Effects of normal blood pressure, prehypertension and hypertension on left ventricular diastolic function and aortic elastic properties

Echocardiographic Assessment of the Left Ventricle in Young Prehypertensive Nigerians

BACKGROUND

 Prehypertension is associated with an increased risk of cardiovascular morbidity and mortality. This risk could partly be explained by the early compromise in left ventricular (LV) structure and function. This study investigated the LV geometry and function in young black prehypertensive subjects.

METHODS AND RESULTS

This cross-sectional descriptive study was conducted at the Usmanu Danfodiyo University Teaching Hospital, Sokoto, Nigeria. Echocardiography-derived LV geometry and function were assessed using standardized methods. Prehypertensive subjects had higher mean systolic blood pressure (BP) (130.78 ± 3.57 mmHg vs 111.42 ± 3.54 mmHg, P<0.001), diastolic BP (79.32 ± 4.13 mmHg vs 66.39 ± 4.42 mmHg, P<0.001), body mass index (BMI) (26.24 ± 3.45 kg/m2 vs 22.20 ± 2.21 kg/m2, P<0.001), waist circumference (WC) (86.93 ± 8.73 cm vs 76.73 ± 6.66 cm, P<0.001), fasting blood glucose (FBG) (93.84 ± 7.28 mg/dl vs 90.08 ± 6.26 mg/dl, P<0.001), and dyslipidemia (21.5% vs 6%. P<0.001) compared to normotensive subjects. LV mass index (LVMI) was greater in prehypertensive subjects compared to normotensive subjects {male (106.84 ± 12.34 g/m2 vs 76.07 ± 10.25 g/m2, P<0.001); female (92.06 ± 8.80 g/m2 vs 66.53 ± 7.21 g/m2, P<0.001)}, with abnormal LV geometry recorded in 17.5%. Linear regression analysis showed that waist circumference, systolic BP, serum creatinine level, and urea level were determinants of LVMI. The prevalence of LV diastolic dysfunction was higher in prehypertensive subjects than in normotensive subjects (14.5% vs. 0.5%, P<0.001), with systolic BP {odds ratio (OR) 0.928, confidence interval (CI) 0.834 - 0.969; P=0.016)} and diastolic BP (OR 0.832, CI 0.722 - 0.958; P=0.011) being independent predictors.

CONCLUSION

 This study showed that prehypertension in young Black subjects was associated with altered LV geometry and impaired diastolic function, and these changes demonstrated linear progression with increasing systolic BP.

RNA editing of Filamin A pre-mRNA regulates vascular contraction and diastolic blood pressure

Epitranscriptomic events such as adenosine-to-inosine (A-to-I) RNA editing by ADAR can recode mRNAs to translate novel proteins. Editing of the mRNA that encodes actin crosslinking protein Filamin A (FLNA) mediates a Q-to-R transition in the interactive C-terminal region. While FLNA editing is conserved among vertebrates, its physiological function remains unclear. Here, we show that cardiovascular tissues in humans and mice show massive editing and that FLNA RNA is the most prominent substrate. Patient-derived RNA-Seq data demonstrate a significant drop in FLNA editing associated with cardiovascular diseases. Using mice with only impaired FLNA editing, we observed increased vascular contraction and diastolic hypertension accompanied by increased myosin light chain phosphorylation, arterial remodeling, and left ventricular wall thickening, which eventually causes cardiac remodeling and reduced systolic output. These results demonstrate a causal relationship between RNA editing and the development of cardiovascular disease indicating that a single epitranscriptomic RNA modification can maintain cardiovascular health.

Histone deacetylase and GATA-binding factor 6 regulate arterial remodeling in angiotensin II-induced hypertension

OBJECTIVE

Histone deacetylase (HDAC) inhibitors have been reported to improve essential and secondary hypertension. However, the specific HDAC that might serve as a therapeutic target and the associated upstream and downstream molecules involved in regulating hypertension remain unknown. Our study was aimed at investigating whether a selective inhibitor of class II HDAC (MC1568) modulates hypertension, elucidating the underlying mechanism.

METHODS

Hypertension was established by administering angiotensin II (Ang II) to mice before treatment with MC1568. SBP was measured.

