High Dialysate Calcium Concentration is Associated with Worsening Left Ventricular Function

Area of Science:

• Nephrology
• Cardiology
• Biochemistry

Background:

• Dialysate calcium concentration (d[Ca]) may influence cardiovascular outcomes in hemodialysis (HD) patients.
• Higher d[Ca] has been associated with improved hemodynamic tolerance during HD.

Purpose of the Study:

• To assess the impact of different d[Ca] levels on global longitudinal strain (GLS) using echocardiography.
• To evaluate the cardiovascular effects of d[Ca] 1.75 mmol/L versus 1.25 mmol/L in HD patients.

Main Methods:

• Observational crossover study involving 19 HD patients.
• Two-dimensional echocardiography with speckle-tracking imaging was used to measure GLS before and during HD.
• Patients underwent HD with d[Ca] of 1.75 mmol/L and 1.25 mmol/L, with identical ultrafiltration.

Main Results:

• The 1.75 mmol/L d[Ca] was associated with a less pronounced drop in blood pressure.
• Post-HD serum total calcium was significantly higher with 1.75 mmol/L d[Ca] (11.5 ± 0.8 mg/dL) compared to 1.25 mmol/L d[Ca] (9.1 ± 0.5 mg/dL).
• GLS significantly decreased from baseline in both groups, with a more pronounced reduction observed with 1.75 mmol/L d[Ca] (-16.1 ± 2.6%) compared to 1.25 mmol/L d[Ca] (-17.3 ± 2.9%).

Conclusions:

• A dialysate calcium concentration of 1.75 mmol/L is associated with higher post-dialysis serum calcium levels.
• This higher serum calcium level contributes to impaired ventricular performance, indicated by worse GLS.
• Further research is needed to determine if these findings indicate myocardial stunning.