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CompletedNCT00588692SACARUpdated May 6, 2014Results posted

Strategies for Aggressive Central Afterload Reduction in Patients With Heart Failure

An interventional study of SphygmoCor in Heart Failure, sponsored by Mayo Clinic. Completed at 2 sites in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2014-05-06.

Sponsored by Mayo Clinic · Not applicable, Interventional, and Treatment

Phase
Not applicable
Study type
Interventional
Enrollment
60
Allocation
Randomized
Ages
18 Years and older
Sex
All
01

Study summary

Heart failure (HF) is the leading cause of hospitalization among Americans over the age of 65 years, affecting greater than 5 million in the U.S. alone. Significant improvements in morbidity and mortality have been achieved through the use of medications that antagonize adverse neurohormonal signaling pathways, particularly therapies that reduce left ventricular (LV) afterload.

Vascular stiffness increases with aging, contributing to the increase in cardiac load. One important repercussion of such stiffening is an increase in pulse wave velocity. As the incident pressure wave generated by cardiac ejection encounters zones of impedance mismatch (such as arterial bifurcations), part of the wave is reflected backward, summing with the incident wave, increasing central blood pressure (CBP). With normal aging, hypertension, and heart failure, increased wave velocity causes the reflected wave to reach the heart earlier, in mid to late systole, considerably increasing late-systolic load, impairing cardiac ejection, and diastolic relaxation in the ensuing cardiac cycle.

The magnitude of this reflected pressure wave can be quantified by the augmentation index (AIx). The use of vasoactive agents which antagonize this increase in late systolic load (and AIx) may prove useful in the treatment of heart failure, by facilitating cardiac ejection during late systole when reflected pressure waves predominate. However, it has never been conclusively shown in humans that CBP-targeted therapy is useful in the management of HF.

LV afterload, measured centrally in the ascending aorta, may differ considerably from brachial cuff-measured pressure, and has traditionally required invasive hemodynamic assessment to determine, limiting the applicability of techniques targeting CBP and late-systolic load. Recently, a novel, hand-held tonometer (SphygmoCor, Atcor Medical) has been developed for the noninvasive assessment of CBP. This pencil-like device is applied over the radial artery, and uses a validated mathematical transformation to derive central aortic pressure. This device has received FDA approval for clinical use in the assessment of central pressures. However, it remains unknown whether knowledge of CBP and late-systolic load (AIx) confers any clinically-significant incremental benefit in the management of patients with heart failure. The primary objective of the proposed investigation will be to determine if this assessment might have such a role.

Read the detailed description

Research Design and Methods

Hypotheses Knowledge of central aortic pressure waveforms (central pressure therapy, CPT) will affect the intensity of antihypertensive medication prescription, and treatment decisions based upon this knowledge in turn will lead to an enhanced reduction in CBP and AIx. Finally, it is hypothesized that this reduction in AIx/CBP will lead to improved exercise performance and LV systolic and diastolic reserve function.

Basic Study Plan This is a single-blind, randomized, controlled, parallel group intervention study examining the effects of a novel, noninvasive diagnostic test for determining AIx and CBP (SphygmoCor, Atcor Medical) on medical care, blood pressure control, exercise performance, and LV functional reserve in patients with chronic heart failure (HF) and systolic dysfunction (25%\<EF\<50%) and with preserved systolic function (EF>50%). Eligible subjects will undergo resting echocardiogram, noninvasive CBP assessment, and metabolic exercise stress testing on a recumbent cycle ergometer to quantify exercise performance. Echocardiography and CBP assessment will be performed at rest, during graded exercise, and immediately after peak exercise to determine indexes of LV systolic and diastolic performance and changes in CBP. Subjects will then be randomized (1:1) to subsequent determination of CBP at 1 month heart failure clinic visits versus sham (tonometry information acquired, but not shared with investigator). Investigators will then make adjustments to subject's medical therapy and antihypertensive regimen based upon the additional data procured via the Sphygmocor device. Subjects randomized to sham will have adjustments made as per standard clinical judgment based upon brachial blood pressure assessment and other clinical variables. In addition to standard clinical assessment, each subject will undergo 6 minute walk test at each visit, administered by the study coordinator.

