[Long-term clinical tolerance of antihypertensive treatment during the HOT study. Groupe français de l'etude HOT]

The objective of the HOT study, an international, prospective, randomised study is to determine the optimal level of the blood pressure under treatment, in linked with the lowest cardiovascular mortality and morbidity. The target diastolic blood pressure of 80, 85 and 90 mmHg was determined at the randomisation. In order to reach the target blood pressure, a strategy of treatment was determined: the 1st step was felodipine (a long acting dihydropyridine) and the next steps (if the blood pressure reduction is not enough) propose the addition of different therapeutic classes and/or the increase of each drug doses. The available data after 2 years of the patients follow-up allow us to evaluate the incidence of the reported side effects according to the target blood pressure assigned by randomisation and the number of hypertension drugs used to reach these targets. The percentage of patients with at least one side effect at 12 and 24 months of follow-up are respectively: for the target group DBP < or = 90 mmHg: 9.2% versus 6%; for the target group DBP < or = 85 mmHg: 8% versus 4.4%; for the target group DBP < or = 80 mmHg: 7.9% versus 4.9%. The overall tolerability is not influenced by the target diastolic blood pressure but depends on the number of hypertension drugs used. At 24 months, 2.8% of patients are under monotherapy; 7% under bitherapy and 9.8% under tritherapy. The incidence of the side effects decreases after the 1st year, but slower than between the third months and the first year. There is an influence of the region on the incidence of the side effects, the south European countries describing more side effects than France or the north European countries. This seems to be linked with a perception of the side effects more than with a higher rate. In conclusion, these results confirm the possibility to reach a targeted blood pressure using a predetermined strategy without increasing dramatically the incidence of the side effects.

[HOT study: quality of the blood pressure control after 2 years follow-up. Pour le Groupe français de l'étude HOT]

The objective of the HOT study, an international, prospective, randomised study was to determine the optimal level of the blood pressure under treatment, linked with the lowest cardiovascular mortality and morbidity. The target diastolic blood pressure of 80, 85 and 90 mmHg was determined at the randomisation. In order to reach the target blood pressure, a strategy of treatment was predefined: the 1st step was felodipine (a long acting dihydropyridine) and the next steps (if the blood pressure reduction was not enough) proposed the addition of different therapeutic classes and/or the increase of the doses of each drug. The blood pressure measurements were made, using the oscillometric method (automatic blood pressure measuring device, Hestia). The quality of the blood pressure control observed in the HOT study was verified after 6 months of follow-up ("Quality of the blood pressure control in the clinical practice and in the HOT study", for the French research group of the HOT study. French hypertension meeting, Paris, December 1994). The aim of this second evaluation was to see if the quality of this control was still effective in France and for all countries after 2 years of follow-up. At the inclusion, the mean diastolic blood pressure was 106 +/- 4 mmHg in France (n = 1.574) and 105 +/- 4 mmHg for all countries (n = 18.790). The results at 24 months were the following, according to the target groups: 79.9 for the < or = 80 mmHg target group; 82.1 for the < or = 85 mmHg target and 83.6 for the < or = 90 mmHg target group. The percentages of patients who reached the target blood pressure were respectively 74; 80; 89% for the 3 target groups. The number of antihypertensive treatments needed to reach this blood pressure control slightly increased in the 3 target groups between the first and the second year with a lower rate of monotherapy and a higher rate of bi and tritherapy. But in the 80 mmHg target group (the most strict), the monotherapy was used in more than half of the patients. In comparison with all countries, France had lower number of bi and tritherapies (i.e. in the 85 mmHg target group: 38.4% of bitherapy in France versus 45.6% in all countries).

CONCLUSION

after 2 years of follow-up, the quality of the blood pressure control is still good. There is a trend toward a slight increase in the number of antihypertensive drugs after the first year in the 3 target groups.

[Value of a predictive model of ambulatory blood pressure integrating physical activity]

OBJECTIVE

To determine how much of the variations of blood pressure during a 24 hour period could be accounted for by a change in activity and establish a predictive model.

MATERIALS AND METHODS

Twenty three healthy subjects (mean age 25 +/- 2 years) were studied. The BP, heart rate (HR), and time of measure (T) were recorded by ambulatory BP monitoring using Spacelabs (4 measures per hour). At each measure the subject noted in a diary the degree of activity on a six level semi-quantitative scale.

