Bleeding and Thromboembolic Events in Patients with Heartmate II Mechanical Circulatory Support

Background Bleeding and thromboembolic events (TE) are common complications following HeartMate II (HMII) implantation. The aim of the study was to review our experience related to bleeding and TE events in patients with a HMII and identify factors associated with increased risk of these events. Methods We retrospectively reviewed 70 consecutive patients who received a HMII between May 2006 and December 2011. The patients were followed for 12 months or until cardiac transplantation, device explantation or death. Major bleeding was defined by INTERMACS criteria with intracranial bleeding events added. Results There were 48 bleeding events in 28 (40%) patients with gastrointestinal bleeding (54.2%) being most common. Patients with bleeding events had significantly higher average INR (p=0.04) and more chronic kidney disease (p=0.03), although 43.8% of bleeding events occurred at an INR <2. Twelve TE events occurred in 9 patients (12.9%), with ischemic stroke the most common (75%). TE events were associated with young age (p=0.04) and non-diabetes status (p=0.03) and were not associated with average INR. There was no association of bleeding or thromboembolism with gender, BMI, HMII speed, pulsatility index, hypothyroidism, smoking history or INTERMACS profile at the time of HMII implantation. Conclusion Different factors are associated with bleeding and TE events. The appropriate target INR range for HMII patients should be chosen to balance the risk between bleeding and TE events based largely on patient factors.