Influence of arterial stiffness on cardiovascular outcome in patients without high blood pressure

Association of central arterial stiffness with atrial myopathy: the Atherosclerosis Risk in Communities (ARIC) study

Atrial myopathy-defined as abnormal left atrial (LA) size and function-is associated with an increased risk of atrial fibrillation, heart failure, and dementia. Central arterial stiffness is associated with increased atrial afterload and fibrosis and may be a risk factor for atrial myopathy. We examined the association of carotid-femoral pulse wave velocity (cfPWV) with LA function and assessed potential causal relationships. We included 2825 Atherosclerosis Risk in Communities (ARIC) study participants from Visit 5 (2011-2013). cfPWV was related to echocardiographic LA function continuously per 1-SD and categorically in quartiles. Mendelian randomization (MR) analysis was performed using U.K. Biobank-derived genetic variants associated with arterial stiffness index and cardiac magnetic resonance measures of LA function. When analyzed per SD increment (297.6 cm/s), higher cfPWV was significantly associated with lower LA reservoir and conduit strain (β = -0.53%, 95% CI [-0.81, -0.25] and β = -0.46%, 95% CI [-0.68, -0.25], respectively) after adjusting for demographics, clinical characteristics, systolic blood pressure, and left ventricular (LV) morphology and function. In MR analyses there was a non-significant inverse association of arterial stiffness index with LA total, passive, and active emptying fractions. Higher cfPWV is associated with lower LA reservoir and conduit strain, independent of systolic blood pressure and LV morphology and function. No evidence for a causal relationship between arterial stiffness index and alterations in LA function was found. Future studies should examine the prospective association of central arterial stiffness with LA function alterations.

Total cholesterol, arterial stiffness, and systolic blood pressure: a mediation analysis

On the basis of 45,092 participants (mean age of 54.04 ± 13.09 years) from the Kailuan study, this study was performed to explore the relationships among total cholesterol (TC), brachial-ankle pulse wave velocity (BaPWV), and systolic blood pressure (SBP) and quantify their separate effects. The correlations among TC, SBP, and BaPWV were analyzed using multivariate linear regression models. Mediation analysis was performed to determine whether the effect of TC on SBP can be explained by arterial stiffness. Multivariate linear regression analysis showed that for every one standard deviation increase in TC and BaPWV, SBP increased by 0.33 mmHg and 0.044 mmHg, respectively; for every one standard deviation increase in TC, BaPWV increased by 5.34 cm/s. Mediation analysis showed that the TC-induced SBP elevation was mediated by arterial stiffness in more than half of the whole cohort (indirect effect, 0.73; percent mediated, 54.5%). Furthermore, the TC-induced SBP elevation was mediated by arterial stiffness in less than half of the males (indirect effect, 0.70; percent mediated, 47.9%); however, the results were not statistically significant in females. In conclusion, TC and BaPWV are positively correlated with SBP, whereas TC is positively correlated with BaPWV. Almost half of the increase in SBP contributed to TC is mediated by arterial stiffness.

State of the Art Review: Brachial-Ankle PWV

The brachial-ankle pulse wave velocity (brachial-ankle PWV), which is measured simply by wrapping pressure cuffs around the four extremities, is a simple marker to assess the stiffness of the medium- to large- sized arteries. The accuracy and reproducibility of its measurement have been confirmed to be acceptable. Risk factors for cardiovascular disease, especially advanced age and high blood pressure, are reported to be associated with an increase of the arterial stiffness. Furthermore, arterial stiffness might be involved in a vicious cycle with the development/progression of hypertension, diabetes mellitus and chronic kidney disease. Increase in the arterial stiffness is thought to contribute to the development of cardiovascular disease via pathophysiological abnormalities induced in the heart, brain, kidney, and also the arteries themselves. A recent independent participant data meta-analysis conducted in Japan demonstrated that the brachial-ankle PWV is a useful marker to predict future cardiovascular events in Japanese subjects without a previous history of cardiovascular disease, independent of the conventional model for the risk assessment. The cutoff point may be 16.0 m/s in individuals with a low risk of cardiovascular disease (CVD), and 18.0 m/s in individuals with a high risk of CVD and subjects with hypertension. In addition, the method of measurement of the brachial-ankle PWV can also be used to calculate the inter-arm systolic blood pressure difference and ankle-brachial pressure index, which are also useful markers for cardiovascular risk assessment.

