Dynamics of the State of Arterial Stiffness as a Possible Pathophysiological Factor of Unfavorable Long-Term Prognosis in Patients after Coronary Artery Bypass Grafting

The aim of this study was to examine the long-term prognostic value of changes in the cardio-ankle vascular index (CAVI) within a year after coronary artery bypass grafting (CABG).

METHODS

Patients with coronary artery disease (n = 251) in whom CAVI was assessed using the VaSera VS-1000 device before and one year after CABG. Groups with improved CAVI or worsened CAVI were identified. We assessed the following events at follow-up: all-causes death, myocardial infarction, and stroke/transient ischemic attack.

RESULTS

All-causes death was significantly more common in the group with worsened CAVI (27.6%) than in the group with CAVI improvement (14.8%; p = 0.029). Patients with worsened CAVI were more likely to have MACE, accounting for 42.2% cases, compared with patients with CAVI improvement, who accounted for 24.5%; p = 0.008. Worsened CAVI (p = 0.024), number of shunts (p = 0.006), and the presence of carotid stenosis (p = 0.051) were independent predictors of death from all causes at 10-year follow-up after CABG. The presence of carotid stenosis (p = 0.002) and the group with worsened CAVI after a year (p = 0.008) were independent predictors of the development of the combined endpoint during long-term follow-up.

CONCLUSIONS

Patients with worsening CAVI one year after CABG have a poorer prognosis at long-term follow-up than patients with improved CAVI. Future research would be useful to identify the most effective interventions to improve CAVI and correspondingly improve prognosis.

Repetitive pain experiences modulate feedforward control of hemodynamics and modification by nitrous oxide/oxygen inhalation in humans

Background

Repetitive experiences of certain stresses evoke feedforward cardiovascular responses via central command (CC)--central signals from the higher brain. However, it is unclear whether the anticipatory cardiovascular responses before pain stimulation occur after repetitive pain experiences and how nitrous oxide/oxygen inhalation (N2O), a sedative widely used in dentistry, affects the responses. We tested the hypothesis that the repetitive cold pressor test (CPT) alters the anticipatory cardiovascular responses, which are attenuated by N2O.

Materials and methods

Beat-to-beat systolic (SBP) and diastolic blood pressure (DBP), heart rate (HR), and finger arterial stiffness (β-stiffness) were measured during the 5-min rest, 30-s countdown (CD) before CPT, 2-min CPT, and 3-min recovery (CPT[1st]) in 15 young adults [age, 28 ± 4 years]. The same protocols were repeated randomly with the second CPT (CPT + CC) or placebo test (PLCB + CC).

Results

SBP and DBP increased from baseline in CPT[1st] and CPT + CC under room air (RA) and 40 % N2O, while SBP was lower under N2O than under RA in CPT[1st]. HR in CPT[1st] was lower under N2O than under RA. The change (Δ) in HR was smaller during CPT[1st] than during CPT + CC under N2O, and a similar trend was observed under RA. ΔSBP by CD was lower under N2O than under RA in CPT[1st] but not in CPT + CC. HR increased with CD in CPT + CC but not in CPT[1st] under both RA and N2O. β-stiffness increased by CD regardless of the pain experience, while it was lower under N2O.

Conclusion

Repetitive pain experiences induce a feedforward HR increase. 40 % N2O decreases vascular stiffness, which may attenuate the anticipatory pressor response only when the feedforward HR increase does not exist.

Cross-Sectional Relationship Between Atrial Conduction Delay and Arterial Stiffness in Patients with Obstructive Sleep Apnea

Aim

Prolonged P-wave duration (PWD), which indicates atrial conduction delay, is a potent precursor of atrial fibrillation (AF) that may be induced by obstructive sleep apnea (OSA). The cardio-ankle vascular index (CAVI), which is an arterial stiffness parameter, is elevated in patients with OSA; moreover, an increased CAVI is associated with atrial conduction delay through left atrium enlargement in association with left ventricular diastolic dysfunction. We aimed to examine the relationship between the CAVI and PWD in patients with OSA.

Methods

We included patients with a sinus rhythm who underwent overnight polysomnography. We measured the PWD and CAVI on standard 12-lead electrocardiograms; further, we analyzed the relationship between PWD and CAVI.

Results

We analyzed data from 300 participants (men, 89.0%; mean age, 52.3 ± 13.1 years; and body mass index, 26.2 ± 3.9 kg/m2). The mean PWD was 104.4 ± 10.4 ms while the mean CAVI was 7.5 ± 1.5. PWD was significantly correlated with CAVI (r = 0.478, p < 0.001); additionally, PWD and CAVI were directly associated with OSA severity (p = 0.002 and p = 0.002, respectively). Multivariate regression analysis revealed an independent significant correlation of PWD and CAVI with OSA severity.

Conclusion

In patients with OSA, an increase in arterial stiffness is associated with atrial conduction delay.

