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NCT Number: NCT00939640

Effects of the Dietary Approaches to Stop Hypertension(DASH) Sodium-restricted Diet in Diastolic Heart Failure

Heart failure with preserved systolic function (HF-PSF, or 'diastolic heart failure') accounts for half of hospitalizations for heart failure in patients over the age of 65. Most HF-PSF patients have systemic hypertension (HTN), and characteristic HTN-induced cardiovascular changes contribute to HF-PSF. However, it is unclear why most patients with HTN never develop HF-PSF or which specific aspects of HTN predispose to HF-PSF.

In the Dahl S rat, the primary animal model of HF-PSF, high dietary sodium intake suppresses the systemic renin-angiotensin-aldosterone system, but upregulates renal and cardiac renin-angiotensin-aldosterone system by inducing oxidative stress. In humans, the magnitude of blood pressure response to sodium ingestion and depletion can categorize subjects as "salt-resistant" and "salt-sensitive." Human salt sensitivity is associated with structural and loading conditions that increase the risk for HF-PSF, including HTN, ventricular hypertrophy and diastolic dysfunction, arterial stiffening, and increased plasma volume. High dietary sodium intake induces oxidative stress in salt-sensitive humans. In humans with HTN and normal ventricular systolic function that do not have heart failure, increased oxidative stress predicts impaired exercise capacity, ventricular hypertrophy, diastolic dysfunction, arterial stiffening, and vascular endothelial dysfunction. The investigators have proposed that "salt sensitivity" and the accompanying oxidative stress on the typical high-sodium Western diet may contribute to the initiation and progression of HF-PSF.

In patients with HF-PSF, the investigators will relate dietary changes to biochemical and cardiovascular functional measures. The investigators will study subjects on ad-lib diet and and following three weeks of rigorous dietary modification with the Dietary Approaches to Stop Hypertension (DASH)/sodium-restricted diet (SRD). This diet is richer in natural antioxidants and lower in sodium than the usual American diet. The DASH/SRD is recommended to lower blood pressure in patients with HTN, and is particularly effective in elderly, obese, and salt-sensitive hypertensives. Dietary sodium restriction is recommended for all HF patients including those with HF-PSF. The investigators hypothesize that the DASH/SRD will have favorable effects on oxidative stress, ventricular and vascular function, and blood pressure control in patients with hypertensive HF-PSF.

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Key information

Conditions

Diastolic Heart Failure Cardiovascular Diseases Heart Diseases Heart Failure Heart Failure, Diastolic Hypertension Hypertensive Heart Disease Vascular Diseases

Age range

50 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

University of Michigan

Ann Arbor, Michigan, 48109, United States

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Satisfy European Society of Cardiology guidelines for the diagnosis of HF-PSF (Paulus WJ et al. Eur. Heart J. 2007;28:2539-2550).
  • Framingham criteria for heart failure satisfied
  • left ventricular ejection fraction ≥ 50% (contrast ventriculography, echocardiography, nuclear scintigraphy)
  • Diastolic dysfunction on previous echocardiogram/catheterization or evidence of abnormal neurohormonal activation (B-type natriuretic peptide (BNP) ≥ 100 pg/ml) with supporting evidence (atrial fibrillation, left atrial enlargement, left ventricular hypertrophy)
  • History of systemic hypertension
  • Willing to adhere to provided diet

Exclusion criteria

  • New York Heart Association Class IV heart failure symptoms
  • Hospitalization for decompensated heart failure within past one month
  • Uncontrolled hypertension (seated systolic blood pressure ≥ 180 or diastolic blood pressure ≥ 110) at rest, on current antihypertensive regimen
  • Changes in medical regimen for heart disease or hypertension within past 1 month, including diuretic dose adjustment
  • Primary exercise limitation due to severe pulmonary disease
  • Poor echocardiographic windows
  • Worse than moderate mitral or aortic stenosis or insufficiency.
  • Serum potassium level > 5.0 mmol/L at baseline or prior history of serum potassium level > 6.0
  • Serum calcium/phosphorus product > 50 at baseline
  • Severe renal insufficiency (current estimated glomerular filtration rate < 30 ml/min)
  • Severe anemia (hemoglobin < 9 g/dL)
  • Uncontrolled diabetes mellitus (hemoglobin A1c > 9%)
  • Non-hypertensive cause of HF-PSF, e.g. amyloidosis, sarcoidosis, constrictive pericardial syndromes
  • Myocardial infarction or unstable angina, including new or worsening anginal syndrome, within the past three months
  • Uncontrolled arrhythmia (including non rate-controlled atrial fibrillation)
  • Terminal illness expected to result in death within six months or active solid-organ cancer
  • Psychiatric disorder or dementia with potential to compromise dietary adherence

