Prevalence and timing of bend relief disconnection in patients supported by the late version HeartMate II left ventricular assist device

Background: On April 4, 2012, the U.S. Food and Drug Administration issued a Class 1R recall of the HeartMate II (Thoratec Corporation, Pleasanton, CA) left ventricular assist device (LVAD) due to spontaneous detachment of the bend relief from its intended position in patients implanted with the most recent version of the HM II. This study examined the incidence and timing of outflow graft bend relief disconnection in patients implanted with the HM II LVAD. Methods: All patients supported with the modified version of the HM II LVAD were asked to report for dedicated abdominal X-ray imaging to assess the position of the bend relief. Also performed was a retrospective review of X-ray images of all patients who had previously been supported with this version but had since received a transplant, undergone LVAD explant, or died. Results: Between March 9, 2011, and April 9, 2012, 59 patients underwent primary implant with the modified version HM II. Follow up X-ray images were available for 56 patients (95%). The bend relief was found fully disconnected in 6 of 56 (11%) and partially disconnected in 13 (23%). Two of 6 patients (33%) with full bend relief disconnection and 1 of 13 of the initially partially disconnected patients (7.7%) required urgent surgical intervention due to symptoms of hemolysis and/or heart failure. Conclusions: Bend relief disconnection is common and may be observed immediately after implant but may also develop over time. Full bend relief disconnect may present with hemolysis and/or heart failure symptoms and often requires surgical revision. Surveillance abdominal X-ray imaging should be performed routinely on all patients who were implanted with the modified version HM II.