SAT0588 PREVALENCE, INCIDENCE, AND THE CARDIOVASCULAR AND CEREBROVASCULAR RISKS OF NONTRAUMATIC AVASCULAR NECROSIS IN SOUTH KOREA
Authors: Y. J. Ha, E. H. Park, E. H. Kang, Y. W. Song, Y. J. Lee
Journal: Annals of the Rheumatic Diseases (2020)

Background: Due to the shared mechanism of nontraumatic avascular necrosis (AVN) and endothelial dysfunction, the associations of AVN with increased cardiovascular and cerebrovascular events have been suggested in the several population-based studies. Objectives: This study aimed to estimate the prevalence and incidence of nontraumatic AVN in South Korea from the Korean National Health Insurance Service Sample Cohort Database 2.0 (2006-2015) and to evaluate the risk of major cardiovascular and cerebrovascular events among patients with nontraumatic AVN. Methods: We defined an incident case as a newly diagnosed and registered patient in the registry in that year, with a 2-year washout period. Prevalent cases were defined as all patients with nontraumatic AVN in the corresponding year. To evaluate the cardiovascular and cerebrovascular risks in patients with AVN, we set AVN group composed of patients with an initial diagnosis of non-traumatic AVN between 2008 and 2010 (n=1,150). The comparison group was composed of randomly selected subject (5 per patient with AVN; n = 5,750) who were matched to the AVN group according to age, sex, resident area, and year of AVN diagnosis. The development of major cardiovascular and cerebrovascular events was tracked in each sampled patient until 2015. Cox proportional hazard regressions were used to calculate the overall risks for the development of major cardiovascular and cerebrovascular events. Results: From 2008 to 2015, the prevalence of nontraumatic AVN increased gradually, but its incidence did not change, with an annual average incidence of 413 per 1 million population and the male-to-female ratio of 1.2:1. The peak incidence occurred in the 50-59 year age group. The incident AVN was more prevalent in male than in female under 70, but there was female predominance after the age of 70 (Figure 1). The patients with AVN had a higher cumulative incidence of major adverse cardiovascular and cerebrovascular events than controls (19.5% versus 14.9%; p = 0.017). Upon univariate Kaplan-Meier method with the log-rank test, there was a significant difference in major cardiovascular and cerebrovascular events-free survival rates between AVN group and control group (p &lt;0.001). However, after adjusting for potential confounders including hypertension, diabetes, dyslipidemia, and use of steroid or statin, the association between AVN group and major adverse cardiovascular and cerebrovascular events was insignificant (adjusted HR 1.114, 95% CI 0.959-1.295, p=0.158) Conclusion: In this population-based cohort study, we provided the updated epidemiologic data of Korean patients with nontraumatic AVN. The increased risk for major cardiovascular and cerebrovascular events among AVN patients was not observed in the representative Korean population. References: [1]Kang JH, Lin HC. Increased risk for coronary heart disease after avascular necrosis of femoral head: a 3-year follow-up study. Am Heart J. 2010;159:803-8. [2]Sung PH, Yang YH, Chiang HJ, Chiang JY, Chen CJ, Yip HK, et al Cardiovascular and cerebrovascular events are associated with nontraumatic osteonecrosis of the femoral head. Clin Orthop Relat Res 2018;476:865-74. Figure 1. Age- and sex-distributed incidence of patients with nontraumatic avascular necrosis in Korea, 2008-2015 Disclosure of Interests: None declared