Vasorelaxant actions of enoximone, dobutamine, and the combination on human arterial coronary bypass grafts.

Enoximone (a type III-selective phosphodiesterase inhibitor) and dobutamine (a beta-receptor agonist) are positive inotropic drugs frequently used in the postoperative management of coronary bypass surgery. The purpose of this study was to characterize their relaxant effects on the human internal mammary artery (IMA) and the gastroepiploic artery (GEA) and to test the hypothesis that their combination may have greater than additive relaxant effects. In organ baths, the relaxant effects of enoximone and dobutamine were tested on rings of IMA (n = 86) precontracted with U46619 (a thromboxane A2 mimetic), norepinephrine (NE), or KCl. The relaxant effects of dobutamine and enoximone also were tested on rings of GEA (n = 42) precontracted with U46619 and NE. The effect of the combination of enoximone and dobutamine were tested on rings of IMA (n = 24) precontracted with U46619 or NE. With respect to maximal relaxations induced by papaverine (10(-4) M), enoximone (< or =10(-3) M) caused full relaxations of IMA precontracted with NE, U46619, or KCI. Dobutamine (< or =10(-3) M) caused full relaxations of IMA precontracted with NE or KCI but only 46% (95% CI, 27-65) relaxation in the rings precontracted with U46619. Similar patterns of relaxation were observed in GEA rings, with dobutamine inducing partial relaxation in GEA precontracted with U46619. The pD2 values of enoximone and dobutamine were both significantly lower in segments precontracted with U46619. The in vitro threshold relaxant concentrations were in the upper limits or over the range of therapeutic plasma concentrations. The relaxant effect of the combination was significantly more important than the theoretic additive effect in IMA contracted with U46619 or NE. Enoximone and dobutamine are potent in vitro vasodilators but exert weak relaxant effects in IMA and GEA at concentrations in the therapeutic range. There is, however, a greater than additive vasorelaxant effect of the combination, suggesting that the vasorelaxant effect of the combination, in addition to the additive inotropic effect, may be beneficial to patients undergoing coronary bypass grafting.     

Data on the echocardiogram, pressure profile during exertion, and ambulatory blood pressure measurements in borderline arterial hypertension

Comparative study is performed between echocardiographic measurements (TM), exercise test blood pressure profile (ETP) and ambulatory blood pressure load (BPL) in 26 borderline hypertensive subjects (19 males, 7 females). An abnormal ETP is found for 15 subjects (57 p. 100), an abnormal BPL for 10 subjects (38 p. 100). The diastolic interventricular septum thickness (IVS) and the diastolic posterior wall thickness (PWT) are abnormal (greater than 11 mm) for 6 and 3 subjects. Patient with pathologic ETP or/and BPL have greater IVS and PWT than other subjects (p less than 0,001). A good correlation is found between individual activity systolic blood pressure or 24 hours systolic blood pressure means values and PWT, IVS or left ventricular mass. These 3 examinations lead to a better assessment of cardiovascular strain and allow a better diagnosis and therapeutic approach in borderline hypertensive patients.     

Course in time of the blood pressure profile in effort

Blood-pressure (BP) responses to exercise are worth studying to evaluate the cardiovascular adjustment ability of hypertensive subjects whose daily activities include important physical performances. Some authors also consider that they have a predictive value. Changes in exercise BP over a period of more than 3 years (mean: 5.2 +/- 2.26 years) were studied in 225 subjects, some of whom had normal BP while others had untreated borderline or moderate hypertension. Globally, the mean values of diastolic pressure, heart rate, exacerbated response and BP profile remained remarkably stable with time despite significant differences in some groups of subjects. When each subject was considered separately, a normal BP response to exercise had a very high predictive value, since systolic and diastolic pressure which were normal at the first examination remained normal at the second examination in 85 p. 100 and 93 p. 100 respectively of the subjects. The reproducibility with time of response to exercise is an additional incentive to perform this type of examination.     

European Society of Hypertension scientific newsletter: hypertension and aortic diseases

Hypertension, one of the major cardiovascular risk factors, promotes the formation of atheromatous lesions in the large arteries, including the aorta. It also favors aortic aneurysm and acute aortic syndrome such as aortic dissection or hematoma. In patients with aortic disease, beta-blockers and/or renin-angiotensin-aldosterone system inhibitors should be preferentially used to decrease blood pressure and improve arterial wall properties.     

Different relation between 24-h blood pressure and distensibility at different peripheral arteries. Data from the European Lacidipine Study on Atherosclerosis (ELSA)

INTRODUCTION: The European Lacidipine Study on Atherosclerosis (ELSA) has been planned to investigate the effect of reduction in office and ambulatory blood pressure by lacidipine versus atenolol on carotid artery wall thickness in mild to moderate essential hypertensive patients with no metabolic abnormalities. One prespecified sub-study of ELSA focused on measurements of arterial distensibility in the carotid as well as in the radial artery to determine the relationship of functional arterial properties with office versus ambulatory blood pressure (BP) values as well as the correspondence between functional and structural arterial alterations. METHODS: The sub-study was conducted on 124 patients recruited in four centres (Monza-Milan, Paris, Grenoble and Glasgow). BP was measured both by a mercury sphygmomanometer and by 24-h ambulatory monitoring. Common carotid artery wall thickness was measured by certified sonographers as described in the main study. Common carotid and radial artery distensibility were obtained by echotracking techniques, which allowed to relate changes in arterial diameter with systo-diastolic BP changes. RESULTS: Carotid artery wall distensibility showed (1) a negative correlation with office and more so 24-h average systolic BP (r = -0.45 and -0.58, P < 0.008 and 0.001) but not with office or 24-h diastolic BP) and (2) a negative correlation with the corresponding wall thickness (r = -0.47, P < 0.005). In contrast, at the radial artery level distensibility and thickness showed no correlation with each other and with BP. Carotid (but not radial) artery distensibility also correlated with ambulatory systolic BP variability but the correlation was lost after adjustment for age and mean BP values. CONCLUSION: These data suggest that stiffening of large elastic artery is reflected more by ambulatory than office BP elevations, systolic BP being much more important than diastolic. Alterations of large elastic arteries function is related to structural wall changes. Functional and structural properties of middle-size muscle arteries are independent of BP.     