Rapid Rise in Cardio-Ankle Vascular Index as a Predictor of Impending Cardiovascular Events -Smooth Muscle Cell Contraction Hypothesis for Plaque Rupture

Predictive factors for vascular events have not been established. The vasculature of the atheroma is supplied by penetration of the vasa vasorum through the smooth muscle cell layer from the adventitia. Smooth muscle cell contraction induces compression of the vasa vasorum, resulting in ischemia in intimal atheromatous lesions. Cardio-ankle vascular index (CAVI) has become known as an index of arterial stiffness of the arterial tree from the origin of the aorta to the ankle. CAVI reflects the progress of arteriosclerosis, and a rapid rise in CAVI indicates arterial smooth muscle cell contraction. We hypothesized that rapidly increased arterial stiffness evaluated by CAVI may be a predictor of impending cardiovascular events.

The independent association between salivary alpha-amylase activity and arterial stiffness in Japanese men and women: the Toon Health Study

Psychological stress is considered to be a potential contributor in the development of arterial stiffness. However, an independent association between arterial stiffness and biological markers of stress has not yet been established. We examined the independent association between salivary alpha-amylase (sAA) activity and arterial stiffness, not mediated by cardiometabolic disease associated with arterial stiffness, in a sample of healthy Japanese men and women. Participants (992 in total, 296 men and 696 women aged 30-79 years) had neither previous cardiovascular events or stroke, nor coexisting hypertension, diabetes, or dyslipidemia. Arterial stiffness was measured by the cardio-ankle vascular index (CAVI), and increased CAVI was defined as a CAVI value of 9 or higher. A saliva sample was collected in the morning and sAA was measured with a commercial assay kit. Higher sAA activity was positively associated with greater arterial stiffness particularly among women (β = 0.070; 95% CI = 0.014-0.126; p = 0.01), and not across all participants (β = 0.042; 95% CI = -0.005-0.089; p = 0.08) and in men (β = -0.005; 95% CI = -0.097-0.087; p = 0.91). The association was strongest in the group of women aged 60 years and older (β = 0.121; 95% CI = 0.018-0.224; p = 0.02). Although the association between sAA and increased CAVI (CAVI ≥ 9) was not significant in all and sex subgroups, odds ratios (OR) for CAVI ≥ 7 were significantly high in all participants (OR = 1.25; 95% CI = 1.03-1.53) and women (OR = 1.43; 95% CI = 1.12-1.82). Elevation of sAA was associated with an increase in arterial stiffness, particularly for women aged 60 years or older.

Rapid Rise of Cardio-Ankle Vascular Index May Be a Trigger of Cerebro-Cardiovascular Events: Proposal of Smooth Muscle Cell Contraction Theory for Plaque Rupture

Cardiovascular diseases have been recognized as the main cause of death all over the world. Recently, the established cardio-ankle vascular index (CAVI) has become known as an index of arterial stiffness of the arterial tree from the origin of the aorta to the ankle. CAVI reflects the progress of arteriosclerosis, and a rapid rise in CAVI indicates arterial smooth muscle cell contraction. Considering the vasculature of the atheroma where vasa vasorum penetrates the smooth muscle cell layer and supplies blood to the intimal atheromatous lesion, a rapid rise of CAVI means “choked” atheroma. Thus, we proposed a “smooth muscle cell contraction” hypothesis of plaque rupture.

New Horizons of Arterial Stiffness Developed Using Cardio-Ankle Vascular Index (CAVI)

Arterial stiffness is recognized mainly as an indicator of arteriosclerosis and a predictor of cardiovascular events. Cardio-ankle vascular index (CAVI), which reflects arterial stiffness from the origin of the aorta to the ankle, was developed in 2004. An important feature of this index is the independency from blood pressure at the time of measurement. A large volume of clinical evidence obtained using CAVI has been reported. CAVI is high in patients with various atherosclerotic diseases including coronary artery disease and chronic kidney disease. Most coronary risk factors increase CAVI and their improvement reduces CAVI. Many prospective studies have investigated the association between CAVI and future cardiovascular disease (CVD), and proposed CAVI of 9 as the optimal cut-off value for predicting CVD. Research also shows that CAVI reflects afterload and left ventricular diastolic dysfunction in patients with heart failure. Furthermore, relatively acute changes in CAVI are observed under various pathophysiological conditions including mental stress, septic shock and congestive heart failure, and in pharmacological studies. CAVI seems to reflect not only structural stiffness but also functional stiffness involved in acute vascular functions. In 2016, Spronck and colleagues proposed a variant index CAVI₀, and claimed that CAVI₀ was truly independent of blood pressure while CAVI was not. This argument was settled, and the independence of CAVI from blood pressure was reaffirmed. In this review, we summarize the recently accumulated evidence of CAVI, focusing on the proposed cut-off values for CVD events, and suggest the development of new horizons of vascular function index using CAVI.

