Aortic Valve Calcium Associates with All-Cause Mortality Independent of Coronary Artery Calcium and Inflammation in Patients with End-Stage Renal Disease

Coronary artery calcification and aortic valve calcification in patients with kidney failure: a sex-disaggregated study

BACKGROUND

Chronic kidney disease (CKD) is linked to an increased cardiovascular disease (CVD) burden. Albeit underappreciated, sex differences are evident in CKD with females being more prone to CKD development, but males progressing more rapidly to kidney failure (KF). Cardiovascular remodelling is a hallmark of CKD with increased arterial and valvular calcification contributing to CKD. However, little is known regarding sex differences in calcific cardiovascular remodelling in KF patients. Thus, we hypothesise that sex differences are present in coronary artery calcification (CAC) and aortic valve calcification (AVC) in patients with KF.

METHODS

KF patients, males (n = 214) and females (n = 107), that had undergone computer tomography (CT) assessment for CAC and AVC were selected from three CKD cohorts. All patients underwent non-contrast multi-detector cardiac CT scanning, with CAC and AVC scoring based on the Agatston method. Baseline biochemical measurements were retrieved from cohort databases, including plasma analyses for inflammation markers (IL-6, TNF, hsCRP) and oxidative stress by skin autofluorescence measuring advanced glycation end-products (AGE), amongst other variables.

RESULTS

Sex-disaggregated analyses revealed that CAC score was associated with age in both males and females (both p < 0.001). Age-adjusted analyses revealed that in males CAC was associated with diabetes mellitus (DM) (p = 0.018) and CVD (p = 0.011). Additionally, for females CAC associated with IL-6 (p = 0.005) and TNF (p = 0.004). In both females and males CAC associated with AGE (p = 0.042 and p = 0.05, respectively). CAC was associated with mortality for females (p = 0.015) independent of age. AVC in females was not reviewed due to low AVC-positive samples (n = 14). In males, in multivariable regression AVC was associated with age (p < 0.001) and inflammation, as measured by IL-6 (p = 0.010).

CONCLUSIONS

In female KF patients inflammatory burden and oxidative stress were associated with CAC. Whereas in male KF patients oxidative stress and inflammation were associated with CAC and AVC, respectively. Our findings suggest a sex-specific biomarker signature for cardiovascular calcification that may affect the development of cardiovascular complications in males and females with KF.

Cardiac valve calcification as a predictor of cardiovascular outcomes in peritoneal dialysis patients: an inverse probability of treatment weighting analysis

BACKGROUND

Cardiovascular events (CVE) are the leading cause of death in peritoneal dialysis (PD) patients. The predictive value of cardiac valve calcification (CVC) for CVE in dialysis patients remains controversial. In particular, such studies are limited in PD patients. We aimed to examine the predictive role of CVC for CVE and cardiovascular mortality in PD patients.

METHODS

A retrospective analysis was performed on patients who initiated PD in our hospital. According to the result of echocardiography, patients were divided into CVC group and non-CVC group. The differences in baseline demographic characteristics, biochemical variables, comorbidities, and clinical outcomes between the two groups were compared. Kaplan-Meier method was used to obtain survival curves. The Cox regression model was used to evaluate the influence of CVC for cardiovascular outcomes. The inverse probability of treatment weighting (IPTW) was used to eliminate influence of the confounders in the groups.

RESULTS

458 peritoneal dialysis patients were enrolled in this study. 77 patients were in CVC group and 381 patients in non-CVC group. The average follow-up time was (32 ± 21) months. At baseline, the absolute standardized difference (ASD) of age, BMI, history of CVE, diabetes, LVEF, LVMI, albumin, calcium, phosphorus, triglycerides, hsCRP, urine volume, Kt/V, statins and vitamin D intake rate were greater than 0.1 between the two groups. All of ASD dropped to less than 0.1 after IPTW, which meant that the balance had been reached between the two groups. Multivariable logistic analysis showed that advanced age, diabetes, and hyperphosphatemia were associated with CVC. The Kaplan-Meier survival curve showed the cumulative CVE-free survival rate and cardiovascular survival rate of CVC group were significantly lower than that of non-CVC group before and after IPTW (log-rank P < 0.05). After IPTW was used to eliminate the effect of confounders, multivariate Cox regression analysis still showed CVC was an independent risk factor for CVE (HR = 2.383, 95% CI 1.331~4.264, P = 0.003) and cardiovascular mortality (HR = 2.347, 95% CI 1.211~4.548, P = 0.012) in PD patients.

CONCLUSION

The prevalence of CVC is high in peritoneal dialysis patients. CVC is an independent risk factor for CVE and cardiovascular mortality in peritoneal dialysis patients.

