Persistent high serum bicarbonate and the risk of heart failure in patients with chronic kidney disease (CKD): A report from the Chronic Renal Insufficiency Cohort (CRIC) study

• Published in: Journal of the American Heart Association Vol. 4; no. 4
• Main Authors: Dobre, Mirela, Yang, Wei, Pan, Qiang, Appel, Lawrence, Bellovich, Keith, Chen, Jing, Feldman, Harold, Fischer, Michael J, Ham, L L, Hostetter, Thomas, Jaar, Bernard G, Kallem, Radhakrishna R, Rosas, Sylvia E, Scialla, Julia J, Wolf, Myles, Rahman, Mahboob
• Format: Journal Article
• Language: English
• Published: England Blackwell Publishing Ltd 20.04.2015
• Subjects: Bicarbonates - blood; Disease Progression; Diuretics - therapeutic use; Female; Glomerular Filtration Rate; Heart Failure - blood; Heart Failure - etiology; Humans; Longitudinal Studies; Male; Middle Aged; Original Research; Renal Insufficiency, Chronic - blood; Renal Insufficiency, Chronic - complications; Renal Insufficiency, Chronic - drug therapy; Risk Factors; heart failure; CKD; serum bicarbonate
• ISSN: 2047-9980; 2047-9980
• DOI: 10.1161/JAHA.114.001599

Serum bicarbonate varies over time in chronic kidney disease (CKD) patients, and this variability may portend poor cardiovascular outcomes. The aim of this study was to conduct a time-updated longitudinal analysis to evaluate the association of serum bicarbonate with long-term clinical outcomes: heart failure, atherosclerotic events, renal events (halving of estimated glomerular filtration rate [eGFR] or end-stage renal disease), and mortality. Serum bicarbonate was measured annually, in 3586 participants with CKD, enrolled in the Chronic Renal Insufficiency Cohort (CRIC) study. Marginal structural models were created to allow for integration of all available bicarbonate measurements and proper adjustment for time-dependent confounding. During the 6 years follow-up, 512 participants developed congestive heart failure (26/1000 person-years) and 749 developed renal events (37/1000 person-years). The risk of heart failure and death was significantly higher for participants who maintained serum bicarbonate >26 mmol/L for the entire duration of follow-up (hazard ratio [HR] 1.66; 95% confidence interval [CI], 1.23 to 2.23, and HR 1.36, 95% CI 1.02 to 1.82, respectively) compared with participants who kept their bicarbonate 22 to 26 mmol/L, after adjusting for demographics, co-morbidities, medications including diuretics, eGFR, and proteinuria. Participants who maintained serum bicarbonate <22 mmol/L had almost a 2-fold increased risk of renal disease progression (HR 1.97; 95% CI, 1.50 to 2.57) compared with participants with bicarbonate 22 to 26 mmol/L. In this large CKD cohort, persistent serum bicarbonate >26 mmol/L was associated with increased risk of heart failure events and mortality. Further studies are needed to determine the optimal range of serum bicarbonate in CKD to prevent adverse clinical outcomes.