Association of small artery elasticity with incident cardiovascular disease in older adults: the multi-ethnic study of atherosclerosis

Association of fibroblast growth factor-23 with arterial stiffness in the Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Serum fibroblast growth factor-23 (FGF-23) is associated with cardiovascular disease (CVD), yet the mechanisms remain uncertain. Our objective was to determine whether higher FGF-23 concentrations are associated with arterial stiffness.

METHODS

In this cross-sectional study, serum FGF-23 concentrations were measured in 5977 participants without known CVD in the Multi-Ethnic Study of Atherosclerosis. The primary outcomes of interest were large (LAE) and small artery elasticity (SAE), pulse pressure and ankle-brachial index (ABI) > 1.30. LAE and SAE were measured by pulse contour analysis of the radial artery. Pulse pressure was measured with an automated sphygmomanometer using the average of two resting blood pressure measurements. ABI was calculated as the ratio of the ankle and brachial systolic blood pressures.

RESULTS

Serum FGF-23 concentrations were not significantly associated with LAE [relative difference (RD) per doubling: 0%; 95% confidence interval (CI): -2-1%], SAE (RD per doubling: 0%; 95% CI: -3-2%), pulse pressure (β per doubling: 0.44; 95% CI: -0.31-1.19), or a high ABI (odds ratio per doubling: 1.14; 95% CI: 0.84-1.55). Findings were similar irrespective of chronic kidney disease status.

CONCLUSIONS

Higher serum FGF-23 concentrations are not associated with arterial stiffness, as measured by pulse pressure, LAE, SAE or high ABI, in a community-based population without CVD.

Assessment of arterial stiffness among schizophrenia-spectrum disorders using aortic pulse wave velocity and arterial compliance: a pilot study

Cardiovascular disease (CVD) is the leading cause of death in individuals with chronic schizophrenia. Arterial stiffness provides a non-invasive indication of cardiovascular disease risk. To date, arterial stiffness, which has been shown to have independent predictive value for CVD morbidity and mortality, has not been evaluated in this population. We aimed to examine aortic pulse wave velocity (aPWV) as well as large and small artery compliance (Comp1 and Comp2) in patients being treated for schizophrenia, compared to healthy volunteers. Ten patients and 10 age and gendermatched volunteers underwent a comprehensive evaluation of arterial stiffness including: aPWV, Comp1, Comp2, stroke volume, cardiac output, and systemic vascular resistance. Patient aPWV was significantly elevated compared to healthy volunteers (9.1 ± 4.11 vs. 5.7 ± 1.4, P=0.03). Increased age, blood pressure, heart rate, and cigarettes/day were associated with reduced arterial health in patients. This is the first time aPWV has been described in those treated for schizophrenia. Arterial stiffness is increased in this population. Measuring arterial stiffness is a non-invasive, sensitive and effective tool for evaluating CVD risk in this population.

Endothelial dysfunction, but not structural atherosclerosis, is evident early in children with heterozygous familial hypercholesterolemia

Children with heterozygous familial hypercholesterolemia (heFH) are prone to premature atherosclerosis. Vascular endothelial dysfunction may predict increased cardiovascular risk in children with heFH. The aim of this study was to assess for early functional and structural vascular changes in children with heFH. This cross-sectional study included 30 children with heFH (mean age 12 years) and 30 age- and sex-matched controls. Brachial artery flow-mediated dilation (FMD), carotid intima-media thickness (cIMT), carotid-femoral pulse wave velocity, and large- and small vessel compliance were measured noninvasively. HeFH children exhibited significantly greater total and LDL cholesterol, apolipoprotein B, and lipoprotein (a) levels (p < 0.05 for all) and lower FMD (6.23 ± 3.88 vs. 9.46 ± 4.54 %, p < 0.004) compared with controls. When children were divided in age subgroups, FMD was found to be significantly decreased in heFH compared with control subjects only in ages >10 years (p < 0.05). However, FMD was found to be similarly impaired in heFH children in all age subgroups (two-way analysis of variance, p = 0.39). No differences in other vascular function indices were found. In heFH patients, but not in controls, FMD was inversely correlated with cIMT (r = -0.378, p = 0.036). In conclusion, endothelial dysfunction occurs early in heFH children indicating an increased risk for premature cardiovascular disease and reflecting probably the need for early initiation of anticholesterolemic treatment. Decreased FMD is detected before structural atherosclerotic changes occur.

Influence of estrogen therapy on calcium, phosphorus, and other regulatory hormones in postmenopausal women: the MESA study

BACKGROUND

Estrogen therapy (ET) is associated with lower serum calcium and phosphorus concentrations and is known to increase bone mineral density (BMD). Other biomarkers of mineral metabolism may help understand the biological basis of these actions.

