Safety and Efficacy of a Percutaneously Inserted Ventricular Support Device Purge Solution Heparin 25 U/mL

Background:The Impella is a percutaneous ventricular assist device (pVAD) that provides temporary hemodynamic support to patients with cardiogenic shock or for protected percutaneous coronary intervention. The manufacturer recommends a 50-U/mL concentration of heparin purge solution (or 25 U/mL as an alternative), with systemic heparin to maintain therapeutic anticoagulation during device support. Concomitant use of systemic heparin with the purge solution may increase the risk of bleeding.Objectives:The primary objective of this study was to describe the prevalence of thrombosis and bleeding using a less-concentrated heparin purge solution (25 U/mL) in combination with systemic heparin therapy.Methods:This was a retrospective observational cohort study of patients who required at least 12 hours of pVAD support and received 25-U/mL concentration of heparin purge solution between January 1, 2014, and May 31, 2017. The primary end points were the rate of thrombotic and bleeding events. Secondary end points included the percentage of time within the therapeutic activated partial thromboplastin time (aPTT) range. Descriptive statistics were utilized for data analysis.Results:Of the 161 patients screened, 100 met inclusion criteria; 63% of patients experienced a bleeding event, with Bleeding Academic Research Consortium (BARC) type 3a being the most common. Median percentages of subtherapeutic and supratherapeutic aPTT values were similar between the bleeding and nonbleeding groups. Two patients experienced thrombotic events.Conclusion and Relevance:Based on our findings, the device thrombosis rate was 2% and the rate of major bleeding (BARC 3a and higher) was 35%. This study provides descriptive outcomes data of a lower-concentration heparin purge solution.