Klotho as an Early Marker of Acute Kidney Injury Following Cardiac Surgery: A Systematic Review.

Acute kidney injury is a common complication following cardiac surgery (CSA-AKI). Serum creatinine levels require a minimum of 24-48 h to indicate renal injury. Nevertheless, early diagnosis remains critical for improving patient outcomes. A PRISMA-compliant systematic review of the PubMed and CENTRAL databases was performed to assess the role of Klotho as a predictive biomarker for CSA-AKI (end-of-search date: 17 February 2024). An evidence quality assessment of the four included studies was performed with the Newcastle-Ottawa scale. Among the 234 patients studied, 119 (50.8%) developed CSA-AKI postoperatively. Serum Klotho levels above 120 U/L immediately postoperatively correlated with an area under the curve (AUC) of 0.806 and 90% sensitivity. Additionally, a postoperative serum creatinine to Klotho ratio above 0.695 showed 94.7% sensitivity and 87.5% specificity, with an AUC of 92.4%, maintaining its prognostic validity for up to three days. Urinary Klotho immunoreactivity was better maintained in samples obtained via direct catheterization rather than indwelling catheter collection bags. Storage at -80 °C was necessary for delayed testing. Optimal timing for both serum and urine Klotho measurements was from the end of cardiopulmonary bypass to the time of the first ICU lab tests. In conclusion, Klotho could be a promising biomarker for the early diagnosis of CSA-AKI. Standardization of measurement protocols and larger studies are needed to validate these findings.

Raw data were not disclosed in 95% of PubMed-indexed heart failure meta-analyses in 2021: A systematic analysis of transparency.

BACKGROUND: The rising concern of irreproducible and non-transparent studies poses a significant challenge in modern medical literature. The impact of this issue on cardiology, particularly in the subfield of heart failure, remains poorly understood. To address this knowledge gap, we assessed the quality of evidence presented in recent heart failure meta-analyses by exploring several crucial transparency indicators. METHODS: We conducted a cross-sectional study and searched PubMed for meta - analyses themed around heart failure. We included the 100 most recent publications from 2021 and investigated the presence of several indices that are associated with transparency and reproducibility. RESULTS: The vast majority of the papers did not include their raw data (95/100, 95%) nor their analytic code (99/100, 99%). Less than half (42/100, 42%) preregistered their protocol, while only 65/100 (65%) adhered to a reporting guidelines method. Bias calculation for the respective studies included in each meta - analysis was present in 83/100 (83%) papers and publication bias was measured in approximately half (56/100, 56%). CONCLUSIONS: Our study indicates that meta-analyses in the field of heart failure present important information of transparency infrequently. Therefore, reproduction and validation of their findings seems to be practically impossible.