Risk factors for coronary artery calcium among patients with chronic kidney disease (from the Chronic Renal Insufficiency Cohort Study)

Progression of Coronary Artery Calcification and Risk of Clinical Events in CKD: The Chronic Renal Insufficiency Cohort Study

RATIONALE & OBJECTIVE

Coronary artery calcification (CAC) progresses rapidly in people with chronic kidney disease (CKD) compared with the general population. We studied the association between CAC progression and higher risks of atherosclerotic cardiovascular disease (CVD), congestive heart failure, and all-cause mortality among adults with CKD.

STUDY DESIGN

Prospective cohort study.

SETTING

& Participants: 1,310 participants in the Chronic Renal Insufficiency Cohort (CRIC) Study who had at least one CAC scan with no prior history of CVD and with observed or imputed data on changes in CAC over time.

EXPOSURE

Observed or imputed CAC progression, categorized as incident CAC among participants with zero CAC on the baseline scan, or progressive CAC when the baseline scan demonstrated CAC and there was an increase in CAC ≥50 Agatston units per year.

OUTCOMES

Atherosclerotic CVD (myocardial infarction or stroke), congestive heart failure, and all-cause mortality.

ANALYTICAL APPROACH

Cause-specific Cox proportional hazards regression, stratified by presence of CAC at baseline.

RESULTS

A total of 545 participants without and 765 with prevalent CAC at baseline were included. During a mean 3.3 years between CAC assessments, 177 (32.5%) participants without baseline CAC developed incident CAC while 270 participants (35.3%) with baseline CAC developed a ≥50 Agatston units per year increase in CAC. After multivariable adjustment, incident CAC was associated with 2.42-fold higher rate of atherosclerotic CVD (95% confidence interval [CI]: 1.23-4.79) and 1.82-fold higher rate of all-cause mortality (95% CI: 1.03-3.22). Progressive CAC (≥50 units per year) was not associated with atherosclerotic CVD (hazard ratio [HR]: 1.42; 95% CI: 0.85-2.35) but was associated with a 1.73-fold higher rate of all-cause mortality (95% CI: 1.31-2.28). Progressive CAC was not associated with incident heart failure.

LIMITATIONS

Residual confounding and limited statistical power for some outcomes.

CONCLUSIONS

Among adults with CKD stages 2-4, CAC progression over a mean 3.3 years was associated with higher risk of atherosclerotic CVD and all-cause mortality. The associations were strongest among participants without CAC at baseline.

Association between progression of coronary artery calcification and development of kidney failure with replacement therapy: Findings from KNOW-CKD study

BACKGROUND AND AIMS

High coronary artery calcification (CAC) burden is a significant risk factor for adverse cardiovascular and kidney outcomes. However, it is unknown whether changes in the coronary atherosclerotic burden can accompany changes in kidney disease progression. Here, we evaluated the relationship between CAC progression and the risk of kidney failure with replacement therapy (KFRT).

METHODS

We analyzed 1173 participants with chronic kidney disease (CKD) G1 to G5 without kidney replacement therapy from the KoreaN Cohort Study for Outcomes in Patients With Chronic Kidney Disease (KNOW-CKD). Participants were categorized into three groups according to the change in the CAC score between enrollment and year 4 (non-progressors, ≤0 AU; moderate progressors, 1-199 AU; and severe progressors, ≥200 AU). The primary outcome was the development of KFRT.

RESULTS

During a follow-up period of 4690 person-years (median, 4.2 years), the primary outcome occurred in 230 (19.6 %) participants. The incidence of KFRT was 37.6, 54.3, and 80.9 per 1000 person-years in the non-, moderate, and severe progressors, respectively. In the multivariable cause-specific hazard model, the hazard ratios (HRs) for the moderate and severe progressors were 1.71 (95 % confidence interval [CI], 1.02-2.87) and 2.55 (95 % CI, 1.07-6.06), respectively, compared with non-progressors. A different definition of CAC progression with a threshold of 100 AU yielded similar results in a sensitivity analysis.

CONCLUSIONS

CAC progression is associated with an increased risk of KFRT in patients with CKD. Our findings suggest that coronary atherosclerosis changes increase the risk of CKD progression.

Association between IL-2 Receptor and Severe Coronary Artery Calcification in Patients with Coronary Artery Disease

Background

Coronary artery calcification (CAC) is a crucial marker for coronary atherosclerosis, and the extent of CAC is closely linked to the incidence and progression of cardiovascular diseases. The interleukin-2 (IL-2) receptor (IL-2R), which plays a critical role in mediating the proliferation and differentiation of immune cells, may also be involved in the development of CAC. The study aimed to investigate the relationship between IL-2R and CAC, with the goal of providing new insights into cardiovascular diseases.

Methods

In this study, we enrolled 606 patients diagnosed with coronary artery disease to assess CAC. Based on coronary artery calcification score (CACS), patients were divided into two groups: the non-severe CAC group (CACS ≤ 400 Agatston units, AU) and the severe CAC group (CACS > 400 AU).

Results

The results showed that IL-2R levels were significantly higher in patients with severe CAC compared to those with non-severe CAC (383 vs. 352 pg/mL, p = 0.002). Moreover, the level of IL-2R was positively correlated with the severity of CAC, independent of other clinical risk factors. According to Receiver Operating Characteristic (ROC) curve, the IL-2R prediction model demonstrated a good capability in distinguishing severe CAC with the Area Under the Curve (AUC) value of 0.726.

Conclusions

Our study suggests that IL-2R is independently associated with the occurrence of severe CAC in coronary artery disease (CAD) patients. Additionally, IL-2R may play a crucial role in the development of advanced atherosclerosis. Consequently, therapeutic strategies targeting the IL-2/IL-2R pathway may be effective in preventing or treating CAD.

Association between the homeostasis model assessment of insulin resistance and coronary artery calcification: a meta-analysis of observational studies

Background

Insulin resistance (IR), a risk factor for cardiovascular diseases, has garnered significant attention in scientific research. Several studies have investigated the correlation between IR and coronary artery calcification (CAC), yielding varying results. In light of this, we conducted a systematic review to investigate the association between IR as evaluated by the homeostasis model assessment (HOMA-IR) and CAC.

Methods

A comprehensive search was conducted to identify relevant studies in PubMed, Embase, Scopus, and Web of Science databases. In addition, preprint servers such as Research Square, BioRxiv, and MedRxiv were manually searched. The collected data were analyzed using either fixed or random effects models, depending on the heterogeneity observed among the studies. The assessment of the body of evidence was performed using the GRADE approach to determine its quality.

