Association of calciprotein particles with serum phosphorus among patients undergoing conventional and extended-hours haemodialysis.

Background and hypothesis: Extended-hours haemodialysis (HD) is associated with better clinical outcomes than conventional HD. We investigated whether extended-hours HD and conventional HD have varying effects on blood levels of calciprotein particles (CPPs) and phosphorus, which have been identified as major pathogenic molecules for vascular calcification. Methods: Patients who underwent conventional or extended in-centre daytime HD between January and March 2020 were included. Plasma CPP levels, representing only secondary CPPs (CPP-II), were measured in pre-dialysis samples. Linear and non-linear associations between CPPs and serum phosphorus levels were examined across dialysis modalities. Results: A total of 382 participants (185 undergoing extended-hours HD and 197 undergoing conventional HD) were included in the analysis. The median age of participants was 71 years, 65% of the patients were men and the mean phosphorus level was 5.4 mg/dl. Plasma CPP (CPP-II) levels were lower in the extended-hours HD group than in the conventional HD group [40 018 (arbitrary units) AU versus 75 728 AU; P < .01]. Multivariable linear regression analysis showed that extended-hours HD was associated with lower natural logarithmic plasma CPP (CPP-II) levels: -0.64 (95% confidence interval -0.74 to -0.55). A restricted cubic spline function indicated that extended-hours HD was associated with lower plasma CPP (CPP-II) levels across levels of serum phosphorus, with significant differences observed between groups, especially in hyperphosphataemic conditions (P for interaction <.01). Conclusions: The extended-hours HD group had lower CPP levels than the conventional HD group despite no significant differences in serum phosphorus levels, which may contribute to better clinical outcomes in patients on extended-hours HD.

Association between stopping renin-angiotensin system inhibitors immediately before hemodialysis initiation and subsequent cardiovascular events.

It is controversial whether renin-angiotensin system inhibitors (RASIs) should be stopped in patients with advanced chronic kidney disease (CKD). Recently, it was reported that stopping RASIs in advanced CKD was associated with increased mortality and cardiovascular (CV) events; however, it remains unclear whether stopping RASIs before dialysis initiation affects clinical outcomes after dialysis, which this study aimed to evaluate. In this multicenter prospective cohort study in Japan, we included 717 patients (mean age, 67 years; 68% male) who had a nephrology care duration ≥90 days, initiated hemodialysis, and used RASIs 3 months before hemodialysis initiation. The multivariable adjusted Cox models were used to compare mortality and CV event risk between 650 (91%) patients who continued RASIs until hemodialysis initiation and 67 (9.3%) patients who stopped RASIs. During a median follow-up period of 3.5 years, 170 (24%) patients died and 228 (32%) experienced CV events. Compared with continuing RASIs, stopping RASIs was unassociated with mortality (adjusted hazard ratio [aHR]: 0.82; 95% confidence interval [CI]: 0.50-1.34) but was associated with higher CV events (aHR: 1.59; 95% CI: 1.06-2.38). Subgroup analyses showed that the risk of stopping RASIs for CV events was particularly high in patients aged <75 years, with a significant interaction between stopping RASIs and age. This study revealed that patients who stopped RASIs immediately before dialysis initiation were associated with subsequent higher CV events. Active screening for CV disease may be especially beneficial for these patients.

Relationship between peak aortic jet velocity and progression of aortic stenosis in patients undergoing hemodialysis.

BACKGROUND: The natural history of aortic stenosis (AS) progression, especially before severe AS development, is not well documented. We aimed to investigate the time course of peak aortic jet velocity (Vmax) and AS progression risk according to baseline Vmax, particularly whether there is a Vmax threshold. METHODS: In a retrospective multicenter cohort study of patients on hemodialysis with aortic valve calcification, we investigated the time series of Vmax and the relationship between the baseline Vmax and progression to severe AS by analyzing longitudinal echocardiographic data. RESULTS: Among 758 included patients (mean age, 71 years; 65% male), patients with Vmax <1.5, 1.5-1.9, 2.0-2.4, 2.5-2.9, and 3.0-3.9 m/s were 395 (52%), 216 (29%), 85 (11%), 39 (5.1%), and 23 (3.0%), respectively. The Vmax slope was gradual (mean 0.05-0.07 m/s/year) at Vmax <2 m/s, but steeper (mean 0.13-0.21 m/s/year) at Vmax ≥2 m/s. During a median 3.2-year follow-up, 52 (6.9%) patients developed severe AS. While patients with Vmax <2 m/s rarely developed severe AS, the risk of those with Vmax ≥2 m/s increased remarkably with an increasing baseline Vmax; the adjusted incidence rates in patients with Vmax <1.5, 1.5-1.9, 2.0-2.4, 2.5-2.9, and 3.0-3.9 m/s were 0.59, 0.57, 4.25, 13.8, and 56.1 per 100 person-years, respectively; the adjusted hazard ratio per 0.2 m/s increase in the baseline Vmax was 1.49 (95% confidence interval: 1.32-1.68) when Vmax ≥2 m/s. CONCLUSIONS: The risk of progression to severe AS increased with the baseline Vmax primarily at ≥2 m/s; a Vmax threshold of 2 m/s was observed.