CARDIOVASCULAR DISEASE AFTER KIDNEY TRANSPLANTATION: A NATIONWIDE STUDY IN SOUTH KOREA

Abstract

Background: Cardiovascular disease (CVD) is the most common cause of death in end-stage renal disease (ESRD). Kidney transplantation (KT) is an effective treatment for ESRD, and is known as lowering risk for CVD compared to the ESRD patients on the transplantation waiting list. However, there is a lack of large-population studies especially for Asians. Method: We analyzed the nationwide health insurance database of South Korea and identified patients who received kidney transplantation from the year of 2007 to 2015. Patients who were under 20 years of age, had previous CVD identified, or had multiorgan transplantation were excluded from the study. As controls, ESRD and GP groups were extracted after same exclusion and matching with KT recipients by age, sex, and inclusion year. CVD was defined as major cardiovascular events (MACEs) consisted of myocardial infarction, ischemic stroke, and all-cause mortality. Result: During the study period, a total of 13,179 patients received KT. After exclusion, 4,156 KT recipients were selected. The same number of ESRD and GP control were extracted after matching. Mean age was 41.3 ± 10.2 years and 55.2% were men in all 3 groups. KT recipients had similar proportions of diabetes and hypertension and a lower proportion of dyslipidemia compared with ESRD controls, although significantly higher co-morbidities than GP controls. The total number of MACEs was 76 (3.7 per 1000 person-year) in KT recipients, 377 (21.7 per 1000 person-year) in ESRD, 51 (2.5 per 1000 person-year) in GP, respectively. KT recipients showed a significantly lower MACE risk (adjusted HR 0.16, 95% CI 0.12-0.20, p <0.001) than ESRD controls. And the MACE risks were not significantly different between KT recipients and matched GP controls (adjusted HR 0.81, 95% CI 0.52-1.27, p=0.365). When subgroup analysis of age, sex, diabetes and hypertension was performed, similar trends were observed regardless of subgroups. Meanwhile, KT recipients who occurred MACE showed significant elevated risk of all-cause mortality and graft failure (HR 7.45, 95% CI 4.21-13.21, p<0.001 and HR 2.49, 95% CI 1.52-4.09, p<0.001, respectively). Conclusion: In this study, we found that the KT recipients had a lower risk of newly onset MACE after transplantation compared to patients maintaining dialysis in Korea, and showed a similar MACE risk compared to the general population.