At the 6 month follow up visit, subjects will undergo resting and exercise echo/CBP/metabolic stress testing exactly as performed at visit 1. The co-primary endpoints will be the change in central augmentation index (defined below) and change in peak oxygen uptake (VO2) from baseline. Secondary endpoints will include the changes in resting and exercise-induced CBP and brachial blood pressures, number of antihypertensive medications prescribed, resting and exercise change in LV systolic and diastolic function (see below), changes in: cardiac output, exercise time, anaerobic threshold, minute ventilation (VE) over carbon dioxide produced (VCO2) slope (ventilatory efficiency). There will be a total of 7 visits, the first and last for exercise testing; the intervening 5 visits will be routine heart failure clinic follow up appointments.

02

Conditions studied

  • Heart Failure

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Keywords

  • Heart Failure
  • Afterload Reduction
  • Sphygmocor
03

In context

Heart Failure

5,701 studies on the registry are indexed under Heart Failure; 1,220 are open to participants now.

This study's enrollment of 60 is below the median of 72 across 3,736 interventional studies indexed under Heart Failure.

Browse Heart Failure studies →

Lead sponsor

Mayo Clinic is the lead sponsor of 3,218 studies on the registry; 670 are open to participants now.

Of its 445 completed or terminated interventional studies of FDA-regulated products, 313 (70%) have results posted.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
No

Inclusion criteria

  • 18 years of age or greater
  • Cardiac Ejection Fraction (EF) greater than or equal to 25% by echocardiography within 12 months
  • Stable New York Heart Association (NYHA) class II or greater
  • Heart Failure consultation within the last 18 months
  • Ability to exercise on a cycle ergometer
  • Stable angiotensin-converting enzyme inhibitors (ACEI) or angiotensin II receptor blockers (ARB) dosage for greater than 3 months

Exclusion criteria

Exclusion Criteria:

  • Enrollment in a concurrent study that may confound the results of this study
  • Subjects with medical conditions that would limit study participation
  • Pregnancy
  • Brachial Systolic Blood Pressure less than 110 mmHg
  • Baseline AIx less than 15%
  • Cardiac Surgery with 60 days of potential study enrollment
  • Myocardial infarction within 30 days of potential study enrollment
  • Hemodynamically significant valvular stenosis (greater than mild)
  • Heart failure due to thyroid disease
  • Active myocarditis or anemia defined as hemoglobin less than 9 mg/dl
  • Presence of severe renal insufficiency with serum creatinine greater than 2.5 mg/dl
  • Significant pulmonary hypertension or Cor pumonale
  • Irregular heart rhythms
  • Dyspnea due to pulmonary disease
  • Uninterpretable echocardiographic images or radial tonometry data
  • Significant competing cause for exercise intolerance (e.g., severe stable angina)
05

Study design

Phase
Not applicable
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Single (Investigator)
Enrollment
60 participants (actual)

Study arms

  • Active comparator
    SphygmoCor Unblinded

    The use of the sphygmocor values will determine medication adjustments to optimize HF treatment.

    Device: SphygmoCor

  • Placebo comparator
    SphygmoCor Blinded

    Sphygmocor values will be blinded to the investigator.

    Device: SphygmoCor

Interventions

  • DeviceSphygmoCor

    The SphygmoCor, a hand-held tonometer will assess central blood pressure noninvasively. This pencil-like device is applied over the radial artery, and uses a validated mathematical transformation to derive central aortic pressure.

06

What researchers measure

Primary outcomes

  1. Change in Peak Oxygen Uptake (VO2) During Maximal Effort Exercise Stress Test According to Ejection Fraction Subgroups

    Peak oxygen uptake (VO2) is the maximum rate of oxygen consumption as measured during incremental exercise, most typically on a motorized treadmill. Maximal oxygen consumption reflects the aerobic physical fitness of the individual. VO2 data was obtained via standard breath-by-breath expired gas analysis. Ejection Fraction Subgroups are based on participants reported at baseline.

    Time frame: baseline, 6 months

  2. Change in Aortic Augmentation Index (AIx) According to Ejection Fraction Subgroups

    Aortic stiffness increases with aging, further augmenting cardiac load. One important repercussion of aortic stiffening is an increase in pulse wave velocity. As the outgoing pressure wave caused by ventricular ejection encounters zones of impedance mismatch, it is partially reflected backward, summing with the incident wave, to increase central aortic blood pressure. The magnitude of this systolic pressure wave reflection can be quantified by AIx. Aortic pressures were assessed in the seated position after 5 minutes rest. Aortic pulse waveform analysis was performed using a noninvasive, high-fidelity hand held tonometer placed over the radial artery. The built-in, custom software was then used to convert radial pressure waveforms to central aortic waveforms, which more accurately reflect LV afterload. The ratio of this augmented pressure to aortic pulse pressure is defined as the augmentation index (AIx).

