CARDIOVASCULAR JOURNAL OF AFRICA • Vol 22, No 5, September/October 2011
292
AFRICA
2009 and July 2010. The mean age of
patients, 77.5% of whom were men, was
64
±
11 years. Despite the fact that
most of the patients were on beta-blocker
therapy, 22% still experienced angina and
more than a third had high heart rates.
There is therefore a clear need for further
treatment of these patients with heart
rate-lowering agents such as ivabradine
to improve survival, and importantly, to
improve quality of life.
Dr Shirley Middlemost, Hermanus,
Western Cape
The extent of reversal of cardiac remodel-
ling achieved with ivabradine is an impor-
tant observation. With regard to standard
heart-failure therapy, only beta-blockers
and not ACE inhibitors have been able
to significantly reduce left ventricular
end-systolic volume index. An interest-
ing finding was that not only was the
end-systolic volume significantly reduced
but the end-diastolic volume was also
significantly reduced. In spite of these
observations, the ejection fraction was
significantly increased.
Clinicians now accept that heart rate
is an important therapeutic target in both
ischaemic heart disease and heart failure.
In both entities we know that the target
should be less than 70 beats per minute.
Furthermore, current guidelines recom-
mend a target of 55–60 beats per minute
in stable coronary artery disease.
The Quality of Life sub-study in
the SHI
f
T population showed a signifi-
cant improvement in quality of life,
as determined by the Kansaas City
Cardiomyopathy Questionnaire (KCCQ).
This is a significant finding in view of the
fact that patients with moderate to severe
heart failure have a quality of life simi-
lar to that of patients on haemodialysis.
Neither ACE inhibitors nor beta-blockers
have been shown to improve quality of life.
Prof Pinky Sareli, Johannesburg
Heart rate reduction is now clearly estab-
lished as a cardiovascular risk factor. As
clinicians, we can no longer leave this
aspect untreated in our patients.
In question time after the ESC pres-
entations, I asked ‘What do we do about
patients with other conditions, presenting
with raised heart rates; how should they
be treated?’ The SHIfT experts answered
carefully that you would need to assess
each patient individually and that each
patient (if without atrial fibrillation) could
be an own mini-study because ivabradine
is so safe and easy to use.
Instinctively, I think about diastolic
heart failure with preserved ejection frac-
tion, acute decompensated heart failure
due to all forms of cardiomyopathies,
diabetic patients with CAD, and raised
heart rate due to autonomic dysfunc-
tion, also CAD patients who are obese
with raised heart rate. We now have two
classes of agents at our disposal to treat
these patients and we should aim to get
to the target heart rate of below 70 beats
per minute.
1.
Swedberg K,
et al
. Ivabradine and
outcomes in chronic heart failure (SHIfT)
– a randomised placebo controlled study.
Lancet
2010. DOI: 10.1016/S0140-
6736(10)61198–1.
2.
Tardif J-C,
et al
. Effects of selective heart
rate reduction with ivabradine on left
ventricular remodeling and function: results
from the SHIFT echocardiography substudy.
Eur Heart J.
Published online 29th August
2011.
3.
Reil JC,
et al
. Selective heart rate reduction
by ivabradine increases aortic distensibility
as well as LV systolic and diastolic function
in diabetic mice. ESC 2011, Poster 3557.
4.
Ekman I,
et al
. Heart rate reduction with
ivabradine and health-related quality of
life in patients with chronic heart failure.
Results from SHIFT.
Eur Heart J.
Published
online 29 August 2011.
proven drugs, such as the older antiplate-
let agents, ACE inhibitors or ARBs and
statins in the secondary prevention of
cardiovascular disease.
This occurred in low-, middle- and
high-income countries, with the low-
income countries in the study (China,
Columbia and Iran) showing the worst
treatment coverage, with some 80% of
their patients receiving no preventative
medication. Even in high-income coun-
tries (Canada, Sweden and United Arab
Emirates), some 12% of people were not
being treated with these life-saving medi-
cations. In this study, which was set up in
2003 in 17 countries, South Africa was
ranked with the middle-income countries
of Argentina, Brazil, Malaysia, Poland
and Turkey.
Prof DP Naidoo, KwaZulu-Natal
For me personally, the results from the
initial SHI
f
T study, published late last
year, made a good case for heart rate
reduction as a means to reduce cardiovas-
cular risk. Today, with my understanding
of ivabradine’s underlying mechanism of
action, I would place this therapy in a new
category of ‘a disease-modifying agent’,
which carries much more impetus for use.
For example, there are some clear
opportunities emerging for improved care
from the CLARIFY baseline data on coro-
nary artery disease (CAD) to which South
Africa has contributed more than 500
patients. [The CLARIFY (ProspeCtive
observational LongitudinAl RegIstry
oF patients with stable coronary arterY
disease) registry was designed to increase
knowledge and understanding of CAD,
including an assessment of the role that
heart rate plays in the prognosis of CAD
patients. Dr Naidoo is the South African
co-ordinator for this registry.]
CLARIFY had already enrolled 33 649
patients worldwide between November
