Expert consensus document on arterial stiffness: methodological issues and clinical applications

In recent years, great emphasis has been placed on the role of arterial stiffness in the development of cardiovascular diseases. Indeed, the assessment of arterial stiffness is increasingly used in the clinical assessment of patients. Although several papers have previously addressed the methodological issues concerning the various indices of arterial stiffness currently available, and their clinical applications, clinicians and researchers still report difficulties in selecting the most appropriate methodology for their specific use. This paper summarizes the proceedings of several meetings of the European Network for Non-invasive Investigation of Large Arteries and is aimed at providing an updated and practical overview of the most relevant methodological aspects and clinical applications in this area.

Endothelial function and dysfunction. Part I: Methodological issues for assessment in the different vascular beds: a statement by the Working Group on Endothelin and Endothelial Factors of the European Society of Hypertension

An enormous number of studies in the last two decades have been devoted to investigating the role of the endothelium in cardiovascular diseases. Nonetheless, the optimal methodology for investigating the multifaceted aspects of endothelial dysfunction is still under debate. Biochemical markers, molecular genetic tests and invasive and non-invasive tools with and without pharmacological and physiological stimuli have been introduced. Furthermore newer pharmacological tools have been proposed. However, the application of these methodologies should fulfil a number of requirements in order to provide conclusive answers in this area of research. Thus, the most relevant methodological issues in the research on endothelial function and dysfunction are summarized in this paper.

Sympathetic activation in obese normotensive subjects

Human obesity is characterized by profound alterations in the hemodynamic and metabolic states. Whether these alterations involve sympathetic drive is controversial. In 10 young obese subjects (body mass index, 40.5 +/- 1.2 kg/m2, mean +/- SEM) with normal blood pressure and 8 age-matched lean normotensive control subjects, we measured beat-to-beat arterial blood pressure (Finapres technique), heart rate (electrocardiogram), postganglionic muscle sympathetic nerve activity (microneurography at the peroneal nerve), and venous plasma norepinephrine (high-performance liquid chromatography). The measurements were performed in baseline conditions and, with the exception of plasma norepinephrine, during baroreceptor stimulation and deactivation caused by increases and reductions of blood pressure via intravenous infusions of phenylephrine and nitroprusside. Baseline blood pressure and heart rate were similar in obese and control subjects. Plasma norepinephrine was also similar in the two groups. Muscle sympathetic nerve activity, however, was 38.6 +/- 5.1 bursts per minute in obese subjects and less than half that level in control subjects (18.7 +/- 1.3 bursts per minute), the difference being highly statistically significant (P < .02). Muscle sympathetic nerve activity and heart rate were reduced during phenylephrine infusion and increased during nitroprusside infusion, but the changes were about half as great in obese subjects as in control subjects. Thus, even in the absence of any blood pressure alteration, human obesity is characterized by a marked sympathetic activation, possibly because of an impairment of reflex sympathetic restraint. This may be involved in the high rate of hypertension and cardiovascular complications seen in obesity.

Alterations of cardiac structure in patients with isolated office, ambulatory, or home hypertension: Data from the general population (Pressione Arteriose Monitorate E Loro Associazioni [PAMELA] Study)

BACKGROUND

The prevalence and clinical significance of isolated office (or white coat) hypertension is controversial, and population data are limited. We studied the prevalence of this condition and its association with echocardiographic left ventricular mass in the general population of the PAMELA (Pressione Arteriose Monitorate E Loro Associazioni) Study.

METHODS AND RESULTS

The study involved a large, randomized sample (n=3200) representative of the Monza (Milan) population, 25 to 74 years of age. Participants in the study (64% of the sample) underwent measurements of office, home, 24-hour ambulatory blood pressure, and echocardiography. Isolated office hypertension was defined as systolic or diastolic values >/=140 mm Hg or >/=90 mm Hg, respectively. Home and ambulatory normotension were defined according to criteria previously established from the PAMELA Study, for example, <132/83 mm Hg (systolic/diastolic) for home and 125/79 mm Hg for 24-hour average blood pressure. Treated hypertensive subjects were excluded from analysis that was made on a total of 1637 subjects. Depending on normotension being established on systolic or diastolic blood pressure measured at home or over 24 hours, the prevalence of isolated office hypertension ranged from 9% to 12%. In these subjects, left ventricular mass index was greater (P<0.01) than in subjects with normotension both in and outside the office. This was the case also for prevalence of left ventricular hypertrophy. Left ventricular mass index and hypertrophy were similarly greater in subjects found to have normal office but elevated home or ambulatory blood pressure ( approximately 10% of the population).

CONCLUSIONS

Isolated office hypertension has a noticeable prevalence in the population and is accompanied by structural cardiac alterations, suggesting that it is not an entirely harmless phenomenon. This is the case also for the opposite condition, that is, normal office but elevated home or ambulatory blood pressure, which implies that limiting blood pressure measurements to office values may not suffice in identification of subjects at risk.