    Time frame: baseline, 6 months

Secondary outcomes

  1. Change in Heart Rate

    Time frame: baseline, six months

  2. Change in Left Ventricle (LV) End Diastolic Volume

    End-diastolic volume (EDV) is the volume of blood in the right and/or left ventricle at end load or filling in (diastole). An increase in EDV increases the preload on the heart and, through the Frank-Starling mechanism of the heart, increases the amount of blood ejected from the ventricle during systole (stroke volume). Ventricular Data was derived from comprehensive echo-Doppler/Tissue Doppler Echo (TDE) study performed at rest, during and immediately after exercise, along with noninvasive blood pressure assessment (GE Vivid7). LV EDV was determined from the apical 4 and 2 chamber views using Simpson's method of discs, along with ejection fraction (EF).

    Time frame: baseline, 6 months

  3. Change in LV End Systolic Volume

    End-systolic volume (ESV) is the volume of blood in a ventricle at the end of contraction, or systole, and the beginning of filling, or diastole. ESV is the lowest volume of blood in the ventricle at any point in the cardiac cycle. End systolic volume can be used clinically as a measurement of the adequacy of cardiac emptying, related to systolic function. Ventricular Data was derived from comprehensive echo-Doppler/Tissue Doppler Echo (TDE) study performed at rest, during and immediately after exercise, along with noninvasive blood pressure assessment (GE Vivid7). LV end systolic volumes was determined from the apical 4 and 2 chamber views using Simpson's method of discs, along with EF.

    Time frame: baseline, 6 months

  4. Change in LV Ejection Fraction

    The ejection fraction is the percentage of the volume in the left ventricle ejected during a cardiac cycle. The normal ejection fraction is 55 to 75 percent. EF = (EDV - ESV) / EDV where EF = ejection fraction, EDV = volume of blood in the left ventricle at end-diastole, ESV = volume of blood in the left ventricle at end-systole. Ventricular Data was derived from comprehensive echo-Doppler/Tissue Doppler Echo (TDE) study performed at rest, during and immediately after exercise, along with noninvasive blood pressure assessment (GE Vivid7).

    Time frame: baseline, 6 months

  5. Change in Stroke Volume

    Stroke volume (SV) is the volume of blood pumped from one ventricle of the heart with each beat. SV was determined from pulse wave (PW) and continuous wave (CW) Doppler in the LV outflow tract.

    Time frame: baseline, 6 months

  6. Change in Mitral E Velocity

    The Mitral E velocity is the speed at which blood fills the ventricle. It is determined by echocardiography, an ultrasound-based cardiac imaging modality.

    Time frame: baseline, 6 months

  7. Change in Mitral E/A Ratio

    The E/A ratio is a marker of the function of the left ventricle of the heart; it is determined by echocardiography, an ultrasound-based cardiac imaging modality. Abnormalities in the E/A ratio on Doppler echocardiography suggest that the left ventricle, which pumps blood into the circulation, cannot fill with blood properly in the period between contractions. The E/A ratio is the ratio of peak early transmitral inflow velocity and peak late mitral inflow velocity.

    Time frame: baseline, 6 months

  8. Change in Mitral E Wave Deceleration Time

    The deceleration time (DT) is the time taken from the maximum E point to baseline. Normally in adults it is less than 220 milliseconds. The DT was measured by pulse wave doppler.

    Time frame: baseline, 6 months

  9. Change in Brachial Systolic Blood Pressure (BP)

    Blood pressure is a measure of the force of the blood flowing against the walls of your arteries as it moves through your body. There are two numbers in a blood pressure reading. This tells how high in millimeters the pressure of your blood raises a column of mercury. The numbers usually are expressed in the form of a fraction; an example of a blood pressure reading is 120/80 mm Hg. The first, or top, number (120 in the example) is the systolic pressure. The systolic pressure is the measure of your blood pressure as the heart contracts and pumps blood. The second or lower number is the diastolic pressure and is the measure taken when your heart is at rest (80 in the example) Brachial systolic BP was determined by a standard oscillometric device (Dinemap, Critikon).

