Vascular calcification and intradialytic hypotension in hemodialysis patients: Clinical relevance and impact on morbidity and mortality

Circulatory endostatin level and risk of cardiovascular events in patients with end-stage renal disease on hemodialysis

BACKGROUND

Endostatin is released during extracellular matrix remodeling and is involved in the development of vascular pathology and cardiovascular (CV) disease. However, the role of circulating endostatin as a biomarker of vascular calcification and CV events in patients undergoing hemodialysis (HD) remains unclear.

METHODS

A total of 372 patients undergoing HD were prospectively recruited. Plasma endostatin levels were measured at baseline, and their associations with circulating mineral bone disease (MBD) biomarkers and abdominal aortic vascular calcification scores were analyzed. The primary endpoint was defined as a composite of CV and cardiac events.

RESULTS

Plasma levels of patients in endostatin tertile 3 were significantly associated with low-density lipoprotein cholesterol levels and predialysis systolic blood pressure in multivariate analysis. However, endostatin levels did not correlate with circulating MBD biomarkers or vascular calcification scores. Patients in endostatin tertile 3 had a significantly higher cumulative event rate for the composite of CV events (p = 0.006). Endostatin tertile 3 was also associated with an increased cumulative rate of cardiac events (p = 0.04). In multivariate Cox regression analyses, endostatin tertile 3 was associated with a 4.37-fold risk for composite CV events and a 3.88-fold risk for cardiac events after adjusting for multiple variables.

CONCLUSION

Higher circulating endostatin levels were independently associated with atherosclerotic risk factors but did not correlate with MBD markers or vascular calcification. Higher circulating endostatin levels were associated with a greater risk of composite CV events in patients undergoing HD, and endostatin is a biomarker that helps to determine the high risk of CV events.

Prevention of Intradialytic Hypotension in Hemodialysis Patients: Current Challenges and Future Prospects

Intradialytic hypotension, defined as rapid decrease in systolic blood pressure of greater than or equal to 20 mmHg or in mean arterial pressure of greater than or equal to 10 mmHg that results in end-organ ischemia and requires countermeasures such as ultrafiltration reduction or saline infusion to increase blood pressure to improve patient's symptoms, is a known complication of hemodialysis and is associated with several potential adverse outcomes. Its pathogenesis is complex and involves both patient-related factors such as age and comorbidities, as well as factors related to the dialysis prescription itself. Key factors include the need for volume removal during hemodialysis and a suboptimal vascular response which compromises the ability to compensate for acute intravascular volume loss. Inadequate vascular refill, incorrect assessment or unaccounted changes of target weight, acute illnesses and medication interference are further potential contributors. Intradialytic hypotension can lead to compromised tissue perfusion and end-organ damage, both acutely and over time, resulting in repetitive injuries. To address these problems, a careful assessment of subjective symptoms, minimizing interdialytic weight gains, individualizing dialysis prescription and adjusting the dialysis procedure based on patients' risk factors can mitigate negative outcomes.

Aortic arch calcification and risk of all-cause mortality and cardiovascular disease: The Guangzhou Biobank Cohort Study

Background

There were no reports on the associations of aortic arch calcification (AAC) measured by chest X-ray with all-cause mortality and cardiovascular disease (CVD) in older general population. Moreover, previous studies of hemodialysis patients showed that AAC was correlated with left ventricular hypertrophy (LVH) and predicted CVD jointly. Whether the effects remained in the general population is unknown. We examined the associations of AAC with all-cause mortality and CVD in general population and the risk associated with the coexistence of AAC and LVH.

Methods

Presence and severity (grades 0-2) of AAC were measured by chest X-ray, and LVH was identified by 12-lead electrocardiogram in 27,166 Chinese aged 50+ years free of CVD from Guangzhou Biobank Cohort Study. Multivariate Cox regressions were used to examine associations of AAC and LVH with outcomes.

