Medical Research Society
4P
of disrupted plaques. Free cholesterol concentrations are negatively
associated with cap thickness at centre of disrupted plaques (p<O.O5). At
the centre of type A, type B and disrupted plaques, free to esterified
cholesterol ratios were 0.9 (range 0.0-2.7), 0.8 (range 0.0-3.9) and 1.6
(range 0.2-4.0) respectively, reflecting the accumulation of esterified
cholesterol at the centre of type B plaques and accumulation of free
cholesterol at the centre of disrupted plaques. At the edge of disrupted
plaques, the free to esterified cholesterol ratio was 0.5 due to accumulation
of esterified cholesterol. Concentrations of all fatty acids were increased
at the edge of disrupted plaques compared with the centre, but as a
proportion of total fatty acids, o6-polyunsaturated fatty acids (PUFA)
were lower (44% versus 46%, p<O.OI) possibly reflecting oxidation of
PUFA. These data demonstrate differences in lipid composition and
regional distribution of lipid between intact and disrupted plaques.
Increased esterified lipid concentrations at the edge of advanced plaques
and their negative associations with cap thickness, may reflect macrophage
activity and a predisposition to disruption.
We thank the British Heart Foundation for financial support (PGj92082)
M I I ETHNIC VARIATION IN THE SIZE OF CORONARY ARTERIES
VS RATHORE. R KATIRA. C GIBES. IF ISLIM, TA AZEEM. GYH LIP’.
RDS WATSON and S P SINGH (‘MEMBER MRS)
Department of Cardiology, City Hospital NHS Trust, Birmingham, England
Asians from the Indian subcontinent have higher coronary artery disease
(CAD) severity and mortality in comparison to native white Caucasians and
Afro-caribbeans in the UK and other countries. If the coronary arteries are
smaller in size this may give an impression of more severe CAD. A s there is
no study comparing the size of the main coronary arteries in Asians with other
ethnic groups, we studied 85 coronary angiograms in 58 Caucasians (mean
age 55.4 years SD 11.1: 28 males) and 27 Asians (mean age 46.3 years
SD1l.l: 17 males). Coronary angiograms were performed by a standard
Judkin’s method and measurements of the left coronary artery in right anterior
oblique candal and right coronary artery in 30 degrees left anterior oblique
view were taken. Measurements were calibrated against the size of
angiographic catheter used, and adjusted to mean body surface area (BSA).
78 patients had presented with chest pain and 7 with valvular heart disease.
Our results are as follows:
LMS
ASIANS
3.97
CAUCASIAN 4.36
P
0.Cn
mean(mm)
PLAD MLAD DLADPCX
3.22 2.8
2.26 2.93
3.5
3.1
2.44 3.1
0.05 0.24 0.15 0.08
DCX
2.54
2.41
0.20
OM PRC DRC
1.95 3.01 1.64
I.% 335 1.96
0.45
0.03 o.M)5
0.09 0.31 038 0.01 0.42 0.16 0.05
BSA-p=pvalueadj~ddrwBSA~MS-IxflMasS(emPLAWMLAD/DIAD- Proxirml
/ Mid/ Distal Left Anterior Descending. PCX - Proximal Circumflex. Dcx - Distal
Circumflex. OM -0btuscMarginal. PRCiDRC - Proximal I Distal Right Coronary Anery.]
LISA-I,
0.21
0.25
There were significant ethnic differences in size of the left main stem. proximal
right coronary artery and distal right coronary artery. In conclusion. Asians
have smaller coronary arteries than Caucasians as Seen angiographically.
This finding may contribute to the pathophysiology of coronary artery disease
in Asians and have therapeutic implicationswith respect to cardiac interventions.
including coronary artery bypass grafting surgery, angioplasty and stents.
MI2 A COMPARISON OF THE IMPACT ON BLOOD
PRESSURE OF MEDICAL AND SURGICAL PROCEDURES AT
THE CAROTID SINUS
R Steeds, A Sivaguru, P Gaines, J Beard, G
Venables, K Channer
Departments of Cardiology, Neurology, and
Vascular Surgery, Royal Hallamshire Hospital,
and Department of Radiology, Northern General
Hospital, Sheffield
We studied 30 patients with symptomatic carotid
artery stenosis greater than 70% luminal
diameter enrolled in a multicentre study
comparing carotid endarterectomy (CEA) and
carotid angioplasty (PTA). Blood pressure (BP)
was measured 48 hours prior to the index
procedure and 1 month afterwards using 24 hour
ambulatory monitoring (Spacelabs). 12 patients
underwent CEA and 18 patients had PTA.
Baseline BP was higher in the CEA group (mean
BP 115.5 mmHg 5 10.1 cf. 109.4 mmHg 5 11.7) but
this difference was not significant. We
calculated the change in BP from baseline for
each patient, then compared the overall changes
between the two groups using parametric
analysis of covariance methods. In patients
who underwent CEA, there was a significant mean
fall in systolic BP (-12.3 mmHg, 95%CI -21.4 to
-3.3, p=O.Ol), diastolic B P (-6.1 mmHg, 95%CI 10.7 to -1.5, p=O.O2), and mean BP (-9.2 mmHg,
95%CI -15.7 to -2.7, p=O.Ol).
In patients
following PTA, there were no significant
changes-systolic BP (-2.8 mmHg, 95%CI -7.2 to
1.5, p=O.19), diastolic BP (-0.5 mmHg, 95%CI 3.6 to 2.6, p=O.75), mean BP (-1.7 m H g , 95%CI
-5.3 to 1.9, p=O.34).
There were no
significant changes in heart rate in either
group. The fall in BP noted in patients
undergoing CEA may contribute to the long term
reduction in risk of stroke following this
procedure. Temporary disruption of the carotid
sinus during PTA does not lead to alteration Of
BP at 1 month. This may reduce the efficacy of
the procedure in treatment of carotid stenosis.
MI3
S-100 PROTEIN RELEASE IN A RANGE OF CARDIOTHORACIC
SURGICAL PROCEDURES
P KUMAR, K DHITAL,M HOSSEIN-MA, S PATEL, D HOLT & T
TREASURE
Department of Cardothoracic Surgery, St George’s Hospital, Blackshab
Road, London, SW17 OQT, England
Introduction: Measurement of cerebral injury in cardiac surgery by
neuropsychological tests is time consuming and prone to many sources of
inconsistency. The neurospecific S-100 protein is released into the
circulation following neuronal injury in proportion to the magnitude of
damage. Is it sufficiently sensitive to detect differences in patients
undergoing cardiac surgery?
Methods: Four groups of patients with increasing cerebral hazard were
selected: I = lung resection; Il = coronary surgery, Ill = aortic root
replacement and IV = aortic surgery with deep hypothennic circulatory
arrest. Serum S-100 levels were measured before the procedure and 1/2hr,
Ihr, 2hrs. 4hrs and 24hrs post-operatively.
Results: All patients survived the procedure.
Group N
Age
CPB timi
Peak S-100
AUC
meEn
mcg/J.b
mins
I
4
66
0
0.02
0.2
Ll
6
58
100
0.30
1.19
El
4
56
111
1.09
5.92
N
5
64
109
2.5
26.06
Circulatory arrest
5-100 profile
( ~ 0 . 9W
, .04)
Conclusions: Post operative S-100 levels were within normal limits for
thoracotomy patients and were progressively elevated with CABG, AR and
circulatory groups. The AUC S-100 correlated significantly with the
duration of circulatory arrest. S-100 levels may be a useful tool in the
investigation of neuroprotective stratees.
Key Words
Cardiac Surgery, brain injury, serum S-100 level, circulatory arrest.