# Post-Operative Atrial Fibrillation: Novel Predictive Value of CT-Derived Adipose Tissue Density in Minimally Invasive Mitral Surgery

## TL;DR

This study shows that CT scans can predict the risk of post-surgery heart rhythm issues in patients undergoing minimally invasive mitral valve surgery.

## Contribution

CT-derived adipose tissue density is newly identified as a predictive biomarker for post-operative atrial fibrillation.

## Key findings

- Higher visceral and subcutaneous adipose tissue density is linked to increased post-operative atrial fibrillation risk.
- Patients in the highest visceral adipose tissue density quartile had a 5.5-fold higher risk of POAF.
- Intramuscular adipose tissue density showed a positive association with POAF in patients without prior AF.

## Abstract

Postoperative atrial fibrillation (POAF) remains a significant complication following minimally invasive thoracoscopic mitral valve surgery (MITMVS), yet current risk prediction models inadequately capture the underlying metabolic determinants of arrhythmogenesis. We investigated whether computed tomography (CT)-derived body composition parameters, as markers of metabolic status, could predict POAF risk in patients undergoing mitral valve repair. We retrospectively studied 104 consecutive MITMVS patients (2014–2023). Preoperative CT scans quantified skeletal muscle index, muscle density, and visceral/subcutaneous adipose tissue. Patients were grouped by preexisting atrial fibrillation (AF) with concurrent Maze (n=48) vs. no AF history (n=56). The primary outcome was POAF development. Higher visceral (VAT) and subcutaneous (SAT) adipose tissue density showed associations with increased POAF odds in multivariable analysis (VAT: OR 1.075, 95 % CI: 1.010;1.149, p=0.026; SAT: OR 1.073, 95 % CI: 1.011;1.146, p=0.025). Quartile analysis revealed a striking 5.5-fold increased POAF risk in the highest VAT density quartile compared to the lowest (42.3 % vs. 7.7 %). Notably, the relationship between intramuscular adipose tissue (IMAT) density and POAF differed between groups (interaction p=0.029), with a positive association in patients without prior AF (OR 1.167, 95 % CI: 1.011;1.377, p=0.047), but no significant relationship in those with preexisting AF (p=0.175). CT-derived tissue quality parameters, particularly VAT density, demonstrate robust associations with POAF risk following MITMVS. These findings establish preoperative CT-based metabolic assessment as a promising tool for perioperative risk stratification without additional testing burden.