# Hypothermic Ventricular Fibrillation in Redo Minimally Invasive Mitral Valve Surgery: A Promising Solution for a Surgical Challenge

## TL;DR

Hypothermic ventricular fibrillation is a promising alternative to traditional cardioprotection in redo minimally invasive mitral valve surgery, with similar outcomes and fewer complications.

## Contribution

This study demonstrates hypothermic ventricular fibrillation as a viable cardioprotective method in complex redo mitral valve surgeries.

## Key findings

- Patients with hypothermic ventricular fibrillation had similar postoperative outcomes as those with conventional cardioprotection.
- No significant differences were found in stroke, heart attack, or mortality rates between the two groups.
- The technique is promising for high-risk redo surgeries without increasing adverse events.

## Abstract

Background: Minimally invasive mitral valve surgery (MIMVS) is a treatment for severe mitral valve pathologies. In redo cases, especially after coronary artery bypass grafting (CABG) surgery with patent mammary bypass grafts, establishing aortic clamping followed by antegrade cardioplegia application might be challenging. Here, we present the outcome of hypothermic ventricular fibrillation as an alternative to conventional cardioprotection. Methods: Patients who underwent MIMVS either received hypothermic ventricular fibrillation (study group, n = 48) or antegrade cardioprotection (control group, n = 840) and were observed for 30 postoperative days. Data were retrospectively analyzed and collected from January 2011 until December 2022. Results: Patients in the study group had a higher preoperative prevalence of renal insufficiency (p = 0.001), extracardiac arteriopathy (p = 0.001), insulin-dependent diabetes mellitus (p = 0.001) and chronic lung disease (p = 0.036). Furthermore, they had a longer surgery time and a lower repair rate (p < 0.001). No difference, however, was seen in postoperative incidences of stroke (p = 0.26), myocardial infarction (p = 1) and mitral valve re-operation (p = 1) as well as 30-day mortality (p = 0.1) and postoperative mitral valve insufficiency or stenosis. Conclusions: The patients who underwent redo MIMVS with hypothermic ventricular fibrillation did not have worse outcomes or more serious adverse events compared to the patients who received routine conventional cardioprotection. Therefore, the use of hypothermic ventricular fibrillation appears to be a promising cardioprotective technique in this challenging patient population requiring redo MIMVS.