggest spending time on the HCMA website, consulting with an HCM specialist and making a choice that is best for the anatomy of the specific patients heart.

It is important to remember that only an estimated 70% of those with HCM have obstruction, and of that percentage only some (25%) will require septal reduction. It is very important that all options of medical management be attempted prior to septal reduction. Septal reduction will not cure HCM; it will only relieve symptoms related to obstruction.

Based on the medical literature myectomy is still the “gold standard” treatment to relieve obstruction and Alcohol Septal Ablation is still viewed as an alternative in a select few patients and should be entered into with careful consideration and done in centers with ample experience.

Surgical Option

myectomy image

Surgical “myectomy” (removing a small amount of muscle from the ventricular wall) is successful in the relief of symptoms. It is considered in individuals with severe symptoms despite drug treatment, in whom the left ventricular outflow tract narrowing causes obstruction of the blood flow. Typically, if a person has an obstructive gradient greater than 50mm of mercury and is symptomatic and has failed drug therapy it is only then advised they consider this procedure. In this operation the surgeon removes a portion of the thickened muscle from the septum, thereby widening the outflow tract and relieving the obstruction. In rare cases, instead of a myectomy, the mitral valve is replaced with an artificial valve. As described earlier, during obstruction to outflow from the heart, the mitral valve touches the septum and blood leaks back through the valve. If this mitral valve regurgitation is severe, then the valve may be replaced (this is a rare occurrence, in HCM Centers less than 5%). These are major operations which carry a definite risk and therefore are reserved for patients with severe symptoms and certain forms of HCM. It is imperative that the patient choose a center that is experienced in the surgical procedure and a surgeon with ample experience.  Heart block can occur in a small number of patients (under 5%) requiring pacemaker implant post myectomy. ICD implant post surgery occurs in approximately 5% of patients. The choice to implant the ICD is often made prior to the surgery and is often not made as a result of the procedure itself, (see Risk Stratification).

In the most experienced centers this operation has a success rate of 99% for survival and more than 70% of patients have significant improvement in quality of life that persists many years later. In very rare cases the surgery must be done a second time. Cases of reoperation occur primarily in two cases, 1. The patient was young at the time of the first procedure and 2. The first surgery was done by a surgeon with limited experience in the procedure.

Since the first myectomy was performed in the 1960’s there have been significant advances in cardiac surgery that have improved outcomes in all forms of “open heart” procedures.  It is suggested that if you are seeking information about complications and risks from this or any other cardiac procedure that you keep a keen eye on the date the data was published.  The more resent the data the more reliable the data.  In the case of HCM data compiled from the mid 1990’s forward is the most reliable, in the opinion of the HCMA, for evaluating the role of myectomy.

Surgery in the Pediatric Population

The use of myectomy in the pediatric population has been a source of controversy over the years.  However recent data and even historical reviews have proven myectomy to have similar risks in the adult and pediatric populations.

According to an article published December 1996 in The Journal of Thoracic and Cardiovascular Surgery, “Hypertrophic Cardiomyopathy (HCM) in Pediatric Patients: Results of surgical treatment” by Dr.’s D. Theodoro, G. Danielson, R. Feldt, and B. Anderson RN of the Mayo Clinic, Rochester, MN. This paper reports “96% of the young patients (ages between 2 months and 20 years, mean age of 11.2 years) have had significant improvement in preoperative symptoms. There was no early or late mortality.”

See a myectomy here  - warning this is an actual surgery of an HCMA member

Alternatives to Surgery

Alcohol Septal Ablation


In the mid 1990s a new procedure emerged for the treatment of outflow obstruction in HCM patients. A catheterization is performed; alcohol is injected into the septum through a small coronary artery. This causes a ‘controlled’ myocardial infarction, (a small controlled heart attack). The idea is to remove the excess muscle from point the obstruction by “killing” the tissue and opening the flow of blood. This procedure is still new and long term outcomes are yet to be clearly understood.

Some patients have been rendered pacemaker-dependent after this procedure (based on how the procedure is done this number varies greatly from 8 to 25%). There have been deaths associated with this procedure in the United States, which makes the risk comparable to surgery.

Alcohol septal ablation, ASA has several names including PTSMA -Percutaneous Alcohol Septal Ablation and TASH- Transcoronary ablation of septal hypertrophy.  What is interesting to note is that since the creation of this procedure there has been a large jump in the number of patients requiring intervention for obstruction. This has lead many to wonder why?  Since the creation of the procedure known as myectomy nearly 40 years ago approximately 4500 procedures have been preformed around the world.  In stark comparison in the past 10 plus years there have been well over 3000 ablations done worldwide with no significant change in the number of myectomies performed. One area of concern to the HCMA is that many ablations are being performed at hospitals with limited experience with HCM and patient selection has been less then optimal.  Many of these patients require multiple procedures or need to have myectomy performed after the ablation.  Patients who have an ASA who then must move on to have a myectomy are at a much higher risk of requiring a permanent pacemaker post myectomy.  The reason for this is because the ASA leaves a patient with something called a Right Bundle Branch Block, RBBB, and a myectomy leaves patients with a Left Bundle Branch Block, LBBB.  If on branch of the conduction system is blocked it is of little clinical significance, creates no symptoms and the heart can beat rather normally.  If both the right and left are blocked this causes heart block – thus requiring a pacemaker to ensure your heart beats appropriately.

