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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 30, No 4, July/August 2019
AFRICA
203
Atherosclerotic plaque in HIV-positive patients
presenting with acute coronary syndromes
Ahmed Vachiat, Keir McCutcheon, Nqoba Tsabedze, Don Zachariah, Pravin Manga
Abstract
Aim:
This study aimed to characterise the atherosclerotic
plaque and plaque burden in HIV-positive patients presenting
with acute coronary syndromes (ACS), using intravascular
ultrasound (IVUS) and virtual histology (VH).
Methods:
This was a prospective study of 20 HIV-positive
patients who presented with ACS. IVUS and VH were used to
assess plaque burden and plaque characteristics in the culprit
and non-culprit coronary arteries.
Results:
HIV-positive patients with ACS had a mean age
of 51.1
±
8.1 years. There were 13 (65%) male patients.
ST-segment elevation myocardial infarction was the most
common presentation of ACS (75%) with the left ante-
rior descending artery being the most common culprit artery
(60%). In 60% of patients, the total plaque burden was of
moderate degree (40–70% stenosis) while it was of mild
degree (
<
40% stenosis) in 35%, and in 5% of patients it
was severe (
>
70% stenosis). A severe degree of total plaque
burden was more commonly found in the culprit vessel
(30%) than in the non-culprit vessels (5%). Furthermore, the
plaque burden was found to be located predominantly in the
proximal portion of the coronary arteries. The predominant
plaque morphology consisted of fibrous plaque (55.4%) and
fibro-fatty plaque (26.6%), while necrotic core was present in
13.3%. Dense calcium was present in only 4.7% of the cohort.
Conclusions:
IVUS and VH demonstrated a high burden of
atherosclerosis in the left anterior descending artery and prox-
imal vasculature of HIV-positive patients. The atherosclerotic
plaque predominantly comprised non-calcified fibrous and
fibro-fatty plaque.
Keywords:
atherosclerosis, HIV, acute coronary syndromes, intra-
vascular ultrasound, virtual histology
Submitted 2/11/18, accepted 15/3/19
Published online 4/6/19
Cardiovasc J Afr
2019;
30
: 203–207
www.cvja.co.zaDOI: 10.5830/CVJA-2019-016
There are approximately 37 million people living with human
immunodeficiency virus (HIV) infection worldwide, 70% of
whom live in sub-Saharan Africa.
1,2
Studies suggest that HIV
infection confers an overall 1.5- to 2.0-fold increased risk
of developing ischaemic heart disease (IHD).
3-6
Combination
antiretroviral therapies (cART), particularly protease inhibitors
and high levels of traditional cardiovascular disease risk factors
have increased the prevalence of IHD in this population.
7,8
Based upon spectral analysis of ultrasound backscatter,
intravascular ultrasound (IVUS) facilitates the characterisation of
coronary plaque morphology by transforming the coronary vascular
ultrasound images into a colour-coded representation, thereby
creating a virtual histological (VH) assessment of the plaque.
Virtual histological intravascular ultrasound (VH-IVUS) imaging
uses four colour-coded spectral parameters (dark green, yellow-
green, red and white) representing fibrous and fibro-fatty lesions,
necrotic core and calcium, respectively.
9
This spectral analysis of
coronary plaque has been well correlated with histopathology, with
a predicative accuracy of 87.1, 87.1, 88.3 and 96.5% for fibrous,
fibro-fatty, necrotic core and dense calcium, respectively.
10
The characteristics of the atherosclerotic plaque in
HIV-negative patients with IHD are well defined. In a study of
HIV-negative patients with stable angina or troponin-positive
acute coronary syndrome (ACS), VH-IVUS of non-culprit
lesions has shown that fibrous and fibro-fatty plaque was present
in 43.7% of patients, and calcific plaque was present in the
remaining 56.3% of patients.
11
On the other hand, coronary plaque characteristics in
HIV-positive patients have not been well studied and are
poorly elucidated. Autopsy studies in HIV-positive patients
have described coronary lesions as eccentric atherosclerotic
plaques with 80 to 90% reduction of the vascular lumen, and
histopathological findings as hyperplastic endothelial cells lining
a thickened intima, characterised by the proliferation of smooth
muscle cells and monocyte macrophages.
12,13
Using coronary
computed tomography, asymptomatic HIV-positive patients
have been found to have a higher prevalence of coronary
atherosclerosis, a greater degree of coronary plaque volume and
a greater number of coronary segments with plaque compared
to HIV-negative patients with a similar Framingham 10-year risk
for myocardial infarction.
14
To date there are no published data describing plaque
characteristics and plaque burden by direct visualisation using
IVUS in HIV-positive patients with ACS. The primary objective
of this study was to characterise the atherosclerotic plaque and
plaque burden in HIV-positive patients presenting with ACS
using IVUS and VH.
Methods
The studywas a cross-sectional, prospective study of HIV-positive
patients with ACS conducted at a large urban public hospital
Division of Cardiology, Department of Internal
Medicine, Faculty of Health Sciences, University of the
Witwatersrand, Johannesburg, South Africa
Ahmed Vachiat, MB BCh, FCP (SA), MMed, Cert Cardiology (SA),
PhD,
drvachiat@joburgheart.co.zaKeir McCutcheon, MB BCh, MSc, FCP (SA), Cert Cardiology (SA),
PhD
Nqoba Tsabedze, MB BCh, FCP (SA), MMed, Cert Cardiology (SA)
Don Zachariah, MB BCh, FCP (SA), MMed, Cert Cardiology (SA)
Pravin Manga, MB BCh, FCP (SA), PhD
Department of Cardiovascular Medicine, University
Hospitals Leuven, Belgium
Keir McCutcheon, MB BCh, MSc, FCP (SA), Cert Cardiology (SA), PhD