Sympathetic activation in the pathogenesis of hypertension and progression of organ damage

Although animal models of hypertension have clearly shown that high blood pressure is associated with and is probably caused by an increase in sympathetic cardiovascular influences, a similar demonstration in humans has been more difficult to obtain for methodological reasons. There is now evidence, however, of increased sympathetic activity in essential hypertension. This article will review this evidence by examining data showing that plasma norepinephrine is increased in essential hypertension and that this is also the case for systemic and regional norepinephrine spillover, as well as for the sympathetic nerve firing rate in the skeletal muscle nerve district. Evidence will also be provided that sympathetic activation is a peculiar feature of essential hypertension, particularly in its early stages, with secondary forms of high blood pressure not usually characterized by an increased central sympathetic outflow. Humoral, metabolic, reflex, and central mechanisms are likely to be the factors responsible for the adrenergic activation characterizing hypertension, which may also promote the development and progression of the cardiac and vascular alterations that lead to hypertension-related morbidity and mortality, independent of blood pressure values. This represents the rationale for considering sympathetic deactivation one of the major goals of antihypertensive treatment.

Sympathetic activation and loss of reflex sympathetic control in mild congestive heart failure

BACKGROUND

Baroreflex control of sympathetic activity is impaired in severe congestive heart failure (CHF), probably causing the marked sympathetic activation typical of this condition. Little information exists, however, as to whether baroreflex impairment and related sympathetic activation also occur in mild CHF.

METHODS AND RESULTS

We studied 19 patients (age, 57.5 +/- 2.2 years, mean +/- SEM) with CHF in New York Heart Association (NYHA) class III or IV and with a marked reduction in left ventricular ejection fraction (LVEF, 30.1 +/- 1.5% from echocardiography) and 17 age-matched patients with CHF in NYHA class I or II and with an only slightly reduced LVEF (44.9 +/- 3.3%) that never was < 40%. Seventeen age-matched healthy subjects served as control subjects. Primary measurements included beat-to-beat arterial blood pressure (with the Finapres technique), heart rate (from ECG), and postganglionic muscle sympathetic nerve activity (MSNA, from microneurography at the peroneal nerve). Measurements were performed at baseline and during baroreceptor stimulation (intravenous phenylephrine infusion), baroreceptor deactivation (intravenous nitroprusside infusion), and cold-pressor test. Baseline blood pressure was similar in the three groups, whereas heart rate was progressively greater from control subjects to patients with mild and severe CHF, MSNA (bursts per 100 heart beats) increased significantly and markedly from control subjects to patients with mild and severe CHF (47.1 +/- 2.9 versus 64.4 +/- 6.2 and 82.1 +/- 3.4, P < .05 and P < .01, respectively). Heart rate and MSNA were progressively reduced by phenylephrine infusion and progressively increased by nitroprusside infusion. Compared with control subjects, the responses were strikingly impaired in severe CHF patients, but a marked impairment also was seen in mild CHF patients. On average, baroreflex sensitivity in mild CHF patients was reduced by 59.1 +/- 5.5% (MSNA) and 64.8 +/- 4.8% (heart rate). In contrast, reflex responses to the cold-pressor test were similar in the three groups.

CONCLUSIONS

These results demonstrate that in mild CHF patients the baroreceptor inhibitor influence on heart rate and MSNA is already markedly impaired. This impairment may be responsible for the early sympathetic activation that occurs in the course of CHF.

Clinical Presentation and Outcome in a Contemporary Cohort of Patients With Acute Myocarditis: Multicenter Lombardy Registry

BACKGROUND

There is controversy about the outcome of patients with acute myocarditis (AM), and data are lacking on how patients admitted with suspected AM are managed. We report characteristics, in-hospital management, and long-term outcome of patients with AM based on a retrospective multicenter registry from 19 Italian hospitals.

METHODS

A total of 684 patients with suspected AM and recent onset of symptoms (<30 days) were screened between May 2001 and February 2017. Patients >70 years of age and those >50 years of age without coronary angiography were excluded. The final study population comprised 443 patients (median age, 34 years; 19.4% female) with AM diagnosed by either endomyocardial biopsy or increased troponin plus edema and late gadolinium enhancement at cardiac magnetic resonance.

RESULTS

At presentation, 118 patients (26.6%) had left ventricular ejection fraction <50%, sustained ventricular arrhythmias, or a low cardiac output syndrome, whereas 325 (73.4%) had no such complications. Endomyocardial biopsy was performed in 56 of 443 (12.6%), and a baseline cardiac magnetic resonance was performed in 415 of 443 (93.7%). Cardiac mortality plus heart transplantation rates at 1 and 5 years were 3.0% and 4.1%. Cardiac mortality plus heart transplantation rates were 11.3% and 14.7% in patients with complicated presentation and 0% in uncomplicated cases (log-rank P<0.0001). Major AM-related cardiac events after the acute phase (postdischarge death and heart transplantation, sustained ventricular arrhythmias treated with electric shock or ablation, symptomatic heart failure needing device implantation) occurred in 2.8% at the 5-year follow-up, with a higher incidence in patients with complicated forms (10.8% versus 0% in uncomplicated AM; log-rank P<0.0001). β-Adrenoceptor blockers were the most frequently used medications both in complicated (61.9%) and in uncomplicated forms (53.8%; P=0.18). After a median time of 196 days, 200 patients had follow-up cardiac magnetic resonance, and 8 of 55 (14.5%) with complications at presentation had left ventricular ejection fraction <50% compared with 1 of 145 (0.7%) of those with uncomplicated presentation.

