Perioperative temporary microaxial left ventricular assist device support in patients with low ejection fraction undergoing coronary artery bypass grafting

Abstract

Despite advances in mechanical circulatory support (MCS), outcomes in high-risk coronary artery bypass grafting (CABG) with low ejection fraction (EF) remain unclear. We evaluate short-term outcomes associated with temporary microaxial flow pump (TMFP) support in high-risk patients undergoing CABG during the same hospitalization. This retrospective study reviewed 111 patients who underwent CABG with Impella 5.5 or LD TMFP support during the same hospitalization between April 2018 and January 2025. Patients receiving extracorporeal membrane oxygenation (ECMO) were excluded. Baseline demographics, procedural characteristics, and postoperative outcomes were collected. Statistical analyses were performed using R version 4.4.0 with significance defined as p  < 0.05. The cohort ( n  = 111) had a mean age of 69 years and was 75% male (83/111). Comorbidities documented prior to index hospitalization included hypertension (85%, 94/111), diabetes mellitus (57%, 63/111), coronary artery disease (CAD) (47%, 52/111), and at least one prior cardiac surgery or intervention (31%, 34/111). Support was planned in 30% (33/111) of cases and unplanned in 70% (78/111). 30-day survival was 89.2% (99/111) and 1-year survival of 74.8% (83/111). No statistically significant differences in mortality were observed according to performance of concomitant procedures or operative time periods (2018–2020 vs. 2021–2025). In high-risk low-EF patients undergoing CABG, TMFP support during the same hospitalization was associated with acceptable 30-day and 1-year survival outcomes among patients considered unsuitable for PCI and/or advanced therapies at the time of surgery. Mortality was not significantly different among patients undergoing concomitant procedures or between planned vs. unplanned TMFP placement. These findings support TMFP's growing role in complex coronary surgeries and warrant further studies to define optimal application and surgical candidacy.