Combined hemodynamic and echocardiographic ramp tests in continuous flow ventricular assist devices (cfLVAD) may help optimize patient management, according to research published in JACC: Heart Failure.
Researchers conducted ramp tests with right heart catheterization (including central venous pressure [CVP], pulmonary artery pressure [PAP], pulmonary capillary wedge pressure [PCWP], and blood pressure [BP]) and echocardiography on 35 patients with cfLVADs (21 HMII and 14 HVAD systems). These patients were stable outpatients, between 1 to 3 months following LVAD implantation, and the majority were implanted for destination therapy (71.4%).
At their original RPM settings, only 42.9% of patients had normal CVPs and PCWPs. Both the HMII and HVAD devices had similar hemodynamic parameters at baseline speeds (9094 ± 417 RPM for HMII and 2704 ± 147 RPM for HVAD).
Cardiac output was improved by 0.16 ± 0.19 L/min/step (total change: 1.28 ± 1.41 L/min) and PCWP decreased by 1.23 ± 0.85 mm Hg/step (total change: 9.9 ± 6.5 mmHg). Twelve patients (34%) had speed changed by ≥100 RPM in HVAD or ≥400 RPM in HMII. However, CVP and systolic BP did not change significantly with RPMs.
Mean new speeds were 9313 ± 416 for HMII and 2750 ± 158 for HVAD. While there were no differences in average hemodynamic parameters when comparing baseline and final set values, patients with both CVP and PCWP within the normal zone increased from 40% to 56%.
“In this study, an unexpectedly high proportion of clinically stable, seemingly well compensated heart failure patients supported by cfLVAD had abnormal hemodynamic profiles,” the researchers noted. “This suggests that it is clinically challenging to assess volume status and hemodynamic profile in cfLVAD patients based on routine clinical evaluation.”
The study only examined the effect of acute changes in RPMs on hemodynamics—long-term effects associated with RPM-dependent changes in renal perfusion, modulation of autonomic reflex activity, and right heart function may also have an impact on how RPM settings will influence long-term hemodynamics and clinical outcomes.
“We hypothesize that patient outcomes and quality of life could be improved by periodic evaluations of RPMs settings to achieve optimal hemodynamics and guide medical therapy.”
Researchers concluded that further studies should be conducted to ascertain whether using hemodynamic ramp studies to optimize cfLVAD speed leads to improved survival and reduction in complications.
Uriel N, Sayer GT, Addetia K, et al. Hemodynamic ramp tests in patients with left ventricular assist devices. JACC Heart Fail. 2016. doi:10.1016/j.jchf.2015.10.001.