Left Ventricular Assist Device
Conditions
Keywords
left ventricular assist device, cardiopulmonary exercise test, stress echocardiography, heart failure, mechanical circulatory support, peak VO2
Brief summary
To evaluate the concept of dynamic pump speed optimization based on the echocardiographic assessment of aortic valve opening during cardiopulmonary exercise test.
Detailed description
Left ventricular assist devices (LVAD) are becoming a destination therapy in patients with end-stage left ventricular dysfunction. Current generation pumps operate with a fixed rotation speed without the capability of automated speed adjustment. It was shown that acceleration of the pump speed during stress test increases the maximum exercise tolerance. Periodic aortic valve opening (AVO) is used to set up an optimal resting pump speed. The study aimed to evaluate the concept of dynamic pump speed optimization based on the echocardiographic assessment of AVO during the cardiopulmonary exercise test (CPET). Patients with implanted third-generation LVADs with hydrodynamic bearing (HVAD, Medtronic, MN, USA) are prospectively enrolled. Two CPETs are performed after resting speed optimization. The first one with maintained baseline pump speed settings, and the second one with gradually increased speed depending on live echocardiographic imaging. The sequence of tests is random.
Interventions
OTHERCardiopulmonary exercise tests with maintained baseline optimal pump speed settings.
Optimal resting LVAD speed settings is defined as periodic aortic valve opening while maintaining the central position of the intraventricular septum, minimizing mitral regurgitation, and preserving the mean systemic blood pressure above 65 mmHg. The aim is to achieve an aortic valve opening ratio of around 25-33% by changing the pump speed at resting conditions.
OTHERCardiopulmonary exercise test with gradually increased pump speed depending on live echocardiographic imaging.
During the modified speed exercise, when the aortic valve opening ratio rises above 50%, the pump speed is increased by 100 revolutions per minute (RPM). As the aortic valve remains closed the RPM is lowered by 100. Speed increment is not greater than 100 RPM per 45 seconds to enable an echocardiographic analysis of resulting changes and prevent suction events. There is no determined target speed, neither per time period nor maximal.
Sponsors
Cor Aegrum Foundation of Cardiac Surgery Development in Cracow, Poland
Medtronic Poland Spółka z ograniczoną odpowiedzialnością
AGH University of Science and Technology, Krakow, Poland
Karol Wierzbicki
Study design
Allocation
NON_RANDOMIZED
Intervention model
SEQUENTIAL
Primary purpose
DIAGNOSTIC
Masking
NONE
Intervention model description
prospective crossover AB/BA study
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Patients with implanted cardioverter-defibrillator and third-generation centrifugal CF-LVAD with hydrodynamic bearing (HVAD, Medtronic, Minnesota, United States), at least three months after surgery.
Exclusion criteria
* Hemodynamic instability. * Non-therapeutic anticoagulation. * Device or intracardiac thrombus. * Inflammation. * Active bleeding.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Echocardiographic appraisal of aortic valve opening during cycle ergometer exercise. | Immediately, during cycle ergometer exercise | Assessment of aortic valve opening during cycle ergometer exercise in LVAD patients. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in oxygen consumption | Immediately, during cycle ergometer exercise | By using the cardiopulmonary exercise test |
| Change in perceived exertion | Immediately, during cycle ergometer exercise | By using the Borg rating of perceived exertion scale. Score 6-20 (6 - no exertion, 20 - maximal exertion) |
| Change in pump speed | Immediately, during cycle ergometer exercise. | By assessing pump speed (RPM) |
| Change in pump flow | Immediately, during cycle ergometer exercise | By assessing pump flow (l/min) |
| Change in pump power | Immediately, during cycle ergometer exercise | By assessing pump power (W) |
Countries
Poland
Outcome results
None listed