METHODS

We studied 2767 postmenopausal women in the Multi-Ethnic Study of Atherosclerosis, 862 (31%) of whom were using ET. We measured serum concentrations of calcium, phosphorus, 25-hydroxyvitamin D, 24,25-dihydoxyvitamin D, and fibroblast growth factor-23 and urinary fractional excretion of calcium (FEca) and phosphorus (FEphos). We examined the associations of ET with each biomarker. In addition, we tested whether the adjustment for biomarkers attenuated the association of ET with lumbar BMD measured by abdominal computed tomography in a subset of 810 women.

RESULTS

In adjusted models, women who used ET were younger in age [62 (SD 8) vs 66 (9) y, P < .001], had lower mean serum calcium [-13 mg/dL (95% confidence interval [CI] -0.17, -0.10), P < .001] and lower FEca [-0.15% (95% CI -0.21, -0.09), P < .001]. Mean serum phosphorus was lower [-0.19 mg/dL (95% CI -0.23, -0.15), P < .001] and FEphos [0.56% (95% CI 0.16, 0.96), P = .007] was higher in women on ET. Mean 25-hydroxyvitamin D and 24,25-dihydroxyvitamin D were higher [1.52 ng/dL (95% CI 0.57, 2.47), P = .002, and 0.26 ng/mL (95% CI 0.03, 0.48), P = .03, respectively] in women who used ET. Mean PTH and fibroblast growth factor-23 did not differ significantly by the use of ET. ET use was strongly associated with higher lumbar BMD [12.75 mg/cm³ (95% CI 7.77-17.73), P < .001]; however, mineral metabolism measures did not meaningfully alter this association.

CONCLUSIONS

In a multiethnic cohort of postmenopausal women, ET use was associated with lower serum calcium, lower FEca, lower serum phosphorus, and higher FEphos, suggesting these associations are attributable to increased calcium intake into bone and increased urinary phosphorus excretion. ET use was also associated with greater concentrations of vitamin D metabolites. ET-associated differences in these mineral metabolism measures did not meaningfully attenuate the strong association between ET use and lumbar BMD.

No association of 9p21 with arterial elasticity and retinal microvascular findings

OBJECTIVE

How 9p21 variation affects risk of cardiovascular disease is unclear, so we assessed whether 9p21 variants are associated with arterial elasticity or retinal microvascular findings.

METHODS

In the prospective Multi-Ethnic Study of Atherosclerosis (MESA) we assessed 378 SNPs in the 9p21 locus. Within four ethnic groups, we used an additive genetic model to relate the 9p21 SNPs to five vascular phenotypes: small and large elasticity derived from radial diastolic pulse contour analysis; Young's elastic modulus from carotid artery ultrasound measurements; and the diameter of the central retinal arteries and veins.

RESULTS

In neither ethnic-specific nor pooled data was there any statistically significant association between any of the 9p21 SNPs and any of the five vascular phenotypes.

CONCLUSION

Our study does not support an association of 9p21 variation with arterial elasticity or retinal microvascular abnormalities.

Assessment of arterial stiffness for clinical and epidemiological studies: methodological considerations for validation and entry into the European Renal and Cardiovascular Medicine registry

Epidemiological studies have highlighted the role of arterial stiffness as a risk factor for development of cardiovascular (CV) diseases. Moreover, aortic stiffness has been shown to be a significant predictive factor of all-cause and CV mortality in different populations including patients with end-stage renal disease. Pulse-wave velocity (PWV) is the most widely used technique to assess arterial stiffness. Although PWV can be measured on any artery or between any arterial sites, only carotid-to-femoral PWV, representing stiffness of the aorta and iliofemoral axes, has been shown to have predictive value for morbidity and mortality. The several available commercial devices differ according to the type of signal (pressure, distension, flow) or by recording both sites simultaneously or using ECG synchronization. It is also possible to directly measure arterial diameter changes during the cardiac cycle and link them to local pulse-pressure changes, which provides the pressure-diameter relationship and stress-strain relationship if arterial wall thickness is also measured. These techniques are based on high-precision vascular echo tracking or magnetic resonance imaging and applanation tonometry. This paper summarizes the basic principles of arterial haemodynamics and various methodologies to assess stiffness and the latest consensus recommendations for clinical applications.

Parathyroid hormone and arterial dysfunction in the multi-ethnic study of atherosclerosis

OBJECTIVE

High circulating concentrations of parathyroid hormone (PTH) have been associated with increased risks of hypertension, left ventricular hypertrophy, congestive heart failure and cardiovascular mortality. Impaired arterial function is a potential mechanism for these associations. We tested whether serum PTH concentration is associated with measures of arterial function.

DESIGN

Cross-sectional study.

PARTICIPANTS

A total of 6545 persons without clinical cardiovascular disease participating in the community-based Multi-Ethnic Study of Atherosclerosis.

MEASUREMENTS

Brachial artery flow-mediated dilation (FMD) as well as aortic pulse pressure and arterial pulse parameters derived from Windkessel modelling of the radial pressure waveform.

