Strategies for Aggressive Central Afterload Reduction in Patients With Heart Failure

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

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

Population: For the EF subgroup 25-49%, n=48, 24 SphygmoCor Unblinded, 24 SphygmoCor Blinded. For the EF subgroup 35-49%, n=33, 14 SphygmoCor Unblinded,. 19 SphygmoCor Blinded. 2 subjects had EF either \<25 or \>50, and they were not included in the analysis.

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

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

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

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

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

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

Time frame: baseline, six months

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

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

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

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

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

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

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