Cardiovascular Journal of Africa: Vol 30 No 3 (May/June 2019)

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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 30, No 3, May/June 2019 184 AFRICA
SAHS Commentary
South African Hypertension Society commentary on
the American College of Cardiology/American Heart
Association hypertension guidelines
Brian Rayner, Erika Jones, Yusuf Veriava, YK Seedat
Abstract
In late 2017, the publication of the new American College
of Cardiology (ACC)/American Heart Association (AHA)
hypertension guidelines created considerable controversy. The
threshold for hypertension was redefined as > 130/80 mmHg
and target blood pressure < 130/80 mmHg. The purpose
of this commentary is to give clarity on the position of the
Southern African Hypertension Society (SAHS).
In South Africa more than 90% of hypertensives are not
controlled at < 140/90 mmHg. Furthermore, by redefining
hypertension to a level of 130/80 mmHg, this will signifi-
cantly increase the prevalence of hypertension by 43%. The
new targets will necessitate greater use of health services for
increased health visits to monitor patients, greater use of
antihypertensives to achieve the lower target, and increased
use of laboratory services to monitor for adverse effects.
It is the position of SAHS that the new definition and
targets are not relevant to low- and middle-income countries
such as South Africa, the threshold for hypertension remains
at 140/90 mmHg, and a universal target is < 140/90 mmHg
for all categories of hypertension.
Keywords: BP definitions, BP targets, commentary, South African
Hypertension Society
Submitted 13/2/19, accepted 27/4/19
Published online 24/5/19
Cardiovasc J Afr 2019; 30: 184–187
DOI: 10.5830/CVJA-2019-025
Prior to 2009, there was general unanimity on blood pressure
(BP) targets in all major guidelines. For uncomplicated essential
hypertension it was < 140/90 mmHg and for high-risk patients,
diabetics and those with established cardiovascular (CV) disease
it was < 130/80 mmHg.1
However, in 2009, in a reappraisal of the European Society
of Hypertension guidelines, the authors found no evidence to
suggest the lower target for high-risk patients.2 For example,
in patients with diabetes, no study that randomised patients to
conventional versus intensive targets showed benefit in lowering
BP to < 130/80 mmHg. There were also several observational
studies to suggest that there was a U-shaped relationship between
BP and outcome, with patients with both low and high systolic
and diastolic BP having worse CV outcomes.3,4 Low diastolic BP
was of special concern as myocardial perfusion occurs during
diastole and this could be potentially compromised, especially
in those with coronary artery disease and left ventricular
hypertrophy. The major drawback of observational studies is
that they suffer from bias, unaccounted confounding factors and
reverse causality, i.e. low BP was a manifestation of underlying
cardiac disease.
In view of these concerns, major guidelines in 2013 and
2014 revised BP targets and abandoned the lower target for
patients with diabetes and high CV risk.5-7 All major guidelines
then recommended a unitary target of < 140/90 mmHg for all
hypertensives, apart from the elderly, where this was increased
to < 150/90 mmHg in the elderly in two of these publications.5,7
However, in late 2017, the publication of the new ACC/AHA
hypertension guidelines created considerable controversy. 8 The
purpose of this commentary is to give clarity on the position of
the Southern African Hypertension Society (SAHS).
Summary of the AHA/ACC hypertension
guidelines
The AHA/ACC hypertension guideline was a major overview for
the prevention, detection, evaluation and management of high
BP in adults, and the reader is referred to this publication for
full details.8 This was the most controversial guideline developed
in the United States. However, many of the recommendations
were non-controversial. For example, emphasis was placed on
the appropriate technique of BP measurement, the increased
need for out-of-office BP measurement, and treatment of
hypertension after acute stroke and hypertensive emergencies.
The value of risk assessment was recognised and introduced for
the first time.
However, central to the controversy was the redefining of
hypertension and, arising from this, a change in target BP (Tables
1, 2). Hypertension was defined as a BP ≥ 130 systolic and/or
diastolic ≥ 80 mmHg on at least two occasions, and the target BP
Division of Nephrology and Hypertension, and Kidney and
Hypertension Research Unit, University of Cape Town,
Cape Town, South Africa
Brian Rayner, MB ChB, FCP, MMed, PhD,
Erika Jones, MB BCh, FCP, Certificate of Nephrology, PhD
Yusuf Veriava, MB BCh, FCP, FRCP, Hon PhD
YK Seedat, MD, PhD, FRCP, FCP