Purpose HeartWare HVAD flow waveforms provide important clinical information on pump function and patient hemodynamics. We assessed changes in flow waveform during inspiratory breath-hold (IBH) maneuver and whether optimization in device speed and medical therapy improved waveform characteristics. Methods We studied HeartWare HVAD patients at consecutive follow-up visits. Characteristic changes in the HVAD monitor flow waveform with IBH were assessed and compared to baseline for reduced flow waveform pulsatility (RWP); flatline (FL); and suction (S). If suction was induced, management was changed by reduction in pump speed, diuretics or anti-hypertensives. Average flow, peak and trough pump flows, flow pulsatility (peak - trough), speed and power were recorded. Baseline pump parameters were compared between patients who required a change (C) vs no change (NC) in management. Patients in the C group were further assessed post-management change (PC) at next visit. Results Sixteen patients were included: 13 male (81.25%), median age 53.7 years (range 38.7-75.6), median support duration 254 days (range 21-2540). Suction was observed with IBH in 6 (37.5%, group C) vs no suction in n=10 (62.5%, group NC). There was no significant difference in any baseline pump parameter between C vs NC (Table). Of the 6 patients in group C who underwent management change, 4 had pump speed reduction and 2 decreased diuretic medications. Pump speed was significantly lower in the PC group (2533 ± 81.6 vs 2600 ± 63.2 respectively, p=0.025) at follow up. No other significant differences in pump parameters were noted (Table). At follow up (PC) there were significantly fewer waveform abnormalities (including RWP, FL, or S) 0.94 ± 0.90 vs 2.4 ± 0.5, p=0.034. Conclusion Pump parameters and flow waveform observation at rest do not reflect suction risk in stable HVAD outpatients. IBH is a simple clinical intervention to assess suction risk threshold and can be utilized to guide changes in management. HeartWare HVAD flow waveforms provide important clinical information on pump function and patient hemodynamics. We assessed changes in flow waveform during inspiratory breath-hold (IBH) maneuver and whether optimization in device speed and medical therapy improved waveform characteristics. We studied HeartWare HVAD patients at consecutive follow-up visits. Characteristic changes in the HVAD monitor flow waveform with IBH were assessed and compared to baseline for reduced flow waveform pulsatility (RWP); flatline (FL); and suction (S). If suction was induced, management was changed by reduction in pump speed, diuretics or anti-hypertensives. Average flow, peak and trough pump flows, flow pulsatility (peak - trough), speed and power were recorded. Baseline pump parameters were compared between patients who required a change (C) vs no change (NC) in management. Patients in the C group were further assessed post-management change (PC) at next visit. Sixteen patients were included: 13 male (81.25%), median age 53.7 years (range 38.7-75.6), median support duration 254 days (range 21-2540). Suction was observed with IBH in 6 (37.5%, group C) vs no suction in n=10 (62.5%, group NC). There was no significant difference in any baseline pump parameter between C vs NC (Table). Of the 6 patients in group C who underwent management change, 4 had pump speed reduction and 2 decreased diuretic medications. Pump speed was significantly lower in the PC group (2533 ± 81.6 vs 2600 ± 63.2 respectively, p=0.025) at follow up. No other significant differences in pump parameters were noted (Table). At follow up (PC) there were significantly fewer waveform abnormalities (including RWP, FL, or S) 0.94 ± 0.90 vs 2.4 ± 0.5, p=0.034. Pump parameters and flow waveform observation at rest do not reflect suction risk in stable HVAD outpatients. IBH is a simple clinical intervention to assess suction risk threshold and can be utilized to guide changes in management.