Findings

During an average follow-up of 14·3 years, 5,350 deaths and 4,012 CVD occurred. Compared to those without AAC at baseline, those with AAC had higher risks of all-cause mortality (HR 1·24, 95% CI 1·17-1·31) and CVD (HR 1·22, 95% CI 1·14-1·30), with dose-response relationship (P ≤ 0·001). Furthermore, those with coexistence of AAC and LVH had higher risks of all-cause mortality (HR 1·72, 95% CI 1·37-2·15) and CVD (HR 1·80, 95% CI 1·40-2·32) than those without AAC and LVH.

Interpretation

As chest X-ray has been performed commonly for health screening and in hospital patients when first admitted, AAC measured by chest X-ray can be further applied to assist cardiovascular risk stratification in the community and clinical settings.

Funding

The Natural Science Foundation of China (No. 81941019).

Vascular Calcification in Chronic Kidney Disease: Distinct Features of Pathogenesis and Clinical Implication

Vascular calcification (VC) is highly prevalent in patients with chronic kidney disease (CKD) and leads to increased cardiovascular morbidity and mortality. In patients with CKD, traditional factors do not fully explain the high prevalence of VC. This suggests that a CKD-specific pathobiology is involved in the development of VC and mounting evidence indicates that VC in CKD patients has distinct features of clinical presentation and that clinical implications are changed compared to those in the general population. In this review, we discuss the mechanism, diagnostic imaging modalities, clinical features and implications, and management of VC in patients with CKD.

Chronic kidney disease (CKD) is associated with a higher prevalence of vascular calcification (VC) and cardiovascular disease. VC in CKD patients showed different pathophysiological features from those of the general population. The pathogenesis of VC in CKD is a highly organized process, and prior studies have suggested that patients with CKD have their own specific contributors to the phenotypic change of vascular smooth muscle cells (VSMCs), including uremic toxins, CKD-mineral and bone disease (CKD-MBD), inflammation, and oxidative stress. For the diagnosis and monitoring of VC in CKD, several imaging modalities, including plain radiography, ultrasound, and computed tomography have been utilized. VC in CKD patients has distinct clinical features and implications. CKD patients revealed a more intense and more prevalent calcification on the intimal and medial layers, whereas intimal calcification is predominantly observed in the general population. While a higher VC score is clearly associated with a higher risk of all-cause mortality and cardiovascular events, a greater VC score in CKD patients does not fully reflect the burden of atherosclerosis, because they have more calcification at equal volumes of atheromatous plaques. The primary goal of VC treatment in CKD is the prevention of VC progression, and the main management is to control the biochemical components of CKD-MBD. Cinacalcet and non-calcium-containing phosphate binders are the mainstay of VC prevention in CKD-MBD management. VC in patients with CKD is an ongoing area of research and is expected to advance soon.

Low central blood pressure and sympathetic activity predispose for the development of intradialytic hypotension

Intradialytic hypotension (IDH) may lead to a poor life quality and was associated with cardiovascular mortality in patients under hemodialysis. This study investigated the autonomic nerve and cardiovascular function in the IDH episodes.In this case-control study, 70 end stage renal disease patients (198 visits) were recruited. Pulse wave analysis and heart rate variability were evaluated before hemodialysis. Two definitions of IDH were confirmed by medical records. IDH-f indicated a drop of systolic blood pressure or mean arterial pressure, accompanied with symptoms; IDH-n indicated a low nadir systolic pressure during the hemodialysis. All parameters were evaluated for the possible predisposing factors under each definition.A total of 24 IDH-f and 37 IDH-n were noted in 177 visits. For both definitions, central pulse pressure seemed to be a consistent predisposing factor. Furthermore, lower sympathetic activity (odds ratio [OR] 0.55; 95% confidence interval [CI] 0.35-0.87), lower pulse pressure (OR 0.95; 95% CI 0.92-0.98), and higher augmentation index (OR 17.36; 95% CI 1.48-204.10) were the possible predisposing factors for IDH-f. On the contrary, lower mean arterial pressure (OR 0.87; 95% CI 0.78-0.98) was identified as the possible factor for IDH-n.It was suggested that the lower central pulse pressure and sympathetic activity might be involved in the development of IDH.

