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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 30, No 4, July/August 2019
204
AFRICA
in Johannesburg, South Africa, over three years (July 2012 to
July 2015). All HIV-positive patients with ACS at the time of
admission were included in the study. Exclusion criteria included
patients less than 18 years and those with previous ACS or
known atherosclerotic vascular disease. Approval for conducting
of the study was obtained from the local institutional review
board (ethics clearance number M111143).
All patients underwent coronary angiography performed via
the femoral route. Following left ventriculography, a 7F guiding
catheter was engaged in the culprit vessel. A coronary (balanced
middle-weight) guide-wire was introduced through the guiding
catheter and tracked into the distal portion of the coronary
vessel. IVUS imaging was initially performed in the culprit vessel
prior to coronary intervention. Culprit lesions were defined by
electrocardiographic criteria such as ST-segment shift or T-wave
inversion and angiographic appearances such as filling defects
consistent with thrombus, plaque irregularity suggestive of
ulceration or point of maximal stenosis.
In patients who had complete vessel occlusion, flow was first
restored and then IVUS imaging was performed. The non-culprit
vessels were then assessed using IVUS. Fractional flow reserve
(Volcano Corporation, Rancho, California) assessment was used
for intermediate lesions.
A 20-Mhz Eagle Eye (Volcano Corporation, Rancho,
California) IVUS catheter with a motorised pull-back device at
0.5 mm/s from the distal safe position to the guide catheter was
used to acquire IVUS images. Data were captured and analysed
offline using the image analysis software version 3.1 (Volcano
Corporation). This was done independently by an experienced
reader (JD), blinded to the clinical data.
Each artery was divided into proximal, mid and distal
segments. The plaque burden was classified into mild disease
(
<
40% plaque), moderate (40–70% plaque) and severe disease
(
>
70% plaque). Atherosclerotic plaque characteristics as well
as the total plaque burden in both the culprit and non-culprit
arteries were measured. The plaque burden in each of the three
coronary arteries was measured using the difference between the
vessel area and the minimum lumen area. The software of the
IVUS system automatically analysed the coronary vessel area
and narrowest lumen area. Plaque characterisation in our patient
cohort was performed using VH assessment of the IVUS images
in all three major coronary arteries.
Statistical analysis
Results are presented, using descriptive statistics, as mean
±
standard deviation, median
±
interquartile range (IQR) or
percentages, as appropriate. Mean total plaque burden at
different locations was compared using the paired
t
-test. Data
analysis was carried out using SAS version 9.4 for Windows. A
5% significance level was used.
Results
The mean age of the study population was 51.1
±
8.1 years.
Thirteen (65%) patients were male and 17 (85%) were black.
None of the patients had known prior cardiac history. The
median CD4 count of our study group was 301 cells/mm
3
(IQR
205–417). At the time of admission half of the patient cohort
was on cART. The average use of cART in these patients was
24 months (IQR 5–51 months). None of the patients was on
protease inhibitors. Seven (35%) patients in this group were
newly diagnosed with HIV at the time of presentation with ACS.
Fifteen (75%) patients presented with STEMI (eight anterior
and seven inferior MIs), three (15%) with non-STEMI and two
(10%) patients presented with unstable angina. Only three (21%)
of the 15 STEMI patients received thrombolysis within six hours
of presentation. No patient had a known prior ACS event.
Risk factors for IHD included smoking in 11 (55%),
hypertension in six (30%), diabetes in two (10%), dyslipidaemia
in two (10%), and one (5%) patient had a family history of early
IHD. The average body mass index was 24.4
±
5.5 kg/m
2
with a
mean waist circumference of 83.0
±
9.6 cm (Table 1).
A typical presentation in our cohort was of a young patient
with STEMI involving the left anterior descending artery, which
was the most common artery involved (60%), followed by
the right coronary artery (35%) and the left circumflex artery
(20%). Fractional flow reserve assessment was used in only
three patients to assess significance of the proximal left anterior
descending coronary artery lesions and these were all found to be
non-significant. Six second-generation drug-eluting stents were
implanted, with an average length of 22 mm (18–26 mm).
A high thrombus burden, visualised angiographically, was
present in eight patients (40%) and one patient was given
an intracoronary thrombolytic, which resulted in improved
perfusion. Four patients had complete occlusion of the infarct-
related artery.
There were no peri-procedural complications following
percutaneous coronary intervention. No patients required
coronary artery bypass grafting. At six months’ follow up, one
patient had in-stent restenosis and another died due to sudden
cardiac death at home, two weeks after intervention.
In 60% of our patients, the total plaque burden in the
Table 1. Baseline characteristics of the HIV-positive patients
presenting with acute coronary syndrome
Variables
HIV-positive patients with ACS
(
n
=
20)
Age
51.1
±
8.1
Race (black),
n
(%)
17 (75)
Male,
n
(%)
13 (65)
Risk factors,
n
(%)
Smoking
11 (55)
Hypertension
6 (30)
Diabetes
2 (10)
Dyslipidaemia
2 (10)
Family history
1 (5)
Laboratory analysis
Haemoglobin (g/dl)
12.9
Creatinine (mg/dl)
0.84
(mmol/l)
(74.26)
Total cholesterol (mg/dl)
158.3
(mmol/l)
(4.10)
Triglycerides (mg/dl)
46.3
(mmol/l)
(0.52)
HDL-C (mg/dl)
38.6
(mmol/l)
(1.00)
LDL-C (mg/dl)
92.7
(mmol/l)
(2.40)
CD4 (cells/mm
3
)
313
HDL-C: high-density lipoprotein cholesterol, LDL-C: low-density lipoprotein
cholesterol.