Cellular Senescence, Aging and Non-Aging Processes in Calcified Aortic Valve Stenosis: From Bench-Side to Bedside

Aortic valve stenosis (AS) is the most common valvular heart disease. The incidence of AS increases with age, however, a significant proportion of elderly people have no significant AS, indicating that both aging and nonaging pathways are involved in the pathomechanism of AS. Age-related and stress-induced cellular senescence accompanied by further active processes represent the key elements of AS pathomechanism. The early stage of aortic valve degeneration involves dysfunction and disruption of the valvular endothelium due to cellular senescence and mechanical stress on blood flow. These cells are replaced by circulating progenitor cells, but in an age-dependent decelerating manner. When endothelial denudation is no longer replaced by progenitor cells, the path opens for focal lipid deposition, initiating subsequent oxidation, inflammation and micromineralisation. Later stages of AS feature a complex active process with extracellular matrix remodeling, fibrosis and calcification. Echocardiography is the gold standard method for diagnosing aortic valve disease, although computed tomography and cardiac magnetic resonance are useful additional imaging methods. To date, no medical treatment has been proven to halt the progression of AS. Elucidation of differences and similarities between vascular and valvular calcification pathomechanisms may help to find effective medical therapy and reduce the increasing health burden of the disease.

Aortic valve calcification predicts poor outcomes after primary percutaneous coronary intervention

BACKGROUND

Aortic valve calcification (AVC) is associated with increased cardiovascular risk in the general population. We sought to investigate whether AVC identified by transthoracic echocardiography could be a predictor of long-term adverse events after primary percutaneous coronary intervention (PCI) in patients with acute myocardial infarction.

METHODS

Patients undergoing primary PCI were consecutively enrolled in this cohort study between 1 January 2009 and 31 December 31 2018. The presence of AVC was identified by transthoracic echocardiography one to three days after PCI. The primary endpoint was major adverse cardiovascular and cerebral events (MACCE) during follow-up. Propensity score matching was adopted to adjust for the baseline differences between groups.

RESULTS

Of 2117 patients enrolled in the study, 566 (26.7%) were found to have AVC. Patients with AVC were older, more likely to be women, and disposed to have comorbidities and complex lesions. During a median follow-up period of 6.1 years, 699 cases of MACCE occurred, including 243 (42.9%) cases in patients with AVC and 456 (29.4%) cases in patients without AVC. After 1:1 propensity score matching, the presence of AVC increased the risk of MACCE (adjusted hazard ratio: 1.442, 95% confidence interval: 1.186 to 1.754, p < 0.001). This difference persisted when sensitivity and subgroup analyses were made.

CONCLUSIONS

AVC identified by transthoracic echocardiography independently increased the long-term risk of MACCE after primary PCI in patients with acute myocardial infarction. This imaging feature will contribute to better risk stratification in this population.

Epidemiology of Aortic Stenosis/Aortic Valve Replacement (from the Nationwide Swedish Renal Registry)

Contemporary data on the prevalence and incidence of aortic stenosis (AS) and aortic valve replacement (AVR) in patients initiating dialysis are scarce. This observational cohort study aimed to estimate (1) the point prevalence of AS and AVR at dialysis start and (2) the AS incidence and associated factors prospective to dialysis initiation. The study included 14,550 patients initiating dialysis registered in the Swedish Renal Registry between 2005 and 2018. AS was defined by the International Statistical Classification of Diseases, Tenth Revision codes, and AVR by the surgical procedure codes. Associations between covariates and outcomes were assessed in Cox regression models. The median age was 68 (57 to 77), 66% were males, and the point prevalence of AS and AVR was 3.4% and 1.1%, respectively. In those without known AS/AVR at dialysis initiation (n = 14,050), AS was diagnosed in 595 patients (incidence 16.3/1000 person-years, 95% confidence interval [CI] 15.1 to 17.7/1,000 person-years) during a median follow-up of 2.7 years (interquartile range 1.1 to 5.7). In adjusted Cox regression models, higher age (hazard ratio [HR] 1.03, 95% CI 1.02 to 1.04), male gender (HR 1.51, 95% CI 1.25 to 1.83), atrial fibrillation (HR 1.32, 95% CI 1.06 to 1.64), and hypertension (HR 1.65, 95% CI 1.03 to 2.65) were associated with incident AS. Peritoneal dialysis patients had a nonsignificant trend toward higher AS risk compared with hemodialysis (HR 1.18, 95% CI 0.99 to 1.40). About 20% of patients (n = 113) diagnosed with incident AS underwent AVR (incidence 3.1/1000 person-years, 95% CI 2.6 to 3.7/1,000). Only the male gender was associated with AVR (HR 2.07, 95% CI 1.30 to 3.30). In conclusion, the prevalence and incidence of AS and AVR in patients initiating dialysis are high. A fifth of newly diagnosed AS underwent AVR after dialysis onset.