Results

The current research incorporated 15 studies with 60,649 subjects. The analysis revealed that a higher category of HOMA-IR was associated with a greater prevalence of CAC in comparison to the lowest HOMA-IR category, with an OR of 1.13 (95% CI: 1.06-1.20, I2 = 29%, P < 0.001). A similar result was reached when HOMA-IR was analyzed as a continuous variable (OR: 1.27, 95% CI: 1.14-1.41, I2 = 54%, P < 0.001). In terms of CAC progression, a pooled analysis of two cohort studies disclosed a significant association between increased HOMA-IR levels and CAC progression, with an OR of 1.44 (95% CI: 1.04-2.01, I2 = 21%, P < 0.05). It is important to note that the strength of the evidence was rated as low for the prevalence of CAC and very low for the progression of CAC.

Conclusion

There is evidence to suggest that a relatively high HOMA-IR may be linked with an increased prevalence and progression of CAC.

Association of Vitamin K Status with Arterial Calcification and Stiffness in Chronic Kidney Disease: The Chronic Renal Insufficiency Cohort

Background

Arterial calcification and stiffness are common in people with chronic kidney disease (CKD). Higher vitamin K status has been associated with less arterial calcification and stiffness in CKD in cross-sectional studies.

Objectives

To determine the association of vitamin K status with coronary artery calcium (CAC) and arterial stiffness [pulse wave velocity (PWV)] at baseline and over 2-4 follow-up years in adults with mild-to-moderate CKD.

Methods

Participants (n = 2722) were drawn from the well-characterized Chronic Renal Insufficiency Cohort. Two vitamin K status biomarkers, plasma phylloquinone and plasma dephospho-uncarboxylated matrix gla protein [(dp)ucMGP], were measured at baseline. CAC and PWV were measured at baseline and over 2-4 y of follow-up. Differences across vitamin K status categories in CAC prevalence, incidence, and progression (defined as ≥100 Agatston units/y increase) and PWV at baseline and over follow-up were evaluated using multivariable-adjusted generalized linear models.

Results

CAC prevalence, incidence, and progression did not differ across plasma phylloquinone categories. Moreover, CAC prevalence and incidence did not differ according to plasma (dp)ucMGP concentration. Compared with participants with the highest (dp)ucMGP (≥450 pmol/L), those in the middle category (300-449 pmol/L) had a 49% lower rate of CAC progression (incidence rate ratio: 0.51; 95% CI: 0.33, 0.78). However, CAC progression did not differ between those with the lowest (<300 pmol/L) and those with the highest plasma (dp)ucMGP concentration (incidence rate ratio: 0.82; 95% CI: 0.56, 1.19). Neither vitamin K status biomarker was associated with PWV at baseline or longitudinally.

Conclusions

Vitamin K status was not consistently associated with CAC or PWV in adults with mild-to-moderate CKD.

Machine Learning for the Prevalence and Severity of Coronary Artery Calcification in Nondialysis Chronic Kidney Disease Patients: A Chinese Large Cohort Study

PURPOSE

This study sought to determine whether machine learning (ML) can be used to better identify the risk factors and establish the prediction models for the prevalence and severity of coronary artery calcification (CAC) in nondialysis chronic kidney disease (CKD) patients and compare the performance of distinctive ML models with conventional logistic regression (LR) model.

MATERIALS AND METHODS

In all, 3701 Chinese nondialysis CKD patients undergoing noncontrast cardiac computed tomography (CT) scanning were enrolled from November 2013 to December 2017. CAC score derived from the cardiac CT was calculated with the calcium scoring software and was used to assess and stratify the prevalence and severity of CAC. Four ML models (LR, random forest, support vector machine, and k-nearest neighbor) and the corresponding feature ranks were conducted. The model that incorporated the independent predictors was shown as the receiver-operating characteristic (ROC) curve. Area under the curve (AUC) was used to present the prediction value. ML model performance was compared with the traditional LR model using pairwise comparisons of AUCs.

RESULTS

Of the 3701 patients, 943 (25.5%) patients had CAC. Of the 943 patients with CAC, 764 patients (20.6%) and 179 patients (4.8%) had an Agatston CAC score of 1 to 300 and ≥300, respectively. The primary cohort and the independent validation cohort comprised 2957 patients and 744 patients, respectively. For the prevalence of CAC, the AUCs of ML models were from 0.78 to 0.82 in the training data set and the internal validation cohort. For the severity of CAC, the AUCs of the 4 ML models were from 0.67 to 0.70 in the training data set and from 0.53 to 0.70 in the internal validation cohort. For the prevalence of CAC, the AUC was 0.80 (95% confidence interval [CI]: 0.77-0.83) for ML (LR) versus 0.80 (95% CI: 0.77-0.83) for the traditional LR model ( P =0.2533). For the severity of CAC, the AUC was 0.70 (95% CI: 0.63-0.77) for ML (LR) versus 0.70 (95% CI: 0.63-0.77) for traditional LR model ( P =0.982).

CONCLUSIONS

This study constructed prediction models for the presence and severity of CAC based on Agatston scores derived from noncontrast cardiac CT scanning in nondialysis CKD patients using ML, and showed ML LR had the best performance.

Ankle-Brachial Index Predicts Long-Term Renal Outcomes in Acute Stroke Patients

Renal dysfunction is common after stroke. We aimed to investigate the clinical predictability of the ankle−brachial index (ABI) and brachial-ankle pulse wave velocity (baPWV) on poststroke renal deterioration. A total of 956 consecutive participants with acute ischemic stroke between 1 July 2016, and 31 December 2017 were enrolled and a final of 637 patients were recruited for final analysis. By using the group-based trajectory model (GBTM), the patients’ renal function trajectories were grouped into the low, intermediate, and high categories (LC, IC, and HC). Significant deterioration in the slope was noted in the IC (p < 0.001) and LC (p = 0.002) groups but was nonsignificant in the HC (p = 0.998) group. Abnormal ABI (ABI ≤ 0.9) was independently related to LC (adjusted odds ratio: 2.40; 95% CI, 1.16−4.95; p = 0.019) and was also independently associated with increased risks of a ≥30% decline in eGFR (adjusted hazard ratio [aHR], 2.28; 95% CI, 1.29−4.05; p = 0.005), a doubling of serum creatinine (aHR, 3.60; 95% CI, 1.93−8.34; p < 0.001) and ESRD (HR, 3.28; 95% CI, 1.23−8.74; p = 0.018). However, baPWV did not have a significant relationship with any of the renal outcomes. Patients with a lower ABI during acute stroke should receive regular renal function tests and should be closely monitored to improve poststroke renal care.

Envelope method with ignorable missing data

Envelope method was recently proposed as a method to reduce the dimension of responses in multivariate regressions. However, when there exists missing data, the envelope method using the complete case observations may lead to biased and inefficient results. In this paper, we generalize the envelope estimation when the predictors and/or the responses are missing at random. Specifically, we incorporate the envelope structure in the expectation-maximization (EM) algorithm. As the parameters under the envelope method are not pointwise identifiable, the EM algorithm for the envelope method was not straightforward and requires a special decomposition. Our method is guaranteed to be more efficient, or at least as efficient as, the standard EM algorithm. Moreover, our method has the potential to outperform the full data MLE. We give asymptotic properties of our method under both normal and non-normal cases. The efficiency gain over the standard EM is confirmed in simulation studies and in an application to the Chronic Renal Insufficiency Cohort (CRIC) study.