RESULTS

Higher serum PTH concentration was associated with lower brachial artery FMD (mean difference -0·09% per 10 pg/ml PTH), higher aortic pulse pressure (0·53 mmHg per 10 pg/ml) and reduced Windkessel capacitive index C1 (large artery elasticity, -0·12 ml/mmHg × 10 per 10 pg/ml), adjusting for potential confounding variables (all P-values ≤ 0·001). These relationships were independent of serum calcium concentration, serum 25-hydroxyvitamin D concentration and estimated glomerular filtration rate and were consistent across relevant participant subgroups. Associations of PTH with aortic pulse pressure and capacitive index C1 were attenuated after adjustment for blood pressure. Serum PTH concentration was not associated with the oscillatory index C2 (small artery elasticity).

CONCLUSIONS

Higher serum PTH concentration was associated with impaired endothelial function, increased aortic pulse pressure and decreased capacitive index C1 in a large, diverse, community-based population. These relationships may help explain previously observed associations of elevated PTH with cardiovascular disease.

Associations of aortic distensibility and arterial elasticity with long-term visit-to-visit blood pressure variability: the Multi-Ethnic Study of Atherosclerosis (MESA)

BACKGROUND

Although higher visit-to-visit variability (VVV) of blood pressure (BP) is associated with increased cardiovascular disease risk, the physiological basis for VVV of BP is incompletely understood.

METHODS

We examined the associations of aortic distensibility (assessed by magnetic resonance imaging) and artery elasticity indices (determined by radial artery pulse contour analysis) with VVV of BP in 2,640 and 4,560 participants, respectively, from the Multi-Ethnic Study of Atherosclerosis. Arterial measures were obtained at exam 1. BP readings were taken at exam 1 and at 3 follow-up visits at 18-month intervals (exams 2, 3, and 4). VVV was defined as the SD about each participant's mean systolic BP (SBP) across visits.

RESULTS

The mean SDs of SBP were inversely associated with aortic distensibility: 7.7, 9.9, 10.9, and 13.2mm Hg for quartiles 4, 3, 2, and 1 of aortic distensibility, respectively (P trend < 0.001). This association remained significant after adjustment for demographics, cardiovascular risk factors, mean SBP, and antihypertensive medication use (P trend < 0.01). In a fully adjusted model, lower quartiles of large artery and small artery elasticity (LAE and SAE) indices were also associated with higher mean SD of SBP (P trend = 0.02 for LAE; P trend < 0.001 for SAE).

CONCLUSIONS

In this multiethnic cohort, functional alterations of central and peripheral arteries were associated with greater long-term VVV of SBP.

Vascular elasticity and grip strength are associated with bone health of the hemiparetic radius in people with chronic stroke: implications for rehabilitation

BACKGROUND

People with stroke often have increased bone loss and fracture rate. Increasing evidence has demonstrated a link between cardiovascular health and bone loss in other patient populations.

OBJECTIVE

The study objectives were: (1) to compare the bone density and geometry of the radius diaphysis on the left and right sides in people with chronic stroke and people who were matched for age (control participants) and (2) to examine the relationship between the bone strength index at the hemiparetic radius diaphysis and vascular health in people with chronic stroke.

DESIGN

This was a case-control study.

METHODS

The radius diaphysis on both sides was scanned with peripheral quantitative computed tomography in 65 participants with chronic stroke and 34 control participants. Large-artery and small-artery elasticity indexes were evaluated with a cardiovascular profiling system.

RESULTS

The paretic radius diaphysis had significantly lower values for cortical bone mineral density, cortical thickness, cortical area, and the bone strength index but a larger marrow cavity area than the nonparetic radius diaphysis in participants with chronic stroke, whereas no bone measurement showed a significant side-to-side difference in control participants. Multiple regression analyses showed that the large-artery elasticity index and grip strength remained significantly associated with the bone strength index at the hemiparetic radius diaphysis after controlling for age, sex, time since stroke diagnosis, body mass index, and physical activity (R(2)=.790).

LIMITATIONS

This study was cross-sectional and could not establish causality. The radius diaphysis is not the most common site of fracture after stroke.

CONCLUSIONS

Both the integrity of the vasculature and muscle strength were significantly associated with the bone strength index at the hemiparetic radius diaphysis in participants with chronic stroke. The results may be useful in guiding rehabilitative programs for enhancing bone health in the paretic arm after stroke.

