Hemodynamic Optimization Of Left Ventricular Assist Devices During Right Heart Catheterization Ramp Studies

Abstract

Background : Studies have shown that the hemodynamic measurements taken during a Left Ventricular Assist Device (LVAD) ramp study can be used to optimize LVAD speed and improve clinical outcomes, yet these studies lack external validation. Methods : 470 patients, including 3 LVAD subtypes, were retrospectively analyzed at Penn State Hershey Medical Center from January 2015 to September 2020 and 53 ramp studies were identified. Measurements (RA, mean PA, PCWP, and CI) were taken at speeds +/- 20% of manufacturer recommended set speed for HM2, HM3, and HVAD devices. Primary outcomes were all-cause and heart failure (HF) hospitalizations in the 6-month period pre- and post-ramp study. Secondary outcomes included final LVAD speed and hemodynamic measurements following ramp study. Subgroup analysis was performed on LVAD type and subjects who underwent LVAD speed change. Time to first hospitalization and cumulative incidence rate of all-cause and HF hospitalization were reported. Results : 53 ramp studies were analyzed. Baseline characteristics included: mean age of 60.1 (+/- 10.9), 84.9% male, 56.6% ischemic etiology, 71.7% destination therapy, and average NYHA class and INTERMACS of 2.5 (+/- 0.7) and 5.9 (+/- 1), respectively. 38 of 53 studies (71.7%) showed PCWP decompression >20%, with average PCWP decompression of 51.2% (+/- 21.0%), and CI increase of 22.5% (+/- 18.7%). Optimal LVAD speeds were chosen to maintain CI > 2.2, PCWP < 15 and minimize RAP, in the absence of suction events. 31 (58.5%) of studies resulted in an LVAD speed change and 16 (30.2%) of studies resulted in diuretic change. All-cause and HF hospitalizations were significantly decreased in the 6-months following ramp studies compared the 6-months pre-ramp (total days hospitalized for all causes: 12.0 vs 26.6, p=0.0002; total days hospitalized for HF, 4.8 vs 22.1, p=0.00003). Time to first hospitalization was decreased in the subgroup of studies who underwent a speed change during ramp procedure, yet these differences were not statistically significant. Conclusion : This data externally validates previous work showing that LVAD hemodynamic ramp studies decrease hospitalizations. Future, prospective studies with a larger patient cohort and longer follow up time may elucidate specific hemodynamic targets to improve mortality and further reduce rehospitalizations. : Studies have shown that the hemodynamic measurements taken during a Left Ventricular Assist Device (LVAD) ramp study can be used to optimize LVAD speed and improve clinical outcomes, yet these studies lack external validation. : 470 patients, including 3 LVAD subtypes, were retrospectively analyzed at Penn State Hershey Medical Center from January 2015 to September 2020 and 53 ramp studies were identified. Measurements (RA, mean PA, PCWP, and CI) were taken at speeds +/- 20% of manufacturer recommended set speed for HM2, HM3, and HVAD devices. Primary outcomes were all-cause and heart failure (HF) hospitalizations in the 6-month period pre- and post-ramp study. Secondary outcomes included final LVAD speed and hemodynamic measurements following ramp study. Subgroup analysis was performed on LVAD type and subjects who underwent LVAD speed change. Time to first hospitalization and cumulative incidence rate of all-cause and HF hospitalization were reported. : 53 ramp studies were analyzed. Baseline characteristics included: mean age of 60.1 (+/- 10.9), 84.9% male, 56.6% ischemic etiology, 71.7% destination therapy, and average NYHA class and INTERMACS of 2.5 (+/- 0.7) and 5.9 (+/- 1), respectively. 38 of 53 studies (71.7%) showed PCWP decompression >20%, with average PCWP decompression of 51.2% (+/- 21.0%), and CI increase of 22.5% (+/- 18.7%). Optimal LVAD speeds were chosen to maintain CI > 2.2, PCWP < 15 and minimize RAP, in the absence of suction events. 31 (58.5%) of studies resulted in an LVAD speed change and 16 (30.2%) of studies resulted in diuretic change. All-cause and HF hospitalizations were significantly decreased in the 6-months following ramp studies compared the 6-months pre-ramp (total days hospitalized for all causes: 12.0 vs 26.6, p=0.0002; total days hospitalized for HF, 4.8 vs 22.1, p=0.00003). Time to first hospitalization was decreased in the subgroup of studies who underwent a speed change during ramp procedure, yet these differences were not statistically significant. : This data externally validates previous work showing that LVAD hemodynamic ramp studies decrease hospitalizations. Future, prospective studies with a larger patient cohort and longer follow up time may elucidate specific hemodynamic targets to improve mortality and further reduce rehospitalizations.