Strategies for Aggressive Central Afterload Reduction in Patients With Heart Failure

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.