What is Transcatheter Alcohol ablation of Septal Hypertrophy (TASH) for Hypertrophic (obstructive) Cardiomyopathy (HCM / HOCM)?

 

Hypertrophic (obstructive) cardiomyopathy (HCM / HOCM) is a condition where, usually due to genetic factors, the muscle that makes up the heart’s pumping chambers grows too thick (see Figure 1). This thickening can occur so as to block the flow of blood out from the heart’s main pumping chamber into the rest of the body. When thickening occurs of this kind the word obstructive is added to the description of the condition.
 
The abbreviations HCM (or if obstruction is present HOCM) are commonly used. One potential treatment option for HOCM, where medications are no longer effective to control symptoms, is Transcatheter Alcohol ablation of Septal Hypertrophy (TASH). The discussion that follows below is general medical information only, and does not replace the need for specific advice from your treating doctors.

 

Figure 1: Hypertrophic (obstructive) cardiomyopathy (HCM / HOCM)

heart

 
 
 
 

The Transcatheter Alcohol ablation of Septal Hypertrophy (TASH) procedure

The Transcatheter Alcohol ablation of Septal Hypertrophy (TASH) procedure involves the following:

  • General anaesthetic (fully put to sleep) with a breathing machine to support breathing
  • An ultrasound probe (transoesophageal echocardiogram probe) is placed down your food pipe to visualise the heart.
  • Tubes are also inserted in the veins in the neck and or leg in addition to a tube in the artery in the arm / wrist or leg (groin). These tubes are called sheaths.
  • A temporary pacemaker may be inserted via the tubes in the veins.
  • A tube called a catheter is advanced up to the heart under x-ray steered to the heart artery that goes down the front of the heart:
    • – Through this a wire is positioned in to a small artery called the septal artery.
      – A balloon is steered down this wire to block the artery and allow for near 98 % alcohol (ethanol) to be injected into the artery (and nowhere else).
      – See Figure 2.
  • This causes the heart muscle in this area to die (a type of permanent heart attack) reducing the amount of thickened muscle.

 

Figure 2: Transcatheter Alcohol ablation of Septal Hypertrophy (TASH) procedure

fig2

Are there any risks with Transcatheter Alcohol ablation of Septal Hypertrophy (TASH) for Hypertrophic (obstructive) Cardiomyopathy (HCM / HOCM)?

The procedure has many potential risks. The information supplied here is for general reference only based on the published data around the procedure from across the world. Risks specific to your condition and overall situation need to be discussed with your treating doctors. Potential risks of TASH include:
 
 
 

5% or greater risk of:

  • Requiring a permanent pacemaker to be implanted after the procedure.
  • Failure of the procedure to successfully modify the heart enough to improve symptoms (and may require repeat procedures).
  • If the arm / wrist artery is used, 5 – 10% risk of that pulse blocking / disappearing permanently.
  • Bruising and pain, sometimes with a large bruise (called a haematoma) at the area where the tubes go in that can take several weeks to resolve.

1 – 2% risk of:

  • Heart attack leading to heart failure, need for heart transplantation, need for stenting of heart arteries or death.
  • Stroke or embolism (resulting in permanent disability, blindness, limb loss or death).
  • Vascular access complication (problem with the artery or vein leading to the heart) needing an operation or medication injection (thrombin) to fix and or requiring a blood transfusion and uncommonly resulting in permanent nerve damage or loss of limb (rare).
  • Post procedure infection, blood clot (DVT) and pain.

Uncommon / rare events:

  • Adverse reaction to the general anaesthetic leading to permanent disability or death (<1/10,000).

5% or greater risk of:

  • Requiring a permanent pacemaker to be implanted after the procedure.
  • Failure of the procedure to successfully modify the heart enough to improve symptoms (and may require repeat procedures).
  • If the arm / wrist artery is used, 5 – 10% risk of that pulse blocking / disappearing permanently.
  • Bruising and pain, sometimes with a large bruise (called a haematoma) at the area where the tubes go in that can take several weeks to resolve.

1 – 2% risk of:

  • Heart attack leading to heart failure, need for heart transplantation, need for stenting of heart arteries or death.
  • Stroke or embolism (resulting in permanent disability, blindness, limb loss or death).
  • Vascular access complication (problem with the artery or vein leading to the heart) needing an operation or medication injection (thrombin) to fix and or requiring a blood transfusion and uncommonly resulting in permanent nerve damage or loss of limb (rare).
  • Post procedure infection, blood clot (DVT) and pain.

Uncommon / rare events:

  • Adverse reaction to the general anaesthetic leading to permanent disability or death (<1/10,000).