Long-term risks of major adverse cardiovascular events after acute kidney injury: a systematic review and meta-analysis

Background and aims: Acute kidney injury (AKI) is increasingly recognized as a long-term risk factor for chronic kidney disease and cardiovascular disease (CVD). However, it remains uncertain which patients with AKI are at greatest CVD risk. We performed a systematic review and meta-analysis to quantify CVD risks post-AKI and to determine whether these risks differ by AKI severity, duration, and clinical setting. Methods: PubMed and Embase were systematically searched for studies comparing individuals with and without AKI and reporting major adverse cardiovascular events (MACE) or individual outcomes such as myocardial infarction (MI), stroke, heart failure (HF), or cardiovascular mortality. Follow-up was at least 1 year. Relative risks (RRs) were pooled in meta-analyses using random-effect models. Subgroup and metaregression analyses were used to explore heterogeneity across patient and AKI characteristics, and clinical settings. Results: We included 54 studies comprising 1261 090 individuals, of whom 290 648 experienced AKI. Meta-analyses showed that AKI was associated with an RR of 1.97 [95% confidence interval (CI) 1.67-2.27] for MACE (13.9% overall incidence), 1.64 [95% CI 1.38-1.89] for MI (3.5% overall incidence), 1.36 [95% CI 1.13-1.59] for stroke (1.7% overall incidence), 1.92 [95% CI 1.67-2.16] for HF (3.5% overall incidence), and 1.86 [95% CI 1.59-2.13] for cardiovascular mortality (9.4% overall incidence), compared to patients without AKI. Elevated risks were observed across all AKI stages and durations and in patients across all studied clinical settings, including noncardiac care. The highest RRs were shown for more severe AKI stages and longer AKI durations. Older age and lower baseline estimated glomerular filtration rate were associated with even higher risk of MACE compared to patients without AKI. Conclusions: AKI is followed by an increase in CVD risk, even after AKI with low severity. These findings highlight AKI as a clinically relevant CVD risk marker and support the need for targeted post-AKI care management to prevent future cardiovascular events.