CONCLUSIONS

In this contemporary study, overall serious adverse events after AM were lower than previously reported. However, patients with left ventricular ejection fraction <50%, ventricular arrhythmias, or low cardiac output syndrome at presentation were at higher risk compared with uncomplicated cases that had a benign prognosis and low risk of subsequent left ventricular systolic dysfunction.

Mechanisms responsible for sympathetic activation by cigarette smoking in humans

BACKGROUND

The pressor and tachycardic effects of cigarette smoking are associated with an increase in plasma catecholamines, suggesting the dependence of these effects on adrenergic stimulation. Whether the stimulation occurs at a central or a peripheral level and whether reflex mechanisms are involved is unknown.

METHODS AND RESULTS

In nine normotensive healthy subjects (age, 33.0 +/- 3.5 years, mean +/- SEM), we measured blood pressure (Finapres device), heart rate (ECG), calf blood flow and vascular resistance (venous occlusion plethysmography), plasma norepinephrine and epinephrine (high-performance liquid chromatography assay), and postganglionic muscle sympathetic nerve activity (microneurography from the peroneal nerve) while subjects were smoking a filter cigarette (nicotine content, 1.1 mg) or were in control condition. Cigarette smoking (which raised plasma nicotine measured by high-performance liquid chromatography from 1.0 +/- 0.9 to 44.2 +/- 7.1 ng/mL) markedly and significantly increased mean arterial pressure (+13.2 +/- 2.3%), heart rate (+30.3 +/- 4.7%), calf vascular resistance (+12.1 +/- 4.9%), plasma norepinephrine (+34.8 +/- 7.0%), and plasma epinephrine (+90.5 +/- 39.0%). In contrast, muscle sympathetic nerve activity showed a marked reduction (integrated activity -31.8 +/- 5.1%, P < .01). The reduction was inversely related to the increase in mean arterial pressure (r = -.67, P < .05), but the slope of the relation was markedly less (-54.1 +/- 7.5%, P < .05) than that obtained by intravenous infusion of phenylephrine in absence of smoking. The hemodynamic and neurohumoral changes were still visible 30 minutes after smoking and occurred again on smoking a second cigarette. Sham smoking was devoid of any hemodynamic and neurohumoral effect.

CONCLUSIONS

These data support the hypothesis that in humans the sympathetic activation induced by smoking depends on an increased release and/or a reduced clearance of catecholamines at the neuroeffector junctions. Central sympathetic activity is inhibited by smoking, presumably via a baroreceptor stimulation triggered by the smoking-related pressor response. The baroreflex is impaired by smoking, however, indicating that partial inability to reflexly counteract the effect of sympathetic activation is also responsible for the pressor response.

Identification of the Uric Acid Thresholds Predicting an Increased Total and Cardiovascular Mortality Over 20 Years

Serum uric acid (SUA) levels discriminating across the different strata of cardiovascular risk is still unknown. By utilizing a large population-based database, we assessed the threshold of SUA that increases the risk of total mortality and cardiovascular mortality (CVM). The URRAH study (Uric Acid Right for Heart Health) is a multicentre retrospective, observational study, which collected data from several large population-based longitudinal studies in Italy and subjects recruited in the hypertension clinics of the Italian Society of Hypertension. Total mortality was defined as mortality for any cause, CVM as death due to fatal myocardial infarction, stroke, sudden cardiac death, or heart failure. A total of 22 714 subjects were included in the analysis. Multivariate Cox regression analyses identified an independent association between SUA and total mortality (hazard ratio, 1.53 [95% CI, 1.21-1.93]) or CVM (hazard ratio, 2.08 [95% CI, 1.146-2.97]; P<0.001). Cutoff values of SUA able to discriminate total mortality (4.7 mg/dL [95% CI, 4.3-5.1 mg/dL]) and CVM status (5.6 mg/dL [95% CI, 4.99-6.21 mg/dL]) were identified. The information on SUA levels provided a significant net reclassification improvement of 0.26 and of 0.27 over the Heart Score risk chart for total mortality and CVM, respectively (P<0.001). Sex-specific cutoff values for total mortality and CVM were also identified and validated. In conclusion, SUA levels increasing the risk of total mortality and CVM are significantly lower than those used for the definition of hyperuricemia in clinical practice. Our data provide evidence of a cardiovascular SUA threshold that might contribute in clinical practice to improve identification of patients at higher risk of CVM.

