It took another 10 years, after a positive response of a different Review Board,before the first alcohol septal ablation (ASA) could be performed at the Royal Brompton Hospital in London 25 years ago.1 The very first patient, after having been informed in great length and meticulous detail about all possible risks,agreed to an experimental procedure, the outcome of which could not be defined. She had severe left ventricular hypertrophy that created an impressive and highly symptomatic outflow tract gradient despite pacing and drug treatment; after the ablation on June 18, 1994, she remained asymptomatic for >20 years.

1. Circulation. 2019;140:11–12. DOI: 10.1161/CIRCULATIONAHA.119.039889 July 2, 2019 11
The opinions expressed in this article are
not necessarily those of the editors or
of the American Heart Association.
Key Words: ablation techniques ◼
cardiomyopathy, hypertrophic ◼ left
ventricular outflow obstruction
Ulrich Sigwart, MD
T
he answer to this question was a clear no when I put it to the local Institu-
tional Review Board 35 years ago. My request was based on the observation
that a brief angioplasty balloon inflation inside the first major septal branch
of the left anterior descending coronary artery in symptomatic patients with hy-
pertrophic obstructive cardiomyopathy (HOCM) resulted in immediate reduction of
the left ventricular outflow tract gradient.
It took another 10 years, after a positive response of a different Review Board,
before the first alcohol septal ablation (ASA) could be performed at the Royal
Brompton Hospital in London 25 years ago.1
The very first patient, after hav-
ing been informed in great length and meticulous detail about all possible risks,
agreed to an experimental procedure, the outcome of which could not be defined.
She had severe left ventricular hypertrophy that created an impressive and highly
symptomatic outflow tract gradient despite pacing and drug treatment; after the
ablation on June 18, 1994, she remained asymptomatic for 20 years.
Since then the procedure has been performed throughout the world in many
thousands of patients with HOCM resistant to medical treatment, but the dis-
cussion, whether such alternative to surgical myectomy is appropriate, carries on
among cardiologists and cardiac surgeons.
Surgery for HOCM, a logical and straightforward procedure, was pioneered by
Cleland more than half a century ago at the same hospital where the first ASA was
done. Surgical myectomy has a proven track record; 90% of patients return to
work and follow a normal lifestyle.2
The excision by knife of the muscular obstacle
to left ventricular ejection results in immediate gradient reduction or even elimina-
tion. However, the published data on surgical myectomy have been collected at
high volume centers, which may not be accessible to a large portion of patients.
Moreover, there is an important psychological threshold for patients to accept an
open-heart procedure with all its inherent discomfort and extended hospital stay.
Not surprisingly, the majority of patients prefer the nonsurgical solution.3
It did not take long after the introduction of such intervention light to create
fierce scepticism. The heated debate about the safety and efficiency of ASA is
ongoing. For the opponents of the procedure, the danger of creating a substrate
for dangerous arrhythmias remains an important issue. A substantial number of
clinicians and researchers keep evoking the likelihood of sudden death as a result
of iatrogenic myocardial infarction.2
Also, the possibility of injury to the intramyo-
cardial conduction system should not be underestimated, as outlined in numerous
publications, including the American and European guidelines.4,5
Unfortunately, the septal conduction system cannot be localized by today’s
technologies in vivo, but from anatomic studies we know about the proximity to
septal arterial supply. Right bundle-branch block is common after ASA and it is
no secret that, for the time being, we must live with a higher incidence of com-
© 2019 American Heart Association, Inc.
PERSPECTIVE
Therapeutic Myocardial Infarction for
Hypertrophic Obstructive Cardiomyopathy
Is It Appropriate?
Circulation
https://www.ahajournals.org/journal/circ
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2. Sigwart Therapeutic Infarct for HOCM
FRAMEOFREFERENCE
July 2, 2019 Circulation. 2019;140:11–12. DOI: 10.1161/CIRCULATIONAHA.119.03988912
plete heart block after catheter-based procedures in
­comparison with surgical septal reduction. In large se-
ries, up to 15% of ASA procedures will require implan-
tation of a pacemaker. The risk is significantly higher in
the presence of preexisting left bundle-branch block.
This complication occurs clearly less frequently after
surgical myectomy.
Does the implantation of a pacemaker pose a ma-
jor problem? There is certainly a cost issue, because
the implantation of a device increases the price of an
otherwise less expensive intervention. But even under
such circumstances, the final bill will still not reach the
level of the surgical treatment cost. Also, in high-risk
patients, the device can be adapted to cover the risk
of ventricular tachycardia or fibrillation and allows con-
tinuous monitoring of numerous parameters. In some
cases, right ventricular apical pacing can improve left
ventricular outflow tract hemodynamics.
How about long-term follow-up? As of today, there
are numerous studies evaluating symptoms and survival
of patients undergoing ASA or surgery for HOCM. Even
the most recent publications could not find a signifi-
cant difference: the long-term survival rate after either
procedure was 90%, and the pacemaker implantation
rate for ASA did not exceed 15%.
One issue with catheter-based procedures remains
the ease of access: ASA appears so simple that any car-
diologist with angioplasty experience may feel compe-
tent to do it. This is definitely not the case. Experience
with selecting the appropriate vessel to achieve the best
result is crucial. Echocardiographic monitoring of the
target vessel distribution is mandatory. Sometimes un-
orthodox approaches are required, including diagonal
or even right coronary branches for injection. Although
there may be hesitation by many physicians to refer
HOCM patients to centers with large experience, such
referrals would not only benefit patients, but also help
clarify the contemporary role of septal ablation.
To date, no randomized study comparing surgical
with catheter-based septal reduction has been per-
formed. In my view, the time has come to perform
such a trial at institutions with high expertise in both
techniques. Recruitment may present a major obstacle,
but high-volume centers may have sufficient numbers
of patients suitable for both procedures. Such an en-
deavor would probably be the only way to pacify the
disagreement between the 2 camps and allow a sound
statement on the appropriateness of ASA.
Until such evidence is available, we must live with
some degree of uncertainty as to the indication for
therapeutic myocardial infarction for HOCM, and re-
member that the preference of the patient should al-
ways be considered.
ARTICLE INFORMATION
Correspondence
Ulrich Sigwart, MD, FACC, EFESC, FRCP, 1, av. de Miremont, CH-1206 Geneva,
Switzerland. Email ulrich.sigwart@unige.ch
Affiliation
Professor Emeritus, University of Geneva, Switzerland.
Disclosures
None.
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