    Time frame: baseline, 6 months

  10. Change in Brachial Diastolic BP

    Blood pressure is a measure of the force of the blood flowing against the walls of your arteries as it moves through your body. There are two numbers in a blood pressure reading. This tells how high in millimeters the pressure of your blood raises a column of mercury. The numbers usually are expressed in the form of a fraction; an example of a blood pressure reading is 120/80 mm Hg. The first, or top, number (120 in the example) is the systolic pressure. The systolic pressure is the measure of your blood pressure as the heart contracts and pumps blood. The second or lower number is the diastolic pressure and is the measure taken when your heart is at rest (80 in the example) Brachial diastolic BP was determined by a standard oscillometric device (Dinemap, Critikon).

    Time frame: baseline, 6 months

  11. Change in Central Systolic BP

    Central blood pressure (CBP) is the pressure in the aorta, which is the large artery into which the heart pumps. This was determined by noninvasive radial tonometry, which undergoes transfer function using customized software to derive CBP tracings.

    Time frame: baseline, 6 months

  12. Change in Central Diastolic BP

    Central blood pressure (CBP) is the pressure in the aorta, which is the large artery into which the heart pumps. This was determined by noninvasive radial tonometry, which undergoes transfer function using customized software to derive CBP tracings.

    Time frame: baseline, 6 months

  13. Change in Augmentation Index

    Aortic stiffness increases with aging, further augmenting cardiac load. One important repercussion of aortic stiffening is an increase in pulse wave velocity. As the outgoing pressure wave caused by ventricular ejection encounters zones of impedance mismatch, it is partially reflected backward, summing with the incident wave, to increase central aortic blood pressure. The magnitude of this systolic pressure wave reflection can be quantified by AIx. Aortic pressures were assessed in the seated position after 5 minutes rest. Aortic pulse waveform analysis was performed using a noninvasive, high-fidelity hand held tonometer placed over the radial artery. The built-in, custom software was then used to convert radial pressure waveforms to central aortic waveforms, which more accurately reflect LV afterload. The ratio of this augmented pressure to aortic pulse pressure is defined as the augmentation index (AIx).

    Time frame: baseline, 6 months

  14. Change in Arterial Elastance

    Elastance is a measure of the tendency of a hollow organ to recoil toward its original dimensions upon removal of a distending or compressing force. Effective arterial elastance was determined by the ratio of end systolic BP/stroke volume (SV).

    Time frame: baseline, 6 months

07

Results

Posted May 6, 2014

Participant flow

Participant flow — Overall Study
MilestoneSphygmoCor UnblindedSphygmoCor Blinded
Started3030
Completed2327
Not completed73
Withdrew: Withdrawal by subject42
Withdrew: Hip surgery01
Withdrew: Severe peptic ulcer disease10
Withdrew: Cancer10
Withdrew: Death10

Outcome measures

PrimaryChange in Peak Oxygen Uptake (VO2) During Maximal Effort Exercise Stress Test According to Ejection Fraction Subgroups

Peak oxygen uptake (VO2) is the maximum rate of oxygen consumption as measured during incremental exercise, most typically on a motorized treadmill. Maximal oxygen consumption reflects the aerobic physical fitness of the individual. VO2 data was obtained via standard breath-by-breath expired gas analysis. Ejection Fraction Subgroups are based on participants reported at baseline.

Time frame:
baseline, 6 months
Reported as:
Mean · percentage of change in Peak VO2
Change in Peak Oxygen Uptake (VO2) During Maximal Effort Exercise Stress Test According to Ejection Fraction Subgroups
percentage of change in Peak VO2SphygmoCor UnblindedSphygmoCor Blinded
Ejection Fraction Subgroup 25-49%, n=481.5 ± 3.8-0.5 ± 2.5
Ejection Fraction Subgroup 35-49%, n=332.0 ± 5.4-1.0 ± 1.9
Statistical analysis
  • SphygmoCor Unblinded vs SphygmoCor Blinded · ANOVA · p = <0.05
  • SphygmoCor Unblinded vs SphygmoCor Blinded · ANOVA · p = <0.05
PrimaryChange in Aortic Augmentation Index (AIx) According to Ejection Fraction Subgroups