Gender-Related Differences in Chronic Kidney Disease-Associated Vascular Calcification Risk and Potential Risk Mediators: A Scoping Review

Vascular calcification (VC) involves the deposition of calcium apatite in vascular intima or media. Individuals of advanced age, having diabetes mellitus or chronic kidney disease (CKD) are particularly at risk. The pathogenesis of CKD-associated VC evolves considerably. The core driver is the phenotypic change involving vascular wall constituent cells toward manifestations similar to that undergone by osteoblasts. Gender-related differences are observed regarding the expressions of osteogenesis-regulating effectors, and presumably the prevalence/risk of CKD-associated VC exhibits gender-related differences as well. Despite the wealth of data focusing on gender-related differences in the risk of atherosclerosis, few report whether gender modifies the risk of VC, especially CKD-associated cases. We systematically identified studies of CKD-associated VC or its regulators/modifiers reporting data about gender distributions, and extracted results from 167 articles. A significantly higher risk of CKD-associated VC was observed in males among the majority of original investigations. However, substantial heterogeneity exists, since multiple large-scale studies yielded neutral findings. Differences in gender-related VC risk may result from variations in VC assessment methods, the anatomical segments of interest, study sample size, and even the ethnic origins of participants. From a biological perspective, plausible mediators of gender-related VC differences include body composition discrepancies, alterations involving lipid profiles, inflammatory severity, diversities in matrix Gla protein (MGP), soluble Klotho, vitamin D, sclerostin, parathyroid hormone (PTH), fibroblast growth factor-23 (FGF-23), and osteoprotegerin levels. Based on our findings, it may be inappropriate to monotonously assume that male patients with CKD are at risk of VC compared to females, and we should consider more background in context before result interpretation.

The impact of diabetes on heart failure development: The cardio-renal-metabolic connection

Heart failure (HF) and chronic kidney disease (CKD) are often associated in type 2 diabetes (T2D), aggravate each other and exert synergistic effects to increase the risk of cardiac and renal events. The risks of renal worsening in HF patients and HF in CKD patients need to be evaluated to tailor preventive therapy. The recent CV and renal trials enriched our knowledge about the natural history of HF and CKD in T2D and provided evidence for the benefit of sodium-glucose cotransporter 2 inhibitors (SGLT2is) in HF and renal decline prevention. SGLT-2is are the best choice in patients with HFrEF to improve CV prognosis and HF-related outcomes and also to prevent kidney-related outcomes, and in CKD patients to slow down renal failure and also reduce hospitalization for HF and CV death. In both situations the number of patients to treat in order to prevent such events in one patient is lower than in the general T2D population at high CV risk. GLP1-receptor agonists could be an alternative in a patient who is intolerant or has a contraindication to SGLT-2is. A tight collaboration between diabetologists, nephrologists and cardiologists should be encouraged for a holistic and effective strategy to reduce the burden of cardio-renal-metabolic interaction.

Role of Uremic Toxins in Early Vascular Ageing and Calcification

In patients with advanced chronic kidney disease (CKD), the accumulation of uremic toxins, caused by a combination of decreased excretion secondary to reduced kidney function and increased generation secondary to aberrant expression of metabolite genes, interferes with different biological functions of cells and organs, contributing to a state of chronic inflammation and other adverse biologic effects that may cause tissue damage. Several uremic toxins have been implicated in severe vascular smooth muscle cells (VSMCs) changes and other alterations leading to vascular calcification (VC) and early vascular ageing (EVA). The above mentioned are predominant clinical features of patients with CKD, contributing to their exceptionally high cardiovascular mortality. Herein, we present an update on pathophysiological processes and mediators underlying VC and EVA induced by uremic toxins. Moreover, we discuss their clinical impact, and possible therapeutic targets aiming at preventing or ameliorating the harmful effects of uremic toxins on the vasculature.

Uremic Toxins and Vascular Calcification-Missing the Forest for All the Trees

The cardiorenal syndrome relates to the detrimental interplay between the vascular system and the kidney. The uremic milieu induced by reduced kidney function alters the phenotype of vascular smooth muscle cells (VSMC) and promotes vascular calcification, a condition which is strongly linked to cardiovascular morbidity and mortality. Biological mechanisms involved include generation of reactive oxygen species, inflammation and accelerated senescence. A better understanding of the vasotoxic effects of uremic retention molecules may reveal novel avenues to reduce vascular calcification in CKD. The present review aims to present a state of the art on the role of uremic toxins in pathogenesis of vascular calcification. Evidence, so far, is fragmentary and limited with only a few uremic toxins being investigated, often by a single group of investigators. Experimental heterogeneity furthermore hampers comparison. There is a clear need for a concerted action harmonizing and standardizing experimental protocols and combining efforts of basic and clinical researchers to solve the complex puzzle of uremic vascular calcification.

Vitamin D Analogues and Coronary Calcification in CKD Stages 3 and 4: A Randomized Controlled Trial of Calcitriol Versus Paricalcitol

Rationale & Objective

Mineral and bone disorder in chronic kidney disease (CKD) is associated with progression of coronary artery calcification (CAC). Mineral and bone disorder often is treated with calcitriol and other vitamin D receptor activators, including paricalcitol, agents that may have differential effects on calcium, phosphate, and parathyroid hormone levels. Accordingly, we investigated whether these agents have differential effects on CAC progression in patients with CKD.

Study Design

Randomized, double-concealed, 48-week clinical trial.

Setting & Participants

CKD stage 3 or 4 with secondary hyperparathyroidism with CAC score > 0 and no prior treatment with activated vitamin D.

Intervention

Calcitriol versus paricalcitol.

Outcomes

The primary outcome was log-transformed CAC change. Secondary outcomes included percent change in CAC volume, valvular calcifications, and bone mineral metabolism markers.

Results

Among 44 individuals randomly assigned, mean age was 65 years and mean estimated glomerular filtration rate was 27 mL/min/1.73 m². Median CAC score was 140 (IQR, 55-277) Agatston units at baseline. There was no significant difference in CAC progression between treatment arms (P = 0.06). After adjustment for baseline CAC score (log), treatment group remains nonsignificant (P = 0.08). Further adjustment for creatinine level and/or CKD stage did not change the association. In secondary analyses adjusting for dose level of activated vitamin D, treatment group was significant (P = 0.01), and when dose level was also included in the model, the coefficient for individuals in the paricalcitol group was significantly associated with CAC progression (P = 0.02). An interaction term between dosing level and CKD stage was significant at the highest dosing level (P = 0.04).