Lessons learned about stress and the heart after major earthquakes

There is evidence that certain stressors can trigger cardiovascular events. Several studies have now demonstrated an increase in major adverse cardiac events associated with natural disasters such as an earthquake. The purpose of this paper is to review the literature on earthquakes and cardiovascular events. Reports from 13 major quakes were reported. Earthquakes have been associated with a number of cardiac events including sudden cardiac death, fatal myocardial infarction (MI), myocardial infarction, stress cardiomyopathy, heart failure, stroke, arrhythmias, hypertension and pulmonary embolism. Most reports were associated with earthquakes of magnitude 6.0 or greater. Cardiac events were reported within hours of the quakes. In some reports there was a sharp spike in cardiac events followed by a decrease; but in other quakes the increases in cardiac events lasted weeks, months and even years. There often was an association between the cardiac events and amount of personal property loss. The Great East Japan Earthquake was an unusual event in that it was associated with a major tsunami and cardiac events appeared worse in inundated areas due to flooding. Some but not all reports suggested more MIs associated with early morning earthquakes that woke up the population. Hospitals in earthquake-prone areas should consider developing plans for handling increases in myocardial infarctions and other cardiac events that are associated with earthquakes.

Clinical assessment of arterial stiffness with cardio-ankle vascular index: theory and applications

Arterial stiffness is often assessed in clinical medicine, because it is not only an important factor in the pathophysiology of blood circulation but also a marker for the diagnosis and the prognosis of cardiovascular diseases. Many parameters have so far been proposed to quantitatively represent arterial stiffness and distensibility, such as pressure-strain elastic modulus (Ep), stiffness parameter (β), pulse wave velocity (PWV), and vascular compliance (Cv). Among these, PWV has been most frequently applied to clinical medicine. However, this is dependent on blood pressure at the time of measurement, and therefore it is not appropriate as a parameter for the clinical evaluation of arterial stiffness, especially for the studies on hypertension. On the contrary, stiffness parameter β is an index reflecting arterial stiffness without the influence of blood pressure. Recently, this parameter has been applied to develop a new arterial stiffness index called cardio-ankle vascular index (CAVI). Although this index is obtained from the PWV between the heart and the ankle, it is essentially similar to the stiffness parameter β, and therefore it does not depend on blood pressure changes during the measurements. CAVI is being extensively used in clinical medicine as a measure for the evaluation of cardiovascular diseases and risk factors related to arteriosclerosis. In the present article, we will explain the theoretical background of stiffness parameter β and the process to obtain CAVI. And then, the clinical utility of CAVI will be overviewed by reference to recent studies.

Cardio-ankle vascular index (CAVI) differentiates pharmacological properties of vasodilators nicardipine and nitroglycerin in anesthetized rabbits

Cardio-ankle vascular index (CAVI) has been developed for measurement of vascular stiffness from the aorta to tibial artery, which is clinically utilized for assessing the progress of arteriosclerosis. In this study, we established measuring system of the CAVI in rabbits, and assessed whether the index could reflect different pharmacological actions of nitroglycerin and nicardipine on the systemic vasculature. Rabbits were anesthetized with halothane, and the CAVI was calculated from the well-established basic equations with variables obtained from brachial and tibial blood pressure and phonocardiogram. Nicardipine (1, 3 and 10 μg/kg, i.v.) decreased the blood pressure, femoral vascular resistance, and heart-ankle pulse wave velocity (haPWV). Meanwhile, no significant change was detected in the CAVI at the low or middle dose, which reflects the defining feature of the CAVI that is independent of blood pressure. The index increased at the high dose. Nitroglycerin (2, 4 and 8 μg/kg, i.v.) decreased the blood pressure, femoral vascular resistance, and haPWV. Meanwhile, the CAVI was decreased during the nitroglycerin infusion, which may reflect its well-known pharmacological action dilating conduit arteries. These results suggest that the CAVI differentiates the properties of these vasodilators in vivo.

The Role of Monitoring Arterial Stiffness with Cardio-Ankle Vascular Index in the Control of Lifestyle-Related Diseases

Arteriosclerosis is a major contributor to cardiovascular diseases. One of the difficulties in controlling those diseases is the lack of a suitable indicator of arteriosclerosis or arterial injury in routine clinical practice. Arterial stiffness was supposed to be one of the monitoring indexes of arteriosclerosis. Cardio-ankle vascular index (CAVI) is reflecting the stiffness of the arterial tree from the origin of the aorta to the ankle, and one of the features of CAVI is independency from blood pressure at a measuring time. When doxazosin, an α1-adrenergic blocker, was administered, CAVI decreased, indicating that arterial stiffness is composed of both organic stiffness and functional stiffness, which reflects the contraction of arterial smooth muscle. CAVI shows a high value with aging and in many arteriosclerotic diseases, and is also high in persons possessing main coronary risk factors such as diabetes mellitus, metabolic syndrome, hypertension and smoking. Furthermore, when the most of those risk factors were controlled by proper methods, CAVI improved. Furthermore, the co-relationship between CAVI and heart function was demonstrated during treatment of heart failure. This paper reviews the principle and rationale of CAVI, and discusses the meaning of monitoring CAVI in following up so-called lifestyle-related diseases and cardiac dysfunction in routine clinical practice.