Parameters of Left Ventricular Mass and Dementia: Moving the Literature Forward

Cognitive Outcomes in Young Adults with Primary Arterial Hypertension: The Role of Cardiovascular Risk Factors and Hypertension-Mediated Organ Damage

Background and Objectives: We aimed to explore the association between cognitive performance and markers of hypertension-mediated organ damage (HMOD) in young adults with hypertension. Materials and Methods: A group of adults aged 16 to 45 years with primary arterial hypertension completed a battery of paper-pencil as well as computer-based neuropsychological tests across all major cognitive domains. They also underwent office and ambulatory 24 h blood pressure, intima-media thickness measurements, heart ultrasound, and laboratory analysis of their lipid profile, blood uric acid concentration, and urine albumin-creatinine ratio. Associations between cognitive test results and markers of HMOD were explored through correlation analysis and age-, sex-, and body mass index-adjusted linear regression modeling. Results: Seventy-six individuals (62, 81.6% male) aged 36.5 years (interquartile range 18.4 to 42.0 years) were enrolled. After adjusting for age, sex, and body mass index in linear regression models, worse categorical fluency was associated with higher left ventricular mass (βst = -0.264, p = 0.043) and worse performance in a task of sustained attention-with higher left ventricular mass index (βst = -0. 304, p = 0.016). Worse phonemic fluency was related to higher pulse pressure (βst = -0.241, p = 0.049) in the respective model. Better strategy use in the task of spatial working memory was linked to higher daytime mean diastolic blood pressure (βst = -0.343 p = 0.017). Conclusions: Performance among young adults with hypertension across selected cognitive domains was inversely associated with pulse pressure, markers of left ventricular damage, and directly associated with daytime diastolic blood pressure. Our study suggests that the previously reported relationship between cognitive and cardiovascular markers in hypertension exists earlier than in middle or late adulthood.

Mechanical and structural changes in human thoracic aortas with age

Aortic mechanical and structural characteristics have profound effects on pathophysiology, but many aspects of physiologic stress-stretch state and intramural changes due to aging remain poorly understood in human tissues. While difficult to assess in vivo due to residual stresses and pre-stretch, physiologic stress-stretch characteristics can be calculated using experimentally-measured mechanical properties and constitutive modeling. Mechanical properties of 76 human descending thoracic aortas (TA) from 13 to 78-year-old donors (mean age 51±18 years) were measured using multi-ratio planar biaxial extension. Constitutive parameters were derived for aortas in 7 age groups, and the physiologic stress-stretch state was calculated. Intramural characteristics were quantified from histological images and related to aortic morphometry and mechanics. TA stiffness increased with age, and aortas became more nonlinear and anisotropic. Systolic and diastolic elastic energy available for pulsation decreased with age from 30 to 8 kPa and from 18 to 5 kPa, respectively. Cardiac cycle circumferential stretch dropped from 1.14 to 1.04, and circumferential and longitudinal physiologic stresses decreased with age from 90 to 72 kPa and from 90 to 17 kPa, respectively. Aortic wall thickness and radii increased with age, while the density of elastin in the tunica media decreased. The number of elastic lamellae and circumferential physiologic stress per lamellae unit remained constant with age at 102±10 and 0.85±0.04 kPa, respectively. Characterization of mechanical, physiological, and structural features in human aortas of different ages can help understand aortic pathology, inform the development of animal models that simulate human aging, and assist with designing devices for open and endovascular aortic repairs. STATEMENT OF SIGNIFICANCE: This manuscript describes mechanical and structural changes occurring in human thoracic aortas with age, and presents material parameters for 4 commonly used constitutive models. Presented data can help better understand aortic pathology, inform the development of animal models that simulate human aging, and assist with designing devices for open and endovascular aortic repairs.

Clinical Trials of Blood Pressure Lowering and Antihypertensive Medication: Is Cognitive Measurement State-of-the-Art?

Randomized controlled trials of blood pressure (BP) lowering and antihypertensive medication use on cognitive outcomes have often been disappointing, reporting mixed findings and small effect sizes. We evaluate the extent to which cognitive assessment protocols used in these trials approach state-of-the-art. Overall, we find that a primary focus on cognition and the systematic selection of cognitive outcomes across trials take a backseat to other trial goals. Twelve trials investigating change in cognitive functioning were examined and none met criteria for state-of-the-art assessment, including use of at least 4 tests indexing 2 cognitive domains. Four trials investigating incident dementia were also examined. Each trial used state-of-the-art diagnostic criteria to assess dementia, although follow-up periods were relatively short, with only 2 trials lasting for at least 3 years. Weaknesses in each trial may act to obscure or weaken the positive effects of BP lowering on cognitive functioning. Improving trial designs in terms of cognitive outcomes selected and length of follow-up periods employed could lead to more promising findings. We offer logical steps to achieve state-of-the-art assessment protocols, with examples, in hopes of improving future trials.