Aortic stiffness increases with aging, further augmenting cardiac load. One important repercussion of aortic stiffening is an increase in pulse wave velocity. As the outgoing pressure wave caused by ventricular ejection encounters zones of impedance mismatch, it is partially reflected backward, summing with the incident wave, to increase central aortic blood pressure. The magnitude of this systolic pressure wave reflection can be quantified by AIx. Aortic pressures were assessed in the seated position after 5 minutes rest. Aortic pulse waveform analysis was performed using a noninvasive, high-fidelity hand held tonometer placed over the radial artery. The built-in, custom software was then used to convert radial pressure waveforms to central aortic waveforms, which more accurately reflect LV afterload. The ratio of this augmented pressure to aortic pulse pressure is defined as the augmentation index (AIx).

Time frame:
baseline, 6 months
Reported as:
Mean · percentage of change in AIx
Change in Aortic Augmentation Index (AIx) According to Ejection Fraction Subgroups
percentage of change in AIxSphygmoCor UnblindedSphygmoCor Blinded
Ejection Fraction Subgroup 25-49%-6.9 ± 8.8-4.9 ± 6.3
Ejection Fraction Subgroup 35-49%-8.3 ± 8.7-5.5 ± 6.0
SecondaryChange in Heart Rate
Time frame:
baseline, six months
Reported as:
Mean · bpm
Change in Heart Rate
bpmSphygmoCor UnblindedSphygmoCor Blinded
Change in Heart Rate3 ± 7-1 ± 10
Statistical analysis
  • SphygmoCor Unblinded vs SphygmoCor Blinded · ANOVA · p = 0.06
SecondaryChange in Left Ventricle (LV) End Diastolic Volume

End-diastolic volume (EDV) is the volume of blood in the right and/or left ventricle at end load or filling in (diastole). An increase in EDV increases the preload on the heart and, through the Frank-Starling mechanism of the heart, increases the amount of blood ejected from the ventricle during systole (stroke volume). Ventricular Data was derived from comprehensive echo-Doppler/Tissue Doppler Echo (TDE) study performed at rest, during and immediately after exercise, along with noninvasive blood pressure assessment (GE Vivid7). LV EDV was determined from the apical 4 and 2 chamber views using Simpson's method of discs, along with ejection fraction (EF).

Time frame:
baseline, 6 months
Reported as:
Mean · ml
Change in Left Ventricle (LV) End Diastolic Volume
mlSphygmoCor UnblindedSphygmoCor Blinded
Change in Left Ventricle (LV) End Diastolic Volume-24 ± 30-17 ± 32
Statistical analysis
  • SphygmoCor Unblinded vs SphygmoCor Blinded · ANOVA · p = 0.5
  • SphygmoCor Unblinded · t-test, 2 sided · p = <0.05
  • SphygmoCor Blinded · t-test, 2 sided · p = <0.05
SecondaryChange in LV End Systolic Volume

End-systolic volume (ESV) is the volume of blood in a ventricle at the end of contraction, or systole, and the beginning of filling, or diastole. ESV is the lowest volume of blood in the ventricle at any point in the cardiac cycle. End systolic volume can be used clinically as a measurement of the adequacy of cardiac emptying, related to systolic function. Ventricular Data was derived from comprehensive echo-Doppler/Tissue Doppler Echo (TDE) study performed at rest, during and immediately after exercise, along with noninvasive blood pressure assessment (GE Vivid7). LV end systolic volumes was determined from the apical 4 and 2 chamber views using Simpson's method of discs, along with EF.

Time frame:
baseline, 6 months
Reported as:
Mean · ml
Change in LV End Systolic Volume
mlSphygmoCor UnblindedSphygmoCor Blinded
Change in LV End Systolic Volume-18 ± 18-11 ± 20
Statistical analysis
  • SphygmoCor Unblinded vs SphygmoCor Blinded · ANOVA · p = 0.26
  • SphygmoCor Unblinded · t-test, 2 sided · p = <0.05
  • SphygmoCor Blinded · t-test, 2 sided · p = <0.05
SecondaryChange in LV Ejection Fraction

The ejection fraction is the percentage of the volume in the left ventricle ejected during a cardiac cycle. The normal ejection fraction is 55 to 75 percent. EF = (EDV - ESV) / EDV where EF = ejection fraction, EDV = volume of blood in the left ventricle at end-diastole, ESV = volume of blood in the left ventricle at end-systole. Ventricular Data was derived from comprehensive echo-Doppler/Tissue Doppler Echo (TDE) study performed at rest, during and immediately after exercise, along with noninvasive blood pressure assessment (GE Vivid7).