RESULTS

Treatment with MC1568 reduced elevated SBP; attenuated arterial remodeling in the kidney's small arteries and thoracic aorta; and inhibited cell cycle regulatory gene expression, vascular smooth muscle cell (VSMC) proliferation, DNA synthesis, and VSMC hypertrophy in vivo and in vitro. Ang II enhanced the expression of phosphorylated HDAC4 and GATA-binding factor 6 (GATA6) proteins, which were specifically localized in the cytoplasm of cells in the arteries of kidneys and in aortas. Forced expression and knockdown of HDAC4 increased and decreased, respectively, the proliferation and expression of cell cycle genes in VSMCs. GATA6, a newly described binding partner of HDAC4, markedly enhanced the size and number of VSMCs. Calcium/calmodulin-dependent kinase IIα (CaMKIIα), but not HDAC4, translocated from the nucleus to the cytoplasm in response to Ang II. CaMKIIα and protein kinase D1 were associated with VSMC hypertrophy and hyperplasia via direct interaction with HDAC4. MC1568 treatment weakened the association between HDAC4 and CaMKIIα.

CONCLUSION

These results suggest that class II HDAC inhibition attenuates hypertension by negatively regulating VSMC hypertrophy and hyperplasia via the CaMKIIα/protein kinase D1/HDAC4/GATA6 pathway.

Prehypertension and Left Ventricular Diastolic Dysfunction in Middle-Aged Koreans

Background and Objectives

Left ventricular diastolic dysfunction is known to be a marker of myocardial damage, in particular myocardial fibrosis resulting from hypertension (HT). However, few studies have shown an association between the grade of diastolic dysfunction and blood pressure classification. We investigated the association between diastolic dysfunction and prehypertension (preHT) in apparently healthy adults who underwent routine health examinations.

Subjects and Methods

The study sample included 4261 Koreans, 45 to 64 years of age with no previous history of HT, diabetes mellitus, malignancy, proven coronary artery disease, or valvular heart disease based on echocardiography, who underwent routine health examinations including echocardiography. The subjects were classified into three groups based on resting blood pressure: prehypertensive, hypertensive, and normotensive.

Results

The prevalence of preHT in our study was 42.1%. After adjusting for age, gender, smoking status, alcohol consumption, fasting blood sugar, serum lipid profile, and body mass index, left ventricular diastolic dysfunction grades 1 and 2 were significantly more frequent in subjects with preHT (odds ratio [OR] 1.66 [95% confidence interval {CI} 1.40-1.96] and 1.37 [95% CI 0.95-1.97], respectively). When analyzed according to gender, the increased OR was especially notable in males.

Conclusion

Left ventricular diastolic dysfunction appears to be significantly associated with preHT in Korean middle-aged males.

Can Impaired Elasticity of Aorta Predict the Success of Vardenafil Treatment in Patients with Erectile Dysfunction?

Objective. Vardenafil is used in treatment of erectile dysfunction (ED) but reveals variable clinical outcomes. Here, we aimed to evaluate the role of aortic elasticity in predicting vardenafil success among patients with ED. Methods. Sixty-one consecutive male subjects with primary ED and indication for vardenafil treatment were included. All subjects fulfilled 5-item version of the International Index of Erectile Function (IIEF-5) before the vardenafil treatment. Pretreatment aortic stiffness index (ASI) and aortic distensibility (AD) were obtained echocardiographically. Following two-month vardenafil treatment, the patients were reevaluated with IIEF-5. Pretreatment, posttreatment, and ΔIIEF-5 scores and ASI values were compared. Results. Average age was 54 ± 8 years. Pretreatment and posttreatment IIEF-5 and ΔIIEF-5 scores were 9.1 ± 2.5; 18.5 ± 2.3; and 9.4 ± 3, respectively. Mean ASI and AD values were 3.10 ± 0.54 and 4.13 ± 2.55 1/(10(3)  ×  mmHg) accordingly. ASI value of severe pretreatment ED (n = 15) was significantly higher than that of mild-moderate pretreatment ED (n = 12) (p < 0.001). All pretreatment IIEF-5 scores increased significantly compared to posttreatment IIEF-5 scores (p < 0.001). ASI values were significantly correlated to pretreatment IIEF-5 scores (p < 0.001) and ΔIIEF-5 value (p < 0.001) but not to posttreatment IIEF-5 score. Conclusion. Aortic elasticity was impaired in accordance with degree of ED. The subjects with higher ASI values obtained more benefits from vardenafil.

