Hypertension
BMJ 2011; 342 doi: https://doi.org/10.1136/bmj.d1592 (Published 17 March 2011) Cite this as: BMJ 2011;342:d1592
All rapid responses
Rapid responses are electronic comments to the editor. They enable our users to debate issues raised in articles published on bmj.com. A rapid response is first posted online. If you need the URL (web address) of an individual response, simply click on the response headline and copy the URL from the browser window. A proportion of responses will, after editing, be published online and in the print journal as letters, which are indexed in PubMed. Rapid responses are not indexed in PubMed and they are not journal articles. The BMJ reserves the right to remove responses which are being wilfully misrepresented as published articles or when it is brought to our attention that a response spreads misinformation.
From March 2022, the word limit for rapid responses will be 600 words not including references and author details. We will no longer post responses that exceed this limit.
The word limit for letters selected from posted responses remains 300 words.
Dear Editor,
I'm surprised by this answer - that in this patient Conn syndrome is
more likely than essential hypertension.
'Only 4% to 9% of patients have identifiable underlying causes of
hypertension'.(1) So, among patients with hypertension, the prior odds of
essential hypertension are around 10:1.
'Primary hyperaldosteronism is an important cause of hypertension.
Its true prevalence is still a matter of debate, since about 10% of
hypertensives may have underlying hyperaldosteronism'.(2) A benign
cortical tumor of the adrenal gland is found in about two thirds of the
cases of primary aldosteronism (Conn syndrome).(3) So, among patients with
hypertension, the prior odds of Conn syndrome are at most 1:13.
To produce posterior odds of Conn syndrome of >10:1, the positive
likelihood ratio of the combination of indicants in this vignette must be
>130 which is unusually high. I wonder if the authors could furnish
references.
Yours sincerely,
Wilfrid Treasure
1. Henri HC, Rudd P. Chapter 7. Hypertension: context and
management. In: Topol EJ, editor. Textbook of Cardiovascular Medicine.
Philadelphia: Lippincott Williams & Wilkins; 2007.
2. Nadar S, Lip GYH, Beevers DG. Primary hyperaldosteronism. Ann
Clin Biochem. 2003;40(Pt 5):439-452.
3. Roffi M, Cattaneo F. Chapter 35A. Endocrine Systems and the
Heart. In: Topol EJ, editor. Textbook of Cardiovascular Medicine.
Philadelphia: Lippincott Williams & Wilkins; 2007.
Competing interests: No competing interests
Presentations of hypertension
This is a good question, as this scenario is not uncommon in general
practice. However, while Conn's syndrome is compatible with this patient's
story, I am not sure that it is the most likely cause of his hypertension.
Even assuming he is compliant with his prescribed medications, the
likeliest diagnosis would be essential hypertension, chiefly because it is
by far the commonest cause overall.
Although low, a serum K of 3.4 mmol/L is not strikingly abnormal and
there is ample room to increase the calcium channel blocker and beta
blocker, As such his hypertension is not necessarily difficult to control.
Non-functioning adrenal adenomas are more common than aldosterone
producing adenomas, which makes adrenal imaging an unattractive
investigation. If the peripheral renin:angiotensin ratio is compatible
with Conn's syndrome (and if Conn's syndrome is present), renal vein
sampling for aldosterone would be a better way to lateralise the adenoma
if surgery would be contemplated.
In practice, medical treatment with spironolactone along with
additional antihypertensives if needed will often be sufficient to control
the blood pressure and avoid surgical intervention.
Renal artery stenosis (RAS) would only be expected to be associated
with impaired renal function if the condition is bilateral (or in a single
functioning kidney) and the GFR is angiotensin II dependent, which is not
the case in the majority of patients with RAS even in the older patient
with bilateral atherosclerotic renovascular disease.
As has been noted in the past, a common condition with an uncommon
presentation is still more likely than an uncommon condition with the same
presentation.
Competing interests: No competing interests