# MicroRNAs as Biomarkers of Short-Term Complications After Cardiac Surgery

## TL;DR

This review explores how microRNAs can predict complications after heart surgery, offering faster and more accurate diagnosis than traditional methods.

## Contribution

The paper identifies specific microRNAs with strong diagnostic potential for postoperative complications, highlighting their advantages over existing biomarkers.

## Key findings

- miR-499 and miR-133a outperform troponins in diagnosing PMI with high sensitivity and specificity.
- miR-483-5p shows promise for predicting POAF with an AUC of 0.78.
- Emerging microRNAs like miR-223, miR-21, and miR-210-3p are linked to AKI, bleeding, and neurological injury but require further validation.

## Abstract

Cardiac surgery carries substantial risk of early postoperative complications including postoperative atrial fibrillation (POAF, 30–50%), periprocedural myocardial infarction (PMI), acute kidney injury (AKI, 3.8–54.4%), bleeding (3–5%), stroke, and cognitive dysfunction. This narrative review synthesizes 30+ studies on circulating microRNAs (miRNAs) as perioperative biomarkers, identifying strongest evidence for cardiac-enriched miR-499 (AUC 0.93, sensitivity 85.7%, specificity 93.3%) and miR-133a (peaks 1–3 h post-declamping) in PMI diagnosis -outperforming troponins’ 6h kinetics. POAF prediction favors preoperative miR-483-5p (AUC 0.78), while AKI, bleeding (miR-223), and neurological injury show emerging but less validated candidates (miR-21, miR-210-3p). We critically analyze limitations across studies and outline clinical translation barriers (3–6 h assay times, heparin inhibition, lacking standardization) with solutions for point-of-care implementation.