Time frame:
baseline, 6 months
Reported as:
Mean · percentage of LV blood volume
Change in LV Ejection Fraction
percentage of LV blood volumeSphygmoCor UnblindedSphygmoCor Blinded
Change in LV Ejection Fraction2 ± 2-0.0 ± 2
Statistical analysis
  • SphygmoCor Unblinded vs SphygmoCor Blinded · ANOVA · p = 0.4
SecondaryChange in Stroke Volume

Stroke volume (SV) is the volume of blood pumped from one ventricle of the heart with each beat. SV was determined from pulse wave (PW) and continuous wave (CW) Doppler in the LV outflow tract.

Time frame:
baseline, 6 months
Reported as:
Mean · ml
Change in Stroke Volume
mlSphygmoCor UnblindedSphygmoCor Blinded
Change in Stroke Volume10 ± 2110 ± 21
Statistical analysis
  • SphygmoCor Unblinded vs SphygmoCor Blinded · ANOVA · p = 0.9
  • SphygmoCor Unblinded · t-test, 2 sided · p = <0.05
  • SphygmoCor Blinded · t-test, 2 sided · p = <0.05
SecondaryChange in Mitral E Velocity

The Mitral E velocity is the speed at which blood fills the ventricle. It is determined by echocardiography, an ultrasound-based cardiac imaging modality.

Time frame:
baseline, 6 months
Reported as:
Mean · cm/sec
Change in Mitral E Velocity
cm/secSphygmoCor UnblindedSphygmoCor Blinded
Change in Mitral E Velocity5 ± 154 ± 12
Statistical analysis
  • SphygmoCor Unblinded vs SphygmoCor Blinded · ANOVA · p = 0.9
SecondaryChange in Mitral E/A Ratio

The E/A ratio is a marker of the function of the left ventricle of the heart; it is determined by echocardiography, an ultrasound-based cardiac imaging modality. Abnormalities in the E/A ratio on Doppler echocardiography suggest that the left ventricle, which pumps blood into the circulation, cannot fill with blood properly in the period between contractions. The E/A ratio is the ratio of peak early transmitral inflow velocity and peak late mitral inflow velocity.

Time frame:
baseline, 6 months
Reported as:
Mean · ratio
Change in Mitral E/A Ratio
ratioSphygmoCor UnblindedSphygmoCor Blinded
Change in Mitral E/A Ratio-0.1 ± 0.3-0.1 ± 0.3
Statistical analysis
  • SphygmoCor Unblinded vs SphygmoCor Blinded · ANOVA · p = 0.9
SecondaryChange in Mitral E Wave Deceleration Time

The deceleration time (DT) is the time taken from the maximum E point to baseline. Normally in adults it is less than 220 milliseconds. The DT was measured by pulse wave doppler.

Time frame:
baseline, 6 months
Reported as:
Mean · milliseconds (ms)
Change in Mitral E Wave Deceleration Time
milliseconds (ms)TreatmentControl
Change in Mitral E Wave Deceleration Time-25 ± 58-5 ± 43
Statistical analysis
  • Treatment vs Control · ANOVA · p = 0.3
SecondaryChange in Brachial Systolic Blood Pressure (BP)

Blood pressure is a measure of the force of the blood flowing against the walls of your arteries as it moves through your body. There are two numbers in a blood pressure reading. This tells how high in millimeters the pressure of your blood raises a column of mercury. The numbers usually are expressed in the form of a fraction; an example of a blood pressure reading is 120/80 mm Hg. The first, or top, number (120 in the example) is the systolic pressure. The systolic pressure is the measure of your blood pressure as the heart contracts and pumps blood. The second or lower number is the diastolic pressure and is the measure taken when your heart is at rest (80 in the example) Brachial systolic BP was determined by a standard oscillometric device (Dinemap, Critikon).