Role of GDF-15, YKL-40 and MMP 9 in patients with end-stage kidney disease: focus on sex-specific associations with vascular outcomes and all-cause mortality

BACKGROUND

Sex differences are underappreciated in the current understanding of cardiovascular disease (CVD) in association with chronic kidney disease (CKD). A hallmark of CKD is vascular aging that is characterised, amongst others, by; systemic inflammation, microbiota disbalance, oxidative stress, and vascular calcification-features linked to atherosclerosis/arteriosclerosis development. Thus, it is the necessary to introduce novel biomarkers related to athero-/arteriosclerotic damage for better assessment of vascular ageing in patients CKD. However, little is known about the relationship between uraemia and novel CVD biomarkers, such as growth differentiation factor-15 (GDF-15), cartilage glycoprotein-39 (YKL-40) and matrix metalloproteinase-9 (MMP-9). Therefore, we hypothesise that there are sex-specific relationships between GDF-15, YKL-40, MMP-9 levels in end-stage kidney disease (ESKD) patients in relation to gut microbiota, vascular calcification, inflammation, comorbidities, and all-cause mortality.

METHODS

ESKD patients, males (n = 151) and females (n = 79), not receiving renal replacement therapy were selected from two ongoing prospective ESKD cohorts. GDF-15, YKL-40 and MMP9 were analysed using enzyme-linked immunosorbent assay kits. Biomarker levels were analysed in the context of gut microbiota-derived trimethylamine N-oxide (TMAO), vascular calcification, inflammatory response, oxidative stress, comorbidities, and all-cause mortality.

RESULTS

Increased GDF-15 correlated with higher TMAO in females only, and with higher coronary artery calcification and IL-6. In females, diabetes was associated with elevated GDF-15 and MMP-9, whilst males with diabetes only had elevated GDF-15. No associations were found between biomarkers and CVD comorbidity. Deceased males and females had higher GDF-15 concentrations (p = 0.01 and p < 0.001, respectively), meanwhile only YKL-40 was increased in deceased males (p = 0.02).

CONCLUSIONS

In conclusion, in males GDF-15 and YKL-40 were related to vascular calcification, inflammation, and oxidative stress, whilst in females GDF-15 was related to TMAO. Increased levels of YKL-40 and GDF-15 in males, and only GDF-15 in females, were associated with all-cause mortality. Our findings suggest that sex-specific associations of novel CVD biomarkers have a potential to affect development of cardiovascular complications in patients with ESKD.

Valvular Calcific Deposits and Mortality in Peritoneal Dialysis Patients: A Propensity Score-Matched Cohort Analysis

OBJECTIVE

This study aimed to compare mortality between peritoneal dialysis (PD) patients with and without cardiac valve calcification (CVC).

METHODS

Patients undergoing PD at the dialysis center of the Second Affiliated Hospital of Soochow University from January 1, 2009, to June 31, 2016, were included and followed through December 31, 2018. The inclusion criteria were (1) age ≥18 years and (2) PD vintage ≥1 month. The exclusion criteria were (1) a history of hemodialysis or renal transplantation before PD; (2) diagnosed congenital heart disease, rheumatic heart disease, or hyperthyroid heart disease; and (3) loss to follow-up. Differences in mortality rates were compared using a Fine-Gray proportional hazards model.

RESULTS

A total of 310 patient cases were included in this study, including 237 cases without CVC (non-CVC group). The CVC group included 59 cases with aortic valve calcification (AVC), 6 cases with mitral valve calcification (MVC), and 8 cases of AVC associated with MVC. After propensity score matching, 68 pairs were selected. The multivariate competing risk regression analysis revealed that age (hazard ratio [HR]: 1.06, 95% confidence interval [95% CI]: 1.03-1.10, p < 0.001) and CVC group (HR: 1.83, 95% CI: 1.04-3.20, p < 0.05) were independent risk factors associated with mortality. No significant difference was observed in technique survival between the 2 groups.

CONCLUSION

CVC is an independent risk factor for mortality in PD patients.

Functional vitamin K insufficiency, vascular calcification and mortality in advanced chronic kidney disease: A cohort study

Patients with chronic kidney disease (CKD) suffer from vitamin K deficiency and are at high risk of vascular calcification (VC) and premature death. We investigated the association of functional vitamin K deficiency with all-cause mortality and whether this association is modified by the presence of VC in CKD stage 5 (CKD G5). Plasma dephosphorylated-uncarboxylated matrix Gla-protein (dp-ucMGP), a circulating marker of functional vitamin K deficiency, and other laboratory and clinical data were determined in 493 CKD G5 patients. VC was assessed in subgroups by Agatston scoring of coronary artery calcium (CAC) and aortic valve calcium (AVC). Backward stepwise regression did not identify dp-ucMGP as an independent determinant of VC. During a median follow-up of 42 months, 93 patients died. Each one standard deviation increment in dp-ucMGP was associated with increased risk of all-cause mortality (sub-hazard ratio (sHR) 1.17; 95% confidence interval, 1.01-1.37) adjusted for age, sex, cardiovascular disease, diabetes, body mass index, inflammation, and dialysis treatment. The association remained significant when further adjusted for CAC and AVC in sub-analyses (sHR 1.22, 1.01-1.48 and 1.27, 1.01-1.60, respectively). In conclusion, functional vitamin K deficiency associates with increased mortality risk that is independent of the presence of VC in patients with CKD G5.