Showing papers by "Joseph L. Izzo published in 2015"

Research Article Ambulatory 24-hour cardiac oxygen consumption and blood pressure-heart rate variability: effects of nebivolol and valsartan alone and in combination

Abstract: We compared an angiotensin receptor blocker (valsartan; VAL), a beta–blocker (nebivolol; NEB) and the combination of NEB/VAL with respect to 24–hour myocardial oxygen consumption (determined by 24–hour ambulatory heart rate–central systolic pressure product [ACRPP]) and its components. Subjects with hypertension (systolic blood pressure >140 or diastolic blood pressure >90; n ¼ 26) were studied in a double–blinded, double-dummy, forced–titration, crossover design with 3 random-order experimental periods: VAL 320 mg, NEB 40 mg, and NEB/VAL 320/40 mg daily. After 4 weeks of each drug, ambulatory pulse wave analysis (MobilOGraph) was performed every 20 minutes for 24 hours. All three treatments resulted in nearly identical brachial and central systolic blood pressures. NEB alone or in combination with VAL resulted in lower ACRPP (by 11%–14%; P < .001 each) and heart rate (by 18%–20%; P < .001 each) compared with VAL, but stroke work (ACRPP per beat) was lower with VAL. Relative and adjusted variability (standard deviation and coefficient of variation) of heart rate were also lower with NEB and NEB/VAL than VAL. Results in African Americans, the majority subpopulation, were similar to those of the entire treatment group. We conclude that the rate–slowing effects of NEB cause ambulatory cardiac myocardial oxygen consumption to be lower with NEB monotherapy or NEB/VAL combination therapy than with VAL monotherapy. NEB/VAL is not superior to NEB alone in controlling heart rate, blood pressure, or ACRPP. Heart rate variability but not ACRPP variability is reduced by NEB or the combination NEB/VAL. There is no attenuation of beta–blocker–induced rate–slowing effects of in African Americans. J Am Soc Hypertens 2015;9(7):526–535. 2015

Effects of aging and blood pressure on timing and amplitude of central pulse contour landmarks

Abstract: An arterial pulse contour can be defined by its amplitude and timing landmarks. We studied the effects of aging and hypertension on central blood pressure landmarks in a reference cohort of normotensive and hypertensive individuals (treated and untreated (n1⁄4376, age 16-90) designed to mimic the NHANES III cohort. Each participant had standard cuff BP (oscillometry, Omron CP705) and radial artery tonometry (Sphygmocor) after >5 min sitting. In a subset (n1⁄463), supine heart-femoral pulse wave velocity (hfPWV, Colin VP 1000) and systemic vascular resistance (SVR, impedance cardiography, Bio-Z) were also measured. Variables were inter-correlated (Pearson) and the group was dichotomized at age 55 for landmark comparisons (ttests) and ensemble wave averaging. Mean age of the younger (Y) group (n1⁄4213) was 33 years; the older (O) group (n1⁄4163) was 66 years. Figure 1 demonstrates the ensemble waveforms and landmarks for Y (gray line) and O (black line), with timing (Y long vertical lines, O short verticals) and pressure (vertical intersections for Y, filled dots for O) landmarks. Mean timing values for each landmark deviated by only a few msec between Y and O, with T2/P2 always occurring in late systole. P2 amplitude was most strongly correlated with age and P2 differed most between Y and O groups (highest T-statistic). Amplitude at each pressure landmark correlated with age, brachial BP, hfPWV and SVR, with the highest values occurring in late systole (P2). Further, the amplitude of the first diastolic peak (DT1/DP1) was not greater in Y than O absolutely or relative to other pressure landmarks. A very similar