Serum Phosphorus Levels are Associated with Intradialytic Hypotension in Hemodialysis Patients

BACKGROUND

Intradialytic hypotension (IDH) is a common serious complication in hemodialysis (HD) patients. Hyperphosphatemia is also common in HD patients and promotes vascular calcification. Given the association between vascular calcification and IDH, we investigated the association between IDH and serum phosphorus in HD patients.

METHODS

We enrolled 173 patients who received HD for 3 months or more. IDH was defined as a nadir systolic blood pressure (SBP) <90 mm Hg or as a decrease in SBP ≥20 mm Hg or a decrease in mean arterial pressure by 10 mm Hg with the occurrence of hypotension-related symptoms requiring intervention. Serum phosphorus levels were analyzed both as a continuous variable and as a categorical variable.

RESULTS

IDH occurred in 40 (23.1%) of the 173 patients. The mean phosphorus level was 4.9 mg/dL. A 1 mg/dL higher serum phosphorus resulted in a 2.1-fold greater odds of IDH. The fully adjusted odds ratio (OR) and 95% confidence interval (CI) were 2.11 (1.48-3.01). High categorized phosphorus levels were also associated with IDH. The highest tertile of serum phosphorus was associated with 6.5-fold greater odds of developing IDH compared to the referent group (the middle tertile of serum phosphorus, 4.0-<5.3 mg/dL); the fully adjusted OR (95% CIs) were 6.53 (2.23-19.09). In subgroup analyses, diabetes and pre-dialysis SBP modified the association between IDH and phosphorus levels, with a more pronounced association in diabetic patients and pre-dialysis SBP ≥140 mm Hg.

CONCLUSION

In HD patients, higher phosphorus levels were associated with an increased occurrence of IDH.

Intradialytic hypotension and associated factors among patients on maintenance hemodialysis: A single-center study in cameroon

Intradialytic hypotension (IDH), one of the most frequent acute complications of hemodialysis (HD), is associated with increased patient's morbidity and mortality. The aim of this study was to determine its prevalence and associated factors among patients on maintenance HD in Cameroon. This was a prospective longitudinal study carried out from June 20, to July 30, 2016 (5 weeks), including adult patients on HD >3 months at a tertiary hospital in Douala. During this period, patients were followed up at each HD session, and their blood pressure and occurrence of clinical events possibly related to IDH were recorded. In this study, IDH was defined as a decrease in systolic BP by >20 mm Hg or a decrease in mean arterial pressure by >10 mm Hg, associated to a clinical event. Logistic regression analysis was used to determine associated factors. We included 104 patients (69 males) with a mean age of 50.74 ± 15.18 years and a median duration on HD of 30.5 (interquartile range: 12.25-58.75) years. Hypertension 99/104 (95.2%) and diabetes 32/104 (30.8%) were the main comorbidities encountered. A total of 1032 HD sessions were followed up with an average of 9.88 ± 1.57 sessions per patient. IDH occurred in 11.6% of HD sessions. Associated factors were age, female sex, HIV infection, feeding during dialysis, and use of antihypertensive drug during or within 2 h before dialysis. The prevalence of IDH in our study was low. Associated factors were mainly related to patient's characteristics and comorbidities.

