Abstract
We investigated the recovery pattern from acute kidney injury (AKI) following acute myocardial infarction (AMI) and its association with long-term mortality. The retrospective study included AMI patients (2002-2027), who developed AKI during hospitalization. Creatinine (Cr) measurements were collected and categorized into 24 h timeframes up to 7 days from AKI diagnosis. The following groups of recovery patterns were defined: rapid (24-48 h)/no rapid and early (72-144 h)/no early recovery. Specific cut-off points for recovery at each AKI stage and timeframe were determined through receiver operating characteristic (ROC) curves. The probability of long-term (up to 10 years) mortality as a post-AKI recovery was investigated using a survival approach. Out of 17,610 AMI patients, 1069 developed AKI. For stage 1 AKI, patients with a Cr ratio <1.5 at 24 h and/or <1.45 at 48 h were defined as 'rapid recovery'; for stages 2-3 AKI, a Cr ratio <2.5 at 96 h was defined as 'early recovery'. Mortality risk in stage 1 AKI was higher among the non-rapidly recovered: AdjHR = 1.407; 95% CI: 1.086-1.824; p = 0.010. Among stages 2-3 AKI patients, the risk for long-term mortality was higher among patients who did not recover in the early period: AdjHR = 1.742; 95% CI: 1.085-2.797; p = 0.022. The absence of rapid recovery in stage 1 AKI and lack of early recovery in stages 2-3 AKI are associated with higher long-term mortality.