Association between the Hemoglobin Level and Cardiothoracic Ratio in Patients on Incident Dialysis

Impact of anemia treatment for left ventricular hypertrophy using long-acting erythropoietin-stimulating agents from the pre-dialysis to maintenance dialysis period in patients with chronic kidney disease, retrospective longitudinal cohort study

BACKGROUND

Anemia in patients with chronic kidney disease (p-CKDs) may initiate or exacerbate left ventricular hypertrophy (LVH). This study aimed to determine whether treatment using long-acting erythropoietin-stimulating agents (L-ESAs) is independently associated with LVH during the pre-dialysis to maintenance dialysis period in p-CKDs.

METHODS

Physical and laboratory examinations were performed 120 days before initiating dialysis in p-CKDs (baseline). To evaluate the left ventricular mass index (LVMI) after starting dialysis, the mean hemoglobin (Hb) was defined as the average at the start of dialysis and 6 months after starting dialysis. Changes in the LVMI were observed in three groups according to mean Hb levels (Hb < 10.1, 10.1 < Hb < 11.0, and Hb > 11.0 g/dL for Groups 1, 2, and 3, respectively). LVMI was evaluated using echocardiography at the pre-dialysis, initiation, and maintenance dialysis periods.

RESULTS

A lower LVMI at dialysis initiation and an improvement in LVMI were detected in the highest tertile group of mean Hb (11.0 g/dl). Consequently, in the high Hb group (Hb level > 11.0 g/dl), LVMI remained low from dialysis initiation until after 6 months.The relationship between Hb and LVMI was not significant; however, a constant correlation with β ≥ 0.4 in the absolute value was maintained.

CONCLUSION

L-ESAs may correlate with Hb and LVMI after administration, independent of the baseline LVMI and Hb values. These findings have therapeutic implications in the treatment strategies for p-CKDs during the pre-dialysis to maintenance dialysis period.

Machine learning approaches for the mortality risk assessment of patients undergoing hemodialysis

Introduction:

Mortality is a major primary endpoint for long-term hemodialysis (HD) patients. The clinical status of HD patients generally relies on longitudinal clinical observations such as monthly laboratory examinations and physical examinations.

Methods:

A total of 829 HD patients who met the inclusion criteria were analyzed. All patients were tracked from January 2009 to December 2013. Taken together, this study performed full-adjusted-Cox proportional hazards (CoxPH), stepwise-CoxPH, random survival forest (RSF)-CoxPH, and whale optimization algorithm (WOA)-CoxPH model for the all-cause mortality risk assessment in HD patients. The model performance between proposed selections of CoxPH models were evaluated using concordance index.

Results:

The WOA-CoxPH model obtained the highest concordance index compared with RSF-CoxPH and typical selection CoxPH model. The eight significant parameters obtained from the WOA-CoxPH model, including age, diabetes mellitus (DM), hemoglobin (Hb), albumin, creatinine (Cr), potassium (K), Kt/V, and cardiothoracic ratio, have also showed significant survival difference between low- and high-risk characteristics in single-factor analysis. By integrating the risk characteristics of each single factor, patients who obtained seven or more risk characteristics of eight selected parameters were dichotomized as high-risk subgroup, and remaining is considered as low-risk subgroup. The integrated low- and high-risk subgroup showed greater discrepancy compared with each single risk factor selected by WOA-CoxPH model.

Conclusion:

The study findings revealed WOA-CoxPH model could provide better risk assessment performance compared with RSF-CoxPH and typical selection CoxPH model in the HD patients. In summary, patients who had seven or more risk characteristics of eight selected parameters were at potentially increased risk of all-cause mortality in HD population.

