Strategies in Diagnosis and Therapy of External Outflow Graft Obstruction in Patients with a Fully Magnetically...

Background: The HeartMate 3 (HM3, Abbott) left ventricular assist device (LVAD) is the only commercially available option considered suitable for long-term circulatory support. External compression of the outflow graft causing obstruction (eOGO) is a serious adverse event affecting patients on long-term support. The obstruction occurs due to the accumulation of gelatinous substance between the bend relief and outflow graft. This systematic review evaluated all available studies with regard to the diagnosis and therapy of eOGOs. Methods: A systematic literature review and analysis of individual patient data was performed using MEDLINE/PubMed following PRISMA guidelines. Original works dating up to 31 October 2024 were considered. Results: Twenty-four publications that met the inclusion criteria were identified, providing individual data from 113 patients with a median support time to eOGO diagnosis of 809 days [588, 1095] and follow-up after treatment of 365 days [33, 605]. eOGO severity classification was performed on 108 patients according to our grading system. For treatment, most patients underwent surgery (n = 38) or stenting (n = 29). A hazard ratio of 0.75 [0.28, 2.03] was calculated for the surgical group versus the stenting group (p = 0.570). Conclusions: Concerning 30-day mortality, we did not find a significant difference between the eOGO severity of survivors and non-survivors. We found no significant differences in outcome between patients with differing eOGO severity and treatment strategy, namely stenting and surgery. Due to an increase in eOGO incidence after one year of support, we propose that clinicians monitor their patients for this complication when support time surpasses one year.