Proof of Concept : Hemodynamic Response to Long-Term Partial Ventricular Support With the Synergy Pocket Micro-Pump

ObjectivesThe purpose of this study was to test the hemodynamic effects of partial ventricular support in patients with advanced heart failure.BackgroundThe use of current left ventricular assist devices (VADs) that provide full circulatory support is restricted to critically ill patients because of associated risks. Smaller, less-invasive devices could expand VAD use to a larger pool of less-sick patients but would pump less blood, providing only partial support.MethodsThe Synergy Pocket Micro-pump device (CircuLite, Inc., Saddle Brook, New Jersey) pumps ∼3.0 l/min, is implanted (off pump) via a mini-thoracotomy, and is positioned in a right subclavicular subcutaneous pocket (like a pacemaker). The inflow cannula inserts into the left atrium; the outflow graft connects to the right subclavian artery.ResultsA total of 17 patients (14 men), age 53 ± 9 years with ejection fraction 21 ± 6%, mean arterial pressure 73 ± 7 mm Hg, pulmonary capillary wedge pressure 29 ± 6 mm Hg, and cardiac index 1.9 ± 0.4 l/min/m2received an implant. Duration of support ranged from 6 to 213 (median 81) days. In addition to demonstration of significant acute hemodynamic improvements in the first day of support, 9 patients underwent follow-up right heart catheterization at 10.6 ± 6 weeks. These patients showed significant increases in arterial pressure (67 ± 8 mm Hg vs. 80 ± 9 mm Hg, p = 0.01) and cardiac index (2.0 ± 0.4 l/min/m2vs. 2.8 ± 0.6 l/min/m2, p = 0.01) with large reductions in pulmonary capillary wedge pressure (30 ± 5 mm Hg vs. 18 ± 5 mm Hg, p = 0.001).ConclusionsPartial support appears to interrupt the progressive hemodynamic deterioration typical of late-stage heart failure. If proven safe and durable, this device could be used in a relatively large population of patients with severe heart failure who are not sick enough to justify use of currently available full support VADs. (Safety and Performance Evaluation of CircuLite Synergy; NCT00878527).