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- Anthony N. DeMaria, MD, MACC, Editor-in-Chief, Journal of the American College of Cardiology∗ ()
- ↵∗Address correspondence to:
Dr. Anthony N. DeMaria, Editor-in-Chief, Journal of the American College of Cardiology, 3655 Nobel Drive, Suite 630, San Diego, California 92112
My last Editor's Page, prior to the annual Highlights of the Year in JACC paper, was devoted to a consideration of the definition of translational research. Specifically, I wondered at the imprecision of the definition and the fact that it meant different things to different people. This uncertainty existed despite the fact that translational research had increasingly crept into the medical lexicon and was frequently referred to in both publications and presentations.
Having gotten my frustration with the term “translational research” off my chest, I decided to address the other expression that I find confusing, that is, structural heart disease. This term is appearing with increasing frequency throughout cardiology. Patients are said to have structural heart disease, programs have been developed specifically to deal with the problem, individual cardiologists proclaim themselves to be experts in the area, and even JACC is complicit in having devoted an entire focus issue to the subject (1). All of this attention has been directed to the entity of structural heart disease despite the fact that it remains uncertain, at least to me, what exactly is meant by the name.
My first encounter with the term “structural heart disease” goes back many years to when I was a resident in internal medicine. In those days, when a patient presented with symptoms and findings consistent with congestive heart failure, the first question we asked was whether the patient had “structural heart disease.” Sometimes the words “intrinsic” or “organic” were substituted. The question was meant to distinguish whether the condition was due to heart disease or to noncardiac causes, such as acute renal failure or pulmonary abnormalities with leaky capillaries, etc. Failure due to arrhythmias, accelerated hypertension, and so on, straddled the boundary. It also prompted us to think of just what type of heart disease it might be. This terminology was ultimately dropped, in part due to the uncertainty of just what was meant by “structural,” although the simple phrase “heart disease” is often used to accomplish the same goals. Even now, however, I find it difficult to conceive how anyone could have heart failure without an abnormality of some cardiovascular structure.
When the term “structural heart disease” first began to appear as a distinct entity a few years ago, I sought help from dictionaries to understand exactly what was being referred to. I first “Googled” the term, and found that there were 14,400,000 listings; in fact there were 3,100,000 entries under the definition alone. The first definition offered was “a structural or functional abnormality of the heart, or of the blood vessels supplying the heart, that impairs its normal functioning” (2). I was confident that this is not what was being referred to as a unique entity. So, I went to the time-honored Merriam-Webster dictionary, but without much success, because the word “structural” was defined as “of, relating to, or affecting structure” (3). Stymied by these approaches, I went to the medical literature. The Society of Cardiac Angiography and Intervention offered the definition of “any abnormality, or defect, of the heart muscle or the heart valves,” whereas a review paper devoted to the topic in the European Heart Journal characterized structural heart disease as “non-coronary cardiovascular disease processes and related interventions” (4). Clearly, I was not getting anywhere with this search, and was discouraged that even these august bodies could not seem to agree.
After considerable reflection, I think that I have begun to understand the concept based upon how it evolved. Clearly, the major focus of cardiology and cardiac surgery over the last 50 years has been coronary artery disease, not only due to its prevalence, but also due to the many therapeutic modalities available for treatment. This focus upon ischemic heart disease and its treatment began to be blunted several years ago with the development of innovative therapies, particularly percutaneous approaches, to noncoronary disorders such as valve and congenital disease. Because these techniques were brand new, a few individual physicians soon developed a special capability in the area and sought a designation for this expertise. And so, in my view, it was the creation of interventional therapeutic modalities that gave birth to the concept of structural heart disease. As currently used now, it seems that the term refers to noncoronary heart disease for which some therapy, surgical or percutaneous, exists. Obvious examples are aortic stenosis, atrial septal defect, and known or potential left atrial appendage clots. In addition to the valve and congenital disorders, some would include cardiomyopathy, particularly hypertrophic, for which both surgical and percutaneous interventions exist.
There are some obvious difficulties with the definition advanced above. It goes without saying that coronary artery disease involves an abnormality of cardiovascular structure. Moreover, both systemic and pulmonary hypertension can produce abnormalities of heart structure, as can heart rhythm disorders. (In fact, with the early success of renal artery denervation for the treatment of resistant hypertension, we may be on the verge of adding hypertension to the group of structural heart diseases.) So, it seems a bit disingenuous to exclude disorders that can alter cardiac structure from the category of “structural” disease. Nevertheless, the term is being increasingly adopted into standard medical parlance, and it will be difficult to dislodge. This is despite the fact that only the specialists in the area appear to have a clear understanding of what the terminology refers to, whereas many of the rest of us see a disconnect between the words and reality.
I think it is unfortunate that the nomenclature chosen for this category of cardiovascular disorders and their therapy has involved the word “structural.” The concept engendered by the term and the reality of cardiac pathology are inconsistent, and this has led to some degree of confusion. Having said that, I am not certain that I can think of a better terminology. As I said above, it seems to me that what we are really talking about is noncoronary heart disease that is susceptible to percutaneous interventional therapy. Of course, such phraseology would not be well suited to describe the expertise of a highly trained physician or the special advantage of a focused and designated program. It may well be that I am making too much of the lack of precision of the term; the most important thing is that everyone understands what is meant when it is used. In fact, as someone interested in cardiac ultrasound, it provides the opportunity for me to say that I am a specialist in the diagnosis of structural heart disease. Nevertheless, I believe that we should always strive to designate things as precisely as possible, and it appears that structural heart disease is another example of a term that has been coined for convenience rather than accuracy.
- American College of Cardiology Foundation
- ↵(2011) Focus issue: structural heart disease. J Am Coll Cardiol 58:2143–2262.
- ↵Structural heart disease. Web definitions. Available at: https://www.google.com/search?q=structural+heart+disease&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a#q=structural+heart+disease+definition&rls=org.mozilla:en-US:official. Accessed January 9, 2014.
- ↵Merriam-Webster. Structural. Available at: http://www.merriam-webster.com/dictionary/structural. Accessed January 9, 2014.
- Steinberg D.H.,
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- et al.