Dexrazoxane protects breast cancer patients with diabetes from chemotherapy-induced cardiotoxicity

BACKGROUND

To evaluate the cardioprotective effect of dexrazoxane (DEX) on chemotherapy in patients with breast cancer with concurrent type 2 diabetes mellitus (DM2).

METHODS

Eighty female patients with breast cancer with DM2 were randomly assigned to receive chemotherapy only or chemotherapy plus DEX. All patients received 80 mg/m epirubicin and 500 mg/m cyclophosphamide by intravenous infusion every 3 weeks for a total of 6 cycles. The group assigned to receive chemotherapy alone received placebo 30 minutes before epirubicin administration. The group assigned to receive chemotherapy plus DEX received 800 mg/m DEX 30 minutes before epirubicin administration. Cardiac function and hematology before and after 6 cycles of chemotherapy were analyzed.

RESULTS

There was no difference in baseline systole or diastole function between the 2 DM2 groups. Patients receiving chemotherapy alone experienced significantly greater reductions in Ea and significantly greater elevations in E/Ea and Tei index in comparison with patients receiving chemotherapy plus DEX. After chemotherapy, superoxide dismutase was significantly reduced, and serum malondialdehyde (MDA) was significantly increased in patients with DM2. Serum superoxide dismutase levels were comparable between the 2 groups before and after chemotherapy, MDA levels were comparable between the 2 groups before chemotherapy, whereas serum MDA was significantly higher after chemotherapy in the chemotherapy alone group in comparison with the group that received DEX.

CONCULSIONS

DEX protects against cardiotoxicity induced by chemotherapy in patients with breast cancer with concurrent DM2.

Impaired aortic elasticity and diastolic functions are associated with findings of coronary computed tomographic angiography

BACKGROUND

Coronary artery disease (CAD) is the leading cause of mortality and morbidity worldwide. Aortic elasticity and diastolic functions are helpful parameters in assessment of CAD. In this study we aimed to learn whether diastolic function and aortic elastic properties measured by echocardiography are associated with coronary calcium score (CACS), epicardial fat volume (EFV), and plaque area measured by coronary tomographic angiography.

MATERIAL AND METHODS

We enrolled 106 consecutive patients suspected of CAD undergoing coronary CTA and transthoracic echocardiography in this prospective study. Total CACS, plaque area, and EFV were calculated via CTA. Aortic stiffness index (ASI) and aortic distensibility (AD) were measured via echocardiography.

RESULTS

The patients with diastolic dysfunctions of any degree had significantly higher ASI, higher CACS, higher plaque area, and EFV. We found that as the ASI increases, the CACS and total coronary plaque area both increase, showing that there is a strong positive correlation between ASI, CACS, and total coronary plaque area. There was a significant correlation between ASI and EFV, but with a lower statistical value.

CONCLUSIONS

Aortic elasticity was correlated with CACS and plaque area. Diastolic dysfunction was observed more commonly among patients with higher CACS and EFV. Epicardial fat volume was not as strong as CACS in reflecting aortic elasticity.

Association of early adult modifiable cardiovascular risk factors with left atrial size over a 20-year follow-up period: the CARDIA study

OBJECTIVES

We investigate how early adult and 20-year changes in modifiable cardiovascular risk factors (MRF) predict left atrial dimension (LAD) at age 43-55 years.

METHODS

The Coronary Artery Risk Development in Young Adults (CARDIA) study enrolled black and white adults (1985-1986). We included 2903 participants with echocardiography and MRF assessment in follow-up years 5 and 25. At years 5 and 25, LAD was assessed by M-mode echocardiography, then indexed to body surface area (BSA) or height. Blood pressure (BP), body mass index (BMI), heart rate (HR), smoking, alcohol use, diabetes and physical activity were defined as MRF. Associations of MRF with LAD were assessed using multivariable regression adjusted for age, ethnicity, gender and year-5 left atrial (LA) size.