Impacts of Coronary Artery Calcification on Intradialytic Blood Pressure Patterns in Patients Receiving Maintenance Hemodialysis

Intradialytic blood pressure abnormalities are associated with adverse outcomes in patients with end-stage renal disease on dialysis. Vascular calcification is a common complicating feature, but whether this complication results in intradialytic blood pressure abnormalities remains uncertain. Therefore, this study investigated the relationship between coronary artery calcium score and intradialytic blood pressure abnormalities in patients with end-stage renal disease on maintenance hemodialysis. Thirty-six patients who received nongated chest computed tomography scans were included. Intradialytic hypotension was defined as a minimum intradialytic systolic blood pressure of <100 mmHg or a pre-dialysis blood pressure – minimum intradialytic systolic blood pressure >30 mmHg. Intradialytic hypertension was defined as >10 mmHg increase in systolic blood pressure (pre- to post-dialysis). Patients were classified as 22 (61.1%) with coronary artery calcium score <400 and 14 (38.9%) with coronary artery calcium score ≥400. Median systolic and diastolic blood pressures were equivalent, but median pulse pressure was higher in patients with coronary artery calcium score ≥400 than in those with scores <400. Coronary artery calcium score was comparable according to both intradialytic hypotension and hypertension, and had no correlation with systolic blood pressure fall and nadir systolic blood pressure. Coronary artery calcium score predicted the occurrence of cardiovascular events and all-cause mortality (hazard ratio 1.001 and 1.001; p=0.058 and 0.010). Coronary vascular calcification could be irrelevant to intradialytic blood pressure abnormalities in patients with end-stage renal disease on dialysis.

Effects of sertraline in the prevention of low blood pressure in patients undergoing hemodialysis

INTRODUCTION

Intradialytic hypotension (IDH) is a major complication of hemodialysis, with a prevalence of about 25% during hemodialysis sessions, causing increased morbidity and mortality.

OBJECTIVE

To study the effects of sertraline to prevent IDH in hemodialysis patients.

METHODS

This was a double-blind, crossover clinical trial comparing the use of sertraline versus placebo to reduce intradialytic hypotension.

RESULTS

Sixteen patients completed the two phases of the study during a 12-week period. The IDH prevalence was 32%. A comparison between intradialytic interventions, intradialytic symptoms, and IDH episodes revealed no statistical difference in the reduction of IDH episodes (p = 0.207) between the two intervention groups. However, the risk of IDH interventions was 60% higher in the placebo group compared to the sertraline group, and the risk of IDH symptoms was 40% higher in the placebo group compared to the sertraline group. Survival analysis using Kaplan-Meier estimator supported the results of this study. Sertraline presented a number needed to treat (NNT) of 16.3 patients to prevent an episode from IDH intervention and 14.2 patients to prevent an episode from intradialytic symptoms.

CONCLUSION

This study suggests that the use of sertraline may be beneficial to reduce the number of symptoms and ID interventions, although there was no statistically significant difference in the blood pressure levels.

Vascular calcification and left ventricular hypertrophy in hemodialysis patients: interrelationship and clinical impacts

Background: We examined the relationship and combined effect of vascular calcification (VC) and left ventricular hypertrophy (LVH) on deaths and cardiovascular events (CVEs) in hemodialysis (HD) patients. Methods: Maintenance HD patients (n=341) were included. Echocardiography data and plain chest radiographs were used to assess LVH and aortic arch VC. Results: VC was found in 100 patients (29.3%). LVH was more prevalent in patients with VC compared with those without VC (70% vs. 50.2%, P=0.001). VC was independently associated with a 2.42-fold increased risk of LVH (95% CI, 1.26-4.65). In multivariate analysis, compared with patients with neither VC nor LVH, the coexistence of VC and LVH was independently associated with CVE (HR, 2.01; 95% CI, 1.09-3.72), whereas VC or LVH alone was not. Patients with both VC and LVH had the highest risk for a composite event of deaths or CVE (HR, 1.88; 95% CI, 1.15-3.06). Significant synergistic interaction was observed between VC and LVH (P for interaction=0.039). Conclusions: VC was independently associated with LVH. The coexistence of VC and LVH was associated with higher risk of deaths and CVEs than either factor alone. VC and LVH showed a synergistic interaction for the risk of deaths and CVEs.