The Impact of Intrapericardial versus Intrapleural HeartMate 3 Pump Placement on Clinical Outcomes

Background: The integrated design of the HeartMate 3 (Abbott Laboratories, Chicago, IL, USA) affords flexibility to place the pump within the pericardium or thoracic cavity. We sought to determine whether the presence of a left ventricular assist device (LVAD) in either location has a meaningful impact on overall patient outcomes. Methods: A retrospective cohort study was conducted of all 165 patients who received a HeartMate 3 LVAD via a median sternotomy from November 2014 to August 2019 at our center. Based on operative reports and imaging, patients were divided into intrapleural (n=81) and intrapericardial (n=84) cohorts. The primary outcome of interest was in-hospital mortality, while secondary outcomes included postoperative complications, cumulative readmission incidence, and 3-year survival. Results: There were no significant between-group differences in baseline demographics, risk factors, or preoperative hemodynamics. The overall in-hospital mortality rate was 6%, with no significant difference between the cohorts (9% vs. 4%, p=0.20). There were no significant differences in the postoperative rates of right ventricular failure, kidney failure requiring hemodialysis, stroke, tracheostomy, or arrhythmias. Over 3 years, despite similar mortality rates, intrapleural patients had significantly more readmissions (n=180 vs. n=117, p<0.01) with the most common reason being infection (n=68/165), predominantly unrelated to the device. Intrapleural patients had significantly more infection-related readmissions, predominantly driven by non-ventricular assist device-related infections (p=0.02), with 41% of these due to respiratory infections compared with 28% of intrapericardial patients. Conclusion: Compared with intrapericardial placement, insertion of an intrapleural HM3 may be associated with a higher incidence of readmission, especially due to respiratory infection.