Metabolic syndrome in the Pressioni Arteriose Monitorate E Loro Associazioni (PAMELA) study: daily life blood pressure, cardiac damage, and prognosis

The prevalence of the metabolic syndrome (National Cholesterol Education Program Adult Treatment Panel III criteria) and its relationships with daily life blood pressures, cardiac damage, and prognosis were determined in 2013 subjects from a Northern Italian population aged 25 to 74 years. Home blood pressure, 24-hour blood pressure, and left ventricular mass index (echocardiography) were also measured. Cardiovascular and noncardiovascular deaths were registered over 148 months. Metabolic syndrome was found in 16.2% of the sample, an office blood pressure elevation being the most frequent (95.4%) and the blood glucose abnormality the least frequent (31.5%) component. There was in metabolic syndrome a frequent elevation in home and/or 24-hour average blood pressure, as well as a greater left ventricular mass index and prevalence of left ventricular hypertrophy, which was manifest even when data were adjusted for between-group differences, including blood pressure. The adjusted risk of cardiovascular and all-cause mortality was greater in metabolic syndrome subjects (+71.0% and +37.0%; P<0.05), a further marked increase being observed with left ventricular hypertrophy or "in-office" and "out-of-office" blood pressure elevations. The increased risk was related to the blood pressure and the blood glucose component of metabolic syndrome, with no contribution of the remaining components. Thus, metabolic syndrome is common in a Mediterranean population in which it significantly increases the long-term risk of death. Cardiac abnormalities and increases in home and 24-hour blood pressure are common in metabolic syndrome, and their occurrence further enhances the risk. The contribution of metabolic syndrome components to the risk, however, is unbalanced and mainly related to blood pressure and glucose abnormalities.

Prevalence, Characteristics, and Outcomes of COVID-19-Associated Acute Myocarditis

Background:

Acute myocarditis (AM) is thought to be a rare cardiovascular complication of COVID-19, although minimal data are available beyond case reports. We aim to report the prevalence, baseline characteristics, in-hospital management, and outcomes for patients with COVID-19–associated AM on the basis of a retrospective cohort from 23 hospitals in the United States and Europe.

Methods:

A total of 112 patients with suspected AM from 56 963 hospitalized patients with COVID-19 were evaluated between February 1, 2020, and April 30, 2021. Inclusion criteria were hospitalization for COVID-19 and a diagnosis of AM on the basis of endomyocardial biopsy or increased troponin level plus typical signs of AM on cardiac magnetic resonance imaging. We identified 97 patients with possible AM, and among them, 54 patients with definite/probable AM supported by endomyocardial biopsy in 17 (31.5%) patients or magnetic resonance imaging in 50 (92.6%). We analyzed patient characteristics, treatments, and outcomes among all COVID-19–associated AM.

Results:

AM prevalence among hospitalized patients with COVID-19 was 2.4 per 1000 hospitalizations considering definite/probable and 4.1 per 1000 considering also possible AM. The median age of definite/probable cases was 38 years, and 38.9% were female. On admission, chest pain and dyspnea were the most frequent symptoms (55.5% and 53.7%, respectively). Thirty-one cases (57.4%) occurred in the absence of COVID-19–associated pneumonia. Twenty-one (38.9%) had a fulminant presentation requiring inotropic support or temporary mechanical circulatory support. The composite of in-hospital mortality or temporary mechanical circulatory support occurred in 20.4%. At 120 days, estimated mortality was 6.6%, 15.1% in patients with associated pneumonia versus 0% in patients without pneumonia (P=0.044). During hospitalization, left ventricular ejection fraction, assessed by echocardiography, improved from a median of 40% on admission to 55% at discharge (n=47; P<0.0001) similarly in patients with or without pneumonia. Corticosteroids were frequently administered (55.5%).

Conclusions:

AM occurrence is estimated between 2.4 and 4.1 out of 1000 patients hospitalized for COVID-19. The majority of AM occurs in the absence of pneumonia and is often complicated by hemodynamic instability. AM is a rare complication in patients hospitalized for COVID-19, with an outcome that differs on the basis of the presence of concomitant pneumonia.

Heart rate-dependence of arterial distensibility in vivo

OBJECTIVES

Viscous and inertial components contribute to arterial distensibility and compliance in vitro. The purpose of our study was to determine whether this phenomenon is of relevance in vivo, namely, whether arterial compliance is altered by an increase in heart rate.

DESIGN

Arterial diameter was assessed by an echo-Doppler device in a common carotid and femoral artery, namely, in a large elastic and a muscle artery. The studies were performed in 12-week-old pentobarbitone-anaesthetized Wistar-Kyoto rats subjected to atrial pacing via a transjugular unipolar catheter at five different randomly sequenced rates (280, 310, 340, 370 and 400 beats/min). After each stage, spontaneous sinus rhythm was allowed to return. Blood pressure was measured via a catheter inserted into the carotid or femoral artery contralateral to the vessels in which the diameter was measured. Arterial compliance and distensibility values were derived according to the Langewouters formula.

RESULTS

A progressive increase in heart rate caused by pacing was accompanied by progressive and marked reductions in carotid artery compliance and distensibility. When quantified by the area under the distensibility-pressure or compliance-pressure curve the reduction was in the range 15-43%. Although a tendency to a similar phenomenon was observed in the femoral artery, in the latter vessel the reduction in distensibility and compliance was less marked and statistically insignificant.

CONCLUSIONS

In the anaesthetized rat acute increases in heart rate are accompanied by reductions in arterial compliance and distensibility. The effect is greater in elastic than in muscle arteries.