DATA ANALYSIS

A model was constructed using an analysis of covariance. Different parameters were added in succession to reach a model of the type P: P0 + A + beta + (HR-HR0) + H, were P = predicted systolic pressure, P0 = mean systolic BP over the 24 hours. A variation in systolic BP for activity level, beta = the slope of the regression between systolic BP and HR during activity A, and HR0 the mean HR during this activity.

RESULTS

1) In order to test the model, the values measured in one subject were compared to the predicted values from the model in 22 others. The procedure was then repeated for the other subjects. This common model predicted 41 +/- 21% of fluctuations in BP of the subject analysed with a range of 0 to 66%. 2) In order to refine the individual model two subjects were explored 7 times over 24 h of non consecutive days. The measures of the last recording were compared to the predicted values from the application of the model to the six preceding recordings. The model then predicted 81% and 66% of the BP values of the test day. The mean of the 24 hour individual difference over a one hour period between the measures and its predicted value by the model was 0.13 +/- 4.8 mmHg, and -0.75 +/- 7.7 mmHg.

CONCLUSION

This study expresses in a quantitative fashion the importance of the level of activity in the evaluation of the level of ambulatory BP. The introduction of this method of quantification and analysis seems logical in therapeutic trial. The difference in the predictions by the model for some subjects poses the problem of uniform coding of activities and that of the recognition of other events such as stress and dreaming in sleep.

Assessment of antihypertensive effect by blood pressure monitoring: applications to bisoprolol and lisinopril in a double-blind study

The aim of this study was to evaluate the antihypertensive effect of drugs according to the initial ambulatory blood pressure (BP) level. After a 15-day placebo run-in period, 105 patients with moderate essential hypertension (mean age, 52 years) underwent 24-h BP monitoring (spacelabs: 1 measure/15 min). Patients were subdivided into two groups: the "High" group, with 24-h mean values of systolic BP (SBP) > 137 or diastolic BP (DBP) > 87 mm Hg, and the "Low" group, with SBP < or = 137 and DBP < or = 87 mm Hg. All patients received, in a random and double-blind design, either bisoprolol (10 mg q.d.) or lisinopril (20 mg q.d.) for 8 weeks. At the end of this active treatment period, office and ambulatory BP measurements were performed. Casual measurements revealed similar BP decreases in all subgroups receiving bisoprolol and lisinopril; BP monitoring showed that the antihypertensive effect depended on the baseline mean 24-h value; -15/-12 mm Hg for bisoprolol and -18/-13 mm Hg for lisinopril in the High group; -7/-6 mm Hg for bisoprolol and -6/-6 mm Hg for lisinopril in the Low group. This study shows that the antihypertensive effect depended on initial ambulatory BP values, with a lower BP decrease in the Low group. Assessment of the antihypertensive effect on ambulatory BP is useful in clinical trials.

[Treatment of hypertension with indapamide 1.5 mg sustained-release form: synthesis of results]

In accordance with international recommendations on the need to decrease doses of antihypertensive drugs, a low-dose (1.5 mg) sustained-release form of indapamide was developed so as to optimize the safety/efficacy ratio, while maintaining a once-daily administration. The new formulation ensures that the active ingredient release occurs in a sustained manner over 24 hours, with mean concentrations close to the maximal concentration over a prolonged period, while avoiding peak plasma concentrations. Clinical data were obtained mainly through two European multicenter, randomized, double-blind trials, totalling 690 patients. Firstly, the antihypertensive efficacy' of the new indapamide 1.5 mg form was demonstrated by measuring blood pressure 24 hours after the last drug intake, using a mercury sphygmomanometer; the equivalence of its antihypertensive efficacy with the immediate-release form of indapamide 2.5 mg was then verified. Biochemical safety data showed better acceptability with indapamide 1.5 mg with in particular a reduction of more than 50% of the number of patients with kalemia < 3.4 mmol/l; clinical safety data confirmed the good acceptability observed with the 2.5 mg immediate-release form of indapamide since many years, especially regarding glucose and lipid neutrality. In conclusion, the 1.5 mg sustained-release form of indapamide has an improved antihypertensive efficacy/safety ratio which is in accordance with international recommendations for the usage of low doses of antihypertensive drugs and diuretics in the first-line treatment of hypertension.