Limitations

Pilot single-center study.

Conclusions

In patients with CKD with secondary hyperparathyroidism naive to activated vitamin D therapy, there was no difference in CAC or valvular progression in participants receiving calcitriol compared with paricalcitol during a 48-week period.

Funding

Abbvie, Inc.

Trial Registration

NCT00752102.

Peripheral arterial disease diagnosed by ankle-brachial index: Predictor for early renal replacement therapy in chronic kidney disease

Our study aimed to investigate the relationship between ankle-brachial index (ABI) and need for early renal replacement therapy (RRT) in predialysis patients with chronic kidney disease (CKD). A total of 112 patients (62% men) with pre-dialysis CKD, seen in the outpatient clinic, were included, and ABI was obtained as per standard protocol. Peripheral arterial disease (PAD) was defined as ABI <0.9 or >1.3 in either leg. The clinical data were analyzed, and the risk factors for early RRT were determined by multivariate logistic regression analysis. The prevalence of PAD was 44% in predialysis CKD patients. Over three years' follow- up, 14.2% required RRT; 11.3% developed major cardiovascular event (myocardial infarction, stroke, or death). A total of 26 events occurred. The incidence of all events was significantly higher in patients with abnormal ABI than in those with normal ABI (34.7% vs. 12.7%; log rank P = 0.02). PAD was associated with all events [hazard ratio (HR): 2.72; 95% CI: 1.04-7.17; P = 0.042] as also the need for RRT (HR 3.2; 95% Cl: 1.005-10.23; P = 0.049), on univariate cox proportional hazard analysis. Multivariate logistic regression analysis adjusted for other risk factors identified that PAD remained an independent predictor for the need for early RRT (HR: 12.2; 95%Cl: 2.2-66.5; P = 0.004) and all events (HR: 3.5; 95% Cl: 0.9-13.5; P = 0.032). PAD was an independent predictor for RRT requirement in predialysis CKD.

Epicardial fat, cardiovascular risk factors and calcifications in patients with chronic kidney disease

Background

Epicardial adipose tissue (EAT) exerts cardiopathogenic effects, but the independent association between EAT and cardiovascular (CV) calcification in patients with chronic kidney disease (CKD) remains controversial. We therefore assessed the association between EAT, CV risk factors and CV calcifications.

Methods

257 patients with CKD Stage 3 and/or overt proteinuria underwent quantification of EAT, coronary artery calcification and aortic valve calcification by computed tomography. Framingham and American College of Cardiology and American Heart Association (ACC-AHA) 10-year CV event risk scores were calculated for each patient.

Results

Using multivariable regression analysis, higher EAT was significantly associated with the majority of investigated risk factors {higher age: odds ratio [OR] 1.05/year [95% confidence interval (CI) 1.02-1.08]; male sex: OR 4.03 [95% CI 2.22-7.31]; higher BMI: OR 1.28/kg/m² [95% CI 1.20-1.37]; former smoking: OR 1.84 [95% CI 1.07-3.17]; lower high-density lipoprotein cholesterol: OR 0.98/mg/dL [95% CI 0.96-1.00] and lower estimated glomerular filtration rate: OR 0.98/mL/min/1.73 m² [95% CI 0.97-0.99]; all P < 0.05} and was not associated with diabetes mellitus, hypertensive nephropathy, total cholesterol and albuminuria. EAT was positively associated with higher ACC-AHA and Framingham risk scores. EAT correlated with coronary artery calcification and aortic valve calcification [Spearman ρ = 0.388 (95% CI 0.287-0.532) and r _rb = 0.409 (95% CI 0.310-0.556), respectively], but these correlations were dependent on CV risk factors.

Conclusions

The increase of EAT can be explained by individual CV risk factors and kidney function and correlates with 10-year risk for CV event scores, suggesting that EAT is a modifiable risk factor in patients with CKD. Although EAT correlates with CV calcifications, these relations depend on CV risk factors.

Serum Calcification Propensity and Coronary Artery Calcification Among Patients With CKD: The CRIC (Chronic Renal Insufficiency Cohort) Study

RATIONALE & OBJECTIVE

Coronary artery calcification (CAC) is prevalent among patients with chronic kidney disease (CKD) and increases risks for cardiovascular disease events and mortality. We hypothesized that a novel serum measure of calcification propensity is associated with CAC among patients with CKD stages 2 to 4.

STUDY DESIGN

Prospective cohort study.

SETTING & PARTICIPANTS

Participants from the Chronic Renal Insufficiency Cohort (CRIC) Study with baseline (n=1,274) and follow-up (n=780) CAC measurements.

PREDICTORS

Calcification propensity, quantified as transformation time (T₅₀) from primary to secondary calciprotein particles, with lower T₅₀ corresponding to higher calcification propensity. Covariates included age, sex, race/ethnicity, clinical site, estimated glomerular filtration rate, proteinuria, diabetes, systolic blood pressure, number of antihypertensive medications, current smoking, history of cardiovascular disease, total cholesterol level, and use of statin medications.

OUTCOMES

CAC prevalence, severity, incidence, and progression.

ANALYTICAL APPROACH

Multivariable-adjusted generalized linear models.

RESULTS

At baseline, 824 (65%) participants had prevalent CAC. After multivariable adjustment, T₅₀ was not associated with CAC prevalence but was significantly associated with greater CAC severity among participants with prevalent CAC: 1-SD lower T₅₀ was associated with 21% (95% CI, 6%-38%) greater CAC severity. Among 780 participants followed up an average of 3 years later, 65 (20%) without baseline CAC developed incident CAC, while 89 (19%) with baseline CAC had progression, defined as annual increase≥100 Agatston units. After multivariable adjustment, T₅₀ was not associated with incident CAC but was significantly associated with CAC progression: 1-SD lower T₅₀ was associated with 28% (95% CI, 7%-53%) higher risk for CAC progression.

LIMITATIONS

Potential selection bias in follow-up analyses; inability to distinguish intimal from medial calcification.

CONCLUSIONS

Among patients with CKD stages 2 to 4, higher serum calcification propensity is associated with more severe CAC and CAC progression.

eGFR and coronary artery calcification in chronic kidney disease

BACKGROUND

The independent association between eGFR and coronary artery calcification (CAC) is complex and not clear. The aim of this study is to investigate the relationship between eGFR calculated from different equations and CAC in predialysis CKD patients in Korea.

METHODS

In this cross-sectional study, we analyzed 1,533 patients from the KNOW-CKD cohort. eGFR was calculated by a four-variable MDRD equation (eGFR_MDRD ), CKD-EPI creatinine equations (eGFR_{C r} ), CKD-EPI Cystatin C equation (eGFR_{C ys} ), and CKD-EPI Creatinine-Cystatin equation (eGFR_{C rC ys} ). Participants were divided into eGFR categories (< 30, 30-59, 60-89, ≥ 90 ml/min/1.73 m² ). CACS (coronary artery calcium score) was measured using cardiac computed tomography. CAC was defined as CACS > 100.