Time frame:
baseline, 6 months
Reported as:
Mean · mmHg
Change in Brachial Systolic Blood Pressure (BP)
mmHgSphygmoCor UnblindedSphygmoCor Blinded
Change in Brachial Systolic Blood Pressure (BP)-9 ± 17-9 ± 24
Statistical analysis
  • SphygmoCor Unblinded vs SphygmoCor Blinded · ANOVA · p = 0.9
  • SphygmoCor Unblinded · t-test, 2 sided · p = <0.05
  • SphygmoCor Blinded · t-test, 2 sided · p = 0.24
SecondaryChange in Brachial Diastolic BP

Blood pressure is a measure of the force of the blood flowing against the walls of your arteries as it moves through your body. There are two numbers in a blood pressure reading. This tells how high in millimeters the pressure of your blood raises a column of mercury. The numbers usually are expressed in the form of a fraction; an example of a blood pressure reading is 120/80 mm Hg. The first, or top, number (120 in the example) is the systolic pressure. The systolic pressure is the measure of your blood pressure as the heart contracts and pumps blood. The second or lower number is the diastolic pressure and is the measure taken when your heart is at rest (80 in the example) Brachial diastolic BP was determined by a standard oscillometric device (Dinemap, Critikon).

Time frame:
baseline, 6 months
Reported as:
Mean · mmHg
Change in Brachial Diastolic BP
mmHgSphygmoCor UnblindedSphygmoCor Blinded
Change in Brachial Diastolic BP-2 ± 8-4 ± 14
Statistical analysis
  • SphygmoCor Unblinded vs SphygmoCor Blinded · ANOVA · p = 0.6
SecondaryChange in Central Systolic BP

Central blood pressure (CBP) is the pressure in the aorta, which is the large artery into which the heart pumps. This was determined by noninvasive radial tonometry, which undergoes transfer function using customized software to derive CBP tracings.

Time frame:
baseline, 6 months
Reported as:
Mean · mmHg
Change in Central Systolic BP
mmHgSphygmoCor UnblindedSphygmoCor Blinded
Change in Central Systolic BP-8 ± 19-9 ± 18
Statistical analysis
  • SphygmoCor Unblinded vs SphygmoCor Blinded · ANOVA · p = 0.9
  • SphygmoCor Unblinded · t-test, 2 sided · p = <0.05
  • SphygmoCor Blinded · t-test, 2 sided · p = <0.05
SecondaryChange in Central Diastolic BP

Central blood pressure (CBP) is the pressure in the aorta, which is the large artery into which the heart pumps. This was determined by noninvasive radial tonometry, which undergoes transfer function using customized software to derive CBP tracings.

Time frame:
baseline, 6 months
Reported as:
Mean · mmHg
Change in Central Diastolic BP
mmHgSphygmoCor UnblindedSphygmoCor Blinded
Change in Central Diastolic BP-7 ± 10-3 ± 9
Statistical analysis
  • SphygmoCor Unblinded vs SphygmoCor Blinded · ANOVA · p = 0.11
  • SphygmoCor Unblinded · t-test, 2 sided · p = <0.05
  • SphygmoCor Blinded · t-test, 2 sided · p = 0.16
SecondaryChange in Augmentation Index

Aortic stiffness increases with aging, further augmenting cardiac load. One important repercussion of aortic stiffening is an increase in pulse wave velocity. As the outgoing pressure wave caused by ventricular ejection encounters zones of impedance mismatch, it is partially reflected backward, summing with the incident wave, to increase central aortic blood pressure. The magnitude of this systolic pressure wave reflection can be quantified by AIx. Aortic pressures were assessed in the seated position after 5 minutes rest. Aortic pulse waveform analysis was performed using a noninvasive, high-fidelity hand held tonometer placed over the radial artery. The built-in, custom software was then used to convert radial pressure waveforms to central aortic waveforms, which more accurately reflect LV afterload. The ratio of this augmented pressure to aortic pulse pressure is defined as the augmentation index (AIx).

Time frame:
baseline, 6 months
Reported as:
Mean · percentage of change in AIx
Change in Augmentation Index
percentage of change in AIxSphygmoCor UnblindedSphygmoCor Blinded
Change in Augmentation Index-7 ± 9-5 ± 6
Statistical analysis
  • SphygmoCor Unblinded vs SphygmoCor Blinded · ANOVA · p = 0.4
  • SphygmoCor Unblinded · t-test, 2 sided · p = <0.05
  • SphygmoCor Blinded · t-test, 2 sided · p = <0.05
SecondaryChange in Arterial Elastance

Elastance is a measure of the tendency of a hollow organ to recoil toward its original dimensions upon removal of a distending or compressing force. Effective arterial elastance was determined by the ratio of end systolic BP/stroke volume (SV).

