Honoring Two Decades of Alcohol Septal Ablation for Hypertrophic Cardiomyopathy

In 1994, Dr Ulrich Sigwart infused alcohol directly into a coronary artery of a patient with hypertrophic obstructive cardiomyopathy (HCM). His dream was to provide a minimally-invasive alternative to surgery, particularly for those patients who were not good surgical candidates. Although it was a radical concept, it worked. The hypertrophied septum infarcted, resulting in acute alleviation of obstruction, widening of the outflow tract over time, and sustained improvements in hemodynamics and heart failure symptoms. In 1995, he published his results as a single-author manuscript in Lancet.¹ Next year marks the 20th anniversary of this procedure.

I became involved with alcohol septal ablation (ASA) as a trainee, and performed my first procedure independently in 2004. Since then, I have witnessed firsthand how this procedure, when performed with care, diligence, and discipline, can transform the lives of patients living with severe heart failure. Today, in addition to running a cardiac catheterization laboratory, I am the medical director of an HCM treatment center serving 400 patients and families, coordinating all aspects from consultation to longitudinal care, advanced imaging, non-invasive testing, genetic counseling, pediatrics, electrophysiology, and invasive therapy. The vast majority, of course, need nothing more than education, reassurance, and medical therapy; however, the concept of the HCM center is something I strongly believe in, as quality care for an uncommon disease can best be accomplished through a concentration of experience in a specialized program.

ASA has not been without controversy. Indeed, it is among the most debated of procedures. To understand this controversy, one must look at its history, which can be divided into three eras. The first, from roughly 1995 through 2001, was the era of initial deployment of technique. There was an unfortunate sense that the procedure was simple, entailing straightforward injection of several milliliters of ethanol into (always) the first septal perforator, guided only by hemodynamics, and that most, if not all, patients qualified. This era, which encompasses the early learning curve, resulted in relatively good clinical efficacy, with reductions in gradient and improvement in symptoms, but at two major costs.² First were complications, including complete heart block necessitating pacemaker placement in a large minority, early ventricular arrhythmia, and even death or distant myocardial infarction from coronary complication or inadvertent spillage of ethanol.² During this time, the procedure was performed with exuberance at relatively high volume, with some estimating that more ASAs were being performed than surgical myectomies, giving a perception to onlookers that the procedure was being undertaken too frequently with little thought or consideration of the expertise of the operator. This perception was the second cost — and it was a significant one.

The next era, between 2001 and 2010, entailed the increasing incorporation of myocardial contrast echo as a guide, in order to select the correct septal perforator (not always the first one, or even the entirety of a perforator), reduction of ethanol volume, avoidance of acute complications, and approaches to maximize the benefit-to-risk ratio. As it happened, right around the same time that procedural volume began to decrease due to the fallout from the negative perceptions created in the first era, ASA was being performed more judiciously with better results, including pacemaker rates less than 10%.³ However, case selection was not completely understood, for while many patients could get ASA, we were only beginning to truly understand which among them would derive the greatest and most predictable and sustained benefit from the procedure. And, despite the steady improvement in acute safety and efficacy, there was a theoretic concern that the ASA scar may negatively impact survival.

The current era, from 2010 to the present, marks a more robust understanding of technique and case selection, including most importantly the nuances of anatomic appropriateness. When it is performed by experienced operators in the appropriate patient, mortality is now less than 1% (similar to surgery, despite being performed in significantly older patients). Acute complications are almost unheard of, and new pacemaker rate is approximately 8%. Gradients are markedly reduced, clinical symptoms are diminished, and remodeling of the heart assures continued and sustained improvements, with no apparent differences in survival when compared to surgery out to 8 years.^4-6 As a result, the 2011 ACCF/AHA Guidelines for the Diagnosis and Management of HCM, on which I had the privilege of being co-author and SCAI representative, advocates for ASA as a good alternative to surgery in those with significant comorbidity or advanced age, and allows the procedure for those at lower surgical risk after a balanced discussion.⁷

But we face a major challenge today. At this moment in time, when the procedure is able to be performed with very good results, only a small number of practitioners are aware of its capabilities. This may be partly explained by the results of the first era that have cast a dense shadow on the next two eras of development, and resulted in a nationwide approach adopted by many United States HCM experts to favor surgery over ASA, despite the marked advances in recent years. This has led to few training centers and experienced operators for ASA and a general disbelief among clinicians (mainly due to national lectures on the topic, rather than direct observation) that the procedure as it is performed today by experienced operators can be as good as surgery, both for short- and long-term outcomes. This is important because not all patients can withstand surgery and elderly patients may be particularly suited for ASA, given the tendency for a focal septal bulge. Thus, this alternative will always be needed and perhaps even ideal for many patients. In addition, it is indeed possible that ASA could take over the lion’s share of the business (for adults with acceptable anatomy at any age), as it has done in Europe and the rest of the world, with comparable safety, efficacy, and long-term survival, especially if longer-term (ie, >10 years) survival curves continue to show benefits that mirror surgery.

