This multicenter, prospective study prospectively enrolled patients undergoing cardiovascular surgery. Detailed perioperative clinical data and biospecimens were collected at multiple time points. The primary aim is to develop an early warning model for postoperative acute kidney injury (AKI) by integrating clinical data and biomarkers. Additionally, through long-term follow-up, the study seeks to characterize outcome trajectories and establish a prognostic model for AKI patients.

This study addresses four key questions: 1) Integration of clinical information and biomarkers to develop an early predictive model for cardiac surgery-associated acute kidney injury (CSA-AKI); 2) Identification of risk factors for CSA-AKI occurrence; 3) Determinants of prognosis in patients with CSA-AKI; and 4) Enhanced prediction of near- and long-term clinical event risks in this patient population.

Participants will receive standard perioperative management. The study protocol includes the following procedures:(1) Clinical Data Collection: Comprehensive perioperative clinical data will be systematically recorded. (2) Biospecimen Sampling: Serial blood and urine samples will be obtained at predefined time points throughout the perioperative period. (3) In-Hospital Monitoring: Clinical outcomes will be continuously monitored during the hospital stay. (3) Post-discharge Follow-up: Participants will be assessed at regular intervals after discharge to track the occurrence of major adverse events.

These findings provide a foundational basis for the development of a data-driven early-warning system. Such a system is designed to facilitate the prompt identification of high-risk patients and enable the initiation of personalized treatment strategies, thereby potentially improving clinical outcomes and optimizing resource allocation

Inclusion Criteria:

• Age ≥ 18 years；
• Scheduled to undergo elective cardiac surgery；
• Able to complete baseline data collection and provide written informed consent.

Exclusion Criteria:

• Preoperative serum creatinine > 353 μmol/L, history of or currently receiving dialysis therapy.
• History of kidney transplantation.
• Presence of malignant tumors.

Fuwai Hospital, CAMS & PUMC, Peking University People's Hospital; Guangdong People's Hospital; Fuwai Hospital Shenzhen (Sun Yat-sen Cardiovascular Hospital, Shenzhen); Huaxi Hospital, Sichuan University; Yantai Yuhuangding Hospital; Fuwai Centarl China Cardiovascular Hospital; Fuwai Yunnan Hospital, Academy of Medical Science; Yinzhou District Center for Disease Control and Prevention, Ningbo; Peking University First Hospital