Risk-Stratified Prognostic Implications of Contrast-Associated Acute Kidney Injury After Percutaneous Coronary Intervention

BACKGROUND: The clinical importance of contrast-associated acute kidney injury (CA-AKI), the most common complication after percutaneous coronary intervention (PCI), is debated. OBJECTIVES: We aimed to assess the association between CA-AKI and long-term outcomes, overall and across the National Cardiovascular Data Registry (NCDR) AKI risk categories. METHODS: We analyzed patients undergoing PCI between September 2008 and October 2021 from a Japanese registry aligned with the NCDR and categorized them by the NCDR AKI risk score tertiles (low-risk [<4.9%], intermediate-risk [4.9%-6.7%], and high-risk [≥6.7%]) groups. CA-AKI was defined as a 0.3 mg/dL increase or 50% increase in creatinine or the initiation of dialysis. Cox regression analyses assessed the association between CA-AKI and 2-year major adverse cardiovascular events (MACE; all-cause mortality, acute coronary syndrome, heart failure hospitalization, or stroke), and interactions were tested to examine whether preprocedural risk modified the association of CA-AKI with outcomes. RESULTS: Of 7,916 patients, 723 (9.1%) developed CA-AKI; its incidence for low-risk, intermediate-risk, and high-risk groups was 2.3%, 7.3%, and 17.9%, respectively. CA-AKI was associated with an increased risk of MACE (adjusted HR [aHR]: 1.64; 95% CI: 1.37-1.97). The interaction between AKI risk profile and MACE was not significant (P interaction = 0.14), and a consistent association of CA-AKI and MACE across risk categories was observed (high-risk, aHR: 1.60; 95% CI: 1.30-1.98; intermediate, aHR: 1.64; 95% CI: 1.10-2.44; and low, aHR: 2.84; 95% CI: 1.43-5.65, respectively). CONCLUSIONS: CA-AKI was associated with long-term outcomes across all AKI risk profiles in PCI patients, underscoring the importance of interventions to reduce periprocedural CA-AKI.