[Evaluation of trough/peak ratio of indapamide 1.5 mg sustained-release form assessed by ambulatory blood pressure monitoring]

Because of the high variability of casual blood pressure measurements. ABPM has become a complementary clinical tool for evaluating antihypertensive treatment. Nevertheless, there is still a lack of practical guidelines to interpret the data. A review of the literature shows that ABPM efficacy data are analyzed differently, especially the trough-to-peak ratio proposed by the Food and Drug Administration. Published trough-to-peak ratios are widely disparate due to the diversity of the calculation methods which are most often not justified. Thus inappropriate comparisons of these results can easily produce incorrect conclusions. The aim of this review is to select, through the literature, basic methodological requirements commonly agreed on for accurate assessment of trough-to-peak ratio, and to apply them to the ABPM data on indapamide, a diuretic related to the thiazides. Six methodological requirements commonly agreed on at this time are the following: 1. study design: placebo-controlled study with a placebo run-in period; 2. patients selection: compliance with the study protocol, record obtained before and after treatment for each patient; 3. population analysis: whole and responder population: 4. quality control of the records: 5. placebo effect subtraction; 6. global and individual calculation with the indication of median values. Given that, no T/P ratio, especially for a diuretic, has yet been calculated according to these requirements, the above methodological points were taken into account for the T/P calculation of indapamide, from a placebo-controlled dose-finding study involving 285 patients.

[Heart rate and blood pressure variabilities in mild to moderate hypertensive patients with or without left ventricular hypertrophy]

AIM OF THE STUDY

To compare heart rate (HR) and blood pressure (BP) variability in hypertensives with or without left ventricular hypertrophy (LVH).

METHODS

Thirty-three mild to moderate hypertensive patients, mean age 45 +/- 15 years, underwent an echocardiogram, a 24 hr ambulatory BP monitoring (ABPM), a 24 hr ECG monitoring and a continuous BP recording over 15 minutes both in supine and standing positions, by using digital plethysmography (Finapres device).

STATISTICAL ANALYSIS

non parametric tests.

RESULTS

[table: see text]

CONCLUSION

LVH is associated with a reduction in the markers of sympathetic activity and a decreased baroreflex sensitivity.

[Short and long-term clinical tolerance of hypertensive treatment during the HOT study (Hypertension Optimal Treatment)]

International, prospective, randomized HOT study aims to determine the optimal BP level under treatment in order to reduce at the most the cardiovascular morbidity/mortality. Defined by randomization, the level to obtain is DBP < or = 80, 85, 90 mmHg. The treatment is started by felodipine 5 mg/day then, if necessary, a bitherapy is prescribed and then, if necessary, a tritherapy. 19,193 patients have been included (BP at randomization 170 +/- 15/105 +/- 4 mmHg). After 1 year treatment, it is possible to search for the influence on the clinical tolerance of sex, age, BP goal, geographic area, time and treatment. The percentage of patients with side effects by BP goals and by treatment type are, during the time and in different geographic areas, the following (NE/Northern Europe = Norway, Switzerland, Belgium, Hungary, Sweden, Denmark, Finland, The Netherlands, UK, Germany, Austria; SE/Southern Europe = Italy, Spain, Greece): [table: see text] The target BP and age don't nearly influence the clinical tolerance. The side effects reported by the physicians are more numerous at the treatment start than at longeur terme. That is due to the therapeutic modifications of the physicians or to a better acceptation of the drugs by the patients or to a real disappearance of the side effects. Reported side effects are more frequent in Southern Europe, France than Northern Europe and more frequent among women that men. The incidence of side effects is proportional to the number of prescribed drugs. Time and the number of antihypertensive drugs appear as the most important factors.

[Diagnostic value of renal scintigraphy with MAG 3 and DTPA in the diagnosis of renal artery stenosis]

Angiography still remains the first line investigation to demonstrate a renal artery stenosis. We have evaluated the sensitivity and the specificity of renal scintigraphy in the diagnosis of renal artery stenosis using two technetium markers, MAG 3 and DTPA.