Regression of radial artery wall hypertrophy and improvement of carotid artery compliance after long-term antihypertensive treatment in elderly patients

OBJECTIVES

The present study was designed to assess whether a diuretic- or an angiotensin-converting enzyme inhibitor-based treatment can reduce arterial wall hypertrophy of a distal muscular medium-sized artery--the radial artery--and the stiffness of a proximal large elastic artery--the common carotid artery.

BACKGROUND

Large-artery wall thickness and stiffness are increased during sustained essential hypertension and contribute to the increased risk of complications. Whether antihypertensive treatment can normalize the wall hypertrophy of conducting arteries has not yet been determined.

METHODS

Seventy-seven elderly hypertensive patients were randomized to receive 9 months of double-blind treatment with perindopril (2 to 8 mg/day) or the diuretic combination of hydrochlorothiazide (12.5 to 50 mg/day) plus amiloride (1.25 to 5 mg/day) after a 1-month placebo washout period. If systolic blood pressure remained at >160 mm Hg after 5 months, chlorthalidone or atenolol was added, respectively. Arterial variables, including radial artery mass and common carotid artery compliance, were calculated from noninvasive measurements of internal diameter and wall thickness with the use of high resolution echo-tracking systems at baseline and after 5 and 9 months.

RESULTS

During treatment, blood pressure and arterial variables changed to the same extent in both groups. After a 9-month treatment, systolic, diastolic and pulse pressures and radial artery wall thickness, mass and thickness/radius ratio decreased significantly (p < 0.01), whereas carotid compliance increased (p < 0.001). The decrease in radial artery thickness/radius ratio after a 9-month treatment was significantly related to the reduction in pulse pressure (p < 0.01), whereas the improvement in carotid compliance was related to the reduction in mean arterial pressure (p < 0.01). In healthy subjects and untreated hypertensive patients, radial artery diameter, wall thickness and thickness/radius ratio and carotid artery compliance did not change significantly during a 9-month observation period.

CONCLUSIONS

These results indicate that in elderly hypertensive patients, both angiotensin-converting enzyme inhibitor- and diuretic combination-based treatments can reduce radial artery wall hypertrophy and improve carotid artery compliance.

Sympathetic tone restrains arterial distensibility of healthy and atherosclerotic subjects

BACKGROUND

Sympathetic activation induced by cold pressor test or cigarette smoking is accompanied by a marked reduction of radial artery distensibility. It is not known, however, whether arterial distensibility is under tonic sympathetic restraint, or whether this restraint involves arteries greater than the radial one in both normal and pathological conditions.

METHODS

We studied the distensibility of radial artery by continuous ultrasonographic assessment of the changes in arterial diameter over the diasto-systolic pressure range (finger pressure measurement) in eight patients with a Dupuytren disease before and 20 min after ipsilateral brachial plexus anaesthesia. We also studied ultrasonographic distensibility of femoral artery in seven subjects before and 20 min after ipsilateral subarachnoid anaesthesia, performed before arthroscopic surgery, and in five patients with claudicatio intermittens before and 1 month after ipsilateral removal of the lumbar sympathectomy chain. In all three conditions, the contralateral artery served as control.

RESULTS

The three interventions did not cause any significant alteration in blood pressure and heart rate. Radial artery distensibility was markedly increased by ipsilateral anaesthesia of the brachial plexus (+36%, P<0.01). This was the case also for femoral artery distensibility both following ipsilateral subarachnoid anaesthesia in healthy subjects (+47%, P<0.05) or ipsilateral sympathetic gangliectomy in patients with peripheral artery disease (+26%, P<0.05). In all three instances, the distensibility of the contralateral artery remained unaffected.

CONCLUSIONS

These data indicate that the sympathetic nervous system exerts a marked tonic restraint of arterial distensibility. This restraint involves medium-size and large muscular arteries and can also be seen in subjects with peripheral artery disease. This stiffening influence may increase the traumatic effect of intravascular pressure on the vessel wall and favour atherosclerosis.

Hyperuricemia and Risk of Cardiovascular Outcomes: The Experience of the URRAH (Uric Acid Right for Heart Health) Project

The latest European Guidelines of Arterial Hypertension have officially introduced uric acid evaluation among the cardiovascular risk factors that should be evaluated in order to stratify patient's risk. In fact, it has been extensively evaluated and demonstrated to be an independent predictor not only of all-cause and cardiovascular mortality, but also of myocardial infraction, stroke and heart failure. Despite the large number of studies on this topic, an important open question that still need to be answered is the identification of a cardiovascular uric acid cut-off value. The actual hyperuricemia cut-off (> 6 mg/dL in women and 7 mg/dL in men) is principally based on the saturation point of uric acid but previous evidence suggests that the negative impact of cardiovascular system could occur also at lower levels. In this context, the Working Group on uric acid and CV risk of the Italian Society of Hypertension has designed the Uric acid Right for heArt Health project. The primary objective of this project is to define the level of uricemia above which the independent risk of CV disease may increase in a significantly manner. In this review we will summarize the first results obtained and describe the further planned analysis.

Early impairment of large artery structure and function in type I diabetes mellitus

AIMS/HYPOTHESIS

Diabetes mellitus is associated with an increased incidence of atherosclerosis. How early functional and structural alterations of large arteries that may preceded atherosclerosis occur in the course of this disease has, however, never been conclusively documented.

