Clinical Trial: Heart Failure and a Preserved Ejection Fraction
Study Status: Completed
Recruit Status: Completed
Study Type: Observational
Official Title: The Role of Vascular Dysfunction in Limiting Cardiovascular Reserve in Patients With Heart Failure and a Preserved Ejection Fraction
Brief Summary: This will be a cross sectional study comparing patients with HFpEF and age-matched, non-HF controls recruited from the community. This design will allow for determination of biologically relevant differences in baseline ventricular and vascular function, and importantly, differences in the ability to augment ventricular and vascular function dynamically during exercise stress, when symptoms of HF typically are first noted. The endpoint of exercise-reserve function is novel and has been little examined in the existing HFpEF literature.
Detailed Summary:
Congestive heart failure (HF) is the leading cause of hospitalization among older Americans.1 Approximately half of affected patients have apparently normal systolic function (HF with preserved ejection fraction, HFpEF).2-4 In contrast to HF with low EF, there are no proven treatments for HFpEF, due largely to a lack of mechanistic understanding.4 HFpEF patients are typically older, hypertensive and female,2,3 and each of these characteristics is associated with vascular stiffening and dysfunction.5-7 Diastolic abnormalities may contribute to symptoms of exertional intolerance3,8, but non-cardiac limitations have recently been shown to be equally important.9-11 Patients with HFpEF display impaired decreases in mean vascular resistance in response to exercise, significantly limiting performance,9 yet this represents only one component of ventricular afterload. With aging and particularly in HFpEF, pulsatile load due to vascular stiffening and increased wave reflections becomes more magnified.6,12 The latter can be quantified by pulse wave velocity, arterial compliance and carotid augmentation index. These can be determined noninvasively, and while they have been shown to be abnormal in HFpEF patients at rest10,11, little is known about changes in each during exercise stress, or how this might modulate ventricular performance. Recent evidence indicates that endothelial and autonomic dysfunction are present in HFpEF9, but it is not known how these abnormalities might limit ventricular-vascular function with exercise. The primary objective of this proposal is to compare resting and exercise-induced changes in vascular function in patients with HFpEF and age-matched controls, to determine how these factors may affect exercise performance and cardiovascular reserve function.
Specific Aim 1. Contrast resting and exercise-induced changes in vascular stiffness, endothelial functio
Sponsor: Mayo Clinic
Current Primary Outcome: Contrast resting and exercise-induced changes in vascular stiffness, endothelial function, and afterload in patients with HFpEF to age-matched controls. [ Time Frame: Throughout single visit. ]
Original Primary Outcome: Same as current
Current Secondary Outcome:
- Determine how baseline and exercise-induced changes in the vascular parameters measured are related to LV systolic and diastolic functional reserve, cardiac output response, metabolic exercise performance, and changes in pulmonary cap [ Time Frame: Throughout single visit ]
- Determine if vascular and ventricular stiffness properties measured in specific aim 1 are associated with abnormal neurohormonal responses to exercise. [ Time Frame: Immediately pre and post exercise ]
Original Secondary Outcome: Same as current
Information By: Mayo Clinic
Dates:
Date Received: December 21, 2007
Date Started: April 2007
Date Completion:
Last Updated: October 13, 2010
Last Verified: October 2010