PATIENTS

45 hypertensive (HT) patients (WHO criteria) referred for investigation of renovascular hypertension according to the criteria of the AHA Scientific Council and were found to have a unilateral renal artery stenosis of varying severity. Age was 61 > +/- 13 years; sex-ratio F/M 21/24; creatinine < 150 mumol/l. There were non insulin dependent diabetics, and none had been treated with ACE inhibitors or diuretics for 15 days. Bilateral arterial stenosis was excluded a posteriori.

METHODS

MAG3 and DTPA scintigraphy were performed one hour after a dose of 25 mg of captopril plus hydration with 500 ml of intravenous saline. Blood pressure was measured by dynamap every 15 min from minus one hour to the end of the study. The principle outcome measure was nephorgram phase and the secondary measure was the angiographic phase (two images per second). The two scintigraphy techniques were performed at a mean interval of 2.9 +/- 2.1 days. Digitized angiography via the arterial route was performed using left anterior oblique and right anterior oblique images.

RESULTS

[table: see text]

CONCLUSION

There was only one false positive scintigraphy result with a polar artery. In contrast 45% of unilateral stenoses were not diagnosed by scintigraphy. Both markers gave similar results even if subjectively the MAG3 images were of better quality. Analysis of the angiographic phase and of the size of the kidneys did not improve the diagnostic accuracy and could lead to false positive results.

[Short term blood pressure variability and baroreflex sensitivity in mild and moderate hypertensive patients "dipper and non dipper"]

AIM OF THE STUDY

To compare heart rate (HR) and blood pressure (BP) variability in hypertensive patients with or without a fall in BP during the night.

METHODS

33 mild to moderato hypertensive patients, mean age 45 +/- 15 years, underwent an echocardiogram, a 24-hr ambultory BP monitoring (ABPM), and a 24-hr ECG monitoring. In addition, a continuous BP recording over 15 minutes was performed between 9 and 11 a.m. both in supine and standing positions, by using digital plethysmography (Finapres device).

STATISTICAL ANALYSIS

non parametric tests.

RESULTS

[table: see text]

CONCLUSION

In non dippers, morning BP and HR low-frequency oscillations are shifted to a lower level, as compared to dippers. This characteristic is associated with a reversed circadian pattern of sympathetic activity.

Benefits of electronic pillboxes in evaluating treatment compliance of patients with mild to moderate hypertension

OBJECTIVE

This study was designed to assess the compliance of hypertensive patients with a once-daily regimen of the angiotensin converting enzyme (ACE) inhibitor trandolapril and to evaluate the antihypertensive efficacy of the drug in relation to the time interval between taking the final dose and measuring the blood pressure (BP).

DESIGN

After a 2-week wash-out period, hypertensive patients, recruited by cardiologists, received trandolapril 2 mg once daily in the morning for 4 weeks.

METHODS

In order to assess compliance, each patient's supply of trandolapril capsules was presented in a pillbox that incorporated in its lid a microprocessor that recorded the date and time of each occasion that it was opened. BP was measured using validated semi-automatic devices, at the end of both the wash-out and the treatment period.

RESULTS

A total of 590 patients entered the study. Compliance data were evaluable for 501 patients. Overall compliance, defined as the ratio of the number of openings recorded to the number of doses prescribed was less than 80, 80-100, and more than 100% in 17, 63 and 20% of patients, respectively. The average number (+/- SD) of missed doses was 4.5 +/- 8 (median 2). The average interval between successive openings was 25 h 07 min mean +/- 13 h (median 24 h). The average number of delayed doses (a delayed dose being defined as the box being opened 25-36 h after the previous occasion) was 5.6 +/- 3 (median 6). Patients living in the Paris area had more forgotten and delayed doses than those living in the provinces (7.9 versus 3.8 forgotten; P<0.0001 and 6.3 versus 5.5 delayed; P<0.005). Doses were forgotten and delayed more often during weekends than on weekdays. The greatest number of delayed doses occurred in those patients under 60 years of age (6.0 versus 5.2; P<0.01). Decreases in systolic blood pressure (SBP and diastolic blood pressure (DBP) were 20.3/12.8 mmHg, for patients whose final drug was taken on the same day as the BP measurement, and 18.9/11.2 mmHg for patients whose final dose was taken on the previous day.