METHODS

We evaluated arterial wall distensibility in the radial artery, common carotid artery and abdominal aorta in 133 patients (aged 35.4 +/- 0.9 years, means +/- SEM) with Type I (insulin-dependent) diabetes mellitus and no macrovascular complications. Arterial distensibility was derived from continuous measurements of arterial diameter through echotracking techniques and use of either the Langewouters (radial artery) or the Reneman (carotid artery and aorta) formula. The same echotracking techniques enabled us to obtain radial artery and carotid artery wall thickness. Data were compared with those from 70 age-matched normotensive control subjects.

RESULTS

In diabetic patients arterial distensibility was consistently less (p < 0.01) than in control subjects, the reduction averaging 26%, 14% and 25% for the radial artery, carotid artery and aorta, respectively. This was accompanied by an increase (p < 0.01) in both radial and carotid artery wall thickness. The changes were more pronounced in patients with microalbuminuria, retinopathy or neuropathy or both. They were evident also in those without microvascular complications. This was the case also when subjects in whom diabetes was associated with hypertension (n = 30) were excluded from data analysis. Carotid and aortic wall abnormalities showed a relation with the duration of disease and blood pressure whereas radial artery abnormalities showed a relation with glycated haemoglobin.

CONCLUSION/INTERPRETATION

Type I diabetes is characterised by diffuse arterial wall stiffening and thickening which progress with the severity of the disease but can clearly be seen also in the absence of any diabetic-related complication. This suggests that in diabetes stiffening and thickening are an early marker of vascular damage.

Effects of cigarette smoking on carotid and radial artery distensibility

OBJECTIVE

Cigarette smoking acutely induces a marked increase of blood pressure and heart rate. This is accompanied by a marked reduction of radial artery distensibility. Whether this reflects an alteration of arterial mechanics of large elastic arteries as well is not established, however.

DESIGN AND METHODS

In this study we addressed the acute effects of smoking on the stiffness of a peripheral medium-sized muscular artery and a large elastic vessel. We studied seven healthy normotensive smokers (age 28+/-7 years, mean+/-SEM), in the absence of smoking for at least 24 h. Radial artery (NIUS 02) and carotid artery diameter (WTS) were concomitantly acquired beat-to-beat in the 5 min before, during and after smoking of a cigarette containing 1.2 mg of nicotine. Blood pressure and heart rate were concomitantly recorded by a Finapres device. Radial and carotid artery distensibility were calculated according to the Langewouters and Reneman formulae, respectively. Data were collected for consecutive 30 s periods. Statistical comparisons were performed between the three different phases and, within each phase, between 30 s periods. In five subjects the protocol was repeated after 1 week using a stran rather than a cigarette to obtain data under sham smoking.

RESULTS

Smoking increased systolic blood pressure by 14%, diastolic blood pressure by 10% and heart rate by 27%. Radial artery diameter was reduced during smoking (-3.7%) and more so after smoking (-14.8%), while carotid artery diameter did not change significantly either during or after smoking. Radial artery distensibility was also significantly reduced only after smoking (-41.3%, P < 0.01), while carotid artery distensibility was significantly reduced both during (-33.3%) and after smoking (-27.2%) (P < 0.01 versus before). No changes in blood pressure, heart rate and arterial wall mechanics were induced by sham smoking.

CONCLUSIONS

Acute cigarette smoking reduces distensibility not only in medium-sized but also in large elastic arteries, therefore causing a systemic artery stiffening. The mechanisms of these effects remain to be determined. However, it is likely that adrenergic mechanisms are responsible for the arterial distensibility alterations.

Cardiopulmonary reflex before and after regression of left ventricular hypertrophy in essential hypertension

Studies that have examined the cardiopulmonary receptor control of circulation in hypertension have produced conflicting results. In 10 normotensive subjects and in age-matched essential hypertensive subjects without (n = 10) or with left ventricular hypertrophy (n = 12), as well as in seven subjects of the latter group restudied after 1 year of treatment that induced regression of cardiac hypertrophy, we examined the cardiopulmonary reflex by increasing central venous pressure and stimulating cardiopulmonary receptors through passive leg raising and by reducing central venous pressure and deactivating cardiopulmonary receptors through nonhypotensive lower body negative pressure. Reflex responses were measured as changes in forearm vascular resistance (mean blood pressure divided by plethysmographically measured blood flow), plasma norepinephrine concentration, and plasma renin activity. In hypertensive subjects without left ventricular hypertrophy, stimulation and deactivation of cardiopulmonary receptors caused changes in forearm vascular resistance, norepinephrine concentration, and plasma renin activity that were modestly reduced as compared with those in normotensive subjects. However, all these changes were markedly reduced in hypertensive subjects with left ventricular hypertrophy. Following regression of left ventricular hypertrophy, the changes in vascular resistance, plasma norepinephrine, and plasma renin activity induced by cardiopulmonary receptor manipulation all improved markedly. These results demonstrate that cardiopulmonary receptor regulation of peripheral vascular resistance and of neurohumoral variables is impaired in essential hypertension and that the impairment is much more pronounced when this condition is associated with cardiac structural alterations. Therapeutic regression of these alterations, however, leads to a marked improvement of this reflex, with consequent favorable effects on circulatory homeostasis.

