53 / 78
CARDIOVASCULAR JOURNAL OF AFRICA • Volume 30, No 1, January/February 2019
AFRICA
51
1298–1305.
29. De Rosa S, Caiazzo G, Torella D,
et al
. What accounts for the higher
clinical efficacy of intracoronary abciximab?
Int J Cardiol
2013;
168
:
4410.
30. Zimarino M, Radico F, Dalby K,
et al
. Intracoronary vs intravenous
abciximab in interventional cardiology: a reopened question?
Vasc
Pharmacol
2015;
73
: 8–10.
31. Addad F, Gouider J, Boughzela E,
et al.
Management of patients treated
for acute ST-elevation myocardial infarction in Tunisia.
Ann Cardiol
Angeiol
2015;
64
: 439–445.
32. Akoukad H, El Khorb N, Sekkali N,
et al
. Acute myocardial infarction
in Morocco: FES-AMI registry data.
Ann Cardiol Angeiol
2015;
64
:
434–438.
33. Delport R. Toward developing guidelines and systems of care to facili-
tate early reperfusion for ST-elevation myocardial infarction in Africa.
Cardiovasc J Afr
2014;
25
: 256–258.
Extreme exercise and middle-aged athletes’ hearts
For the past decade or so, there’s been increasing concern
that high-volume, high-intensity exercise could injure the
heart. A large US study found that in middle-aged men,
extreme exercise did not raise the risk for cardiovascular or
all-cause mortality, even with elevated coronary calcium, a
footprint of atherosclerosis.
Exercise is often cited as the best preventive medicine,
but how much is too much for the hearts of middle-aged
athletes? Sports cardiologist Dr Benjamin Levine led a study
to find the answer. Levine is a professor of internal medicine
and director of the Institute for Exercise and Environmental
Medicine, a collaboration between UT Southwestern Medical
Centre and Texas Health Presbyterian Hospital Dallas.
Coronary calcium scanning is an imaging test that helps
physicians classify patients without cardiac symptoms as
low, intermediate, or high risk for heart attack. It represents
how much calcium (and therefore cholesterol deposits) has
accumulated in the blood vessels that supply the heart. The
scan can help physicians determine the need for medication,
lifestyle modification and other risk-reducing measures.
‘The question has never been whether exercise is good
for you, but whether extreme exercise is bad for you. For
the past decade or so, there’s been increasing concern that
high-volume, high-intensity exercise could injure the heart.
We found that high volumes of exercise are safe, even when
coronary calcium levels are high,’ Levine said.
High-volume, high-intensity exercise was defined in this
study as at least five to six hours per week at a pace of 10
minutes per mile. The average amount of high-intensity
exercise in this group was eight hours per week.
Coronary calcium is a footprint of atherosclerosis, a
disease in which plaque builds up in the arteries and gives
rise to heart attack and stroke. When coronary calcium is
detected in the heart, the clogging process within the blood
vessels has begun. The majority of high-intensity athletes had
low levels of coronary calcium, although their odds of having
higher levels were 11% greater than men who exercised less.
Most importantly, the researchers found that higher calcium
scores did not raise the high-intensity athletes’ risk for
cardiovascular or all-cause mortality.
Levine studied data from the Cooper Centre Longitudinal
Study. A total of 21 758 generally healthy men ages 40 to 80
years and without cardiovascular disease were followed for
mortality between 1998 and 2013. The athletes, a majority
of them in middle age, reported their physical activity levels
and underwent coronary calcium scanning. Most were
predominantly runners, but some were cyclists, swimmers
or rowers. A subgroup of athletes trained in three of these
sports.
Women were not included in the study as their mortality
rates are lower than for men.
Despite the findings that extreme exercise does not raise
heart disease risk, Levine advises against using the protective
effect of exercise to excuse poor lifestyle habits. ‘You cannot
overcome a lifetime of bad behaviours – smoking, high
cholesterol, hypertension – just from doing high levels of
physical activity, so don’t use that as a magical cure,’ said
Levine, who holds the distinguished professorship in exercise
sciences at UT Southwestern.
He also recommends caution when starting a new training
programme. ‘If you want to train for a marathon, you have to
have a long-range plan to build up slowly before you achieve
those volumes and intensity of exercise.’
‘The known benefits of regular physical activity in the
general population include decreased incidence of mortality,
heart disease, diabetes and many other medical conditions,
which reminds us how important it is participate in regular
physical activity as recommended by the 2018 Physical
Activity Guidelines,’ said Dr Laura DeFina, chief scientific
officer of the Cooper Institute and co-author of the study.
‘The current study shows no increased risk of mortality in
high-volume exercisers who have coronary artery calcium.
Certainly, these high-volume exercisers should review their
cardiovascular disease risk with their primary care doctor
or cardiologists and the study results provide helpful clinical
guidance.’
‘The most important take-home message for the exercising
public is that high volumes of exercise are safe. The benefits
of exercise far outweigh the minor risk of having a little more
coronary calcium,’ Levine said.
Source:
Medical Brief 2019