Kidney Week

Abstract: TH-PO073

Preoperative Ionized Calcium Levels and Risk of AKI after Cardiac Surgery

Session Information

• AKI: Clinical, Outcomes, and Trials - Epidemiology and Pathophysiology
  October 24, 2024 | Location: Exhibit Hall, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Acute Kidney Injury

• 102 AKI: Clinical, Outcomes, and Trials

Authors

• Moon, Sung Jin, Catholic Kwandong University International Saint Mary's Hospital, Incheon, Korea (the Republic of)

Sung Jin Moon, MD, PhD

• Ji-Ho, Lee, Catholic Kwandong University International Saint Mary's Hospital, Incheon, Korea (the Republic of)

Lee Ji-Ho

• Lee, Jin Hyeog, Catholic Kwandong University International Saint Mary's Hospital, Incheon, Korea (the Republic of)

Jin Hyeog Lee, MD

• Chang, Jae Hyun, Gachon University Gil Medical Center, Incheon, Korea (the Republic of)

Jae Hyun Chang, MD, PhD

• Park, Jung Tak, Yonsei University Institute of Kidney Disease, Seodaemun-gu, Seoul, Korea (the Republic of)

Jung Tak Park, MD, PhD

• Koh, Hee Byung, Catholic Kwandong University International Saint Mary's Hospital, Incheon, Korea (the Republic of)

Hee Byung Koh, MD

Group or Team Name

• International St. Mary’s Hospital, Catholic Kwandong University, Incheon, Republic of Korea.

Background

Despite its close correlation with cardiovascular diseases, the association between serum calcium levels and postoperative AKI is not fully elucidated.

Methods

Patients aged ≥18 years who underwent cardiac surgery at two tertiary hospitals between 2006 and 2020 were retrospectively evaluated. Their preoperative serum ionized calcium levels were categorized into quartiles. The primary outcome was postoperative AKI within 48 hours, classified in accordance with the KDIGO criteria. AKI was further categorized into mild AKI (stage 1) and moderate-to-severe AKI (stage 2-3).

Results

Of the 9,779 patients (mean age, 64.0 years; male, 60.1%), postoperative mild AKI and moderate-to-severe AKI were noted in 3,848 (39.3%) and 719 (7.4%) patients, respectively. AKI were more prevalent in patients with lower ionized calcium levels (mild AKI: 46.9%, 38.7%, 35.1%, and 36.8%; moderate-to-severe AKI: 11.6%, 7.1%, 5.4%, and 5.3% from Q1-4, respectively, both P-trend <0.001). In logistic regression analysis, compared with Q4, the adjusted odds ratios (aORs) [95% CI] for mild AKI were 1.57 [1.38-1.79], 1.16 [1.02-1.32], and 0.99 [0.87-1,13] for Q1-3, respectively (P-trend <0.001). Similar results were observed in analysis for the moderate-to-severe AKI (aOR of Q1-3; 2.11 [1.66-2.68], 1.35 [1.05-1.73], and 1.04 [0.80-1.36] compared with Q4; P-trend <0.001). In mediation analysis, cardiopulmonary bypass time and intra-operative inotropic use explained 12.1-16.9% and 12.9-19.5% of the association between calcium levels and AKI, respectively (all of P <0.001).

Conclusion

Lower serum ionized calcium levels were associated with a higher incidence of AKI in patients undergoing cardiac surgery. Hemodynamic factors may have influenced this association, and further studies are needed to investigate the underlying mechanism.

Association between preoperative ionized calcium levels quartiles and clinical outcomes