Page 256 - Read Online

Page 2 of 10 Idhrees et al. Vessel Plus 2020;4:23 I http://dx.doi.org/10.20517/2574-1209.2020.15

INTRODUCTION
Takayasu arteritis (TA) is a chronic vasculitis involving large vessels. It mainly involves the aorta and its
branches, pulmonary artery and coronary artery. Though the cause of TA is unclear, there is a strong
association with genetic predisposition, environmental factors and role of microbes. The arterial wall
hosts the pathogenic activated T lymphocytes and macrophages leading to granulomatous inflammation
and ultimately vessel wall damage. Proinflammatory cytokines, namely interleukin-6 (IL-6) and tumor
[1]
necrosis factor-α (TNF-α), are elevated in TA, which correlates with disease activity . It is more common
among young women and the Asian population. Recent surveys show that TA is increasing in prevalence
among all ethnicities. In this review, we will discuss the management of the cardiac manifestations in TA -
myocardial failure, pulmonary arteritis and involvement of coronary artery and aortic valve.

EPIDEMOLOGY
TA is rare, but most commonly seen in the Asian population and immigrant Asian population in Western
countries. The prevalence of TA in Scandinavian countries has increased, probably because of the higher
[2]
rates of immigration from Asia and Africa in the last decade . The incidence and prevalence of TA in
the northwestern part of Turkey is similar to that of Japan. Norway and Sweden has reported higher a
[3,4]
prevalence rate of TA than previously observed . The disease has a predilection for females with wide
geographic variation ranging from 8:1 in Japan to 1.2:1 in Israel. In a recent Japanese study, females less
than 40 years of age constituted a major proportion (83.8%) of the study cohort. The disease is five times
more common in females than men, and an interesting feature reported in the study was that there was
[5]
a larger proportion of elderly compared to a previous study . TA presents commonly in the second and
third decades of life. In women, the disease peaks at 20 years of age . There are geographic variations of
[6]
the involvement of the aorta and its branch vessels.

GENETIC PREDISPOSITION
The pathogenesis of TA has been associated with the human leukocyte antigen (HLA) class I (HLA-A,
HLA-B, and HLA-C), HLA class II (HLA-DR, HLA-DQ, and HLA-DP) and non-HLA genes . Though
[7]
[7,8]
an elaborate list of genes exists in literature, a few are shown in Table 1 . There is definite HLA B52 allele
[1]
association in TA beyond ethnicity . The correlation with TNF-α 308/G polymorphism has also been
reported in TA. FCGR2A/FCGR3A, IL-12B, IL-6, RPS9/LILRB3 are the non-HLA loci related to TA. A
report from Italy demonstrated an association with HLA DRB1 *0405 for early onset vasculitis . DRB1,
[8]
DR2, DQ 1 are among other alleles related to TA.

DIAGNOSIS AND MANAGEMENT
Clinical presentation
Symptoms such as fever, weight loss, malaise, fatigue and myalgia due to systemic inflammatory reactions
constitute the initial presentation of the disease. The inflammation of the carotid artery can cause
carotidynia. Patients with vascular compromise may present with features of claudication pain, angina
pectoris, transient ischemia attack and stroke. It is important to note that TA patients can be asymptomatic
with underlying progressive disease . The appearance of a new vascular sign in patients such as femoral
[9]
bruits, absent pulses, or blood pressure differences should alert the physician. Usually, vascular signs
are late manifestations of TA, but they can be the presenting symptom of a patient. The specificity and
sensitivity of these clinical signs are more than 90% when two abnormal findings are present and not
when a pair of examination findings is present . In a series from Japan, the commonest complication was
[10]
systemic hypertension followed by aortic regurgitation (AR). The complications were more common in
[5]
men and patients with late referrals .