Arterial stiffness and multiple organ damage: a longitudinal study in population

AIMS

Previous cross-sectional observation identified arterial aging, indexed as pulse-wave velocity (PWV), as a key determinant of the simultaneous multiple organ damage (heart, carotid artery, and kidney). The aim of the present cohort study is to investigate trajectories of repeated measures of PWV and traditional CV risk factors in subjects who eventually presented clinical evidence of multiple organ damage in the SardiNIA study.

METHODS AND RESULTS

Organ damage was measured in the heart (left ventricular hypertrophy, LVH), the common carotid artery (intima-media thickness > 0.9 mm and/or plaque), and the kidney (eGFR < 60 ml/min/1.73 m²) of 2130 men and women of a broad age range participating the SardiNIA study. SHATS was defined as the simultaneous occurrence of all the three-organ damages. Trajectory in traditional CV risk factors and PWV was analyzed retrospectively (four observations over 9 years) according to the number of organ damage (from 0 to 3). Compared to subjects with no organ damage, after controlling for traditional CV risk factors, each 1 m/s increase in baseline PWV was accompanied by a 93% higher odds of developing SHATS; and each 1 cm/s (0.01 m/s) annual increase in PWV by a 31% greater odds of developing SHATS.

CONCLUSIONS

Arterial stiffness, a proxy of arterial aging that can be measured clinically as PWV, is an integrated predictive marker of multiple age-associated organ damage recognized as clinical diseases.

Aging, Arterial Stiffness, and Blood Pressure Association in Chinese Adults

Arterial stiffness and blood pressure (BP) both increase with aging synchronously. Whether elevated BP results from thickening of arterial wall or vice versa is controversial in previous studies. This study included 17 862 participants without history of myocardial infarction, stroke, atrial fibrillation or flutter, or cancer and with brachial-ankle pulse wave velocity (baPWV) and BP measurements during 2010 to 2016. Age was calculated from the self-reported birthdate to the first date of baPWV examination. Mediation analyses were applied to assess the mediation effect by baPWV in the association between age and BP. Temporal relation between baPWV and BP was assessed by cross-lagged analyses among 1508 participants with repeated assessment of baPWV. We found that systolic BP increased 0.47 (95% CI, 0.45-0.49) mm Hg per 1 year older by the mediation effect of baPWV and that the direct effect of aging on systolic BP was -0.07 (95% CI, -0.09 to -0.05) mm Hg per 1 year older. The standard regression coefficient from baseline baPWV to follow-up systolic BP was 0.09 (95% CI, 0.04-0.15), which was greater than the standard regression coefficient from baseline systolic BP to follow-up baPWV (0.01; 95% CI, -0.04 to 0.06). Arterial stiffness mediated the positive association between aging and BP, and arterial stiffness might precede elevated BP. Clinical Trial Registration- URL: http://www.chictr.org.cn . Unique identifier: ChiCTR-TNRC-11001489.

The comparison of the impact of arterial stiffness and central pressure on left ventricular geometry and diastolic function

Background

This study was performed to compare the associations of brachial-ankle pulse wave velocity (baPWV) and central blood pressure (CBP) measurements with left ventricular (LV) geometry and diastolic function.

Methods

A total of 77 subjects (64.5 ± 10.8 years, 67.5% females) without documented cardiovascular disease were prospectively recruited. All subjects underwent transthoracic echocardiography, baPWV and noninvasive measurement of CBP on the same day.

Results

In simple linear correlation analyses, neither baPWV nor CBP was associated with LV mass index or relative wall thickness (P > 0.05 for each). Although baPWV significantly correlated with septal e´ velocity in simple linear correlation analyses (r = 0.258, P = 0.025), the significance was lost after controlling for potential confounder (P = 0.881). In simple linear correlation analyses, central systolic blood pressure (CSBP) and central pulse pressure (CPP) significantly correlated with both septal e´ velocity or E/e´ (P <  0.05 for each); however, neither central diastolic nor mean arterial pressures was associated with both septal e´ velocity and E/e´ (P > 0.05 for each). After controlling for confounders, including age, sex and body mass index, CSBP correlated with septal e´ velocity (β = − 0.258, P = 0.025), but not with E/e´ (P = 0.074). CPP correlated with both septal e´ velocity (β = − 0.300, P = 0.014) and E/e´ (β = 0.428, P = 0.002) in the same multivariable model.

