CARDIOVASCULAR JOURNAL OF AFRICA • Vol 24, No 7, August 2013
AFRICA
247
Cardiovascular Topics
Analysis of mortality in low-risk patients undergoing
coronary artery bypass grafting
CANTURK CAKALAGAOGLU, CENGIZ KOKSAL, TAYLAN ADADEMIR, MUSTAFA YILDIZ, ALI FEDAKAR,
MÜSLÜM ŞAHIN, FIKRI KUTLAY, BESIM YIGITER
Abstract
Aim:
The aims of this study were to determine the early
mortality rate in low-risk coronary artery bypass graft
(CABG) patients and examine the causes of death, to identify
problems that could be avoided in future surgeries.
Methods:
All low-risk patients (EuroSCORE
≤
2) who died
after CABG were included. Their peri-operative informa-
tion was meticulously studied by internal and independent
external reviewers to identify causes of death, which were
classified as: cardiac or non-cardiac; and a further division
as: (1) non-preventable, (2) preventable (technical error), and
(3) preventable (system error).
Results:
Early mortality was 0.93% (24/2 570). Eleven
patients (45.8%) were classified as preventable deaths. In
six of them the main problem was identified as graft throm-
bosis, which was secondary to a technical error of either the
harvesting or anastomosis of the left internal mammarian
artery. There were also five system errors identified as delays
in the treatment of an identified and potentially reversible
problem.
Conclusions:
Correction of technical and system errors, such
as harvesting of the left internal mammarian artery, haemo-
stasis during surgery, and establishing standard protocols for
the transfer of patients from ward to intensive care units will
eventually lead to improvement in both the quality of care
and patient outcomes, even in low-risk groups.
Keywords:
coronary artery bypass grafting, myocardial infarc-
tion, risk assessment, low risk
Submitted 6/6/13, accepted 24/5/13
Cardiovasc J Afr
2013;
24
: 247–250
DOI: 10.5830/CVJA-2013-040
Scoring systems that predict the risk of operative mortality
have been under development for more than a decade and
one of the most frequently used systems, EuroSCORE, has
been established.
1,2
EuroSCORE divides patients into three risk
groups, based on the score obtained during assessment: low-risk
patients (value
≤
2) have a predicted mortality of 1.27–1.29%
and an observed mortality of 0.4–1.0%.
2-7
Although the reasons for mortality have been extensively
studied in high-risk patients,
8,9
only a few reports have analysed
the reasons for and possible preventive strategies of mortality
in low-risk patients undergoing coronary artery bypass grafting
(CABG).
10,11
Drawing on the FIASCO study,
10
we reviewed the
mortality in our own low-risk CABG patient population in order
to identify whether death could be considered preventable, and if
so, whether it was due to a technical or system error.
Methods
The study was approved by the local hospital ethics committee.
All cardiac surgical patients were prospectively risk stratified
using the additive and logistic EuroSCORE.
12
The cardiac
surgery unit recorded all patients’ characteristics, operation
details and postoperative outcomes contemporaneously in a
computer database. Patients with an additive EuroSCORE
≤
2 who died in the early postoperative period (death from any
cause within 30 days of the operation) were identified from the
database.
For the study, patient inclusion criteria were: women
undergoing CABG with no other risk factors (one point) or
with any risk factor adding one point (two points), and men
undergoing CABG with one or two risk factors of one point
or with one two-point risk factor. We exluded patients with
moderate and high EuroSCOREs. All of the operations were
performed on-pump; combined operations (CABG
+
heart
vessel/carotid/aorta surgery/etc.) and emergencies surgeries were
also excluded.
The details of each case were reviewed and analysed by
the cardiac surgery and anaesthetic teams. The details of the
patients were also reviewed by an independent surgeon from
Cardiovascular Surgery Clinic, Kartal Kosuyolu Research
and Training Hospital, Kartal, Istanbul, Turkey
CANTURK CAKALAGAOGLU, MD
CENGIZ KOKSAL, MD
TAYLAN ADADEMIR, MD,
ALI FEDAKAR, MD
Department of Cardiology, Sakarya University, Sakarya,
Turkey
MUSTAFA YILDIZ, MD
Cardiology Clinic, Kartal Kosuyolu Research and Training
Hospital, Kartal, Istanbul, Turkey
MÜSLÜM ŞAHIN
Cardiovascular Surgery Clinic, Veni Vidi Hospital, Dagkapi,
Diyarbakir, Turkey
FIKRI KUTLAY, MD
Cardiovascular Surgery Clinic, Isvicre Hospital, Icerenkoy,
Istanbul, Turkey
BESIM YIGITER, MD