Effect of sympathectomy on mechanical properties of common carotid and femoral arteries

Sympathetic stimulation is accompanied by a reduction of arterial distensibility, but whether and to what extent elastic and muscle-type arterial mechanics is under tonic sympathetic restraint is not known. We addressed this issue by measuring, in the anesthetized rat, the diameters of the common carotid and femoral arteries with an echo-Doppler device (NIUS 01). Blood pressure was measured by a catheter inserted contralaterally and symmetrically to the vessel where the diameter was measured. Arterial distensibility over the systolic-diastolic pressure range was calculated according to the Langewouters formula. Data were collected in 10 intact (vehicle pretreatment) and 9 sympathectomized (6-hydroxydopamine pretreatment) 3-month-old Wistar-Kyoto rats. Compared with the intact animals, sympathectomized rats showed a marked increase in arterial distensibility over the entire systolic-diastolic pressure range. When quantified by the area under the distensibility-pressure curve, the increase was 59% and 62% for the common carotid and femoral arteries, respectively (P<.01 for both). In the femoral but not in the common carotid artery, sympathectomy was accompanied also by an increase in arterial diameter (+18%, P<.05 versus intact). Therefore, in the anesthetized normotensive rat, sympathetic activity exerts a tonic restraint on large-artery distensibility. This restraint is pronounced in elastic vessels and even more pronounced in muscle-type vessels.

HIV and metabolic syndrome: a comparison with the general population

OBJECTIVE

To compare the prevalence of metabolic syndrome (MS) in HIV-positive patients with that from a sample of a general Italian population.

DESIGN

Cross-sectional study.

METHODS

A total of 1263 HIV-infected patients 18 years of age or older were recruited in 18 centers for infectious diseases in northern and central Italy. Controls were 2051 subjects aged 25 to 74 years representative of the residents of Monza, a town in Milan province, who were enrolled in the Pressioni Arteriose Monitorate E Loro Associazioni study.

RESULTS

The prevalence of MS in the HIV group was 20.8%, whereas in the control group, it was only 15.8%, with the difference being statistically significant. The age- and gender-adjusted risk of having MS in HIV-infected patients was twice as great as that in controls. Compared with controls, HIV-infected patients had a greater prevalence of the impaired fasting glucose, increased plasma triglycerides, and reduced high-density lipoprotein cholesterol components. MS prevalence was similar in treated and never-treated HIV-infected patients, and so were the various MS components.

CONCLUSIONS

The risk of MS is greater in HIV-infected patients compared with the general population because of a greater prevalence of lipid and glucose abnormalities. The prevalence of MS and its components is similar in treated and untreated HIV-positive patients.

Impact of Body Mass Index and Waist Circumference on the Long-Term Risk of Diabetes Mellitus, Hypertension, and Cardiac Organ Damage

Obesity is associated with a higher risk of developing diabetes mellitus (DM), hypertension (HT), and left ventricular hypertrophy (LVH). The present study assessed in the general population the impact of body weight and visceral obesity on the development of alterations in glucose metabolism and cardiac structure, as well as of elevation in blood pressure. In 1412 subjects randomly selected and representative of the general population of Monza, we assessed twice (in 1990/1991 and 2000/2001) body mass index (BMI); waist circumference; office, home, and 24-hour ambulatory (24-hour) blood pressure, fasting glycemia, and left ventricular mass (echocardiography). New-onset high-risk conditions were DM; impaired fasting glucose; office, home, and 24-hour HT; and LVH. The incidence of new-onset DM; impaired fasting glucose; office, home, and 24-hour HT; and LVH increased progressively from the quintile with the lowest to the quintile with the highest BMI values. Adjusting for confounders, the risk of developing new-onset DM; impaired fasting glucose; office, home, and 24-hour HT; and LVH increased significantly for an increase of 1 kg/m 2 of BMI and 1 cm of waist circumference (respectively, 8.4% [ P <0.01], 9.5% [ P <0.0001], 4.2% [ P <0.0001], 3.9% [ P <0.001], 2.5% [ P <0.05], and 5.1% [ P <0.001] for BMI and 3.2% [ P <0.001], 3.5% [ P <0.0001], 1.8% [ P <0.0001], 1.5% [ P <0.0001], 1.4% [ P <0.001], and 2.6% [ P <0.0001]). These data provide evidence that an increase in BMI and waist circumference is associated with a linearly increased adjusted risk of developing conditions with high cardiovascular risk, such as DM, impaired fasting glucose, in- and out-of-office HT, and LVH.

Home blood pressure monitoring: methodology, clinical relevance and practical application: a 2021 position paper by the Working Group on Blood Pressure Monitoring and Cardiovascular Variability of the European Society of Hypertension

The present paper provides an update of previous recommendations on Home Blood Pressure Monitoring from the European Society of Hypertension (ESH) Working Group on Blood Pressure Monitoring and Cardiovascular Variability sequentially published in years 2000, 2008 and 2010. This update has taken into account new evidence in this field, including a recent statement by the American Heart association, as well as technological developments, which have occurred over the past 20 years. The present document has been developed by the same ESH Working Group with inputs from an international team of experts, and has been endorsed by the ESH.