RESULTS

The participants were 30±4 years; 55% white; 44% men. LAD and LAD/height were modest but significantly higher over the follow-up period, but LAD/BSA decreased slightly. Increased baseline and 20-year changes in BP were related to enlargement of LAD and indices. Higher baseline and changes in BMI were also related to higher LAD and LAD/height, but the opposite direction was found for LAD/BSA. Increase in baseline HR was related to lower LAD but not LAD indices, when only baseline covariates were included in the model. However, baseline and 20-year changes in HR were significantly associated to LA size.

CONCLUSIONS

In a biracial cohort of young adults, the most robust predictors for LA enlargement over a 20-year follow-up period were higher BP and BMI. However, an inverse direction was found for the relationship between BMI and LAD/BSA. HR showed an inverse relation to LA size.

Effects of prediabetes and diabetes on left ventricular and coronary microvascular functions

BACKGROUND

Coronary flow reserve (CFR) provides independent prognostic information in diabetic patients with known or suspected coronary artery disease. However, there have been no substantial data to evaluate CFR in prediabetics. Accordingly, we aimed to evaluate CFR in subjects with prediabetes using second harmonic transthoracic Doppler echocardiography.

METHODS AND RESULTS

We measured CFR of 65 subjects with prediabetes, 45 patients with overt type 2 diabetes, and 43 sex and age matched normoglycemic healthy subjects with normal glucose tolerance. Ages, gender, existence of hypertension or hypercholesterolemia, smoking status were similar among the groups. CFR was significantly lower in diabetics (2.15 ± 0.39) than in prediabetics (2.39 ± 0.45) and controls (2.75 ± 0.35); in addition, it was significantly lower in prediabetics than controls. Only 2 (5%) of control subjects had abnormal CFR (<2) but 11 (17%) prediabetic subjects and 19 (42%) diabetic patients had abnormal CFR. We found that only age (β=-0.31, P<0.01) and presence of the diabetes (β=-0.57, P<0.01) were significant predictors of lower CFR in a multivariable model that adjusted for other variables. CFR was significantly and inversely correlated with age (r=-0.15, P=0.04), fasting glucose level (r=-0.27, P=0.001), postprandial glucose level (r=0.43, P<0.001), hemoglobin A1C level (r=-0.34, P<0.001), LDL cholesterol level (r=0.22, P=0.009), mitral A velocity (r=-0.27, P=0.001) and Tei index (r=-0.19, P=0.02), whereas mitral E/A ratio, mitral Em (r=0.18, P=0.02), mitral Em/Am ratio (r=0.23, P=0.004) were significantly and positively correlated with CFR.

CONCLUSION

CFR is impaired in subjects with prediabetics, but this impairment is not as severe as that in diabetics.

The normal impact of age and gender on right heart structure and function

BACKGROUND

As the proportion of elderly population increases rapidly, it might be difficult to differentiate physiological changes in cardiac function due to age from the pathophysiological ones. In addition, cardiac function variations with gender are well established. The right ventricular (RV) plays an important role in the overall cardiac function, but reference values varying with age and gender are lacking.

MATERIAL AND METHODS

We studied 255 healthy individuals from a general population register, mean age of 58 ± 19 (range 22-89) years, 125 were females. We used 2D and M-mode echocardiography to measure RV inflow tract (RVIT) and RV outflow tract (RVOT) dimensions and fractional shortening (fs). Spectral Doppler echocardiography was also used.

RESULTS

We found a modest decrease in RVIT dimensions (P < 0.05), but increase in RVOT dimensions with advancing age (P < 0.05). A small decrease in RVOT fs with age was also found (P < 0.05). Estimated pulmonary pressures and pulmonary vascular resistance increased (P < 0.001) as did RVOT wall thickness (P < 0.001), but RV diastolic function was not altered (P < 0.001) with age. Despite correction for the BSA, males showed larger RVIT dimensions (P < 0.001 for both), but RVOT end-diastolic dimension was larger in females (P < 0.05). RVIT and RVOT fractional shortening were increased in females (P < 0.01 for both).

CONCLUSION

In a cohort of normal individuals, age has significant impact on RV structure and function, inlet area falls and outflow tract dimensions increase and fractional shortening also increase in females. In addition, RVOT wall thickness significantly increases and Doppler markers of pulmonary vascular resistance show a consistent rise. The age-related changes should carefully be considered when commenting on normality and when using absolute values.

