Kyung Won Kim

Introduction: Pregnancy in women with end-stage kidney disease (ESKD) remains rare and high-risk, despite advancements in dialysis and supportive care. Using a nationwide database in South Korea, this study examined the maternal and neonatal outcomes among women undergoing maintenance hemodialysis, with a particular focus on dialysis modality and treatment patterns. Methods: This population-based retrospective cohort study utilized data from the Korean National Health Insurance Service database. The study included all live births between 1 January 2014 and 31 December 2022, linked to mothers who underwent hemodialysis at least twice per week during pregnancy. Results: Between 2014 and 2022, in the Republic of Korea, 31 live births were recorded among 29 women undergoing hemodialysis. The mean maternal age at delivery was 36.1 ± 4.94 years, and most patients had significant comorbidities, including hypertension (79.3%), and diabetes mellitus (48.3%). Cesarean section was the predominant mode of delivery (75.9%). Pregnancy-related complications included preterm delivery (48.4%), preeclampsia (16.1%), and gestational diabetes (16.1%). A total of 16.1% of the neonates had atrial septal defects. During the peripartum period, 93.1% of deliveries occurred at tertiary care centers, and trimester-wise escalation in dialysis frequency was observed. Conclusions: This study provided real-world data on pregnancy-related outcomes among women with ESKD undergoing maintenance dialysis in Korea. Given the rarity of this clinical condition, our findings may serve as a valuable reference for the management of pregnant women with ESKD.

Chronic kidney disease (CKD) is prevalent among patients with heart failure with preserved ejection fraction (HFpEF), significantly affecting their outcomes. Although the prognostic risk factors remain unclear, peak oxygen consumption (peak VO2) may be used to objectively assess the risk of kidney damage due to overlapping factors affecting kidney function and aerobic exercise capacity. This study aimed to evaluate the association between peak VO2 levels and incident CKD risk among patients with HFpEF. A total of 342 patients with HFpEF and an estimated glomerular filtration rate (eGFR) >60 mL/min/1.73 m2 who underwent cardiopulmonary exercise testing between January 2012 and April 2021 were included. Aerobic exercise capacity was evaluated using the peak VO2 values. Incident CKD development was defined as two consecutive eGFR measurements <60 mL/min/1.73 m2 separated by ≥90 days. The mean patient age was 62.9 ± 10.6 years, with 35.7% being male. Baseline left ventricular ejection fraction and eGFR were 66.7% ± 6.9% and 88.4 ± 12.6 mL/min/1.73 m2 , respectively. For over 940.0 person-years of follow-up (median, 2.9 years), 51 patients developed CKD. CKD incidence rate gradually increased with lower peak VO2 levels. Multivariable Cox analysis showed an association between a 1-standard-deviation peak VO2 increase and a 51% reduction in CKD risk. The adjusted hazard ratio (95% confidence interval) for the lowest peak VO2 tertile group was 3.29 (1.23-8.84) compared with the highest tertile group. Reduced aerobic exercise capacity, indicated by lower peak VO2 levels, is closely associated with an increased CKD risk in patients with HFpEF.

Background: The impact of facility-level comorbidity burden on the prognosis of hemodialysis patients remains unclear. This study aimed to investigate the association between facility-level comorbidity burden and hemodialysis outcomes. Methods: We examined 15,481 participants receiving hemodialysis at primary clinics participating in the Periodic Hemodialysis Quality Assessment by Health Insurance Review and Assessment Service in Korea. Facility-level comorbidity burden, defined as the sum of the Charlson Comorbidity Index of all patients divided by the number of nurses in each hemodialysis center, was the primary predictor. The primary outcome was major adverse cardiac and cerebrovascular events (MACCE). Results: During a median follow-up of 6.8 years, MACCE and all-cause mortality occurred in 9,797 (63.3%) and 8,513 participants (55.0%), respectively. Participants in the highest facility-level comorbidity burden had the highest incidence rates of both MACCE and all-cause mortality. Hazard ratios (HRs) of MACCE and all-cause mortality in the highest vs. the lowest quartile were 1.10 (95% confidence interval [CI], 1.03–1.18) and 1.14 (95% CI, 1.06–1.22), respectively. Applying the facility-level comorbidity burden as a continuous variable, each 10-unit increase in facility-level comorbidity burden was associated with a 4% and 8% higher risk of MACCE and all-cause mortality, respectively. These associations remained consistent across subgroups. Conclusion: Our findings revealed that the facility-level comorbidity burden in hemodialysis centers was associated with a higher hazard of poor outcomes in patients undergoing hemodialysis.