RESULTS

CAC was found in 334 (21.8%) patients, and was more prevalent in the lower eGFR groups (p < 0.001). In multivariate Tobit regression, CACS increased gradually as eGFR_{C rC ys} decreased (p for trend = 0.034). In multivariate logistic regression, there were gradual associations between lower eGFR and CAC when an eGFR_{C ys} or eGFR_{C rC ys} was used. The adjusted OR for CAC in the group with eGFR < 30 ml/min/1.73m² compared to the group with eGFR ≥ 90 ml/min/1.73m² was 2.64 (95% CI, 1.09-3.60) when eGFR_{C rC ys} was used. Of the four eGFR formulas, only adding eGFR_{C rC ys} significantly improved CAC prediction models without eGFR (p = 0.046).

CONCLUSIONS

There was a gradual and independent association between low eGFR and CAC in a predialysis CKD cohort in Korea. eGFR_{C rC ys} predicted CAC better than other equations in this population. This article is protected by copyright. All rights reserved.

Atherosclerosis and Microvascular Complications: Results From the Canadian Study of Longevity in Type 1 Diabetes

OBJECTIVE

Type 1 diabetes carries a significant risk for cardiovascular mortality, but it is unclear how atherosclerosis associates with microvascular complications. We aimed to determine the relationships between atherosclerotic burden and neuropathy, retinopathy, and diabetic kidney disease (DKD) in adults with a ≥50-year history of type 1 diabetes.

RESEARCH DESIGN AND METHODS

Adults with type 1 diabetes (n = 69) underwent coronary artery calcification (CAC) volume scoring by wide-volume computerized tomography. Microvascular complications were graded as follows: neuropathy by clinical assessment, electrophysiology, vibration and cooling detection thresholds, heart rate variability, and corneal confocal microscopy; retinopathy by ultra-wide-field retinal imaging; and DKD by renal hemodynamic function measured by inulin and para-aminohippurate clearance at baseline and after intravenous infusion of angiotensin II. The cohort was dichotomized to high (≥300 Agatston units [AU]) or low (<300 AU) CAC and was stratified by diabetes status. A comparator group without diabetes (n = 73) matched for age and sex also underwent all study procedures except for retinal imaging.

RESULTS

CAC scores were higher in participants with type 1 diabetes (median Agatston score 1,000 [interquartile range = 222, 2,373] AU vs. 1 [0.75] AU in comparators, P < 0.001). In participants with type 1 diabetes, high CAC scores associated with markers of neuropathy and retinopathy, but not with DKD, or renal hemodynamic function at baseline or in response to angiotensin II.

CONCLUSIONS

The presence of high CAC in adults with longstanding type 1 diabetes was associated with large nerve fiber neuropathy and retinopathy but not with renal hemodynamic function, suggesting that neuropathy, retinopathy, and macrovascular calcification share common risk factors.

Fractional excretion of phosphorus and vascular calcification in stage 3 chronic kidney disease

The role of renal excretion of Pi in relation to vascular calcification (VC) in patients in the early stages of chronic kidney disease (CKD) is controversial. Thus, we determine the relation between fractional excretion of phosphorus (FEP) and VC, measured using two methods in a cross-sectional study of patients with stage 3 CKD. We recorded demographic data, anthropometry, comorbidities and active treatment. We measured 24-hour urine FEP and, in serum, measured fibroblast growth factor 23 (FGF23), α-Klotho, intact parathyroid hormone (iPTH), calcium and phosphorus. VC was measured by lateral abdominal radiography (Kauppila index (KI)) and CT of the abdominal aorta (measured in Agatston units). In 57% of subjects, abnormal VC was present when measured using CT, and in only 17% using lateral abdominal radiography. Factors associated with VC using CT were age, cardiovascular risk factors, vascular comorbidity, microalbuminuria and levels of FGF23, phosphorus and calcium x phosphorus product (CaxP); although only age (OR 1.25, 95% CI 1.11 to 1.41), smoking (OR 21.2, CI 4.4 to 100) and CaxP (OR 1.21, CI 1.06 to 1.37) maintained the association in a multivariate analysis. By contrast, only age (OR 1.35, 95% CI 1.07 to 1.74), CaxP (OR 1.14, CI 1.13 to 1.92) and FEP (OR 1.07,95% CI 1004 to 1.14) were associated with abnormal VC in the lateral abdominal radiography. In conclusion, in patients with stage 3 CKD, the detection of VC by abdominal CT is more sensitive than conventional X-rays. Moreover, CaxP is associated with cardiovascular risk factors and vascular comorbidity; quantification of FEPi in these patients provides additional clinical information in advanced VC detected by KI.

Extracellular Fluid Excess Is Significantly Associated With Coronary Artery Calcification in Patients With Chronic Kidney Disease

BACKGROUND

Extracellular fluid (ECF) excess is an independent predictor of cardiovascular morbidity in patients undergoing dialysis. This study aimed to investigate the relationship between ECF status, which is affected by renal function, and coronary artery calcification (CAC), which is a marker of cardiovascular disease, in patients with chronic kidney disease (CKD).

METHODS AND RESULTS

A total of 1741 patients at all stages of pre-dialysis CKD from the prospective observational cohort of CMERC-HI (Cardiovascular and Metabolic Disease Etiology Research Center-High Risk) were analyzed for the association between ECF status and CAC. ECF status was defined as extracellular water-to-total body water ratio (ECW/TBW) measured using bioelectrical impedance analysis. ECF excess was defined as ECW/TBW ≥0.390 or ≥0.400 depending on its severity. To define CAC, Agatston coronary artery calcium scores were measured. A total coronary artery calcium score of ≥400 was defined as CAC. The CKD stages were defined according to estimated glomerular filtration rate calculated using the CKD Epidemiology Collaboration equation. ECW/TBW and the proportion of ECF excess increased with progressing CKD stages. Multivariable logistic regression analyses showed that ECW/TBW was independently associated with CAC (per 0.01 increase of ECW/TBW, odds ratio 1.168, 95% confidence interval, 1.079-1.264, P<0.001). The adjusted R2 for predicting higher coronary artery calcium scores and CAC significantly improved after ECW/TBW was added to conventional factors. This association was further confirmed by net reclassification and integrated discriminant improvements, sensitivity analysis, and subgroup analysis.

CONCLUSIONS

ECF status is independently associated with a high risk of CAC in patients with CKD.

STUDY REGISTRATION

URL: https://www.clinicaltrials.gov/. Unique identifier: NCT02003781.