Echocardiographic predictors of progression from prehypertension to hypertension

BACKGROUND

Prehypertension (PHT) was recently introduced by replacing former categories of high-normal and above-optimal blood pressure (BP). The rationale for redefining this new category was to emphasize the excess cardiovascular risk associated with BP in this range and to focus high risk for developing hypertension (HT). However, no clear definite markers to identify prehypertensive patients at high risk of progressing to HT have been established yet. Accordingly, we aimed to establish echocardiographic predictors of progression from PHT to HT.

METHODS AND RESULTS

The study population consisted of 98 eligible prehypertensive patients. All patients underwent echocardiographic examination including coronary flow reserve (CFR) at baseline. Twenty-nine (30%) patients developed HT during the 3-year follow-up period. Creatinine level, left ventricular mass index (LVMI), mitral Em and Em/Am had a trend towards a significant crude odds ratio (OR) for the development of HT; however, only baseline SBP [OR = 1.18, 95% confidence interval (CI) = 1.06-1.31; P = 0.002), having metabolic syndrome (OR = 3.75, 95% CI = 1.43-9.78; P = 0.007), high-density lipoprotein (HDL) cholesterol (OR = 0.92, 95% CI = 0.86-0.98; P = 0.01), presence of microalbuminuria (OR = 3.53, 95% CI = 1.11-11.2; P = 0.03) and CFR (OR = 0.65, 95% CI = 0.53-0.77; P = 0.02) were significant independent predictors of progression of PHT into HT. The best cutoff value of CFR to predict incident HT was 1.98 with 94% sensitivity and 79% specificity.

CONCLUSION

This prospective study suggested that baseline SBP, having metabolic syndrome, HDL cholesterol level, presence of microalbuminuria and CFR reflecting coronary microvascular function, but not left ventricular diastolic function parameters, were significant independent markers to identify participants with PHT at high risk for incident HT.

Vascular inflammation and aortic stiffness relate to early left ventricular diastolic dysfunction in prehypertension

Prehypertension is characterized by an increased cardiovascular risk and by an increased prevalence of target organ damage compared with the pure normotensive state. The present study was designed to assess in prehypertensive subjects the possible relationships between early left ventricular dysfunction, vascular inflammation and aortic stiffness. The study population consisted of 31 untreated prehypertensive subjects (age: 34 ± 6 years, mean ± SD) and 31 age-matched pure normotensive controls. Left ventricular function was assessed by echocardiography, aortic distensibility parameters were derived from aortic diameters measured by ultrasonography, and high-sensitivity C-reactive protein was assessed by latex-enhanced reagent. Prehypertensive subjects displayed a significantly lower E/A ratio and a significantly greater deceleration time and isovolumetric relaxation time compared with normotensive controls. They also displayed aortic systolic diameter, diastolic diameter and mean aortic stiffness index beta significantly increased while systo-diastolic diameter change, mean aortic distensibility and aortic strain were significantly reduced compared with controls. Values of inflammatory markers were increased. At multiple regression analysis, E/A ratio was significantly related to high-sensitivity C-reactive protein and aortic stiffness index beta, after correction for age, left ventricular mass index and mean blood pressure (β coefficient = -0.49, overall r(2) = 0.24, p = 0.01 and β coefficient =-0.46, overall r(2) = 0.21, p = 0.02, respectively). Thus, in prehypertension, left ventricular dysfunction is significantly related to vascular inflammation and aortic stiffness, suggesting that early cardiac and vascular alterations may have an increased inflammatory process as a common pathophysiological link.

Body mass index contributes to sympathovagal imbalance in prehypertensives

BACKGROUND

The present study was conducted to assess the nature of sympathovagal imbalance (SVI) in prehypertensives by short-term analysis of heart rate variability (HRV) to understand the alteration in autonomic modulation and the contribution of BMI to SVI in the genesis of prehypertension.