Patients who wish to consider this treatment option would benefit from a consult from a center with a complete HCM program and learning about ALL options and their various pro’s and con’s.

Patient selection for a successful alcohol septal ablation is the most important step to ensure a positive outcome.  Patients must have a septal measurement of greater than 1.8 but less than 3.0, the mitral valve must not be a contributing factor to obstruction and the patient must have the proper anatomy to allow access to the area creating obstruction (a good 1st septal perforator located in the proper position).

Patients need to be aware they are having a procedure that induces a myocardial infarction, a heart attack, and this will create a scar in the heart that may create a pro-arrhythmic situation in your heart, which due to your diagnosis of HCM your heart already has a propensity for arrhythmia. Also it is not recommended for younger patients to utilize this treatment modality.

Patients over the age 55 or those with serious co-existing diseases should discuss with their doctors the potential benefits of alcohol ablation should all other factors point to this as a treatment option.

It should be clearly noted that according to the ACC/ESC consensus document on the treatment and management of HCM myectomy remains the gold standard treatment for obstruction.

Questions to ask your doctor should he/she recommend alcohol septal ablation:

If you doctor has recommended to you that you should have an alcohol septal ablation here are some questions to ask him/her:

  • ·How many patients with HCM do you see annually, how many are obstructed and how many non-obstructed?

  • · How many times have you (or your center) performed alcohol septal ablation?

  • · Where did you receive your training for alcohol septal ablation?

  • · How many myectomies does your center perform annually?

  • · How many patients have you referred to other doctors for second options or treatment of their HCM?

Lastly – make sure you have spoken to a cardiac surgeon prior to your final decision.

If your doctor has not seen many patients, has only done a few procedures, has not received training from a center that also performs myectomies, they do not offer myectomy or have only done a handful and/or your doctor does not refer to specialty centers it would be advisable to seek a second opinion.  At any point should you have questions please feel free to contact the HCMA office for more information.

As this is a newer procedure, the HCMA suggests caution and careful planning when reviewing this option. We have had a number of members of the HCMA undergo this procedure with varied outcomes. It is important to note that the variable nature of long and short term outcome is far different than the results we have seen from myectomy which provides a much more consistent positive outcome.


 Maron BJ, McKenna WJ, Danielson GK, Kappenberger LJ, Kuhn HJ, Seidman CE, Shah PM, Spencer WH, Spirito P, ten Cate FJ, Wigle ED. American College of Cardiology/European Society of Cardiology Clinical Expert Consensus Document on Hypertrophic Cardiomyopathy. A report of the American College of Cardiology Task Force on Clinical Expert Consensus Documents and the European Society of Cardiology Committee for Practice Guidelines Committee to Develop an Expert Consensus Document on Hypertrophic Cardiomyopathy. J Am Coll Cardiol 2003;42:1687-1713 and Eur Heart J 2003;24:1965-1991.

Maron, B.J. and Salberg, L.  Hypertrophic Cardiomyopathy: For patients, their families and interested physicians.  Blackwell Futura: 1st edition 2001,81 pages; 2nd edition 2006, 113 pages; 3rd edition pending publication 2014

Maron BJ, Bonow RO, Salberg L, Roberts WC, Braunwald E.  The first patient clinically diagnosed with hypertrophic cardiomyopathy.  Am J Cardiol. 2008 Nov 15;102(10):1418-20

Nagueh SF, Buergler JM, Quinones MA, Spencer WH 3rd, Lawrie GM. Outcome of surgical myectomy after unsuccessful alcohol septal ablation for the treatment of patients with hypertrophic obstructive cardiomyopathy.  J Am Coll Cardiol. 2007 Aug 21;50(8):795-8.

Maron BJ, Ommen SR, Nishimura RA, Dearani.JA. Myths about surgical myectomy: rumors of its death have been greatly exaggerated. Am J Cardiol. 2008 Mar 15;101(6):887-9

Olivotto I, Ommen SR, Maron MS, Cecchi F, Maron BJ. Surgical myectomy versus alcohol septal ablation for obstructive hypertrophic cardiomyopathy. Will there ever be a randomized trial? J Am Coll Cardiol. 2007 Aug 28;50(9):831-4

Valeti US, Nishimura RA, Holmes DR, Araoz PA, Glockner JF, Breen JF, Ommen SR, Gersh BJ, Tajik AJ, Rihal CS, Schaff HV, Maron BJ. Comparison of surgical septal myectomy and alcohol septal ablation with cardiac magnetic resonance imaging in patients with hypertrophic obstructive cardiomyopathy. J Am Coll Cardiol. 2007 Jan 23;49(3):350-7

Maron BJ, Dearani JA, Ommen SR, Maron MS, Schaff HV, Gersh BJ, Nishimura RA. The case for surgery in obstructive hypertrophic cardiomyopathy.J Am Coll Cardiol. 2004 Nov 16;44(10):2044-53

Fifer MA. Controversies in cardiovascular medicine. Most fully informed patients choose septal ablation over septal myectomy. Circulation. 2007 Jul 10;116(2):207-1