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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 28, No 2, March/April 2017
AFRICA
77
The role of genetics in coronary artery bypass surgery
patients under 30 years of age
Sabit Sarikaya, Ebuzer Aydin, Yucel Ozen, Tanıl Ozer, Kaan Kirali, Murat Bulent Rabus
Abstract
Aim:
We undertook genetic assessment of coronary artery
disease (CAD) in 20 patients aged 30 years or less undergoing
coronary artery bypass grafting (CABG) surgery, to investi-
gate the prognostic value of pre-defined genes.
Methods:
Twenty patients, who underwent CABG surgery
between December 2001 and May 2013, were retrospectively
analysed to find out the role their genetic make-up played in
their disease. We used three genetic diagnostic tests, the plas-
minogen activator inhibitor
(PAI)-1
gene, the A1/A2 poly-
morphism of glycoprotein IIIa (
GpIIIa
) gene, and common
polymorphisms of the methylenetetrahydrofolate reductase
(
MTHFR
) gene.
Results:
The mean age of patients was 26.35
±
3.51 (19–30)
years, and 90% were male (
n
=
18). One patient had diabetes,
three had hypertension, 11 (55%) had dyslipidaemia and 16
(80%) were smokers. Eight of the patients (40%) had left
ventricular ejection fraction (LVEF)
<
50%, and functional
capacity was poor in only two (10%) patients (NYHA III–
IV). Follow up was completed in all patients (100%). We
found five homozygous and 11 heterozygous mutations in
the
MTHFR
gene, which predisposes individuals to coro-
nary artery disease or deep-vein thrombosis. Eight patients
were found to have a
GpIIIa
gene polymorphism, which is
associated with increased risk of myocardial infarction (MI).
Fifteen patients had a polymorphism in the promoter region
of the
PAI-1
gene, which is a major inhibitor of the fibrino-
lytic system.
Conclusion:
MTHFR
C677T polymorphism, and
GpIIIa
and
PAI-1
genes are risk factors for CAD. In young patients,
genetic studies promise to revolutionise early diagnosis, treat-
ment and prevention of CAD and MI.
Keywords:
coronary artery bypass graft (CABG), plasminogen
activatorinhibitor
(PAI)-1
,glycoproteinIIIa(
GpIIIa
),methylene-
tetrahydrofolate reductase (
MTHFR
), young patient
Submitted 13/6/14, accepted 3/4/16
Published online 21/10/16
Cardiovasc J Afr
2017; 28: 77–80
www.cvja.co.zaDOI: 10.5830/CVJA-2016-042
Although atherosclerotic cardiovascular disease is known as a
disease of the elderly, an advanced stage of disease requiring
interventionmay be also encountered in younger people. Increased
experience in interventional procedures and technological
improvements enable us to treat young individuals who have the
disease, thereby avoiding a deterioration in their quality of life.
Although percutaneous interventional treatment is the first
choice in appropriate cases, surgical treatment may also be
selected as the first choice in young adult patients with advanced
and multi-vessel disease, and is accompanied by early mobilisation
and decreased duration of hospitalisation.
1,2
When coronary artery
bypass graft surgery (CABG) is indicated in young patients, the
choice of operative technique, conduit selection and postoperative
risk-factor modification should be carefully considered to prolong
the graft patency and to avoid premature death.
3
Although cardiovascular genetic studies lag behind genetic
studies on other diseases, many advances have been made recently.
Polymorphisms are gene variations that have only modest effects
on the function of coded proteins or enzymes. However, they are
common and can act as a risk factor together with the presence of
environmental risk factors (cholesterol, stress, tobacco).
Current advances in molecular biology make it possible to
detect numerous polymorphisms that might have a detrimental
effect on vascular pathology, hence the hypothesis that multiple
polymorphisms in the presence of environmental factors could
act synergistically in the pathogenesis of atherosclerosis and
coronary artery disease (CAD), which are typically polygenic
and multifactorial diseases. There are many genetic diagnostic
tests and we selected three for this study, the plasminogen
activator inhibitor
(PAI)-1
gene, the A1/A2 polymorphism of
glycoprotein IIIa (
GpIIIa
) gene, and a common polymorphism
of the methylenetetrahydrofolate reductase (
MTHFR
) gene, the
thermolabile C677T.
Methods
CABG was performed either isolated or concomitantly with other
cardiac surgical interventions on 16 281 patients between December
2001 and May 2013 at our clinic. Twenty patients who were 30
years of age or older were included in this retrospective study.
Pre-, intra- and post-operative characteristics of the patients were
evaluated. The study protocol was approved by the Institutional
Ethics Committee, and all patients gave consent to participate in the
study. Medical data of the patients were reviewed, and patients were
also called on to gather information about their recent health status.
Cardiac operations were performed on a beating heart or by
providing cardiac arrest under cardiopulmonary bypass. Various
techniques were used for cardiac stabilisation in operations
performed on a beating heart. Isothermic, hyperkalaemic blood
cardioplegia was used via the antegrade route and/or retrogradely
in order to provide cardiac arrest. Grafts were prepared peri-
operatively as autogenous grafts. The left (LIMA) and right
Cardiovascular Surgery Department, Kartal Kosuyolu
Research and Education Hospital, Istanbul, Turkey
Sabit Sarikaya, MD
Ebuzer Aydin, MD
Yucel Ozen, MD
Tanıl Ozer, MD
Kaan Kirali, MD
Murat Bulent Rabus, MD,
muratrabus@yahoo.com