Alcohol septal ablation for HOCM - private in London.
A percutaneous, catheter-based alternative to open septal myectomy for hypertrophic obstructive cardiomyopathy. A consultant interventional cardiologist injects a small volume of pure ethanol into a septal perforator artery to shrink the thickened basal septum and relieve left ventricular outflow tract obstruction.
What it is
A controlled, targeted infarct of the thickened septum.
Alcohol septal ablation (ASA), also known as percutaneous transluminal septal myocardial ablation (PTSMA), is a percutaneous catheter procedure for hypertrophic obstructive cardiomyopathy (HOCM).
In HOCM, the basal interventricular septum is abnormally thick and, combined with systolic anterior motion of the mitral valve, causes dynamic obstruction of the left ventricular outflow tract (LVOT). This drives breathlessness, chest pain, presyncope and syncope, and can cause heart failure. Beta-blockers, disopyramide and, more recently, mavacamten are the first line of treatment. When symptoms persist despite optimal medication and the LVOT gradient remains above 50 mmHg at rest or on provocation, septal reduction therapy is offered.
ASA delivers that septal reduction without opening the chest. A consultant interventional cardiologist advances a small over-the-wire balloon into the first or second septal perforator branch of the left anterior descending coronary artery. Contrast echocardiography confirms that the balloon perfuses the exact hypertrophied basal segment causing the obstruction. Between 1 and 3 ml of pure (dehydrated) ethanol is then injected slowly through the balloon, inducing a small, controlled myocardial infarction limited to the target septal territory. Over the following weeks and months the treated segment thins and scars, the LVOT widens and the gradient falls.
Who it is for
Symptomatic HOCM, medication no longer enough.
A short list of who we typically consider suitable at the HCM MDT for alcohol septal ablation rather than surgical myectomy.
Persistent symptoms despite optimal medication
Breathlessness, chest pain, presyncope or syncope despite maximally tolerated beta-blocker, disopyramide and, where appropriate, mavacamten.
LVOT gradient above 50 mmHg
Resting or provocable (Valsalva, exercise) left ventricular outflow tract gradient above 50 mmHg on echocardiography.
Suitable septal anatomy
Basal septal thickness typically 16 to 25 mm on echo and cardiac MRI, with a septal perforator artery that reliably supplies the target segment on contrast echo.
Older patient or higher surgical risk
Age above 60, significant comorbidity, prior sternotomy or frailty that make open cardiac surgery a higher-risk option.
Patient preference
Where anatomy is suitable for either option, an informed preference for a percutaneous procedure with overnight admission over open surgery.
Confirmed HOCM diagnosis
Diagnosis confirmed on cardiac MRI with tissue characterisation and, where relevant, genetic testing at a specialist HCM centre.
When it is not the right option
Where surgery is the better answer.
Alcohol septal ablation is not appropriate for every HOCM patient. These are the anatomies where a specialist HCM MDT will steer you towards surgical septal myectomy.
Very thick septum (above 30 mm)
Above 30 mm the ethanol volume needed exceeds what can be delivered safely and the residual gradient after ASA is often unacceptably high. Surgical myectomy resects tissue directly.
Significant intrinsic mitral valve disease
Extensive systolic anterior motion (SAM) with structural mitral leaflet abnormality or significant primary mitral regurgitation needs surgical repair alongside myectomy.
Coexisting cardiac disease needing surgery
Severe coronary artery disease requiring bypass grafting, aortic valve disease needing replacement, or a subaortic membrane are all better addressed in one surgical operation.
Unsuitable septal perforator anatomy
If no septal perforator reliably supplies the target segment on contrast echo, or perfusion extends to the free wall or right ventricle, ASA is unsafe and myectomy is preferred.
Younger patients
Below 50 years old, surgical myectomy is generally preferred because the durability data are longer, the pacemaker rate is lower and a permanent scar is avoided.
Pre-existing left bundle branch block
Left bundle branch block before the procedure means an ablation-induced right bundle branch block will produce complete heart block, so a pacemaker is essentially inevitable.
How the procedure works
Step by step, in the catheter lab.
A single 60 to 90 minute procedure under local anaesthetic and conscious sedation, in a fully equipped cardiac catheter lab.
Step 1
Access and coronary angiography
Right femoral or radial arterial access under local anaesthetic. A full diagnostic coronary angiogram maps the septal perforator branches of the left anterior descending artery to identify the target vessel.
Step 2
Temporary pacing wire
A temporary pacing wire is placed in the right ventricle through a femoral vein sheath to manage transient heart block during and after ethanol delivery.
Step 3
Balloon in the septal perforator
A small over-the-wire balloon is advanced into the target septal perforator and inflated to occlude the vessel. Baseline LVOT gradient is measured invasively with pull-back pressures.
Step 4
Contrast echo to confirm the target
Echocardiographic contrast is injected through the balloon while transthoracic echo images the septum. Only the exact hypertrophied segment causing SAM and obstruction should light up - not the free wall, apex or right ventricle.
Step 5
Slow ethanol injection
Between 1 and 3 ml of pure ethanol is injected slowly through the inflated balloon, typically over 5 to 10 minutes, inducing a controlled infarct of the target septal segment. The gradient usually drops on the table.
Step 6
Overnight monitoring
Transfer to CCU or step-down. Temporary pacing wire kept in for 24 to 48 hours while conduction is watched. Serial ECGs, troponin, echocardiography and telemetry. Discharge at 2 to 4 days.
Outcomes
What the data show.
Numbers from large registry and cohort studies at high-volume HCM centres. Individual outcomes depend on anatomy, operator volume and comorbidity.
50-80%
Reduction in resting and provocable LVOT gradient at 3 to 6 months.