Higher-order clinical risk factor interaction analysis for overall mortality in maintenance hemodialysis patients

BACKGROUND AND AIMS

In Taiwan, approximately 90% of patients with end-stage renal disease receive maintenance hemodialysis. Although studies have reported the survival predictability of multiclinical factors, the higher-order interactions among these factors have rarely been discussed. Conventional statistical approaches such as regression analysis are inadequate for detecting higher-order interactions. Therefore, this study integrated receiver operating characteristic, logistic regression, and balancing functions for adjusting the ratio in risk classes and classification errors for imbalanced cases and controls using multifactor-dimensionality reduction (MDR-ER) analyses to examine the impact of interaction effects between multiclinical factors on overall mortality in patients on maintenance hemodialysis.

METERIALS AND METHODS

In total, 781 patients who received outpatient hemodialysis dialysis three times per week before 1 January 2009 were included; their baseline clinical factor and mortality outcome data were retrospectively collected using an approved data protocol (201800595B0).

RESULTS

Consistent with conventional statistical approaches, the higher-order interaction model could indicate the impact of potential risk combination unique to patients on maintenance hemodialysis on the survival outcome, as described previously. Moreover, the MDR-based higher-order interaction model facilitated higher-order interaction effect detection among multiclinical factors and could determine more detailed mortality risk characteristics combinations.

CONCLUSION

Therefore, higher-order clinical risk interaction analysis is a reasonable strategy for detecting non-traditional risk factor interaction effects on survival outcome unique to patients on maintenance hemodialysis and thus clinically achieving whole-scale patient care.

Risk of cardiovascular mortality predicted by the serum calcium level and calcification score at the initiation of dialysis

BACKGROUND

The relationship between serum corrected calcium (CCa) level and vessel calcification at dialysis initiation and survival has seldom been evaluated. Therefore, we evaluated the efficacy of CCa levels and the calcification score at the initiation of dialysis for predicting all-cause and cardiovascular (CV) mortality in patients with end-stage renal disease (ESRD).

METHODS

The study group included 407 patients with ESRD, who started hemodialysis between January 2009 and December 2016 at the Red Cross Ishinomaki Hospital. The primary outcomes were the 1- and 3-year all-cause and CV mortality rate, with the association between CCa level and CVD-specific mortality evaluated using the Kaplan-Meier method and Cox proportional hazard regression analysis.

RESULTS

Patients with a high initial CCa level were at higher risk for CVD-related, but not all-cause, mortality than patients with a low initial CCa level [hazard ratio (HR) 2.81; 95% confidence interval 1.05-7.55]. The HR for CVD-related mortality was also higher for patients with an Agatston vessel calcification score > 2000 (HR 13.9; 95% CI 1.63-118.2). Overall, the 3-year CVD-free rate was 88.2% (range 76.4-94.3%). Higher CCa level was associated with a higher Agatston score and cardiac valve calcification.

CONCLUSION

High serum CCa levels and an Agatston score > 2000 are independent risk factors of CVD mortality due to advanced vessel calcification.

Association between serum aluminum levels and cardiothoracic ratio in patients on chronic hemodialysis

The cardiothoracic ratio (CTR) and serum aluminum levels are both associated with mortality in hemodialysis patients. However, limited data regarding the association between serum aluminum levels and the CTR have been published to date. Therefore, we aimed to elucidate this association in patients on chronic hemodialysis (CHD). We investigated the association between the serum aluminum level and the CTR in CHD in a retrospective cross-sectional study of 547 Taiwanese patients on CHD. The mean age of patients was 62.5±13.2 years, with a mean hemodialysis time of 7.1±5.2 years. Among the patients, 36.9% were diabetic and 47.9% were male. After natural logarithmic transformation (ln(aluminum)), the serum aluminum level exhibited an independent and linear relationship with the CTR (β: 1.40, 95% confidence interval (CI), 0.6–2.2). A high serum aluminum level (≥6 ng/dL) was significantly associated with a CTR >0.5 in the crude analysis (odds ratio (OR): 2.15, 95% CI, 1.52–3.04) and remained significant after multivariable adjustment (OR: 2.45, 95% CI, 1.63–3.67). Moreover, the ln(aluminum) value was significantly associated with a CTR >0.5 (OR: 1.71, 95%CI, 1.28–2.29) in multivariable analysis, indicating a dose effect of aluminum on cardiomegaly. In conclusion, the serum aluminum level was independently associated with cardiac remodeling (elevated CTR) in patients on CHD.