CONCLUSIONS

Electronic compliance monitoring allows refined analysis of the behaviour of hypertensive patients. In this study doses were missed and delayed frequently during the first month of treatment, depending on the patient's lifestyle.

Urinary hexane diamine as an indicator of occupational exposure to hexamethylene diisocyanate

The occupational exposure of 19 men to hexamethylene diisocyanate (HDI) vapour was monitored during one 8-h shift. It ranged from 0.30 to 97.7 micrograms/m3. This was compared with the urinary output of hexane diamine (HDA) liberated by acid hydrolysis from its conjugates in post-shift samples. The excretion varied from 1.36 to 27.7 micrograms g creatinine, and there was a linear association of HDI air concentration with urinary HDA excretion. The validity of the urinary analysis was confirmed by simultaneous blind analysis in another laboratory. The results had an excellent linear concordance. Thus, it seems that while the gas chromatographic-mass spectrometric detection method requires sophisticated apparatus, the results are very useful to occupational health practices. A biological exposure index limit of 19 micrograms HDA/g creatinine in a post-shift urine specimen is proposed as an occupational limit level of HDI monomer (time-weighted average = 75 micrograms/m3). Most importantly, biological monitoring of HDA is sensitive enough to be used at and below the current allowable exposure limit levels.

Drug-induced changes in ambulatory blood pressure and pulse pressure in patients with or without sustained hypertension

We retrospectively studied 216 mild to moderate hypertensive patients receiving either an angiotensin converting enzyme inhibitor (ACEI) or a calcium antagonist (CA), as a once-a-day monotherapy; their blood pressure had been measured using both a sphygmomanometer and an ambulatory blood pressure recorder. Numerous discrepancies were found between the two methods of blood pressure measurement with respect to systolic blood pressure (SBP) and diastolic blood pressure (DBP), as well as pulse pressure (PP). Clinic blood pressure measurement did not show any significant differences between the effects of ACEI and those of CA, whereas ambulatory blood pressure measurements (ABPM) showed that in patients with normal ambulatory blood pressure (so-called 'white coat' hypertensive patients), ACEI only (but not CA) significantly lowered SBP, DBP and PP. Accordingly, a threshold of efficacy was sought: it appeared to be lower for ACEI than for CA (120/80 vs 140/85 mmHg). Furthermore, for a given degree of DBP lowering, SBP and PP were more lowered by ACEI than by CA, indicating a greater effect of ACEI on arterial compliance. Likewise, for a given level of mean blood pressure, SBP and PP were lower and DBP slightly higher in patients on ACEI than in those on CA. Our data are consistent with some recent papers, emphasizing a heightened activity of the renin-angiotensin system in 'white coat' hypertensive patients.

[Ambulatory measurement of blood pressure]

The advent of new techniques has greatly contributed to the development of ambulatory measurement as a noninvasive method for evaluating blood pressure. The technique implies use of a validated and reliable standardized apparatus. The operator must strictly comply with operating procedures, which must also be explained to the patient. Ambulatory measurement can be meaningful only if the results are compatible with reference values, which have now been established, and if the causes of possible error can be recognized and interpreted. Ambulatory blood pressure measurement has greatly improved our knowledge of physiological and pathological variations over the circadian cycle including day/night variability and the effects of psychosensorial stimulation. Diagnostic indications are clearly identified and include borderline hypertension suspected but not identified after about 3 months, the white coat effect, severe hypertension when modifications in the circadian cycle are suspected, paroxysmal hypertension, suspected pheochromocytoma, and gravid hypertension or an inversion of the circadian cycle possibly preceding an episode of eclampsia. There are also a certain number of particular indications in patients with degenerative or primary conditions affecting their autonomy. The true prognostic value of these recordings was recognized several years ago and has been confirmed by clinical trials. For example, the white blouse effect has no significant implication in terms or predicting less favourable morbidity or mortality. Finally, ambulatory blood pressure measurement has been definitively shown to be a valid method for evaluating the therapeutic effect of an anti-hypertensive drug in a given patient, especially when resting levels are questioned. For therapeutic trials, ambulatory measurements serve as a reference to evaluate the effect of treatment on the circadian cycle. Peak/dip levels can thus be determined in comparison with the residual effect of the drug. A large number of studies remain to done to identify the full potential of this method.