Current and future initiatives for vascular health management in clinical practice

Central arterial structure and function comprise a primary determinant of vascular health, and are integral to the important concept of ventriculo-vascular coupling or interaction. Central aortic stiffening is a major influence on central blood pressure, and directly relates to coronary perfusion. The joint session of the International Society of Vascular Health (Eastern Region) and the Ukrainian Congress of Cardiology was held in Kiev, Ukraine, on September 23, 2011; it provided an expert forum to discuss arterial evaluations, clinical applications, and progress toward translating arterial protection into cardiovascular benefits. The conclusions of the expert panel were: 1. Aortic stiffness is not presently a treatment target but may be useful for substratifying cardiovascular risk in individuals in order to better target the intensity of conventional therapy, and it may be useful in assessing response to treatment. 2. Crosstalk between macro- and microcirculation in hypertension has important implications for pharmacological treatment. An antihypertensive regimen should abolish the vicious cycle between the increased resistance in the microcirculation and the increased stiffness of the larger arteries. Such treatment should be based on drugs with multiple actions on the vascular tree, or on drug combinations that target the various segments of the arterial system. 3. Several blood pressure-independent mechanisms of large artery stiffness exist. Future considerations for clinical understanding of large artery stiffness should involve new drugs and new evaluation methods - with a focus on vascular health, for the initiation of cardiovascular prevention, for newly designed studies for treatment evaluation, and for new studies of drug combinations. 4. Arterial stiffening is a sign of cardiovascular aging and is a major factor affecting the biomechanics of large arteries. Arterial stiffness is an attractive therapeutic target in terms of vascular aging. Healthy lifestyle, physical exercise, and smoking cessation are the most effective ways of preventing and treating early vascular aging. Long-term effects of cardiovascular drugs on arterial stiffness need to be further investigated. 5. The emerging clinical data on the cardio ankle vascular index (CAVI) technique of arterial health assessment is presented, showing that the CAVI is elevated in aging, coronary artery diseases, chronic kidney disease, hypertension, diabetes mellitus, smoking, and stress. The CAVI decreased with the administration of statins, angiotensin II receptor blocking agents, and calcium channel blockers. The CAVI is suggested as an important predictor of cardiovascular diseases. Future development of a clinical understanding of large artery stiffness is important and should include consideration of new drugs and new evaluation methods, with a focus on vascular health aimed at cardiovascular prevention.

Treatment of isolated systolic hypertension in the elderly

Systolic hypertension is a major health economy problem within our aging society. Increased arterial stiffness is the vascular phenotype of systolic hypertension, especially of the large arteries. Elevated systolic blood pressure is even more associated with cardiovascular morbidity and mortality than diastolic blood pressure. Treatment of systolic hypertension in the elderly should be based on nonpharmacological measures and medical therapy if the systolic hypertension cannot be controlled by conservative therapy alone. The HYVET study provided evidence-based medicine data showing that, in the very elderly, lowering blood pressure to a level of 150/80 mmHg is still very beneficial. Antihypertensive therapy needs to be tailored in the elderly because of comorbid conditions, such as ischemic heart disease, heart failure, atrial fibrillation, renal insufficiency and diabetes. Angiotensin-converting enzyme inhibitors or angiotensin II-receptor blockers should be considered in combination with diuretics or with a dihydropyridine calcium antagonist. β-blockers seem to be less effective for cardiovascular disease protection in comparison with other antihypertensive drug classes, such as diuretics, dihydropyridines, angiotensin-converting enzyme inhibitors or angiotensin II-receptor blockers. Major effort is required to reduce the therapeutic inertia and increase therapeutic adherence for better blood pressure control in the elderly with systolic hypertension.

Classical and novel biomarkers for cardiovascular risk prediction in the United States

Cardiovascular risk prediction models based on classical risk factors identified in epidemiologic cohort studies are useful in primary prevention of cardiovascular disease in individuals. This article briefly reviews aspects of cardiovascular risk prediction in the United States and efforts to evaluate novel risk factors. Even though many novel risk markers have been found to be associated with cardiovascular disease, few appear to improve risk prediction beyond the powerful, classical risk factors. A recent US consensus panel concluded that clinical measurement of certain novel markers for risk prediction was reasonable, namely, hemoglobin A1c (in all adults), microalbuminuria (in patients with hypertension or diabetes), and C-reactive protein, lipoprotein-associated phospholipase, coronary calcium, carotid intima-media thickness, and ankle/brachial index (in patients deemed to be at intermediate cardiovascular risk, based on traditional risk factors).

Supplementation with n3 fatty acid ethyl esters increases large and small artery elasticity in obese adults on a weight loss diet

