Incidence and clinical management of life-threatening left ventricular assist device (LVAD) failure

Abstract

Mechanical device failure can be life-threatening, and its incidence and clinical management have not been adequately studied. This is increasingly important with longer periods of support as bridge to recovery/ transplantation (Tx) (support lengthening due to donor shortage) or as destination therapy. From 1995 to date 82 Thoratec TCI Heartmate (62 Vented Electric (VE) and 20 pneumatic) and 21 Thoratec devices have been implanted at our institution (total support 46.3 patient yrs). We investigated the incidence and management of major device failure in these patients. The cumulative probability of device failure was 0.06 at 6 mths, 0.12 at 1 yr, 0.27 at 18 mths and 0.64 at 2 yrs. Major failure occurred in a total of 8 (7.8%) patients. Four patients presented as an emergency with VE device failure at a mean of 498 (340–641) days, 3 due to a seized motor were supported on the pneumatic driver for a mean of 43.3 days to explantation (in 1), Tx (in 1) and device change (in 1). Another had a ruptured pump diaphragm and was maintained for 1 day, but died of a Type B Aortic dissection. Four patients underwent elective device change - 2 change of a TCI VE pump, 1 due to inlet valve regurgitation and a fractured power cable at 414 days and 1 due to inlet valve regurgitation at 656 days, these underwent Tx and explantation 289 days and 208 days later respectively. One patient with VE failure at 340 days was maintained on the pneumatic driver for 83 days, then underwent Thoratec implantation without mediansternotomy and was Tx 97 days later. One Thoratec patient developed LVAD chamber thrombus at 40 days, underwent pump replacement and was Tx 126 days later. A further patient on the pneumatic TCI developed a pneumoperitoneum due to a leak at the junction of the pneumatic driveline at 153 days which was repaired by inserting a new driveline and 288 days later he underwent successful heart and kidney Tx. In conclusion life-threatening mechanical pump failure is not uncommon but can be successfully managed in the majority of patients, encouraging the longer term use of these devices.