Time frame:
baseline, 6 months
Reported as:
Mean · mmHg/ml
Change in Arterial Elastance
mmHg/mlSphygmoCor UnblindedSphygmoCor Blinded
Change in Arterial Elastance-0.3 ± 0.4-0.3 ± 0.4
Statistical analysis
  • SphygmoCor Unblinded vs SphygmoCor Blinded · ANOVA · p = 0.9
  • SphygmoCor Unblinded · t-test, 2 sided · p = <0.05
  • SphygmoCor Blinded · t-test, 2 sided · p = <0.05

Adverse events

Collected over Participants were followed for safety reporting at monthly visits over the 6-month study period.. Non-serious events are listed at a 0% frequency threshold.

Adverse event summary by group
GroupDeathsSeriousOther
Treatment—3/24 (12.5%)10/24 (41.7%)
Control—2/27 (7.4%)5/27 (18.5%)
Most frequent serious events
Most frequent serious events
EventTreatmentControl
Heart Failure HospitalizationCardiac disorders2/242/27
DeathCardiac disorders1/240/27
Most frequent other events
Most frequent other events
EventTreatmentControl
DizzinessNervous system disorders8/245/27
Worsening Renal FunctionRenal and urinary disorders2/240/27

Baseline characteristics

Only the participants who completed the trial were included in the baseline analysis.

Age, Continuous
Age, Continuous(years)SphygmoCor UnblindedSphygmoCor BlindedTotal
Mean74 ± 872 ± 873 ± 8
Sex: Female, Male
Sex: Female, Male(Participants)SphygmoCor UnblindedSphygmoCor BlindedTotal
Female7411
Male162339
Region of Enrollment
Region of Enrollment(participants)SphygmoCor UnblindedSphygmoCor BlindedTotal
United States232750
Body Mass Index
Body Mass Index(kg/m^2)SphygmoCor UnblindedSphygmoCor BlindedTotal
Mean29.2 ± 4.529.9 ± 4.629.6 ± 4.6
History of Hypertension
History of Hypertension(participants)SphygmoCor UnblindedSphygmoCor BlindedTotal
Prior Hypertension202646
No Prior Hypertension314
Diabetes
Diabetes(participants)SphygmoCor UnblindedSphygmoCor BlindedTotal
Prior History of Diabetes121224
No History of Diabetes111526
Obesity
Obesity(participants)SphygmoCor UnblindedSphygmoCor BlindedTotal
Obese at Baseline101424
Not Obese at Baseline131326
08

Study locations

2 sites
  • University of Arizona
    Phoenix, Arizona 85004, United States
  • Mayo Clinic
    Rochester, Minnesota 55905, United States
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References and documents

Publications

  • Wohlfahrt P, Melenovsky V, Redfield MM, Olson TP, Lin G, Abdelmoneim SS, Hametner B, Wassertheurer S, Borlaug BA. Aortic Waveform Analysis to Individualize Treatment in Heart Failure. Circ Heart Fail. 2017 Feb;10(2):e003516. doi: 10.1161/CIRCHEARTFAILURE.116.003516. PubMed 28159826 ↗
  • Borlaug BA, Olson TP, Abdelmoneim SS, Melenovsky V, Sorrell VL, Noonan K, Lin G, Redfield MM. A randomized pilot study of aortic waveform guided therapy in chronic heart failure. J Am Heart Assoc. 2014 Mar 20;3(2):e000745. doi: 10.1161/JAHA.113.000745. Erratum In: J Am Heart Assoc. 2014 Aug;3(4):e001214. Abdelmoneim Mohamed, Sahar [Corrected to Abdelmoneim, Sahar S]. PubMed 24650926 ↗
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Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on May 6, 2014, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
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Registry details

Key details

Study ID
NCT00588692
Lead sponsor
Mayo Clinic
Collaborators
AtCor Medical, Inc.
Responsible party
Barry Borlaug (MD, Mayo Clinic) — Principal investigator
First posted
Jan 8, 2008
Start date
Jul 2007
Primary completion
Nov 2012
Completion
Dec 2012
Results posted
May 6, 2014
Last update
May 6, 2014

Study contacts

Barry A. Borlaug, MD
principal investigator · Staff Physician, Mayo Clinic

Oversight

Data monitoring committee
No
View the source record on ClinicalTrials.gov ↗

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