80-90%
Symptomatic improvement (NYHA class fall of 1 or more), sustained at 5 to 10 years.
10-20%
Permanent pacemaker rate. Higher than surgical myectomy (2 to 5 percent).
<1%
Procedural mortality at expert centres. Similar to surgical myectomy in high-volume hands.
Around 10 to 15 percent of patients need a repeat ablation or a later crossover to surgical myectomy for incomplete relief, most often where the septum was very thick or the initial perforator only partially supplied the target segment. Long-term survival is comparable to age-matched HCM patients treated with myectomy in observational data.
Indicative pricing
What private alcohol septal ablation costs in London.
All-inclusive private packages at our partner London HCM centres.
In short
£22,000-£38,000 all-inclusive, home in 2-4 nights.
| Item | Indicative range | Stay |
|---|---|---|
| HCM consultation with interventional cardiologist | £300-£500 | Outpatient |
| Full workup (echo, cardiac MRI, angiogram, bloods) | £2,500-£4,500 | 5-10 days |
| Alcohol septal ablation, standard anatomy | £22,000-£30,000 | 2-3 nights |
| Alcohol septal ablation, complex anatomy | £28,000-£38,000 | 3-4 nights |
| Permanent pacemaker (if needed) | £10,000-£16,000 | Additional |
Prices vary by centre, operator and anatomy. NHS alcohol septal ablation is available at specialist HCM centres.
Where it is done in London
A small panel of London HCM centres.
HOCM is a niche condition and alcohol septal ablation should only be done at high-volume centres with a specialist inherited cardiac conditions service.
Royal Brompton (Guy’s and St Thomas’ NHS Foundation Trust, private care)
Long-established inherited cardiac conditions service with a national referral HOCM caseload, on-site cardiothoracic surgery and cardiac MRI.
Bart’s Heart Centre Private (St Bartholomew’s)
One of the largest cardiac centres in Europe, with a dedicated HCM MDT, interventional and surgical septal reduction under one roof.
King’s Private HCM programme
Specialist HCM service at King’s College Hospital with combined cardiology, cardiac imaging and cardiothoracic surgery input for septal reduction therapy.
ASA vs septal myectomy
Alcohol septal ablation compared to surgical myectomy.
Both procedures reduce the LVOT obstruction that drives HOCM symptoms. They differ in invasiveness, durability, pacemaker rate and who they suit best.
| Feature | Alcohol septal ablation | Surgical septal myectomy |
|---|---|---|
| Approach | Percutaneous catheter via groin or wrist | Open cardiac surgery, sternotomy, cardiopulmonary bypass |
| Anaesthesia | Local anaesthetic with conscious sedation | General anaesthetic |
| Hospital stay | 2-4 nights | 4-7 nights |
| Full recovery | 4-6 weeks | 8-12 weeks |
| Gradient relief | 50-80 percent reduction, less complete for thick septa | Near-complete and definitive, all septal thicknesses |
| Permanent pacemaker rate | 10-20 percent | 2-5 percent |
| Procedural mortality (expert centres) | Below 1 percent | Near zero |
| Best suited to | Older, higher surgical risk, favourable septal anatomy, patient preference | Younger patients, very thick septa, coexisting mitral valve or coronary disease |
The choice is not one or the other in isolation. Both options are discussed at the specialist HCM MDT with cardiology, cardiac imaging and cardiothoracic surgery in the room, and the recommendation reflects your anatomy, age, comorbidity and preference.
Related
Related private cardiology treatments.
Frequently asked
Everything patients ask about alcohol septal ablation.
Quick answers on success rate, pacemaker risk, repeat procedures, recovery, insurance and how it compares to surgery.
What is the success rate?
In experienced HCM centres, alcohol septal ablation reduces the LVOT gradient by 50 to 80 percent and produces symptomatic improvement in 80 to 90 percent of patients, sustained at 5 to 10 years. Around 10 to 15 percent need a repeat ablation or later surgical myectomy for incomplete relief.
What is the pacemaker risk?
A permanent pacemaker is needed in around 10 to 20 percent of patients, higher than after surgical myectomy (2 to 5 percent). The conduction system runs through the basal septum, so the deliberate infarct can cause complete heart block. Pre-existing right bundle branch block is the strongest risk factor.
Might I need a repeat procedure?
Around 10 to 15 percent of patients need a second intervention, either a repeat ablation of a different septal perforator or a crossover to surgical septal myectomy. Very thick septa above 25 mm and unfavourable perforator anatomy predict incomplete first-time relief.
How long does recovery take?
Hospital stay is typically 2 to 4 nights with overnight telemetry and a temporary pacing wire. Most patients are back to light activity within a week, driving in 1 to 2 weeks (subject to DVLA rules and any pacemaker), and full activity by 4 to 6 weeks. Peak symptomatic benefit is at 3 to 6 months as the septal scar contracts.
Do UK insurers cover it?
Most major UK insurers (Bupa, AXA Health, Vitality, Aviva, WPA, Cigna) cover alcohol septal ablation for HOCM where clinical criteria are met and the case has been discussed at a specialist HCM MDT. Pre-authorisation is essential.
How does it compare to surgery?
Surgical septal myectomy is open cardiac surgery through a sternotomy with cardiopulmonary bypass, 4 to 7 nights in hospital, near-zero mortality in expert centres and the most complete and durable relief, especially for very thick septa or coexisting mitral valve disease. Alcohol septal ablation is percutaneous, overnight admission with 2 to 4 nights stay, higher pacemaker rate (10 to 20 percent) and slightly less complete gradient relief in thicker septa. Choice depends on age, anatomy, surgical risk and patient preference and is made at a specialist HCM MDT.