Counterpulsation with Symphony Prevents Retrograde Carotid, Aortic, and Coronary Flows Observed with Intra-aortic Balloon Pump Support

A counterpulsation device (Symphony) is being developed to provide long-term circulatory support for advanced heart failure (HF) patients. In acute animal experiments, flow waveform patterns in the aortic, carotid, and coronary arteries were compared during Symphony and intra-aortic balloon pump (IABP) support. Human data were examined for similarities. The 30-mL Symphony was compared to a 40-mL IABP in calves with cardiac dysfunction (80-100 kg, n = 8). Aortic pressures and aortic, carotid, and coronary artery flows were simultaneously recorded at baseline (devices off) and during 1:1 and 1:2 support. Forward, retrograde, and mean flows were calculated and compared for each test condition. Findings were also compared to aortic flow measurements recorded in HF patients (n = 21) supported by 40-mL IABP. IABP caused significant retrograde flows in the aorta, coronary (IABP: -24 ± 8 mL/min, Symphony: -6 ± 2 mL/min, baseline: -2 ± 1 mL/min, P < 0.05), and carotid arteries (IABP: -30 ± 5 mL/min, Symphony: -0 ± 0 mL/min, baseline: -0 ± 0 L/min, P < 0.05) during ventricular systole compared to the Symphony. IABP support produced higher diastolic pressure and flow augmentation compared to Symphony. Due to retrograde flows during IABP support, Symphony provided higher overall coronary, carotid, and aortic flows. Similar reduction in total aortic flows due to retrograde flow was observed in HF patients during IABP support. Counterpulsation with an IABP via aortic volume displacement produces retrograde flows during rapid balloon deflation that reduces total flow. Counterpulsation with Symphony via volume removal eliminates retrograde flow and improves total flow more than that achieved with IABP. The Symphony may provide long-term hemodynamic benefits in HF patients.