Increased arterial stiffness is associated with enhanced risk of cardiovascular disease in obese individuals. Whether n3 fatty acid ethyl ester (FAEE) supplementation improves arterial stiffness in obese participants on a weight loss diet has not yet been investigated. The objective of the study was to carry out a 12-wk randomized, single-blind trial to test the effect of a 25% energy deficit weight loss diet alone (WL) (n = 12) or WL plus 4 g/d Omacor (46% EPA and 38% DHA) supplementation (WL+FAEE) (n = 13) on arterial elasticity in obese adults. Large (C1) and small artery elasticity (C2) were measured by pulse contour analysis of the radial artery. WL alone reduced (P < 0.05 in all) body weight (-3%), waist circumference (-4%), systolic (-3%) and diastolic (-3%) blood pressures, cardiac output (-4%), plasma TG concentration (-25%), and the homeostasis model assessment (HOMA) score (-12%) and increased plasma HDL cholesterol (+9%) and adiponectin (+18%) concentrations. However, WL alone did not alter C1 and C2. The WL+FAEE intervention significantly reduced body weight (-4%), waist circumference (-4%), systolic (-8%) and diastolic (-5%) blood pressures, pulse pressure (-5%), heart rate (-8%), plasma TG concentration (-36%), and HOMA score (-12%) and increased stroke volume (+3%), plasma HDL cholesterol (+6%) and adiponectin concentrations (+28%), and C1 (+20%) and C2 (+22%) artery elasticity. The changes in systolic blood pressure, heart rate, plasma TGs, C1, and C2 were significantly greater in the WL+FAEE group than in the WL group. Supplementation with n3 FAEEs improves C1 and C2 independently of weight loss in obese adults.

Metabolic syndrome and arterial elasticity in youth

OBJECTIVE

To compare arterial elasticity in children, adolescents, and young adults with and without metabolic syndrome (MetS), and to assess which MetS components, demographic measures, and body composition measures are associated with arterial elasticity.

MATERIALS/METHODS

Two-hundred six subjects (107 females and 99 males) between the ages of 10 and 20years were recruited by local newspaper advertisements, university email advertisements, and informational flyers. Subjects were assessed on MetS components, demographic measures, body composition measures, and arterial elasticity via radial tonometry. Forty-five subjects (22%) had MetS, as defined by the International Diabetes Federation, and 161 subjects (78%) did not.

RESULTS

The primary novel finding was that group differences were not observed for large artery elasticity index (LAEI) (MetS=16.1±4.4 (ml×mmHg(-1))×10 (mean±SD), control=15.4±4.9, (ml×mmHg(-1))×10, p=0.349), and small artery elasticity index (SAEI) (MetS=9.2±2.7 (ml×mmHg(-1))×100, control=8.4±2.9, (ml×mmHg(-1))×100, p=0.063). In the MetS group, fat free mass was positively associated with arterial elasticity, and was the strongest multivariate predictor of LAEI (partial R(2)=0.41) and SAEI (partial R(2)=0.29).

CONCLUSIONS

Youth with MetS did not exhibit differences in LAEI and SAEI compared to controls. Furthermore, fat free mass of youth with MetS was positively associated with arterial elasticity, and was the strongest predictor of both LAEI and SAEI. The clinical implication is that exercise intervention designed to increase fat free mass might increase arterial elasticity in youth, particularly in youth with MetS.

Small artery elasticity predicts future cardiovascular events in chinese patients with angiographic coronary artery disease

Arterial elasticity has been shown to predict cardiovascular disease (CVD) in apparently healthy populations. The present study aimed to explore whether arterial elasticity could predict CVD events in Chinese patients with angiographic coronary artery disease (CAD). Arterial elasticity of 365 patients with angiographic CAD was measured. During follow-up (48 months; range 6-65), 140 CVD events occurred (including 34 deaths). Univariate Cox analysis demonstrated that both large arterial elasticity and small arterial elasticity were significant predictors of CVD events. Multivariate Cox analysis indicated that small arterial elasticity remained significant. Kaplan-Meier analysis showed that the probability of having a CVD event/CVD death increased with a decrease of small arterial elasticity (P < .001, respectively). Decreased small arterial elasticity independently predicts the risk of CVD events in Chinese patients with angiographic CAD.

Associations among lung function, arterial elasticity, and circulating endothelial and inflammation markers: the multiethnic study of atherosclerosis

A parallel physiological pathway for elastic changes is hypothesized for declines in arterial elasticity and lung function. Endothelial dysfunction and inflammation could potentially decrease elasticity of both vasculature and lung tissue. We examined biomarkers, large arterial elasticity and small arterial elasticity (SAE), and forced vital capacity (FVC) in a period cross-sectional design in the multiethnic study of atherosclerosis, which recruited 1823 women and 1803 men, age range 45 to 84 years, black, white, Hispanic, and Chinese, free of clinically recognized cardiovascular disease. Radial artery tonometric pulse waveform registration was performed and large arterial elasticity and SAE were derived from diastole. Spirometric data and markers of endothelial dysfunction and inflammation (soluble intracellular adhesion molecule-1, fibrinogen, hs-C-reactive protein, and interleukin-6) were obtained. Mean large arterial elasticity was 13.7 ± 5.5 mL/mm Hg × 10 and SAE was 4.6 ± 2.6 mL/mm Hg × 100. Mean FVC was 3192 ± 956.0 mL and forced expiratory volume in 1 second was 2386 ± 734.5 mL. FVC was about 40 ± 5 mL higher per SD of SAE, stronger in men than women. The association was slightly weaker with large arterial elasticity, with no sex interaction. After regression adjustment for demographic, anthropometric, and cardiovascular risk factors, the biomarkers tended to be related to reduced SAE and FVC, particularly in men. These biomarker associations suggest important cardiovascular disease risk alterations that occur concurrently with lower arterial elasticity and lung function. The observed positive association of SAE with FVC and with forced expiratory volume in 1 second in middle-aged to older free-living people is consistent with the hypothesis of parallel physiological pathways for elastic changes in the vasculature and in lung parenchymal tissue.