Relationship of Office, Home, and Ambulatory Blood Pressure to Blood Glucose and Lipid Variables in the PAMELA Population

Alterations in blood glucose and cholesterol are more frequently detectable in hypertensive than in normotensive conditions. However, no information exists as to whether this phenomenon involves only office or also home and 24-hour ambulatory blood pressure (ie, when values are representative of daily life). In 2045 subjects enrolled in the Pressioni Arteriose Monitorate E Loro Associazioni (PAMELA) study, we measured home, 24-hour, and office blood pressure. Measurements also included fasting blood glucose and serum total and HDL cholesterol values. Prevalence of diabetes (> or =126 mg/dL or use of antidiabetic drugs), impaired fasting blood glucose (> or =110 to <126 mg/dL), and hypercholesterolemia (serum total cholesterol > or =240 mg/dL or 200 mg/dL) increased progressively from "optimal" to "normal," "high-normal," and "elevated" office systolic or diastolic blood pressure. Fasting blood glucose and total serum cholesterol also increased progressively from the first to the fourth group, with HDL cholesterol values showing a concomitant progressive decrease. This was also the case for quartiles of office, home, and 24-hour blood pressure. In the whole population, there was a positive correlation between serum cholesterol or blood glucose and all blood pressure values (P always <0.0001), with a much smaller and less consistent relationship with heart rate. In a multivariate analysis that included gender, body mass index, age, and antihypertensive treatment, all blood pressure values remained highly significantly related to values of either metabolic variables. Thus, in the PAMELA population, glucose and lipid values are independently related to blood pressure. This is also the case when daily life blood pressure values are considered.

Early alterations of the baroreceptor control of heart rate in patients with acute myocardial infarction

Experimental coronary occlusion is accompanied by an acute impairment of the baroreceptor-heart rate reflex. This study was planned to determine whether this impairment also occurs in humans. In 30 patients admitted to a coronary care unit for an anterior (n = 14) or inferior (n = 16) transmural myocardial infarction (MI), we measured 1) the increase in RR interval induced by stimulating carotid baroreceptors through progressive reductions in neck chamber pressure, 2) the increase in RR interval induced by stimulating arterial baroreceptors through intravenous boluses of phenylephrine, and 3) the reduction in RR interval induced by deactivating arterial baroreceptors through intravenous boluses of nitroglycerin. Measurements were performed 49.5 +/- 2.4 hours (mean +/- SEM) after the MI. The results were compared with those of five age-matched patients admitted to the coronary care unit for chest pain and found free from ischemic heart disease. The sensitivity of the carotid baroreceptor-heart rate reflex (slope of the linear regression of RR interval over neck pressure changes) was markedly less in MI than in control patients (3.8 +/- 0.5 vs. 5.9 +/- 0.6 msec/mm Hg, p less than 0.05), the reduction being similar in patients with anterior and inferior MI. This was the case also for the baroreflex sensitivity measured by the phenylephrine and the nitroglycerin methods (slope of the linear regression of RR interval over systolic blood pressure changes). However, 10.2 +/- 0.3 days later, the baroreflex sensitivity measured by all three methods increased significantly (p less than 0.05 or 0.01) and became similar to that of control subjects, which showed no significant change from the early to the late period after admission into the coronary care unit. Thus, MI is accompanied by an acute marked impairment of the baroreceptor control of the heart in humans, and this is the case both for an anterior and an inferior MI. The impairment is largely transient in nature, however, and a clear-cut recovery of the baroreflex can be seen a few days later.

Sympathetic modulation of radial artery compliance in congestive heart failure

Animal studies have suggested that arterial compliance can be modulated by adrenergic influences. Whether this adrenergic modulation also occurs in humans is still a matter of debate. In the present article we address this issue by examining the relationships between sympathetic tone and arterial compliance in a variety of physiological and pathophysiological conditions. We have found that cigarette smoking, ie, an action that produces a marked sympathetic activation, causes a significant reduction in radial artery compliance, as measured by an echotracking device capable of providing continuous beat-to-beat evaluation of this hemodynamic variable. When expressed as compliance index, ie, as the ratio between the area under the compliance-pressure curve and pulse pressure, the reduction amounted to 35.7 +/- 4.8% (mean +/- SEM) and was independent of the smoking-related blood pressure increase. Furthermore, pharmacological stimulation of adrenergic receptors located in the arterial wall was also shown to affect arterial compliance because the radial artery compliance index was markedly reduced (- 29.5 +/- 3.9%) during phenylephrine infusion in the brachial artery at doses devoid of any systemic blood pressure effect. Evidence was also obtained that the relationship between sympathetic activation and arterial compliance has pathophysiological relevance, because in 17 patients with congestive heart failure (New York Heart Association classes II through IV) there was a significant inverse correlation (r = .62, P < .01) between muscle sympathetic nerve activity (directly measured by microneurography in the peroneal nerve) and radial artery compliance.(ABSTRACT TRUNCATED AT 250 WORDS)