# Coronary Artery Bypass Grafting on Microaxial Flow Pump Support in Patients With Severely Reduced Left Ventricular Ejection Fraction

## TL;DR

This study explores the use of a microaxial flow pump during heart surgery in patients with very weak heart function, showing it's feasible but comes with risks like strokes.

## Contribution

The paper presents early clinical results of coronary artery bypass grafting supported by microaxial flow pumps in high-risk patients with severely reduced heart function.

## Key findings

- Seven out of 12 patients showed myocardial recovery with mAFP support.
- Four patients required durable left ventricular assist devices, and one died during mAFP support.
- Thromboembolic strokes occurred in three patients during mAFP manipulations.

## Abstract

Patients with coronary artery disease (CAD) and severely reduced left ventricular ejection fraction (LVEF) face high perioperative risks during surgical revascularization. This case series examines outcomes in CAD patients with LVEF ≤ 25% undergoing surgical revascularization on microaxial flow pump (mAFP) support.

We retrospectively analyzed 12 patients at Deutsches Herzzentrum der Charité who underwent scheduled protected coronary artery bypass grafting (CABG) with full‐flow mAFP support. Patients with acute myocardial infarction or no myocardial viability were excluded.

The cohort had a median age of 60 years [59; 66], 92% male, BMI 26 ± 6.2 kg/m2, median LVEF 18% [15; 24], and LVEDD 69 mm [59; 78]. Seven patients had diabetes mellitus and chronic renal failure, and five had prior myocardial infarctions. The mean EUROSCORE II was 2.5 ± 0.6.

Surgical revascularization was performed with ongoing mAFP support, with a median of 3 distal anastomoses. Complete revascularization was achieved in 11 cases and surgical time was 254 min [187; 266]. Myocardial recovery occurred in seven patients, while four required durable left ventricular assist device implantation, and one died on mAFP support. Two (16.6%) patients died during a follow‐up period of 93 days. Median Impella support lasted 6 days [3; 9], invasive ventilation 13 h [11; 20], and ICU stays 4.5 days [4; 17].

Complications included one bleeding requiring revision, two mAFP exchanges due to thrombosis/dislodgement, and four thromboembolic strokes in three patients during mAFP explantation/exchange.

Revascularization with mAFP support is a feasible approach for high‐risk CAD patients but is associated with support‐related complications, including thromboembolic strokes during mAFP manipulations (e.g., explantation or exchange). Prospective randomized trials are essential to evaluate the potential benefits of intraoperative mAFP support during surgical revascularization compared to alternative mechanical support strategies and/or pharmacological measures.

Coronary artery revascularization with microaxial flow pump support in patients with severely reduced left ventricular ejection fraction is an emerging technique in cardiac surgery. In this manuscript, we present early results, highlight the advantages, and discuss the key limitations of this approach.