Endothelial dysfunction and cardiac allograft vasculopathy

Cardiac allograft vasculopathy remains a major challenge to long-term survival after heart transplantation. Endothelial injury and dysfunction, as a result of multifactorial immunologic and nonimmunologic insults in the donor and the recipient, are prevalent early after transplant and may be precursors to overt cardiac allograft vasculopathy. Current strategies for managing cardiac allograft vasculopathy, however, rely on the identification and treatment of established disease. Improved understanding of mechanisms leading to endothelial dysfunction in heart transplant recipients may provide the foundation for the development of sensitive screening techniques and preventive therapies.

Underuse of cardiovascular preventive pharmacotherapy in patients presenting with ST-elevation myocardial infarction

BACKGROUND

Multiple medications have proven efficacy for the primary prevention of coronary heart disease (CHD), but the appropriate patient population remains controversial. Even in the presence of multiple cardiovascular risk factors, many patients are not considered high risk and are not offered preventive medications despite proven efficacy.

METHODS

We analyzed a prospective cohort of 1,710 consecutive ST-elevation myocardial infarction (STEMI) patients treated in a regional STEMI system from May 2007 to July 2010 and enrolled in a comprehensive database that includes preadmission medications.

RESULTS

Of the 1,707 patients analyzed, 1,180 (69.1%) did not have known CHD before their event; and 482 (41.7%) of those patients had premature events (men <55 years old, women <65 years old). In patients without known CHD, cardiovascular risk factors were abundant (52.1% had hypertension, 43.6% had dyslipidemia, 41.4% had a family history of CHD, 58.5% were current or former smokers, and 14.9% were diabetic). Despite the high prevalence of risk factors, only 24.1% were on aspirin, 16.1% were on a statin, and only 7.8% were taking an aspirin and statin. Use of preventive medications was even less common in patients with premature events, including aspirin (15.2% vs 30.2%, P value < .001), statins (11.1% vs 19.5%, P value < .001), and the combination (5.6% vs 9.4%, P value < .001).

CONCLUSIONS

Approximately 70% of a contemporary STEMI population did not have known CHD before their event, and >40% of those events would be considered premature. Despite the significant burden of cardiovascular risk factors, use of preventive therapy was alarmingly low in patients presenting with STEMI.

Metformin use among individuals at risk for type 2 diabetes

Excess total and cardiovascular morbidity and mortality remain very high among those with type 2 diabetes versus those without diabetes. Clinical trials to lower blood glucose have been disappointing probably because the participants were too late in the natural history of diabetes and already had extensive vascular disease. Insulin resistance measured simply by elevated fasting blood insulin is an early marker of β-cell stress and peripheral insulin resistance. Metformin will prevent development of diabetes among patients with impaired fasting glucose but only for the short term. Metformin reduces risk of coronary heart disease. The drug is safe, low cost, and may also prevent cancer. The combination of diet and exercise followed by metformin in the early phase of "insulin resistance" may reduce or delay both atherosclerosis and arteriosclerosis complications associated with diabetes. Preventive therapy must begin much earlier than before clinical diagnosis of diabetes and aim to initially lower blood insulin levels or insulin resistance.

Associations of noninvasive measures of arterial compliance and ankle-brachial index: the Multi-Ethnic Study of Atherosclerosis (MESA)

BACKGROUND

The association between measures of arterial compliance and peripheral arterial disease (PAD) is unclear. Early changes in arterial wall compliance could be a useful marker of patients at high risk for developing lower extremity atherosclerosis.

METHODS

We used linear and logistic regression models on baseline data from 2,803 female and 2,558 male participants in the Multi-Ethnic Study of Atherosclerosis (MESA) to study associations between tonometry-derived baseline measures of arterial compliance (large artery compliance (C1) and small artery compliance (C2)) and the baseline ankle-brachial index (ABI), as well as change in the ABI over ~3 years of follow-up.

RESULTS

In cross-sectional analyses, lower C1 and C2 values, indicating poorer arterial compliance, were associated with lower ABI. There were significant linear trends across strata of ABI, especially in C2 which ranged from 3.7 ml/mm Hg × 100 (95% confidence interval (CI) 3.3-4.2) in women with an ABI < 0.90 to 4.2 ml/mm Hg × 100 (95% CI 4.1-4.3 P < 0.001) in women with ABI 1.10 - <1.40. Similar significant trends (P < 0.001) were seen in men. In prospective analyses, those with the lowest tertile of C2 values at baseline had a greater multivariable-adjusted odds for decline in ABI of ≥ 0.15 over 3 years compared to those with the highest C2 values at baseline (odds ratio (OR) 1.80, 95% CI 1.23-2.64).