So, where do we go from here? For ASA to be successfully used in the United States, we need to ensure that operators are trained in case selection, optimal technique, and longitudinal care. This means that operators need to have a clear understanding about when ASA is ideal (eg, elderly, poor surgical candidate, focal septal bulge, no/minimal mitral valve involvement), when it is contraindicated (eg, the very young, massive hypertrophy, significant mitral valve or papillary muscle abnormality), and when it is reasonable to consider as an alternative to surgery, as well as when ASA is not the best approach, when anatomic, hemodynamic and clinical criteria are not strictly met. By centralizing resources and personnel around ASA at HCM Centers, training the operators in case selection, technique, and follow-up, ASA can be recognized as one of two acceptable ways to substantively improve the lives, and possibly even longevity,^4,8 for those living with severe HCM, and regain its rightful place as a viable therapeutic option. 

To this end, I have recently helped set two things into motion. First, working alongside SCAI and ACC colleagues, we developed a category 1 CPT code and associated RVU valuation for ASA last year. This has now been passed by the American Medical Association, and a dedicated code will go into place in 2014 to provide assured and standardized reimbursement. Second, several of us are planning a formal training program for ASA to coincide with its 20th anniversary. By bringing together leaders in the field, proctoring 8-10 interventional cardiologists at a time with detailed lectures followed immediately by live cases, and focusing only on those operators who can achieve the 5-10 procedures per year required by national guidelines and competency statements, typically within the confines of an HCM Center,^7,9 we hope to initiate the next era in the ASA saga; that is, the controlled release of a mature procedure with excellent safety, efficacy, and survival data to coincide with the rise of regionalized, expert, high-volume HCM care. Only then can Dr Sigwart’s dream be fully realized, and perhaps this would be a fitting anniversary present.

References

1. Sigwart U. Non-surgical myocardial reduction for hypertrophic obstructive cardiomyopathy. Lancet. 1995;346(8969):211-214.
2. Fernandes VL, Nagueh SF, Wang W, Roberts R, Spencer WH 3rd. A prospective follow-up of alcohol septal ablation for symptomatic hypertrophic obstructive cardiomyopathy — the Baylor experience (1996–2002). Clin Cardiol. 2005;28(3):124-130.
3. Agarwal S, Tuzcu EM, Desai MY, et al. Updated meta-analysis of septal alcohol ablation versus myectomy for hypertrophic cardiomyopathy. J Am Coll Cardiol. 2010;55(8):832-834.
4. Sorajja P, Ommen SR, Holmes DR Jr, et al. Survival after alcohol septal ablation for obstructive hypertrophic cardiomyopathy. Circulation. 2012;126(20):2374-2380.
5. Leonardi RA, Kransdorf EP, Simei DL, Wang A. Meta-analysis of septal reduction therapies for obstructive hypertrophic cardiomyopathy: comparative rates of overall mortality and sudden cardiac death after treatment. Circ Cardiovasc Interv. 2010;3(2):97-104.
6. Nagueh SF, Groves BM, Schwartz L, et al Alcohol septal ablation for the treatment of hypertrophic obstructive cardiomyopathy: a multicenter North American Registry. J Am Coll Cardiol. 2011;58(22):2322-2328.
7. Gersh BJ, Maron BJ, Bonow RO, et al. 2011 ACCF/AHA guidelines for the diagnosis and treatment of hypertrophic cardiomyopathy. Circulation. 2011;124(24):2761-2796.
8. Ball W, Ivanov J, Rakowski H, et al. Long-term survival in patients with resting obstructive hypertrophic cardiomyopathy: comparison of conservative versus invasive treatment. J Am Coll Cardiol. 2011;58(22):2313-2321.
9. Harold JG, Bass TA, Bashore TM, et al. ACCF/AHA/SCAI. 2013 Update of the clinical competency statement on coronary artery interventional procedures. J Am Coll Cardiol. 2013 May 2 (Epub ahead of print).

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Dr Srihari S. Naidu is Director of the Cardiac Catheterization Laboratory, Interventional Cardiology Fellowship Program and Hypertrophic Cardiomyopathy Treatment Center at Winthrop University Hospital on Long Island, and Associate Professor of Medicine at SUNY – Stony Brook School of Medicine. He is a Trustee of the Society for Cardiovascular Angiography and Interventions (SCAI), Trustee of the Corporation of Brown University, and Appointed Member of the American College of Cardiology Interventional Scientific Council (ACC-ISC).