Timing of acute kidney injury detection and survival in patients with acute myocardial infarction following percutaneous coronary intervention: a multicenter cohort study

The development of acute kidney injury (AKI) is associated with increased mortality in patients with acute myocardial infarction (AMI) following percutaneous coronary intervention (PCI). However, the impact of AKI detection timing on survival has not been systematically evaluated. A total of 3,112 AMI patients undergoing PCI with consecutive 3‑day postoperative serum creatinine (SCr) monitoring were included from the Cardiorenal Improvement II (CIN‑II) cohort. Patients were categorized into four groups: no AKI, AKI first detected within 24 h (24 h AKI), AKI first detected between 24 and 48 h (48 h AKI), and AKI first detected between 48 and 72 h (72 h AKI). AKI detection timing was defined as the time at which the diagnostic SCr criteria were first met, recognizing that this reflects the time of diagnosis rather than the biological onset of injury. AKI was first detected in 10.9% of patients within 24 h, 9.1% within 24–48 h, and 6.4% within 48–72 h post-PCI. After multivariable adjustment, 24 h AKI (90-day HR 2.29, 95% CI: 1.58–334; 1-year HR 2.07, 95% CI: 1.49–2.88; 3-year HR 1.73, 95% CI: 1.31–2.29) and 48 h AKI (90-day HR 2.42, 95% CI: 1.55–3.78; 1-year HR 2.25, 95% CI: 1.53–3.31; 3-year HR 2.05, 95% CI: 1.49–2.83) were independently associated with significantly higher mortality compared with no AKI (all P < 0.05). AKI first detected at 48–72 h was not associated with a statistically significant increase in mortality ( P > 0.05 for all time points); however, this finding should be interpreted with caution given the smaller subgroup size and does not exclude a clinically meaningful association. In AMI patients undergoing PCI, AKI detected within 48 h was associated with higher mortality, whereas AKI first detected at 48–72 h did not reach statistical significance for mortality association. These findings underscore the importance of SCr monitoring in the first 48 h after PCI for early risk stratification. However, continued monitoring beyond 48 h may still be warranted in higher-risk patients.