Centralized echocardiogram quality control in a multicenter study of regression of left ventricular hypertrophy in hypertension.

OBJECTIVE: To test the feasibility and utility of instituting centralized echocardiographic quality control during a multicenter study of regression of left ventricular hypertrophy in hypertension. DESIGN AND METHODS: The LIVE (Left Ventricular Hypertrophy: Indapamide Versus Enalapril) study is an ongoing multicenter, double-blind, controlled study of regression of echocardiographic left ventricular mass index in hypertensive patients with left ventricular hypertrophy (left ventricular mass indexes > 100 g/m2 for women and > 120 g/m2 for men) treated for 1 year with 1.5 mg indapamide sustained-release coated tablets versus 20 mg enalapril. A centralized evaluation committee has validated a prestudy sample echocardiogram from each center, and is now reviewing all videotapes recorded during this study for quality control; final results will be based on a further randomized blinded analysis by this centralized evaluation committee. RESULTS: Since December 1994, 878 patients have been preselected (videoechocardiographic recordings sent for assessment), 645 selected (videoechocardiographic recordings validated), and 576 randomly allocated to treatment. After preliminary quality control, 27% (233) of baseline echocardiograms were rejected by our centralized evaluation committee, and 22% (142) of postinclusion echocardiographic measurements had to be repeated, mainly because they were of poor echogenic quality. Analysis of approved baseline echocardiograms for the first 274 randomly allocated patients with digitized data showed that there was a significant correlation between centralized evaluation committee and investigator calculations of left ventricular mass index (r = 0.76, P < 0.001), with consistently higher values for investigator calculations, independently of level of left ventricular mass index (correlation between difference and mean of investigator and centralized evaluation committee measurements, r = 0.08, P = 0.28). The mean difference was 8 +/- 20 g/m2 (P < 0.001). CONCLUSION: Early results of the LIVE study quality control showed that real-time 'live', centralized echocardiographic reading was not only feasible, but also useful for avoiding unquantifiable echocardiograms and overestimation of left ventricular mass index. Thus, real-time, centralized echocardiographic quality control should be recommended for multicenter studies of regression of left ventricular hypertrophy.

[Treatment of hypertension with indapamide 1.5 mg sustained-release form: synthesis of results]. / Traitement de l'hypertension artérielle par l'indapamide 1,5 mg comprimé enrobé à libération prolongée: synthèse des résultats.

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]. / Evaluation du rapport vallée/pic de l'indapamide 1,5 mg comprimé enrobé a libération prolongée par la mesure ambulatoire de la pression artérielle.

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.

Regression of left ventricular hypertrophy in patients with essential hypertension. Results of 6 month treatment with indapamide.

Left ventricular hypertrophy (LVH) is a major risk factor for cardiovascular morbidity in hypertensive patients. The effects of diuretics on LVH have raised controversies, but recent studies suggest that diuretics are able to reduce LVH in hypertensive patients, mainly through a reduction in ventricular diameter. The present multicenter open study was designed to test the effects of indapamide, a widely used nonthiazide diuretic, on LVH in patients with essential hypertension. Patients had to have mild-to-moderate essential hypertension (supine diastolic blood pressure [sDBP] 95 to 115 mm Hg) with echocardiographic evidence of LVH (left ventricular mass index [LVMI] > 130 g/m2 for men and > 110 g/m2 for women). After a 2 week placebo run-in period, eligible patients underwent a 6 month treatment with 2.5 mg indapamide daily. All echograms were performed by the same investigator before and after 6 months of indapamide. Clinical and biological acceptability and quality of life (visual analog scale) were also studied. One hundred and thirty patients were included in the study and 112 completed the trial. Indapamide induced a significant reduction i systolic and diastolic blood pressures. Indapamide induced a marked reduction in posterior wall thickness (from 12.1 +/- 2.0 to 11.2 +/- 1.6 mm) and in interventricular wall thickness (from 12.7 +/- 1.7 to 11.8 +/- 1.9 mm; each P < .001) and a slight decrease in left ventricular diameter (P = .049). This resulted in a 13% reduction in LVMI (from 161.9 +/- 37.9 to 140.7 +/- 33.8 g/m2, P < .001). Left ventricular fractional shortening remained unchanged. There was no significant relation between changes in LVMI and changes in systolic, diastolic, or mean blood pressure. No significant adverse clinical or biological effects were reported during the study. The increased score of the visual analog scale indicated that overall well-being was improved (P < .001). Our study indicates that indapamide, in addition to blood pressure control, is able to reduce LVH. This effect was achieved mainly through a reduction in wall thicknesses rather than in internal cavity diameter.

[Therapeutic benefit of a low dose of indapamide: results of a double-blind against placebo European controlled study]. / Bénéfice thérapeutique d'une faible dose d'indapamide: résultats d'une étude européenne contrôlée en double aveugle contre placebo.

Indapamide is a diuretic prescribed in the treatment of hypertension at the dosage of 2.5 mg per day. In accordance with international recommendations concerning the need to use low doses of antihypertensives, a new lower-dose form of indapamide has been developed to achieve the best safety/efficacy ratio by decreasing the incidence of hypokalemia. A new pharmaceutical sustained-release (SR) form was developed to give a smooth pharmacokinetic profile in comparison with the indapamide instant release (IR) form. The aim of this study was to determine the lowest new dosage of the SR form producing similar hypertensive efficacy as the LR form, and decreasing the percentage of patients with a serum potassium concentration below 3.4 mmol/l. This multicenter study was designed as a single-blind, run-in, placebo period of 1 month, followed by a double-blind, active treatment period of 2 months, using parallel groups: 285 patients with essential uncomplicated mild-to-moderate hypertension (95 mmHg < or = supine diastolic blood pressure (sDBP) < or = 114 mmHg) were included and randomly treated by either IR indapamide (2.5 mg) or SR indapamide (1.5, 2.0, 2.5 mg). After 2 months of active treatment, the one-way analysis of variance on the principal criterion (difference in sDBP between M2 and M0) revealed a significant treatment effect (p = 0.016). The mean drop in sDBP (+/- standard deviation) was 5.8 mmHg (+/- 8.6) after 2 months of placebo; 10.1 mmHg (+/- 7.0) after indapamide IR 2.5 mg; and 11.0 mmHg (+/- 9.4), 8.9 mmHg (+/- 9.4), and 10.5 mmHg (+/- 8.5) after indapamide SR 1.5 mg, 2 mg, and 2.5 mg, respectively. The difference between the placebo and indapamide treatment was significant (p < or = 0.05). No significant difference was detected between the various indapamide treatments, i.e., no difference between the IR and SR formulations, no difference between the various dosages of the SR form, and therefore no dose/effect relationship in the dose interval tested (SR 1.5, 2, and 2.5 mg). The incidence of patients with a serum potassium concentration less than 3.4 mmol/l was lower with indapamide SR 1.5 mg (11%) than with indapamide 2.5 mg, SR 2 mg, and SR 2.5 mg, respectively: 29%, 18% and 14%. These results show the interest of a low dose of indapamide in improving the safety while producing the same antihypertensive efficacy.