[Behavior of patients with mild-to-moderate arterial hypertension in relation to their treatment. Contribution of an electronic pillbox]

The objective of the MACH1 study (MEMS for the Assessment of Compliance of Hypertensives) was to evaluate the real behaviour of patients in relation to antihypertensive treatment administered as a single daily dose. After a 2-week period during which no other antihypertensive was allowed to be administered, 590 patients with mild-to-moderate hypertension received 2 mg of trandolapril as a single daily dose in the morning between 7:00 a.m. and 9:00 a.m. for 4 weeks. Treatment was packaged in electronic pillboxes recording the date and time of each opening. Various profiles were distinguished on the basis of the individual chronograms for the 501 patients able to be analysed in terms of compliance, and as a function of the deviations observed in relation to the treatment regimen prescribed. One hundred and two patients (20%) omitted more than 20% of the prescribed doses, either consecutive doses or scattered throughout the month of treatment; these patients were referred to as "omitters". The other patients were classified according to the scatter of openings in relation to the mean time of the dose: 10 "metronome" patients (2%), 126 "regular" patients (25%), 221 "irregular" patients (44%) and 42 "anarchic" patients (8%). Irregularities of dose times were more frequent on public holidays than on week days and in patients living in Paris or the Paris region. "Metronome" patients were older than the overall patient population. The use of an electronic pillbox could allow the attending physician to more adequately adapt his therapeutic approach and management of specific problems of compliance observed in hypertensive patients.

Non-invasive ambulatory blood pressure variability and cardiac baroreflex sensitivity

AIM

The objective of this study was to evaluate the relationship between non-invasive ambulatory blood pressure variability and cardiac baroreflex sensitivity in hypertensive patients.

SUBJECTS AND METHODS

Ambulatory blood pressure measurements (15-min intervals for 24 h) and continuous blood pressure measurements (Finapres, 20 min at rest after a 10-min resting period) were performed in 123 untreated hypertensives (resting diastolic blood pressure > or = 90 mmHg; 80 males, 43 females; mean +/- SD age 49 +/- 12 years, range 19-73). Fourier series were used to model 24-h blood pressure profiles (four harmonics). Ambulatory blood pressure variability was assessed by determination of the residuals in each 24-h blood pressure profile (measured minus predicted pressures). Resting blood pressure variability was defined as the SD of the mean Finapres value. Baroreflex sensitivity was evaluated by automatic detection of blood pressure and pulse interval sequences of > or = 3 beats when systolic blood pressure and pulse interval sequences changed in the same direction (increase or decrease: 1 mmHg for systolic blood pressure and 4 ms for RR interval), and was assessed as the slope of the regression line for each sequence.

RESULTS

Ambulatory systolic blood pressure variability increased with age (r = 0.28*) and systolic pressure (r = 0.44**). Baroreflex sensitivity (increasing systolic pressure/pulse interval) decreased significantly with age (r = -0.48**) and systolic pressure (r = -0.23**), and was significantly related to increased ambulatory blood pressure variability (r = -0.33**). In a multivariate stepwise analysis the relationship between ambulatory blood pressure variability and baroreflex sensitivity (increasing systolic pressure/pulse interval) was statistically independent of age and systolic pressure (R = 0.55, P<0.001); this relationship was not observed with the corresponding decreasing sequence.

CONCLUSIONS

This study shows that in uncomplicated hypertension, ambulatory blood pressure variability is related to baroreflex sensitivity independently of the blood pressure level. This finding has prognostic implications for this non-invasive measurement, which needs to be confirmed by large longitudinal studies.

[Baroreflex sensitivity and vascular involvement in hypertension]

Relationships between baroreflex sensitivity (BRS) and arterial distensibility are evaluated by continuous measurement of blood pressure (Finapres) and carotid-femoral pulse wave velocity measurement (PWV); 73 subjects are recruited on WHO criteria (age: 48 +/- 13). An ambulatory measurement of BP is also performed to evaluate the mean BP 24 level. The BRS is evaluated at rest during 20 min of acquisition data in a lying position, using a dedicated software [(automatic detection by of BP sequences were 3 or more systolic BP and RR interval increased of 1 mmHg for SBP and 4 ms for RR (PS+/RR+) or decreased (PS-/RR-)]. The BRS is the slope of the regression line between SBP and RR interval of each sequences (if correlation coefficient > 0.95).

