Background: The Synergy system, a miniature partial circulatory support device, is implanted by an off-pump, minimally invasive surgical approach. The system has been optimized to improve performance in an EU clinical trial for chronic ambulatory heart failure. This therefore offers the possibility of treating elderly chronic heart failure patients who might not usually be considered for long-term circulatory support.
Methods: From June 2007 to December 2012, 63 patients were implanted with the Synergy system (12 patients ≥70 years) using four different releases of the device. Briefly, the system draws blood through the inflow cannula from the left atrium into the micro-pump (placed in a right subclavicular pocket) and pumps it through an outflow graft to the right subclavian artery. In this paper, we present an intermediate analysis of the clinical trial as performed on April 30, 2013, leading to the placing of the CE mark.
Results: Mean duration of support is ongoing at 230 days (range 23-1387). Follow-up showed improved hemodynamic response, with additional improvements in 6-min walk distance (299 ± 144 to 420 ± 119 m) and Minnesota Living with Heart Failure Questionnaire (69.5 ± 20.4 to 49.2 ± 24.3). Older patients had longer mean durations of support (337 vs 188 days). On average, elderly and younger patients showed similar improvements in hemodynamics and 6-min walk distance (107 ± 120 vs 130 ± 121 m). Major adverse cardiac events included bleeding (n=4) with one bleeding related to renal failure resulting in death.
Conclusions: Clinical use of the Synergy device was associated with a significant functional improvement. Very low adverse event rates were reported with the latest device release. Older patients had smaller body sizes and worse renal function than younger patients. Both groups experienced similar hemodynamic benefits and functional improvements. The risk of bleeding and renal dysfunction appears to be increased in the elderly, though still within acceptable ranges compared to other full support devices. Minimally invasive long-term circulatory support devices, like Synergy, offer a new treatment option that might be available even for the elderly chronic heart failure population.