Risk factors for progression of coronary artery calcification in patients with chronic kidney disease: The CRIC study

BACKGROUND AND AIMS

Coronary artery calcification (CAC) is common among patients with chronic kidney disease (CKD) and predicts the risk for cardiovascular disease (CVD). We examined the associations of novel risk factors with CAC progression among patients with CKD.

METHODS

Among 1123 CKD patients in the Chronic Renal Insufficiency Cohort (CRIC) Study, CAC was measured in Agatston units at baseline and a follow-up visit using electron beam computed tomography or multidetector computed tomography.

RESULTS

Over an average 3.3-year follow-up, 109 (25.1%) participants without CAC at baseline had incident CAC and 124 (18.0%) participants with CAC at baseline had CAC progression, defined as an annual increase of ≥100 Agatston units. After adjustment for established atherosclerotic risk factors, several novel risk factors were associated with changes in CAC over follow-up. Changes in square root transformed CAC score associated with 1 SD greater level of risk factors were -0.20 (95% confidence interval, -0.31 to -0.10; p < 0.001) for estimated glomerular filtration rate, 0.14 (0.02-0.25; p = 0.02) for 24-h urine albumin, 0.25 (0.15-0.34; p < 0.001) for cystatin C, -0.17 (-0.27 to -0.07; p < 0.001) for serum calcium, 0.14 (0.03-0.24; p = 0.009) for serum phosphate, 0.24 (0.14-0.33; p < 0.001) for fibroblast growth factor-23, 0.13 (0.04-0.23; p = 0.007) for total parathyroid hormone, 0.17 (0.07-0.27; p < 0.001) for interleukin-6, and 0.12 (0.02-0.22; p = 0.02) for tumor necrosis factor-α.

CONCLUSIONS

Reduced kidney function, calcium and phosphate metabolism disorders, and inflammation, independent of established CVD risk factors, may progress CAC among CKD patients.

Cardiovascular Disease Consequences of CKD

Chronic kidney disease, defined as reduced glomerular filtration rate (estimated using serum creatinine- and/or serum cystatin C-based equations) or excess urinary protein excretion, affects approximately 13% of adult Americans and is linked to a variety of clinical complications. Although persons with end-stage renal disease requiring chronic dialysis therapy experience a substantially high cardiovascular burden, whether mild-to-moderate chronic kidney disease is an independent risk factor for fatal and nonfatal cardiovascular events has been more controversial. This review evaluates the current evidence about the clinical and subclinical cardiovascular consequences associated with chronic kidney disease of varying levels of severity. In addition, it discusses the predictors of adverse cardiovascular outcomes while also focusing on recent insights into the relationships between chronic kidney disease and cardiovascular disease from the Chronic Renal Insufficiency Cohort study, a large current prospective cohort study of adults from across the spectrum of chronic kidney disease.

Chronic kidney disease and coronary artery calcification in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil)

BACKGROUND

Chronic kidney disease is a worldwide public health concern due to the increased prevalence the high fatalities related to heart disease in this population. Among novel cardiovascular risk markers, the coronary artery calcification score (CAC) emerged as an independent predictor of cardiovascular events.

HYPOTHESIS

We aimed to test if glomerular filtration rate or albuminuria are independently associated with coronary calcification.

METHODS

The Brazilian Longitudinal Study of Adult Health is a cohort of men and women aged 35 to 74 years old addressing cardiovascular diseases. We analyzed the association of CAC, estimated glomerular filtration rate (eGFR), albumin-to-creatinine ratio (ACR) according to stages of eGFR (1 = ≥90; 2 = 60-89; 3 = <60 mL/min/1.73 m2 ), and ACR (<30; 30 to 300; >300 mg/g). These associations were estimated by logistic regression with a model including age, sex, race, income, and cardiovascular risk factors.

RESULTS

Among 4189 persons (median age = 51 years, 54% women), 1183 had CAC. The odds ratio (OR) and the 95% confidence interval (95% CI) in the multivariate model was 0.86 (0.58-1.29) for the category of eGFR <60 mL/min/1.73 m2 compared to people with eGFR >90 mL/min/1.73m2 . On the other hand, the OR (95% CI) for individuals with ACR >300 mg/g was 4.31 (1.27-14.64) compared to people with ACR <30 mg/g. A discrete interaction factor for the association with CAC between eGFR and ACR were analyzed as continuous variable.

CONCLUSIONS

Albuminuria was independently associated with coronary calcification, but the reduction of the glomerular filtration rate was not associated with CAC score in this sample of apparently healthy adults.

Evolution of Cardiovascular Disease During the Transition to End-Stage Renal Disease

Cardiovascular disease (CVD) remains the leading cause of morbidity and mortality in patients with chronic kidney disease (CKD) and end-stage renal disease (ESRD). The rate of death in incident dialysis patients remains high. This has led to interest in the study of the evolution of CVD during the critical transition period from CKD to ESRD. Understanding the natural history and risk factors of clinical and subclinical CVD during this transition may help guide the timing of appropriate CVD therapies to improve outcomes in patients with kidney disease. This review provides an overview of the epidemiology of subclinical and clinical CVD during the transition from CKD to ESRD and discusses clinical trials of CVD therapies to mitigate risk of CVD in CKD and ESRD patients.

Serum cystatin C levels are associated with coronary artery calcification in women without chronic kidney disease

BACKGROUND

Chronic renal disease (CKD) is a determinant of coronary artery calcification (CAC), which is a predictor of cardiovascular events. However, in a population without CKD, the association between CAC and renal function is unclear. CAC is affected by sex. This study aimed to determine whether serum cystatin C, a sensitive marker of kidney function, or sex differences are associated with CAC in patients without CKD.

METHODS

We evaluated 456 consecutive patients (61±13 years, 42% women) without CKD and evidence of coronary artery disease. The CAC (Agatston) score was examined by multidetector computed tomography.

RESULTS

When patients were categorized into three CAC groups based on the Agatston score, mild (<10), moderate (11-399), and severe (≥400) in each sex, serum cystatin C levels gradually increased by severity of CAC in women, but not men. Receiver operating characteristic curve analysis showed that, in women, a cut-off value of 0.97mg/l for cystatin C discriminated patients with severe CAC with a sensitivity of 71% and specificity of 77% (area under the curve, 0.74; 95% CI: 0.62-0.86; p<0.01). Multivariate logistic analysis showed that serum cystatin C was not associated with severe CAC in all patients and men, but this association was observed in women (OR: 7.80 for cystatin C≥0.97mg/l, 95% CI: 1.76-34.6, p<0.01).

CONCLUSION

Higher serum cystatin C levels are associated with greater CAC in women without CKD. Measurement of cystatin C may be useful for identifying women who are at high risk for cardiovascular disease.