RESULTS

resting BP: SBP/DBP = 170 +/- 12 mmHg. HR 72 +/- 15 batt/min, PWV = 10.8 +/- 3.2 m/s. Mean BRS is 8.2 +/- 3.8 for PS+/RR+ and 8.7 +/- 3.8 ms/mmHg PS-/RR-. The coefficient of correlation (Pearson) between PWV and BRS is -0.59* for PS+/RR+ and -0.41* for PS-/RR- (*: p < 0.01). In multivariate analyses, these relations were statistically independent of age and BP for the sequences PS+/RR+ but not for the sequences PS-/RR- suggesting a predominant vagal alteration in hypertensive subjects associated with the alteration of carotido-femoral pulse wave velocity.

[Reproducibility of echocardiographic parameters by automatic detection of contours in hypertensive patients]

The reproducibility of automatic outline detection is a echocardiographic reproducibility which has been poorly evaluated in patients with cardiomyopathy. Two independent observers identified the systolic surface and mid and end diastolic surfaces of 27 hypertensive patients, who had been referred to the laboratory for the measurement of left ventricular mass. Each observer examined on two occasions all parameters and all parameters were measured at least 2 hours apart. The coefficient of variation (CV) expresses the reproducibility of each measurement. The intra observer was 10 to 15% and the inter observer 15 to 22% for the measurement of surface area. The coefficient of variation is regularly greater than 20% for measures of maximum speed, which characterise surface changes in diastole. The automatic detection of contours is a echocardiographic tool whose potential is great for evaluating left ventricular function but the current versions can only be applied to very selective group of patients depending on the quality of their echographic window for acoustic quantitation. This technique is very operator dependent, in particular as regards setting the gains and this explains its poor reproducibility and its limited interest in daily clinical practice.

[Paradoxic changes in the morphology of blood pressure wave in hypertensive heart diseases]

The objective is to study the relation between left ventricular (LV) effect (index of LV mass (LVMI) and index of inotropic state) and arterial compliance determined but the proximal aortic pressure waveform and by the carotid femoral pulse wave velocity.

MATERIAL

72 untreated hypertensives; systolic blood pressure (SBP) 170 +/- 18 mmHg/diastolic blood pressure (DBP); heart rate: 69 +/- 9 batt/min; age: 48 +/- 13 years; duration of hypertension 4.6 +/- 4.8 years; sex ratio 49 M/23 F.

OBJECTIVE

Proximal aortic pressure waveform (carotid artery) was studied by applanation tonometry. We derived the index of amplification (AI = Pmax-Pinflex)/PP, %), pulse pressure (PP), the maximum rate of rise of pressure (dpdt, mmHg.s-1). Echocardiography was used to define the index of LV mass (VLMI), end systolic volume (ESV), end systolic stress (ESS), myocardial contractile force (ESS/ESV), inotropic state (SBP/ESV). Carotid-femoral pulse wave velocity was determined by mechanogram (PWW m/s).

RESULTS

1. Relationship of physiological changes of AI and SDA to age, height, PP, DBP, PWV, and LVMI were observed in table I (r-Pearson cor. coefficient, * < p 0.05; **: p < 0.001). [table: see text] In stepwise regression analysis, even allowing for BP, age, and height, there was no relationship between LVMI and the index of aortic amplification (AI). 2. In the subjects with LVH (LVMI > 110 g/m2) we found a bimodal distribution of the AI which defines two groups in agreement with the Murgo Classification. [table: see text] In type B, where AI is weaker, the indices of aortic rigidity are reduced, there is an increased ESS and a paradoxal fall in LV performances.

CONCLUSION

Analysis of proximal aortic pressure waveform don't allow to predict index of LV mass. These results suggest that in the sphere of LV aortic compiling the reduction of LV function contributes to modification of the BP waveform with diminution of dpdt and the index of amplification.