Background: Assessing recent changes in mortality among patients undergoing hemodialysis (HD) can help both to identify the causes of death most closely associated with these changes and to develop prevention strategies. This study explored trends in all-cause and cause-specific mortality among patients undergoing HD in South Korea using an analysis of national data. Methods: We used national death certificate and claims data from 2003 to 2021 provided by the National Health Insurance Service. Age-standardized mortality rates (ASRs) were calculated by standardizing to the 2011 population of patients undergoing HD. Joinpoint regression analysis was performed to calculate the annual percentage change (APC) in mortality. All-cause and cause-specific ASRs and APCs were evaluated for the study period. Results: The proportion of male and older adult patients increased over time. In particular, the proportion of patients aged ≥ 80 years in the 2018–2021 period was more than 4 times higher than in the 2003–2007 period. From 2003 to 2021, there were a total of 136,302 deaths among patients undergoing HD in South Korea. Cardiovascular causes accounted for 13.6% of deaths, and the majority (86.4%) were attributed to noncardiovascular causes. In 2003, the all-cause ASR was 174.1 per 1000 person-years, which steadily decreased to 114.5 per 1000 person-years in 2021. The ASR from cardiovascular disease remained unchanged from 2003 to 2013 but increased by 3.9% (95% confidence interval: 1.3 to 14.0) per year from 2013 to 2021. In contrast, the ASR from noncardiovascular disease decreased during the study period. Conclusions: Nationally representative data showed a declining trend in the ASR among patients undergoing HD from 2003 to 2021. Noncardiovascular disease mortality decreased during the study period, while cardiovascular disease mortality increased.

BACKGROUND: Atrial fibrillation (AF) can lead to stroke, heart failure, and mortality and has a greater prevalence in dialysis patients than in the general population. Several studies have suggested that uremic toxins may contribute to the development of AF. However, the association between dialysis adequacy and incident AF has not been well established. METHODS: In this retrospective nationwide cohort study, we analyzed data from the Korean National Periodic Hemodialysis Quality Assessment from 2013 to 2015 of patients who received outpatient maintenance hemodialysis 3× a week. The main exposure was single pooled Kt/V (spKt/V), which is the dialysis adequacy index, and the primary outcome was the development of AF. For the primary analysis, patients were categorized into quartiles according to baseline spKt/V. The lowest quartile, representing the lowest adequacy, was used as the reference group. Fine-Gray subdistribution hazard models were used, treating all-cause mortality as a competing risk. RESULTS: Of 25 173 patients, the mean age was 60 (51–69) years, and 14 772 (58.7%) were men. During a median follow-up of 5.7 years, incident AF occurred in a total of 3883 (15.4%) patients. Participants with a higher spKt/V tended to have lower AF incidence. In survival analysis, a graded association was observed between the risk of incident AF and spKt/V quartiles: subdistribution hazard ratios and 95% CIs for the second, third, and the highest quartile compared with the lowest quartile were 0.90 (95% CI, 0.82–0.98), 0.84 (95% CI, 0.77–0.93), and 0.79 (95% CI, 0.72–0.88), respectively. CONCLUSIONS: This nationwide cohort study showed that a higher spKt/V is associated with a reduced risk of incident AF. These findings suggests that reducing uremic toxin burden through enhanced dialysis clearance may be associated with a lower risk of AF development in patients undergoing maintenance hemodialysis.