METHODS

Body mass index (BMI), basal heart rate (BHR), blood pressure (BP), rate pressure product (RPP) and HRV indices such as total power (TP), low-frequency power (LF), normalized LF (LFnu), high-frequency power (HF), normalized HF (HFnu), LF-HF ratio, mean heart rate (mean RR), square root of the mean squared differences of successive normal to normal intervals (RMSSD), standard deviation of normal to normal RR interval (SDNN), the number of interval differences of successive NN intervals greater than 50 ms (NN50) and the proportion derived by dividing NN50 by the total number of NN intervals (pNN50) were assessed in three groups of subjects: normotensives having normal BMI (Group 1), prehypertensives having normal BMI (Group 2) and prehypertensives having higher BMI (Group 3). SVI was assessed from LF-HF ratio and correlated with BMI, BHR, BP and RPP in all the groups by Pearson correlation. The contribution of BMI to SVI was assessed by multiple regression analysis.

RESULTS

LF and LFnu were significantly increased and HF and HFnu were significantly decreased in prehypertensive subjects in comparison to normotensive subjects and the magnitude of these changes was more prominent in subjects with higher BMI compared to that of normal BMI. LF-HF ratio, the sensitive indicator of sympathovagal balance had significant correlation with BMI (P=0.000) and diastolic blood pressure (DBP) (P=0.002) in prehypertensives. BMI was found to be an independent contributing factor to SVI (P=0.001) in prehypertensives.

CONCLUSIONS

It was concluded that autonomic imbalance in prehypertensives manifested in the form of increased sympathetic activity and vagal inhibition. In prehypertensives with higher BMI, vagal withdrawal was predominant than sympathetic overactivity. Magnitude of SVI (alteration in LF-HF ratio) was linked to changes in BMI and DBP. BMI had an independent influence on LF-HF ratio. It was advised that life-style modifications such as yoga and exercise would enable achieve the sympathovagal balance and blood pressure homeostasis in prehypertensives.

Intravital microscopy reveals endothelial dysfunction in resistance arterioles in Angiotensin II-induced hypertension

It is known that hypertension is associated with endothelial dysfunction and that Angiotensin II (Ang II) is a key player in the pathogenesis of hypertension. We aimed to elucidate whether endothelial dysfunction is a specific feature of Ang II-mediated hypertension or a common finding of hypertension, independently of underlying etiology. We studied endothelial-dependent vasorelaxation in precapillary resistance arterioles and in various large-caliber conductance arteries in wild-type mice with Ang II-dependent hypertension (2-kidney 1-clip (2K1C) model) or Ang II-independent (volume overload) hypertension (1-kidney 1-clip model (1K1C)). Normotensive sham mice were used as controls. Aortic mechanical properties were also evaluated. Intravital microscopy of precapillary arterioles revealed a significantly impaired endothelium-dependent vasorelaxation in 2K1C mice compared with sham mice, as quantified by the ratio of acetylcholine (ACh)-induced over S-nitroso-N-acetyl-D,L-penicillamine (SNAP)-induced vasorelaxation (2K1C: 0.49±0.12 vs. sham: 0.87±0.11, P=0.018). In contrast, the ACh/SNAP ratio in volume-overload hypertension 1K1C mice was not significantly different from sham mice, indicating no specific endothelial dysfunction (1K1C: 0.77±0.27 vs. sham: 0.87±0.11, P=0.138). Mechanical aortic wall properties and endothelium-dependent vasorelaxation, assessed ex vivo in rings of large-caliber conductance (abdominal and thoracic aorta, carotid and femoral arteries), were not different between 2K1C, 1K1C and sham mice. Endothelial dysfunction is an early feature of Ang II- but not volume-overload-mediated hypertension. This occurs exclusively at the level of precapillary arterioles and not in conduit arteries. Our findings, if confirmed in clinical studies, will provide a better understanding of the pathophysiological mechanisms of hypertension.

Association of N-terminal pro brain natriuretic peptide and impaired aortic elastic property in hypertensive patients

BACKGROUND

N-terminal pro brain natriuretic peptide (NT-proBNP) is closely related to risk stratification in many cardiovascular diseases. The objective of this study was to evaluate the association of NT-proBNP and impaired aortic elastic property in hypertensive patients.

METHODS

One hundred fifty-five hypertensive patients without obvious cardiac dysfunction were included and divided in tertiles based on their NT-proBNP concentration. Eighty-six normotensive healthy volunteers were also enrolled as controls. All subjects underwent Doppler echocardiography to assess cardiac parameters and aortic distensibility index. Plasma NT-proBNP was measured by electrochemiluminescence.