Treatment and study plan

DASH/sodium-restricted diet (SRD)

Behavioral

Baseline diet will be assessed via Block Food Frequency Questionnaire, and 24-hour urinary sodium, potassium, and 8-isoprostanes will be measured. Subjects will then be assigned to 21 days of the DASH/SRD, with all food and beverages provided. Adherence will be assessed through a three-day food diary at the midpoint of the intervention, and at the end of the study urinary sodium, potassium, and 8-isoprostanes will again be measured.

Other names: DASH diet, sodium-restricted diet, low sodium diet, DASH-sodium

Primary outcomes

  1. Brachial Artery Flow-mediated Dilation (FMD)

    Time frame: Prior to and following 21 days of dietary intervention, i.e. day 1 and day 22 of participation

Secondary outcomes

  1. Mean 24-hour Systolic Blood Pressure

    Time frame: Prior to and following 21 days of dietary intervention, i.e. day 1 and day 22 of participation

    Change in 24-hour systolic blood pressure

  2. Diurnal Variation in Ambulatory Blood Pressure

    Time frame: Prior to and following 21 days of dietary intervention, i.e. day 1 and day 22 of participation

    Number of participants with non-dipping of nocturnal blood pressure - nighttime-to-daytime systolic BP ratio of >= 0.9

  3. Aortic Augmentation Index

    Time frame: Prior to and following 21 days of dietary intervention, i.e. day 1 and day 22 of participation

    Aortic augmentation index is the ratio of the augmentation pressure to the central pulse pressure, expressed as a percentage. Both parameters are obtained via mathematical transformation of the radial pulse wave. The augmentation pressure represents the contribution of reflected waves to the pulse pressure. The central pulse pressure is the ratio between maximum aortic systolic pressure and minimum aortic diastolic pressure. A higher aortic augmentation index and central pulse pressure reflect increased arterial stiffness. Increased arterial stiffness is associated with an increased long-term risk of cardiovascular disease.

  4. Carotid-femoral Pulse Wave Velocity

    Time frame: Prior to and following 21 days of dietary intervention, i.e. day 1 and day 22 of participation

  5. Ventricular Diastolic Function

    Time frame: Prior to and following 21 days of dietary intervention, i.e. day 1 and day 22 of participation

    Lateral mitral annulus E/e' ratio

  6. Six Minute Walk Test Distance

    Time frame: Prior to and following 21 days of dietary intervention, i.e. day 1 and day 22 of participation

  7. Urinary 8-isoprostanes

    Time frame: Prior to and following 21 days of dietary intervention, i.e. day 1 and day 22 of participation

Other outcomes

  1. EndoPAT Arterial Endothelial Function

    Time frame: Prior to and following 21 days of dietary intervention, i.e. day 1 and day 22 of participation

  2. Estimated Glomerular Filtration Rate, Serum Potassium, Serum Calcium-phosphorus Product

    Time frame: Prior to and following 21 days of dietary intervention, i.e. day 1 and day 22 of participation

    Safety measures to determine adverse effects of the provided DASH diet home-delivered meals

Sponsors and collaborators

Lead sponsor

University of Michigan

Other

Registry information

Official study title

Effects of the Dietary Approaches to Stop Hypertension(DASH) Sodium-restricted Diet on Ventriculovascular Function in Heart Failure With Preserved Systolic Function

Acronym: DASH-DHF

Important dates

Study start
2009
Primary completion
2011
Study completion
2011
First posted
Jul 15, 2009
Registry last updated
Oct 15, 2019

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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