Coronary Artery Calcification and Risk of Cardiovascular Disease and Death Among Patients With Chronic Kidney Disease

Importance

Coronary artery calcification (CAC) is highly prevalent in dialysis-naive patients with chronic kidney disease (CKD). However, there are sparse data on the association of CAC with subsequent risk of cardiovascular disease and all-cause mortality in this population.

Objective

To study the prospective association of CAC with risk of cardiovascular disease and all-cause mortality among dialysis-naive patients with CKD.

Design, Setting, and Participants

The prospective Chronic Renal Insufficiency Cohort study recruited adults with an estimated glomerular filtration rate of 20 to 70 mL/min/1.73 m2 from 7 clinical centers in the United States. There were 1541 participants without cardiovascular disease at baseline who had CAC scores.

Exposures

Coronary artery calcification was assessed using electron-beam or multidetector computed tomography.

Main Outcomes and Measures

Incidence of cardiovascular disease (including myocardial infarction, heart failure, and stroke) and all-cause mortality were reported every 6 months and confirmed by medical record adjudication.

Results

During an average follow-up of 5.9 years in 1541 participants aged 21 to 74 years, there were 188 cardiovascular disease events (60 cases of myocardial infarction, 120 heart failures, and 27 strokes; patients may have had >1 event) and 137 all-cause deaths. In Cox proportional hazards models adjusted for age, sex, race, clinical site, education level, physical activity, total cholesterol level, high-density lipoprotein cholesterol level, systolic blood pressure, use of antihypertensive treatment, current cigarette smoking, diabetes status, body mass index, C-reactive protein level, hemoglobin A1c level, phosphorus level, troponin T level, log N-terminal pro-B-type natriuretic peptide level, fibroblast growth factor 23 level, estimated glomerular filtration rate, and proteinuria, the hazard ratios associated with per 1 SD log of CAC were 1.40 (95% CI, 1.16-1.69; P < .001) for cardiovascular disease, 1.44 (95% CI, 1.02-2.02; P = .04) for myocardial infarction, 1.39 (95% CI, 1.10-1.76; P = .006) for heart failure, and 1.19 (95% CI, 0.94-1.51; P = .15) for all-cause mortality. In addition, inclusion of CAC score led to an increase in the C statistic of 0.02 (95% CI, 0-0.09; P < .001) for predicting cardiovascular disease over use of all the above-mentioned established and novel cardiovascular disease risk factors.

Conclusions and Relevance

Coronary artery calcification is independently and significantly related to the risks of cardiovascular disease, myocardial infarction, and heart failure in patients with CKD. In addition, CAC improves risk prediction for cardiovascular disease, myocardial infarction, and heart failure over use of established and novel cardiovascular disease risk factors among patients with CKD; however, the changes in the C statistic are small.

Noninvasive Cardiovascular Risk Assessment of the Asymptomatic Diabetic Patient: The Imaging Council of the American College of Cardiology

Increased cardiovascular morbidity and mortality in patients with type 2 diabetes is well established; diabetes is associated with at least a 2-fold increased risk of coronary heart disease. Approximately two-thirds of deaths among persons with diabetes are related to cardiovascular disease. Previously, diabetes was regarded as a "coronary risk equivalent," implying a high 10-year cardiovascular risk for every diabetes patient. Following the original study by Haffner et al., multiple studies from different cohorts provided varying conclusions on the validity of the concept of coronary risk equivalency in patients with diabetes. New guidelines have started to acknowledge the heterogeneity in risk and include different treatment recommendations for diabetic patients without other risk factors who are considered to be at lower risk. Furthermore, guidelines have suggested that further risk stratification in patients with diabetes is warranted before universal treatment. The Imaging Council of the American College of Cardiology systematically reviewed all modalities commonly used for risk stratification in persons with diabetes mellitus and summarized the data and recommendations. This document reviews the evidence regarding the use of noninvasive testing to stratify asymptomatic patients with diabetes with regard to coronary heart disease risk and develops an algorithm for screening based on available data.

Systemic Inflammation Is Associated With Coronary Artery Calcification and All-Cause Mortality in Chronic Kidney Disease

BACKGROUND

Presence of systemic inflammation in chronic kidney disease (CKD) is associated with advanced coronary artery calcification (CAC). The prognostic significance of this association, however, is unknown. We evaluated the associations between CAC, estimated glomerular filtration rate (eGFR) and all-cause mortality, to determine whether the associations differ according to the presence of systemic inflammation.

METHODS AND RESULTS

We followed 30,703 consecutive individuals who underwent CAC measurement for a median of 79 months (IQR, 65-96 months). Patients were categorized according to baseline CAC score (0, 1-99, 100-399 and ≥400), eGFR (<45, 45-59, 60-74, 75-89, 90-104, and ≥105 ml/min/1.73 m(2)) and high-sensitivity C-reactive protein (hsCRP; <2.0, and ≥2.0 mg/L). Prevalence and extent of CAC were greater in those with lower eGFR and higher hsCRP accordingly, even after adjustment. Lower eGFR was strongly associated with higher CAC score (≥400), and the association was more significant in patients with higher hsCRP. The greater CAC burden was associated with worse outcome in the CKD patients (eGFR <60 ml/min/1.73 m(2)) only in those with higher hsCRP.

CONCLUSIONS

Patients with low eGFR and more extensive CAC had greater risk of mortality, and associations differed according to the presence of systemic inflammation. Among the CKD patients, coronary evaluation may be considered for those with elevated hsCRP. (Circ J 2016; 80: 1644-1652).

Ankle Brachial Index and Subsequent Cardiovascular Disease Risk in Patients With Chronic Kidney Disease

BACKGROUND

The clinical implications of ankle-brachial index (ABI) cutpoints are not well defined in patients with chronic kidney disease (CKD) despite increased prevalence of high ABI attributed to arterial stiffness. We examined the relationship of ABI with cardiovascular disease (CVD) and all-cause mortality among CKD patients.

METHODS AND RESULTS

Three thousand six hundred twenty-seven participants without clinical peripheral artery disease (PAD) at baseline from the Chronic Renal Insufficiency Cohort Study were included. ABI was obtained per standard protocol and CVD events were confirmed by medical record adjudication. A U-shaped association of ABI with PAD, myocardial infarction (MI), composite CVD, and all-cause mortality was observed. Individuals with an ABI between 1.0 and <1.4 had the lowest risk of outcomes. Compared to participants with an ABI between 1.0 and <1.4, multiple-adjusted hazard ratios (95% confidence intervals) for those with an ABI of <0.9, 0.9 to <1.0, and ≥1.4 were 5.78 (3.57, 9.35), 2.76 (1.56, 4.88), and 4.85 (2.05, 11.50) for PAD; 1.67 (1.23, 2.29), 1.85 (1.33, 2.57), and 2.08 (1.10, 3.93) for MI; 1.51 (1.27, 1.79), 1.39 (1.15, 1.68), and 1.23 (0.82, 1.84) for composite CVD; and 1.55 (1.28, 1.89), 1.36 (1.10, 1.69), and 1.00 (0.62, 1.62) for all-cause mortality, respectively.

