AFRO-NETS> 1999 WHO-ISH hypertension guidelines

[Jerome Sclafer <jeromjet@easynet.fr>]

1999 WHO-ISH hypertension guidelines
------------------------------------

1999 WHO-ISH guidelines for the management of hypertension are in 
contradiction with current clinical evaluation data. Excessive ex-
trapolations of the data resulting from the HOT study, and the mas-
sive implication of the pharmaceutical industry have been already 
largely underlined (among others: Bradbury J. (Lancet 1999 ; 353: 
563); Open letter to Dr Brundtland "HOT: can we turn WHO around?"). 

Indeed, the claimed therapeutic objective of lowering the blood pres-
sure below 130/85 cannot be based on the HOT study. In the HOT study, 
the lowering of the diastolic blood pressure to 80, 85, 90 or 95 mm 
Hg did not yield a difference in terms of cardiovascular morbidity 
(except in diabetics). Yet the 1999 WHO-ISH working group has sug-
gested that a difference exist. Other statements of the 1999 WHO-ISH 
guidelines are just as disturbing. The WHO-ISH working group proposes 
to use as first choice any anti-hypertensive drug of the six pharma-
cological groups. This does not take into account the different risks 
of adverse effects when drugs are taken for long duration and/or in 
particular settings. It overlooks that diuretics and beta-blockers 
are the anti-hypertensive drugs with the best demonstrated effect on 
cardiovascular morbi-mortality. In addition, the WHO-ISH working 
group does not distinguish drugs within a given pharmacological 
group. 

This proposal is questionable, and even unacceptable for dihydropyri-
dins: clinical trials have shown a higher incidence of myocardial in-
farction with dihydropyridins than with ACE inhibitors in diabetics. 
Indiscriminate use as first choice of any anti-hypertensive drug may 
result in considerably increasing considerably cost without individ-
ual or collective benefit. 

The WHO-ISH working group favours fixed drug combinations, although 
there is no data from randomised clinical trials to justify this 
statement. Hypertension management must be based on the available 
evidence. The strategy must use the existing data of clinical evalua-
tion. In April 1999, "la revue Prescrire" has published recommenda-
tions for the management of high blood pressure based on all relevant 
clinical trials ("Les traitements antihypertenseurs" Rev Prescr 1999; 
19 (194): 288-296). These proposals are in agreement with the inde-
pendent and most recent recommendations (for example NIH no.98 - 
4080, November 1997). 

In mild hypertension, uncomplicated and without diabetes, before 65 
years, diuretic and beta-blockers remain the best validated treat-
ments. In a trial, captopril was a little less effective than a diu-
retic or a betablocker for the prevention of stroke. The preventive 
effect of calcium channel blockers remains uncertain and several data 
raise the assumption of an inferiority of the dihydropyridins to 
other antihypertensive drugs (less effective and safe). Clinical 
trial evaluating the preventive effect of the other anti-hypertensive 
drugs is lacking (i.e., central acting-, alphablockers, angiotensin 
II inhibitors). 

In patients over 65, reduced doses of a diuretic or a beta-blocker 
yield significant benefits, but one ought to be cautious about the 
risk of postural hypotension. In type 2 diabetics, ACE inhibitors and 
beta-blockers are the first choice treatments; in two trials coronary 
events were more frequent with a dihydropyridin than with a ACE in-
hibitor. The use of dihydropyridins must be questioned. It is possi-
ble to choose the antihypertensive drug best adapted to hypertension 
with complication: diuretic after stroke, beta-blockers after myocar-
dial infarction, etc. 

We do wonder what are the reasons which can lead an international or-
ganisation such as WHO to endorse recommendations despite an obvious 
loss of control. We also worry about the growing place of drug indus-
try within WHO, and of an increasingly large number of international 
organisations and scientific societies.

Jerome Sclafer
La Revue Prescrire
BP 459 - 75527 Paris Cedex 11 - France 
Tel: +33-1-4700-9445
Fax: +33-1-4252-1582
mailto:jeromjet@easynet.fr


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