Isolated systolic hypertension: data on a cohort of young subjects from a French working population (IHPAF)

Elderly patients with isolated systolic hypertension (ISH)--systolic blood pressure (SBP) > or =140 mmHg and diastolic blood pressure (DBP) <90 mmHg--have increased mortality and morbidity. The aim was to study the incidence of ISH in a younger population of between 15 and 60 years of age, and to measure pulse pressure (PP), mean arterial pressure (MAP) and heart rate (HR) in these subjects. The study population consisted of 27 783 subjects, aged 15-60 years, untreated for hypertension (HT) from a cohort of employees formed to study the incidence of HT in the French working population (AIHFP). BP and HR were measured with a validated, automatic device after 5, 6 and 7 min at rest. The prevalence of ISH was 6.9% in men, 2.3% in women. This prevalence was over 5% in young men and increased at 40-44 years; it was negligible in young women, but increased at 50-54 years to about 10% (ie to the same level as in men of the same age): PP in subjects with ISH (46.9 mmHg) was significantly higher than in the normotensive group (NT-40.9 mmHg); it was comparable in both young men (65.5 mmHg) and older men (66 mmHg); it was higher in men (63.1 mmHg) than in women (61.5 mmHg). HR was higher in ISH than in NT and it was higher in women ( approximately 5 bpm) in whom it decreased with age. The prevalence of ISH is not negligible in HT (30% men, 25% women), with a high prevalence in young subjects and elevated PP, MAP and HR values. These data should be taken into account as elevated ISH, PP and HR are considered as cardio-vascular risk factors.     

Use of home blood pressure devices in France in 2004

OBJECTIVE: To estimate the number of devices for home blood pressure measurements in the French population in 2004 and to evaluate the use of these apparatus. METHODS: The French League Against Hypertension Survey 2004 (FLAHS-2004) was performed cross-sectionally on 3707 subjects, part of a sample of 5476 subjects selected as being representative of the French metropolitan population for age (35 years and above), gender, socioeconomic status, and place of living. Subjects who declare to take an antihypertensive medication were classified as treated hypertensive patients. A questionnaire evaluating the condition of use of HBP device was given. RESULTS: In 2004, 24% of the French population above the age of 35 years was treated for hypertension, corresponding to an estimate of 7.5 million of subjects. 25% of treated hypertensives and 12% of untreated subjects had a tensiometer. A total of 4 millions of BP devices are owned in the general population with 43% by treated hypertensive patients. 67% of BP devices are wrist cuff. Medical doctors recommended home blood pressure monitoring in only 12% of subjects. CONCLUSION: In 2004, the number of subjects treated for hypertension is 1/4 of the general population over the age of 35 years in France. In this group of subjects, 1/4 possessed a tensiometer but in only 10% medical doctor recommended the use of home blood pressure monitoring.     

Night-time and diastolic hypertension are common and underestimated conditions in newly diagnosed apnoeic patients

BACKGROUND: In newly diagnosed apnoeic patients without a history of hypertension, clinical hypertension is underdiagnosed in at least 40% of the cases. An increase in diastolic blood pressure is the most frequent pattern encountered. OBJECTIVE: To assess clinic and 24-h blood pressure, baroreflex sensitivity and left ventricular mass for identifying the prevalence, the type and the consequences of hypertension in newly diagnosed apnoeic patients. PATIENTS AND METHODS: Fifty-nine unselected patients (age = 48 +/- 12 years, body mass index = 28.1 +/- 4.5 kg/m2) referred to a university hospital sleep laboratory for symptoms suggesting obstructive sleep apnoea were included. Diagnosis of apnoea was accepted when respiratory disturbance index was > or = 15/h of sleep. Blood pressure was considered as normal by their general practitioner and all of them were free of any medication for hypertension. Echocardiography, 24-hour ambulatory blood pressure monitoring and assessment of the baroreflex sensitivity were performed. RESULTS: Forty-two percent of the apnoeic patients demonstrated a clinical hypertension, 34 subjects (58%) had a daytime hypertension, and 45 patients (76%) had a night-time hypertension, using 24-h monitoring. All the daytime hypertensives also had night-time hypertension. Forty-seven of the 59 patients (80%) were hypertensive either in the clinic or using 24-h recording. Diastolic and systolo-diastolic hypertension were the prominent types of hypertension observed both by clinic or ambulatory measurements. Respiratory disturbance index was significantly higher in apnoeic patients suffering isolated diastolic hypertension than in the normotensives (50.9 +/- 26.5/h versus 36.0 +/- 12.3/h, respectively; P = 0.02). The prevalence rate of left ventricular hypertrophy was high (between 15 and 20%) and occurred independently of associated hypertension. Baroreflex sensitivity was altered whatever the type of hypertension and decreased with the severity of obstructive sleep apnoea. CONCLUSION: Hypertension is hugely underdiagnosed in apnoeic patients unknown to be hypertensive. Use of 24-h blood pressure monitoring allowed the diagnosis of twice as much hypertension than did clinical measurement. Even at the beginning of their history of hypertension, apnoeic patients exhibited chronic adaptations of their cardiovascular system, as shown by early changes in baroreflex sensitivity and an increased prevalence of left ventricular hypertrophy.