CONCLUSIONS

This study indicates that ABI <1.0 was related to risk of PAD, MI, composite CVD, and all-cause mortality whereas ABI ≥1.4 was related to clinical PAD. These findings suggest that ABI cutpoints of <1.0 or ≥1.4 for diagnosing PAD and ABI <1.0 for CVD risk stratification should be further evaluated among CKD patients.

Chronic Renal Insufficiency Cohort Study (CRIC): Overview and Summary of Selected Findings

The Chronic Renal Insufficiency Cohort (CRIC) Study is a United States multicenter, prospective study of racially and ethnically diverse patients with CKD. Although the original aims of the study were to identify novel predictors of CKD progression and to elucidate the risk and manifestations of cardiovascular disease among nearly 4000 individuals with CKD, the CRIC Study has evolved into a national resource for investigation of a broad spectrum of CKD-related topics. The study has produced >90 published scientific articles, promoted many young investigative careers in nephrology, and fostered international collaborations focused on understanding the global burden of CKD. The third phase of the CRIC Study will complete enrollment of 1500 additional study participants in 2015 and is designed to answer questions regarding morbidity and mortality in mild-to-moderate CKD and to assess the burden of CKD in older persons. This review highlights some of the salient findings of the CRIC Study in the areas of race and ethnicity, CKD progression, CKD and cognition, and cardiovascular disease outcomes; it also outlines the ongoing and forthcoming opportunities for the global nephrology community to enhance its understanding of CKD and related complications through the study.

A review of the effect of diet on cardiovascular calcification

Cardiovascular (CV) calcification is known as sub-clinical atherosclerosis and is recognised as a predictor of CV events and mortality. As yet there is no treatment for CV calcification and conventional CV risk factors are not consistently correlated, leaving clinicians uncertain as to optimum management for these patients. For this reason, a review of studies investigating diet and serum levels of macro- and micronutrients was carried out. Although there were few human studies of macronutrients, nevertheless transfats and simple sugars should be avoided, while long chain ω-3 fats from oily fish may be protective. Among the micronutrients, an intake of 800 μg/day calcium was beneficial in those without renal disease or hyperparathyroidism, while inorganic phosphorus from food preservatives and colas may induce calcification. A high intake of magnesium (≥380 mg/day) and phylloquinone (500 μg/day) proved protective, as did a serum 25(OH)D concentration of ≥75 nmol/L. Although oxidative damage appears to be a cause of CV calcification, the antioxidant vitamins proved to be largely ineffective, while supplementation of α-tocopherol may induce calcification. Nevertheless other antioxidant compounds (epigallocatechin gallate from green tea and resveratrol from red wine) were protective. Finally, a homocysteine concentration >12 µmol/L was predictive of CV calcification, although a plasma folate concentration of >39.4 nmol/L could both lower homocysteine and protect against calcification. In terms of a dietary programme, these recommendations indicate avoiding sugar and the transfats and preservatives found in processed foods and drinks and adopting a diet high in oily fish and vegetables. The micronutrients magnesium and vitamin K may be worthy of further investigation as a treatment option for CV calcification.

Coronary Artery Calcium Assessment in CKD: Utility in Cardiovascular Disease Risk Assessment and Treatment?

Coronary artery calcification (CAC) is a strong predictor of cardiovascular event rates in the general population, and scoring with multislice computed tomography commonly is used to improve risk stratification beyond clinical variables. CAC is accelerated in chronic kidney disease, but this occurs as a result of 2 distinct pathologic processes that result in medial (arteriosclerosis) and intimal (atherosclerosis) deposition. Although there are data that indicate that very high CAC scores may be associated with increased risk of death in hemodialysis, average CAC scores in most patients are elevated at a level at which discriminatory power may be reduced. There is a lack of data to guide management strategies in these patients based on CAC scores. There are even fewer data available for nondialysis patients, and it is uncertain whether CAC score confers an elevated risk of premature cardiovascular morbidity and mortality in such patients. In this article, we review the evidence regarding the utility of CAC score for noninvasive cardiovascular risk assessment in individuals with chronic kidney disease, using a clinical vignette that highlights some of the limitations in using CAC score and considerations in risk stratification.

Practice patterns for the surgical treatment of T1 renal cell carcinoma: a nationwide population-based register study

OBJECTIVE

Treatment of renal cell carcinoma (RCC) with radical nephrectomy (RN) induces chronic kidney disease more frequently compared with nephron-sparing surgery (NSS), which may have an impact on overall survival. Thus, NSS is recommended for RCCs up to 7 cm (T1). The aim of this study was to determine the extent to which these recommendations are implemented in clinical practice.

MATERIAL AND METHODS

Data were extracted from the Swedish National Kidney Cancer Register, a population-based register covering 98% of all RCCs in Sweden. In total, 3158 patients (1892 men, 1266 women) were primarily diagnosed with cT1N0M0 and treated surgically during 2005-2011. The administered treatments were evaluated between different hospitals as well as between the 21 independent healthcare counties.

RESULTS

In all, 742 patients were treated with NSS, 2339 with RN and 77 with minimally invasive ablative treatments. For cT1a RCC, patients treated with NSS increased from 22% in 2005 to 53% in 2011, and for cT1b from 2% to 10%. Nephron-sparing treatments for cT1a RCC were performed in 62% in university hospitals, 34% in intermediate- and 11% in low-volume hospitals. There was significant (p < 0.001) variation (31-67%) between the university hospitals and also for patient care in the 21 different counties (16-78%). There was an increased relative survival after NSS for T1a patients compared with RN. The register design by itself indicates limitations using data gathered from all Swedish hospitals.

CONCLUSIONS

NSS was underutilized in many hospitals and a patient's chance of being offered NSS varied according to their place of residence. Patients with cT1a RCC treated with NSS had a significantly better relative survival than those treated with RN.

Anti-osteoporotic drugs and vascular calcification: the bidirectional calcium traffic

During the last years, numerous epidemiological studies have demonstrated a direct relationship between vascular calcification and low bone mineral density. This observation is in line with experimental data demonstrating the osteogenic characteristics of calcified arteries. Various common risk factors have been suggested to link vascular calcification and bone loss, including aging, estrogen deficiency, vitamin D and K deficiency, diabetes mellitus, renal failure, smoking, chronic inflammation and oxidative stress. Although the underlying pathogenetic mechanisms are not yet clear, current research is focusing on anti-osteoporotic agents that could potentially affect the deposition of calcium in the arterial wall and thus provide an additional therapeutic strategy in elderly osteoporotic women prone to calcific cardiovascular disease.