CONCLUSIONS

We observed that less compliant arteries were significantly associated with low ABI in cross-sectional analysis and with greater decline in odds of ABI over time.

Vascular injury in cancer survivors

With an increase in the number of patients surviving many years following successful cancer treatment, has come an improved understanding of the long-term effects of cancer therapy and its implications on future health. Premature cardiovascular disease is a significant cause of early morbidity and the leading non-cancer cause of death in this population. Chemotherapeutic agents and radiation therapy are known to be cardiotoxic. However, numerous vascular-related toxicities have also been observed among cancer survivors, such as myocardial ischemia, transient ischemic attacks, and stroke, suggesting a degree of chronic endothelial injury and dysfunction leading to premature atherosclerotic disease. Vascular health in cancer survivors may be further compromised by metabolic abnormalities such as obesity, insulin resistance, and dyslipidemias which have also been reported following cancer therapy. Furthermore, some survivors experience gonadal dysfunction and loss of potentially protective sex steroids or undergo hormonal therapies that induce additional metabolic abnormalities. The effects of cancer therapies upon the endothelial monolayer have not been fully explored. An understanding of potential injury to and dysfunction of the circulatory system among cancer survivors is essential for identifying preventive strategies and therapeutic targets.

Physical activity modifies the association between CYBA gene polymorphisms and small artery elasticity in a Chinese population

Emerging evidence suggests that increased superoxide production is responsible for a significant proportion of endothelial dysfunction. The relationship between variants of the CYBA gene and cardiovascular diseases is currently debated. In the present study, we investigated the influence of CYBA polymorphisms (rs1049255 and rs7195830) on arterial elasticity in a Chinese population. In the 2178 participants enrolled in the GaoYou study, we measured large artery elasticity (C1) and small artery elasticity (C2) non-invasively, genotyped the CYBA polymorphisms and calculated energy expenditure. The AA genotype of the rs1049255 polymorphism was associated with a lower C2 than were the GG/AG genotypes (5.31±0.11 vs. 5.52±0.06 ml mm Hg(-1) × 100; P=0.01). Further analyses revealed an interaction between CYBA polymorphisms and physical activity with respect to C2 (P=0.007 for rs1049255 and P=0.038 for rs7195830). In less physically active participants, the AA genotype of the rs1049255 polymorphism was associated with a significantly lower C2 than the GG/AG genotypes (4.69±0.16 vs. 5.26±0.19 ml mm Hg(-1) × 100; P=0.008). In physically active participants, the GG/AG genotypes of rs7195830 polymorphism were correlated with higher C2 values than the AA genotype (5.84±0.08 vs. 5.08±0.32 ml mm Hg(-1) × 100; P=0.049). Haplotype analyses revealed higher C2 values in rs1049255G-rs7195830G carriers (P=0.0015). In conclusion, the rs1049255 and rs7195830 polymorphisms of the CYBA gene were associated with C2 in a Chinese population; physical activity could modify this genetic effect.

Correlation of arterial blood pressure and compliance with left ventricular structure and function in the very elderly

There are very few data on the relationship between systolic blood pressure (SBP), diastolic blood pressure (DBP), arterial compliance, and left ventricular structure and function, particularly left ventricular hypertrophy (LVH), in the very elderly (>75 years). SBP and arterial stiffness increase with age, and the question is: which of the two is the main stimulus to LVH? This is a cross-sectional study to compare blood pressure and arterial stiffness measures with regard to their correlations with echocardiographic parameters of LV structure and function, controlling for age and cardiovascular risk factors, in a very elderly population. Arterial stiffness was determined by radial pulse waveform using pulse contour analysis. LV dimensions were measured by transthoracic M-mode echocardiography, and diastolic function by tissue Doppler measurements of diastolic mitral annular velocities. There were 179 subjects, all male, with a mean age of 81.8 years. Using age-adjusted partial correlations, SBP, DBP, and mean arterial pressure (MAP) were correlated with parameters of LV structure and function. Correlation coefficients were: SBP versus left ventricular mass index (LVMI), r = 0.246; SBP versus early diastolic mitral annular velocity (MAV), r = -0.179; DBP versus LVMI, r = 0.199; DBP versus MAV, r = -0.199; MAP versus LVMI, r = 0.276; and MAP versus MAV, r = -0.206, all with P < .05. However, neither capacitative nor reflective arterial compliance was significantly correlated with any parameter of LV structure and function. After controlling for age and 10 cardiovascular and metabolic risk factors, the correlation between blood pressure and the measured LV parameters was substantially unchanged, as was the lack of correlation between indices of arterial compliance and the LV indices. Arterial blood pressure is correlated with LV structure and function in the very elderly, but arterial stiffness, as measured by diastolic pulse contour analysis, is not.

