Is It Essential to Change the Term “Essential Hypertension”?
To the Editor:
Barry Materson in the September issue of Hypertension proposes to change the term “essential hypertension” to “primary hypertension.”1 Is it right to correct one wrong with another?
The clinical and scientific communities undoubtedly agree with Dr Materson, who agrees in turn with Dr Kaplan,2 that the term “essential” to describe hypertension of unknown cause is not an ideal term and is possibly misleading. “Essential” indeed implies to the lay person that hypertension is essential for survival in that particular patient with high blood pressure. However, a wise lay person would look in the dictionary for the full meaning of the term “essential” and come up with the interpretation of the phrase “essential hypertension” as an “idiopathic” disease. Looking in the same dictionary for the meaning of “idiopathic,” one would come up with the interpretation “of the nature of a primary morbid state,” And “primary,” a term to replace “essential” as suggested by Dr Materson, implies in turn “of the first order, whether in time or sequence.” Is “essential hypertension” truly primary, of first order? Or is “primary” just another misleading term with respect to hypertension?
When discussing diseases in which one organ plays a central role, such as, for example, in kidney disease, the use of the term “primary” is appropriate, indicating a disease that affects the kidney only or primarily, as opposed to “secondary” in which the kidney is affected as part of a generalized systemic disorder (such as diabetes) that affects also other organ systems. Hypertension cannot at this time be related solely to one organ, much to the chagrin of many nephrologists, as multiple systems are likely to be involved. In this context, how can then hypertension be “primary?” The use of the term “primary” for hypertension, therefore, is misleading and inappropriate.
Should the term “primary” for hypertension be used nonetheless in the context of a disorder of unknown cause, as a synonym to “idiopathic”? Dr Materson surely agrees that the fact that we have not uncovered yet the full spectrum of the etiology and pathophysiological basis of hypertension merely reflects our failure, so far, to decipher complex diseases such as hypertension. It certainly does not imply that hypertension is not secondary to a resetting or malfunction of one or more mechanisms. The causes of hypertension that have already been identified (secondary hypertension) are all within the realm of monogenic diseases in which one gene or one protein sets off a chain of reactions that leads to hypertension. Not so in “essential hypertension” in which multiple genes and proteins are likely to come into action in a highly complex maze that we are having difficulty to uncover or decipher. The hope for the future is that novel technologies in the rapidly developing fields of genomics, transcriptomics, and proteomics will help uncover novel mechanisms in hypertension. These, in turn, will allow us, hopefully in the not so distant future, to classify most if not all cases of hypertension as distinct subentities that are secondary to known mechanisms. Eventually, once the pathophysiological mechanisms are identified, all cases of hypertension are likely to be classified as “secondary” and the term “essential” for hypertension will fade away on its own. Until then, we propose that we do not change one misleading term with another, and stay with hypertension of known cause (“secondary”) and hypertension with as yet unknown cause (“essential”).
Response: Is It Essential to Change the Term “Essential Hypertension”
I thank Drs. Yagil for their interest in and perspective on my letter regarding “essential” hypertension.
We all seem to agree that “essential” is an incorrect term. I agree that “primary” in contrast to known secondary causes of hypertension is not a perfect term, but I do not agree that it is wrong. While I also hope that the term “essential” will fade away once all of the pathophysiological mechanisms of hypertension are identified through rapidly developing technology, I do not expect that this process will be complete for a few decades—if ever.
I do not know how many patients I have seen in the past four decades, but I do not recall one ever telling me that they looked up the word “essential” in the dictionary or elsewhere. More worrisome is the misinterpretation by many patients that hypertension is a nervous disorder. Our track record for controlling hypertension in the estimated 800 million people so afflicted worldwide is poor. Concepts that elevated blood pressure is essential to stay alive or essential to drive blood through partially occluded arteriosclerotic conduits (the original misconception) are contrary to our intensive effort to control it.
The Earth’s axis will not severely tilt if “essential” continues to be used. Indeed, Dr. Kaplan was amused by my interest in continuing his effort at change. On the other hand, I believe that clinicians and scientists do have an obligation to attempt to make our communications with each other, our students and our patients more precise. If “primary” is merely less wrong, then I would consider that to be an advance pending data that permit greater precision.