Conclusions

In subjects without documented cardiovascular disease, CSBP and CPP may be more strongly associated with LV diastolic function than baPWV. Further studies with a larger sample size are needed to confirm our results.

Association between healthy vascular aging and the risk of the first stroke in a community-based Chinese cohort

In this study we tested whether vascular aging is associated with the risk of first stroke in the Kailuan cohort, a community-based Chinese cohort. For participants aged ≥ 50 years, healthy vascular aging (HVA) was defined as an absence of hypertension and a brachial-ankle pulse wave velocity < the mean + 2 standard deviations, which was determined from a reference sample of healthy participants aged < 30 years. The primary outcome was first stroke (ischemic or hemorrhagic). In total, 11,474 participants were enrolled. The prevalence of HVA decreased from 36.0% in participants aged 50-59 years to 4.7% in those aged ≥ 70 years. During a median follow-up of 3.3 years, the incidence of first stroke was 0.5% in the HVA group but was 2.6% in the Non-HVA group. After adjusting for confounding variables, HVA was associated with a 0.32-fold lower risk of first stroke compared to the Non-HVA group (95% confidence interval, 0.18-0.56; p < 0.001). It thus appears that HVA reduced the risk of first stroke in a community-based Chinese population. This suggests that evaluation of vascular aging as part of public health screening may be useful for stroke risk assessment.

Brachial-ankle pulse wave velocity, cardio-ankle vascular index, and prognosis

Background

Brachial–ankle pulse wave velocity (baPWV) and cardio-ankle vascular index (CAVI) are indices of arterial stiffness, and several studies have used these indices. However, there is no comprehensive review of these parameters in the prognostic significance.

Methods

The aim of this study was to review the articles exploring the prognostic significance of these parameters. Articles demonstrating independent significance after multivariate analysis on the Cox proportional hazards model were defined as “successful.” The success rate was compared using Fisher’s exact test. In addition, multivariate logistic regression analysis was performed to explore the independent determinants of the success of prognostic prediction.

Results

The success rate of the baPWV articles (65.7% [46/70]) tended to be higher than that of the CAVI articles (40.0% [6/15]; P=0.083). Multivariate analysis demonstrated that log (number of patients) (OR 11.20, 95% CI 2.45–51.70, P=0.002) and dialysis population (OR 0.28, 95% CI 0.08–0.94, P=0.039) were positive and negative independent determinants of the success of prognostic prediction, respectively. In addition, after redefining two studies as the absence of arteriosclerosis obliterans (ASO) exclusion, baPWV (OR 3.36, 95% CI 0.86–13.20, P=0.083) and the existence of exclusion criteria of ASO (OR 3.08, 95% CI 0.96–9.93, P=0.060) exhibited statistical tendency in the multivariate analysis.

Conclusion

This study demonstrated that the number of study participants and dialysis population were the independent determinants of the success of prognostic prediction. This study also showed the importance of exclusion criteria of ASO when using these indices. In addition, a prospective large-scale study to confirm the superiority in the prognostic prediction of these indices is warranted.

Bio-chemo-mechanics of thoracic aortic aneurysms

Most thoracic aortic aneurysms (TAAs) occur in the ascending aorta. This review focuses on the unique bio-chemo-mechanical environment that makes the ascending aorta susceptible to TAA. The environment includes solid mechanics, fluid mechanics, cell phenotype, and extracellular matrix composition. Advances in solid mechanics include quantification of biaxial deformation and complex failure behavior of the TAA wall. Advances in fluid mechanics include imaging and modeling of hemodynamics that may lead to TAA formation. For cell phenotype, studies demonstrate changes in cell contractility that may serve to sense mechanical changes and transduce chemical signals. Studies on matrix defects highlight the multi-factorial nature of the disease. We conclude that future work should integrate the effects of bio-chemo-mechanical factors for improved TAA treatment.