Background: Giant cell arteritis (GCA) is the most common primary vasculitis in adults. It presents with signs of vascular insufficiency of the extracranial arteries of the head, but may also affect the aorta and its primary and secondary branches. GCA is more prevalent in Caucasians of Scandinavian and Northern European descent, and is considered to be less common in African, Asian, Arab and Latin American populations. ^1,2 However, this may reflect a lack of formal epidemiological data in these populations rather than a true lower incidence. This is evidenced by extensive studies in white populations and a significant paucity of data in other ethnic groups. The most frequent causes of death in GCA are cardiovascular disease (CVD) (39%) followed by cerebrovascular disease (CVA) (14%), infection (13%), and malignancy (12%). ³ Overall, the mortality rate is increased in the first two years and is associated with the disease severity, extent, ischemic, and treatment complications, particularly from glucocorticoids. ^4,5

Objectives: The aim of this study was to compare the rate of cardiovascular and infectious complications in GCA patients among different ethnicities.

Methods: In this retrospective cohort study, we identified patients with biopsy proven GCA based on ICD-10 codes, using the Nationwide Inpatient Sample database (NIS) from 2016 to 2019. We included acute coronary syndrome (ACS), CVA, thoracic ascending aneurysm rupture (TAA), and infection (composite of UTI, sepsis and pneumonia) as our outcomes of interest and compared them between Caucasian, African American (AA), and Hispanic ethnicities. We implemented logistic regression analysis in the univariable and multivariable models. In the multivariable model, we adjusted all outcomes for potential confounders, including age, sex, obesity, hyperlipidemia, congestive heart failure, peripheral vascular diseases, diabetes, hypertension, renal failure, history of smoking or alcohol abuse, history of other drug abuse, prior history of MI, primary coronary intervention, or coronary artery bypass grafting, coagulopathy, liver disease, chronic pulmonary disease, ischemic cardiomyopathy, Elixhauser comorbidity index, type of insurance, bed size of hospital, history of defibrillator or pacemaker, and long-term use of steroids. The analysis was done using the STATA software, version 17.0 (MP2).

Results: We identified 7,750 patients with GCA, of whom 5,710 (74%) were Caucasian, 1,335 (17%) were AA, and 705 (9%) were Hispanic. Our results showed that Hispanics had both a higher prevalence (16.30% vs 9.80% vs 7.50%, p-value = 0.017) and risk for infections (OR: 2.74; 95%-CI 1.4-5.5; p-value = 0.004) when compared to the other racial groups. There was no difference in the risk of ACS among Caucasians (OR: 2.72; 95%-CI 0.6-12.4; p-value = 0.2) and Hispanics (OR: 2.72; 95%-CI 0.4-17.4; p-value = 0.004) when compared to AA population. Similarly, risk of CVA was not different between racial groups (Caucasians: OR: 1.04; 95%-CI 0.6-1.7; p-value = 0.87; Hispanics: OR: 0.8; 95%-CI 0.4-1.7; p-value = 0.567). The prevalence for TAA was only reported in the Caucasian group (0.50%).

Conclusion: ACS and CVA are known complications of GCA. There does not appear to be a difference in the risks of these common cardiovascular complications among racial groups. However, there was a significantly higher rate of infections in the Hispanic population. This may be explained by biologic differences in susceptibility and racial disparities in insurance coverage and access to care.

REFERENCES:

[1]Tehrani, R., et al. Seminar in Ophthalmology. 2008

[2]Gruener, A., et al. JAMA Ophthalmol. 2019

[3]Hill, C., et al. Semin Arthritis Rheum. 2017

[4]Mackie S., et al. Nat Rev Rheumatol. 2014

[5]Therkildsen, P., et al. Rheumatology (Oxford ). 2021

Disclosure of Interests: None declared