The cardiothoracic ratio and all-cause and cardiovascular disease mortality in patients undergoing maintenance hemodialysis: results of the MBD-5D study

BACKGROUND

The cardiothoracic ratio (CTR) is a non-invasive left ventricular hypertrophy index. However, whether CTR associates with cardiovascular disease (CVD) and mortality in hemodialysis (HD) populations is unclear.

METHODS

Using a Mineral and Bone disorder Outcomes Study for Japanese CKD Stage 5D Patients (MBD-5D Study) subcohort, 2266 prevalent HD patients (age 62.8 years, female 38.0%, HD duration 9.4 years) with secondary hyperparathyroidism (SHPT) whose baseline CTR had been recorded were selected. We evaluated associations between CTR and all-cause death, CVD death, or composite events in HD patients.

RESULTS

CTR was associated significantly with various background and laboratory characteristics. All-cause death, CVD-related death, and composite events increased across the CTR quartiles (Q). Adjusted hazard risk (HR) for all-cause death was 1.4 (95% confidential interval, 0.9-2.1) in Q2, 1.9 (1.3-2.9) in Q3, and 2.6 (1.7-4.0) in Q4, respectively (Q1 as a reference). The corresponding adjusted HR for CVD-related death was 1.8 (0.8-4.2), 3.1 (1.4-6.8), and 3.5 (1.6-7.9), and that for composite outcome was 1.2 (1.0-1.6), 1.7 (1.3-2.2), and 1.8 (1.5-2.3), respectively. Exploratory analysis revealed that there were relationships between CTR and age, sex, body mass index, comorbidity of CVD, dialysis duration and intact parathyroid hormone, phosphorus, hemoglobin, and usage of phosphate binder [corrected].

CONCLUSION

CTR correlated with all-cause death, CVD death, and composite events in HD patients with SHPT.

Association between peripheral arterial occlusive disease and cardiothoracic ratio in patients on chronic hemodialysis

The cardiothoracic ratio (CTR) and peripheral arterial occlusive disease (PAOD) are related to mortality in hemodialysis patients. However, data on the association between PAOD and CTR are limited. In this study, we aim to elucidate this relationship in patients on chronic hemodialysis. Using a retrospective cross-sectional study of 622 Taiwanese patients, we investigated the association of PAOD and CTR. PAOD was significantly associated with CTR in the crude analysis. The odds ratio (OR) for CTR >0.5 was 1.77 [95% confidence interval (CI), 1.32-2.37], and the odds ratio for CTR >0.6 was 2.18 [95% CI, 1.44-3.30]. After adjusting for confounding variables, this difference continued to exhibit significant predictive power for CTR >0.6 (OR, 1.88; 95% CI, 1.14-3.11), but the predictive power for CTR >0.5 was attenuated (OR, 1.41; 95% CI, 0.98-2.03). In the subgroup analysis, PAOD was an independent factor for CTR >0.6, particularly in elderly and female patients or patients with hemoglobin >10 mg/dl and with no history of cardiovascular disease. In this research, we showed that the detection of PAOD was independently associated with CTR >0.6 in patients on chronic hemodialysis.

