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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 28, No 2, March/April 2017
100
AFRICA
Chicken or the egg: ST elevation in lead aVR or SYNTAX
score
Levent Cerit
Abstract
Background:
ST-segment elevation in lead aVR (STEaVR)
anticipates left main and/or three-vessel disease (LM/3VD) in
patients with acute coronary syndromes. STEaVR is generally
reciprocal to and accompanied by ST-segment depression
(STD) in the precordial leads. SYNTAX score (SS) is an
angiographic scoring system and is widely used to evaluate
the severity and complexity of coronary artery disease. The
purpose of our study was to assess the relationship between
STEaVR and SS.
Methods:
We performed a retrospective analysis of 117
patients with non-ST-segment elevation acute coronary
syndrome (NSTEACS). Electrocardiograms at presentation
were reviewed, especially for ST-segment elevation of
≥
0.05
mV in lead aVR and STD of
≥
0.05 mV in more than two
contiguous leads. All lesions causing
≥
50% stenosis in a
coronary artery with a diameter of
≥
1.5 mm were included
in the SS calculation. SS was divided into two groups:
≥
23:
high,
<
23: low.
Results:
Among the 117 patients, 80 (68.4%) had STEaVR
and 37 (31.6%) did not. Patients with STEaVR had a higher
SS and higher rate of LM/3VD (85 vs 67.6%,
p
<
0.001; 86.2
vs 72.9%,
p
=
0.03, respectively) than those without STEaVR.
On multivariate analysis, STEaVR [odds ratio (OR) 1.85;
95% confidence interval (CI): 1.20–3.97,
p
=
0.03] and STD
in leads V
1
–V
4
(OR 2.14; 95% CI: 1.46–4.23,
p
=
0.002) were
independent predictors of a high SS.
Conclusion:
This study demonstrated that STEaVR was an
independent predictor of a high SS.
Keywords:
SYNTAX score, electrocardiography, lead aVR
Submitted 18/3/16, accepted 12/5/16
Published online 8/6/16
Cardiovasc J Afr
2017;
28
: 100–103
www.cvja.co.zaDOI: 10.5830/CVJA-2016-062
Previous studies have shown the independent predictive value of
ST-segment elevation in lead aVR (STEaVR) for left main and/
or three-vessel disease (LM/3VD) in non-ST-segment elevation
acute coronary syndrome (NSTEACS).
1,2
STEaVR is generally
reciprocal to and accompanied by ST-segment depression (STD)
in the precordial leads. Patients with acute coronary syndrome
resulting from LM/3VD are at high risk of short- and long-term
adverse cardiovascular events.
3-5
Previous studies have assessed
the independent predictive value of STEaVR for LM/3VD in
NSTEACS and have reported conflicting results.
1,2
SYNTAX score (SS) is a recently developed angiographic
grading tool to evaluate the complexity of coronary artery disease.
It is widely used for determining the optimal revascularisation
strategy. It is also a powerful stratification mechanism, allowing
uniform, standardised assessment of the extent and severity
of coronary artery disease.
6
The purpose of this study was to
assess the relationship between STEaVR and SS in patients with
NSTEACS.
Methods
A retrospective analysis was performed on all patients who had
undergone coronary angiography and coronary artery bypass
grafting (CABG) between January 2013 and January 2016 at the
Near East University Hospital. Myocardial infarction (MI) was
diagnosed according to the criteria of the European Society of
Cardiology and American College of Cardiology.
7
Inclusion criteria for the study were troponin level greater than
the 99th percentile reference value before cardiac catheterisation,
chest pain or ischaemic changes on the electrocardiogram
(ECG), including horizontal or down-sloping STD (
≥
0.05
mV), and absence of ST-segment elevation on the ECG.
Exclusion criteria were previous CABG, bundle branch block
or ventricular pace rhythm, severe aortic stenosis, hypertrophic
cardiomyopathy, cardiac arrest on presentation, ventricular
tachycardia, supraventricular tachycardia with heart rate greater
than 160 beats per min, implantable cardioverter defibrillator
shock, subsequent documented diagnosis of Takotsubo
cardiomyopathy, myocarditis or pulmonary embolism.
The studywas approved by the local ethics committee. Patients’
demographic data and risk factors, including current smoking,
diabetes mellitus (DM), hypertension (HT), hyperlipidaemia,
previous MI, and previous percutaneous coronary intervention
were obtained from medical records.
Cardiac troponin T (cTnT) levels were measured using the
electrochemiluminescence immunoassay method (Roche Cobas
E601). The upper limit of normal for cTnT was 0.014 ng/ml,
which represented the 99th percentile reference value. cTnT was
measured serially at intervals of approximately four hours, both
before and after catheterisation as clinically indicated, with the
highest level noted as the peak cTnT.
Two independent, blinded physicians reviewed ECGs
obtained at presentation. In the event of an interpretative
discrepancy, a consensus between reviewers was reached
through discussion.
ST-segment shifts were measured at the J point for ST-segment
elevation and depression. STD of
≥
0.05 mV in more than two
contiguous leads was recorded. A cut-off value of
≥
0.05 mV for
STD was chosen, in line with the current universal definition
of MI.
8
The location of STD was recorded as the anterior (V
1
–
Near East University Hospital, Nicosia, Cyprus
Levent Cerit, MD,
drcerit@hotmail.com