RESULTS

The parameters of aortic elastic property were decreased and NT-proBNP was significantly increased in hypertensive patients compared with controls (all P<0.05). Among hypertensive patients, higher NT-proBNP tertiles were associated with larger systolic and diastolic aortic diameters, longer deceleration time of the E wave velocity (DT) and isovolumic relaxation time; decreased E/A ratio and more percent of diastolic dysfunction. The parameters of aortic elastic property showed stepwise decreases from the first tertiles to the third tertiles (P<0.05). Multiple linear regression analysis showed that concentrations of NT-proBNP were significantly correlated with age and impaired aortic distensibility.

CONCLUSIONS

NT-proBNP is a marker for impaired aortic elastic property in hypertensive patients. Measurement of NT-proBNP could be indicated in hypertensive patients for further risk stratification.

Early abnormalities of cardiovascular structure and function in middle-aged Korean adults with prehypertension: The Korean Genome Epidemiology study

BACKGROUND

Prehypertension is associated with increased cardiovascular morbidity and mortality. However, there are few population-based studies on the changes of cardiovascular structure and function that characterize prehypertension. The aim of this study was to assess whether prehypertension is associated with abnormalities of cardiovascular structure and function in the general Korean population.

METHODS

We analyzed the cross-sectional relationships between prehypertension and cardiovascular structure and function in a sample from the Korean Genome Epidemiology Study. A total of 1,671 individuals (54.5% women; mean age: 53 ± 6 years) without hypertension and diabetes mellitus were enrolled. Cardiovascular structure and function were assessed by conventional echocardiography, tissue Doppler imaging (TDI), carotid ultrasonography, and pulse wave velocity (PWV).

RESULTS

The left ventricular (LV) mass index was significantly higher in subjects with prehypertension than in those with normotension (41 ± 8 g/m²·⁷ vs. 38 ± 7 g/m²·⁷, P < 0.001). LV diastolic parameters, such as the E/A ratio, TDI E(a) velocity, and E/E(a) ratio, were also impaired in subjects with prehypertension (all P < 0.001). Compared with normotension, prehypertension was characterized by a significantly higher common carotid artery intima-media thickness and a higher brachial-ankle PWV (all P < 0.001). These abnormalities of cardiovascular structure and function remained significant after adjustment for covariates.

CONCLUSIONS

In this population-based cohort, we found that subtle alterations in cardiovascular structure and function were already present at the prehypertensive stage. Whether such subtle alterations convey an increased risk of cardiovascular events and whether the changes are reversible with treatment warrant further study.

Prehypertension and endothelial progenitor cell function

Prehypertension is associated with significant damage to the coronary vasculature and increased rates of adverse cardiovascular events. Circulating endothelial progenitor cells (EPCs) are critical to vascular repair and the formation of new blood vessels. We tested the hypothesis that prehypertension is associated with EPC dysfunction. Peripheral blood samples were collected from 83 middle-aged and older adults (51 M/32 F): 40 normotensive (age 53±2 yr; BP 111/74±1/1 mmHg) and 43 prehypertensive (54±2; 128/77±1/1 mmHg). EPCs were isolated from peripheral blood and EPC colony-forming capacity (colony-forming unit assay), migratory activity (Boyden chamber) and apoptotic susceptibility (active caspase-3 concentrations) were determined. There were no significant differences in either the number of EPC CFUs (10±2 vs. 9±1), EPC migration (1165±82 vs. 1120±84 fluorescent units), or active intracellular caspase-3 concentrations (2.7±0.3 vs. 2.3±0.2 ng/mL) between the normotensive and prehypertensive groups. When groups were stratified into low prehypertension (n=27; systolic BP: 120–129 mmHg) and high prehypertension (n=16; 130–139 mmHg), it was found that EPCs from the high prehypertensive group produced fewer (~65%, P<0.05) CFUs compared with the low prehypertensive (4±1 vs. 12±2) and normotensive adults. In conclusion, EPC colonyforming capacity is impaired only in prehypertensive adults with systolic BP greater than 130 mmHg. Prehypertension is not associated with migratory dysfunction or enhanced apoptosis of EPCs.