[Ambulatory blood pressure monitoring and clinical trials]

Ambulatory blood pressure monitoring (ABPM) is now widely used for the assessment of antihypertensive drugs. This procedure may be used in phase II studies in dose-ranging evaluations as well as in phase III in order to assess the drug efficacy in the patient's natural environment. The increase in the reproducibility related to the repetition of blood pressure measurements by ambulatory monitoring may improve the accuracy of the trial and minimize the numbers of subjects required. Placebo fails to lower ambulatory blood pressure in almost all studies. Nevertheless, placebo is always necessary in clinical studies with ABPM at least for the pre-inclusion phase and in order to study the peak-trough ratio. This ratio may be accurately assessed by ABPM. Finally, ABPM may be useful to rule out "white coat" responders, who are not really hypertensive patients.

[Comparison of blood pressure profile during exercise with benazepril 10 mg and benazepril 5 mg/hydrochlorothiazide 6.25 mg fixed combination]

This double-blind placebo-controlled study was designed to compare the efficacy of benazepril 10 mg (BZ 10) and the low-dose combination benazepril 5 mg/hydrochlorothiazide 6.25 mg (BZ + HCTZ) on exercise blood pressure in 71 patients with mild to moderate hypertension (diastolic blood pressure 95 to 114 mmHg at the end of a 2 week placebo run-in). A significant fall of systolic (SBF) and diastolic (DBP) blood pressure at rest was seen after a 4-week treatment period in the two active groups (-21.9/-10.3 mmHg with BZ 10, -19.5/-11.2 mmHg with BZ + HCTZ) and was greater in these two groups than in the placebo group (-7.5/-2.5 mmHg, p < 0.01). For each level of the exercise test on bicycle ergometer, SBP falls seen after 1 month were significant in the two active groups (from -15 to -23 mmHg depending on the level and treatment group). The evolution of the SBP/heart rate slope was significantly different among the two active groups in favour of the BZ 10 regimen. The exercise test proved to be a valuable tool to show any difference between two treatments with comparable efficacy on SBP/DBP at rest.

Diagnostic and prognostic value of exercise testing

Measuring blood pressure during exercise under a standard protocol could be a useful diagnostic method in high-risk patients and in borderline hypertensive subjects. It may also serve as an adapted test for hypertensive subjects undergoing physical activity at work or at leisure time with a particular cardiovascular work load. It can be used as a method of assessment to confirm the efficacy of an antihypertensive drug, and for prognostic evaluation of cardiovascular risk in terms of morbidity and mortality. An exercise blood pressure profile does not provide information about blood pressure during activities of daily living. For this purpose, ambulatory blood pressure measurement appears to be more relevant.

Examination of variability in arterial blood pressure at rest using spectral analysis in hypertensive patients

INTRODUCTION

We hypothesize that in essential hypertension sympathetic nervous activity is related to the development of left ventricular hypertrophy, which can be regarded as a measure of the severity of hypertension.

METHODS

Using spectral analysis, we studied the short-term variability in resting blood pressure and heart rate in essential hypertensive subjects. We measured blood over 10 min using a Finapres in 88 subjects after 20 min rest. We performed echocardiography to evaluate left ventricular hypertrophy and thereby identified three groups: 23 control subjects (group I), 29 hypertensive subjects (World Health Organization criteria) without left ventricular hypertrophy (group II) and 36 hypertensive subjects with left ventricular hypertrophy (group III). None had been treated for hypertension before the study.

RESULTS

The variability in blood pressure over a low-frequency period considered to be a marker of sympathetic activity was significantly increased in group II compared with groups I and III (analysis of covariance taking into account blood pressure and age). The variability in heart rate was similar in groups II and III, but both groups had a significantly reduced variability in heart rate compared with group I.

CONCLUSION

These data, which examine globally, using a non-invasive method, all neurohormonal factors associated with the development of left ventricular hypertrophy, demonstrate that, in the time course of hypertension, low-frequency oscillations in blood pressure and heart rate are shifted to a lower level, presumably reflecting altered function of the sympathetic nervous system. We suggest that spectral analysis of blood pressure at rest in hypertensive patients can lead to complementary information to single measures of blood pressure and detect differences in the cardiovascular regulatory system.