Anaemia and early phase cardiovascular events on haemodialysis

Although the mechanism of the cardio-renal anaemia syndrome (CRAS) has been elucidated in considerable detail over the past decade, cardiovascular disease (CVD) remains a leading cause of death among patients with end-stage kidney disease (ESKD) undergoing haemodialysis, and these patients' cardiovascular mortality is greater than that of the general population. Recent studies have reported that the CVD risk increases with advancing chronic kidney disease (CKD) stage. Furthermore, the incidence of cardiovascular events is highest during the first week after dialysis initiation, with increased risk in incident haemodialysis patients. This accumulated evidence demonstrates that how patients are managed during the pre-dialysis phase may have important implications on long-term outcomes in ESKD. Anaemia, a non-traditional risk factor for CVD, advances exponentially along with declining kidney function due to insufficient erythropoietin production. Anaemia causes functional abnormalities of the heart, as represented by cardiac hypertrophy, which results from increased cardiac workload induced by an increased preload. Left ventricular hypertrophy (LVH), a traditional risk factor for CVD, is especially associated with advanced CKD stage and could be a major risk factor for cardiovascular complications such as ischaemic heart disease, heart failure, and sudden cardiac death. In ESKD, anaemia develops more severely and requires a higher amount of erythropoiesis-stimulating agent (ESA) therapy before dialysis initiation. This suggests that improvement in anaemia management during the pre-dialysis phase may have a beneficial effect on cardiac hypertrophy and contribute to reducing the CVD risk after initiating haemodialysis.

Relationship between anaemia management at haemodialysis initiation and patient prognosis

AIM

It has been suggested that anaemia management during a transition period to haemodialysis could influence prognosis. In this paper, we have conducted a retrospective investigation on how Hb levels at haemodialysis initiation in patients with chronic kidney disease (CKD) influence the risk of cerebral infarction and cardiovascular events.

METHODS

Seventy-two patients who underwent initial haemodialysis between May 2012 and April 2014 were designated as subjects of the study and the patients were divided into a cohort with Hb levels ≥8 g/dL and a cohort with <8 g/dL at haemodialysis initiation. The occurrence of cardiovascular events was analyzed using the Kaplan-Meier method and Cox proportional hazards model.

RESULTS

The cohort with <8 g/dL Hb levels at haemodialysis initiation demonstrated a tendency toward low dosage of ESA or iron preparation in the pre-haemodialysis (maintenance) phase. Significant incidence of cardiovascular (log rank, P = 0.002) and cerebrovascular (log rank, P = 0.02) events was observed. The results of multivariate analysis of the Cox proportional hazards model indicated that anaemia with <8 g/dL Hb levels at haemodialysis initiation was a significant risk factor for coronary artery (hazard ratio = 12.85, P = 0.003) and cerebrovascular (hazard ratio = 5.11, P = 0.04) diseases post-haemodialysis.

CONCLUSION

The results of this investigation indicate the possible involvement of low Hb levels at haemodialysis initiation as a factor in cardio- and cerebrovascular events. There, our results suggested that the administration of adequate dosage of iron preparations and ESA in the pre-haemodialysis period could help prevent cardio- and cerebrovascular events.

A Higher Cardiothoracic Ratio Is Associated with 2-Year Mortality after Hemodialysis Initiation

A high cardiothoracic ratio (CTR) is indicative of a cardiac disorder. However, few reports have revealed an association between the CTR and mortality in patients starting hemodialysis (HD).

METHODS

Patients with HD initiation (n = 387; mean age, 66.7 ± 12.7 years) were divided into the following three groups according to their CTR at HD initiation: CTR <50%, 50% ≤ CTR < 55%, and CTR ≥55%. Kaplan-Meier analysis was performed to compare 2-year all-cause mortality among these groups. Furthermore, we investigated the factors affecting their 2-year mortality using a Cox proportional hazard regression analysis.

RESULTS

Sixty-five patients (17%) died within 2 years after HD initiation. Kaplan-Meier analysis showed that patients with CTR ≥55% had a higher mortality rate than those in the other groups. Cox proportional hazard regression analysis was performed using parameters with p values <0.1 among these three groups [sex, age, presence or absence of ischemic heart disease, hemoglobin levels, serum albumin levels, CTR, body mass index (BMI)] and confounding factors [presence or absence of diabetes mellitus, and estimated glomerular filtration rate (eGFR)]. Age, eGFR, BMI, and CTR ≥55% at HD initiation were identified as factors influencing 2-year mortality.

CONCLUSION

CTR >55% is one of the most important independent factors to affect 2-year all-cause mortality. Thus, confirming the cardiac condition of patients at HD initiation with a CTR >55% may improve their survival.