Heart Failure，Congestive
Conditions
Brief summary
This study will evaluate how the cardiovascular system interacts with mechanical hearts to provide blood flow to the body during exercise. Two aims are proposed: 1) to determine the impact of a mechanical heart on exercise pressor reflexes in heart failure patients; and 2) to define the primary determinant(s) of exercise capacity in heart failure patients before and after device implantation.
Interventions
None listed
Sponsors
University of Colorado, Denver
Study design
Observational model
COHORT
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
18 Years to 80 Years
Healthy volunteers
Yes
Inclusion criteria
Advanced Heart Failure- Inclusion Criteria: * Individuals with severely reduced left ventricular systolic function that are scheduled to undergo LVAD insertion
Exclusion criteria
* uncontrolled diabetes with peripheral neuropathy (interferes with acquisition of MSNA signal) * Individuals with clinical right ventricular failure, defined as moderate-severely reduced RV systolic function on echocardiography, or clinical evidence of RV failure (elevated jugular venous pressures, significant peripheral edema) * Individuals with moderate-severe preexisting aortic insufficiency, as these patients will typically undergo a Park stitch at time of CF-LVAD insertion to permanently close the aortic valve and prevent worsening aortic insufficiency; and * Disorders that adversely influence exercise ability (e.g. arthritis, peripheral vascular disease, pulmonary disease) Mild Heart Failure - Inclusion Criteria: * Individuals with medically managed left ventricular systolic function that are NOT scheduled to undergo LVAD insertion * HF patients with ejection fraction \<35-40%
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Changes in the sympathetic neural response. | 4 weeks prior to implantation and 6 months post implantation. | The primary outcome will be the difference in the muscle sympathetic neural response (MSNA) to handgrip and post-exercise circulatory arrest (PECA) before and after Continuous-flow left ventricular assist device (CF-LVAD) insertion |
| Change in VO2. | 4 weeks prior to implantation and 6 months post implantation. | The primary outcome will be the change in the VO2 (maximum rate of oxygen consumption) before and after CF-LVAD insertion. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| VO2 relationship and ventilatory threshold (2). | 4 weeks prior to implantation and 6 months post implantation. | Determinants of Qc after CF-LVAD insertion (ie, contribution from device v. contribution from left ventricle). |
| VO2 relationship and ventilatory threshold (3). | 4 weeks prior to implantation and 6 months post implantation. | Qc, VO2, ventilatory threshold and exercise capacity at increased pump speed. |
| Changes in the hemodynamic response. | 4 weeks prior to implantation and 6 months post implantation. | This outcome will evaluate any difference in the hemodynamic response (heart rate and blood pressure) to handgrip and PECA before and after CF-LVAD |
| Oxygen uptake and utilization | 4 weeks prior to implantation and 6 months post implantation. | Cerebral and musculoskeletal oxygen uptake by near-infrared spectroscopy |
| VO2 relationship and ventilatory threshold (4). | 4 weeks prior to implantation and 6 months post implantation. | Bloodflow to the periphery, as measured by transcranial Doppler to assess brain bloodflow during exercise/activity. |
| VO2 relationship and ventilatory threshold (1) | 4 weeks prior to implantation and 6 months post implantation. | Cardiac output (Qc): VO2 relationship and ventilatory threshold before and after CF-LVAD insertion. |
Countries
United States
Outcome results
None listed