Arterial stiffness/elasticity in the contribution to progression of heart failure

Arterial stiffness/elasticity plays a major role in the pathogenesis of heart failure beyond arterial blood pressure. Arterial wave reflections are generated from the periphery of the vascular system, especially at the level of the small arteries. The pattern change of the arterial wave reflections can alter the ventricular-vascular coupling in a pathologic manner, leading to heart failure. Several noninvasive techniques are used to estimate arterial stiffness/elasticity. Small artery elasticity has important predictive value for the diagnosis of heart failure. The beneficial effect of some cardiovascular therapy on arterial stiffness/elasticity has potential to prevent or delay the progression of heart failure.

Association of pulse pressure, arterial elasticity, and endothelial function with kidney function decline among adults with estimated GFR >60 mL/min/1.73 m(2): the Multi-Ethnic Study of Atherosclerosis (MESA)

BACKGROUND

The association of subclinical vascular disease and early declines in kidney function has not been well studied.

STUDY DESIGN

Prospective cohort study.

SETTING & PARTICIPANTS

Multi-Ethnic Study of Atherosclerosis (MESA) participants with estimated glomerular filtration rate (eGFR) ≥60 mL/min/1.73 m(2) with follow-up of 5 years.

PREDICTORS

Pulse pressure, small (SAE) and large arterial elasticity (LAE), and flow-mediated dilation.

OUTCOMES

Kidney function decline.

MEASUREMENTS

SAE and LAE were measured by pulse contour analysis of the radial artery. Kidney function was assessed by eGFR based on serum creatinine (eGFR(SCr)) and cystatin C (eGFR(SCysC)).

RESULTS

For 4,853 adults, higher pulse pressure and lower SAE and LAE had independent and linear associations with faster rates of kidney function decline. Compared with persons with pulse pressure of 40-50 mm Hg, eGFR(SCysC) declines were 0.29 (P = 0.006), 0.56 (P < 0.001), and 0.91 (P < 0.001) mL/min/1.73 m(2)/y faster in persons with pulse pressure of 50-60, 60-70, and >70 mm Hg, respectively. Compared with the highest quartile of SAE (most elastic), eGFR(SCysC) declines were 0.26 (P = 0.009), 0.35 (P = 0.001), and 0.70 (P < 0.001) mL/min/1.73 m(2)/y faster for the second, third, and fourth quartiles, respectively. For LAE, compared with the highest quartile, eGFR(SCysC) declines were 0.28 (P = 0.004), 0.58 (P < 0.001), and 0.83 (P < 0.001) mL/min/1.73 m(2)/y faster for each decreasing quartile of LAE. Findings were similar for eGFR(SCr). In contrast, for 2,997 adults with flow-mediated dilation and kidney function measures, flow-mediated dilation was not associated significantly with kidney function decline. For every 1-standard deviation greater flow-mediated dilation, eGFR(SCysC) and eGFR(SCr) changed by 0.05 (P = 0.3) and 0.06 mL/min/1.73 m(2)/y (P = 0.04), respectively.

LIMITATIONS

We had no direct measure of GFR, in common with nearly all large population-based studies.

CONCLUSIONS

Higher pulse pressure and lower arterial elasticity, but not flow-mediated dilation, were associated linearly and independently with faster kidney function decline in persons with eGFR ≥60 mL/min/1.73 m(2). Future studies should investigate whether treatments to decrease the stiffness of large and small arteries may slow the rate of kidney function loss.

Association of self-reported race/ethnicity and genetic ancestry with arterial elasticity: the Multi-Ethnic Study of Atherosclerosis (MESA)

African Americans have a disproportionate burden of hypertension compared with white, whereas data on Hispanics is less well-defined. Mechanisms underlying these differences are unclear, but could be in part because of ancestral background and vascular function. We studied 660 African Americans and 635 Hispanics from the Multi-Ethnic Study of Atherosclerosis (MESA) with complete data on genetic ancestry, pulse pressure (PP), and large and small arterial elasticity (LAE, SAE). LAE and SAE were obtained using the HDI PulseWave CR-2000 Research CardioVascular Profiling Instrument. Among African Americans, higher European ancestry was marginally associated with higher LAE (P = .05) and lower PP (P = .05); results for LAE were attenuated after adjustment for potential mediators (P = .30). Among Hispanics, higher Native American ancestry was associated with higher SAE (P = .0006); higher African ancestry was marginally associated with lower SAE (P = .07). Ancestry was not significantly associated with LAE or PP in Hispanics. Among African Americans, higher European ancestry may be associated with less large artery damage, as measured by LAE and PP, although these associations warrant further study. Among Hispanics, ancestry is strongly associated with SAE. Future studies should consider genetic ancestry when studying hypertension in race/ethnic minorities, particularly among Hispanics.