Prevalence of Echinococcus multilocularis in the red fox (Vulpes vulpes) in southern Belgium.

Between June 1998 and February 2002, 709 red foxes killed in Wallonia (south of Belgium) were available for parasitological examination of the gut. The identification of Echinococcus multilocularis was based on morphological data. E. multilocularis adults were observed in 20.2% of the animals. The analysis of data revealed marked differences between the geological areas of Wallonia; the highest prevalence (33%) was found in the Ardenne and the lowest (0%) on the Plateau de Herve. Host gender and the collection season had no effect on the prevalence. However, the latter was significantly higher in juveniles (<8 months of age). The geographical distribution of E. multilocularis in Belgium is much wider than originally thought.

High-resolution backscatter electron imaging of colloidal gold in LVSEM.

High-resolution backscatter electron (BSE) imaging of colloidal gold can be accomplished at low voltage using in-lens or below-the-lens FESEMs equipped with either Autrata-modified yttrium aluminium garnet (YAG) scintillators doped with cerium, or with BSE to secondary electron (SE) conversion plates. The threshold for BSE detection of colloidal gold was 1.8 keV for the YAG detector, and the BSE/SE conversion was sensitive down to 1 keV. Gold particles (6, 12 and 18 nm) have an atomic number of 79 and were clearly distinguished at 500,000x by materials contrast and easily discriminated from cell surfaces coated with platinum with an atomic number of 78. BSE imaging was relatively insensitive to charging, and build up of carbon contamination on the specimen was transparent to the higher energy BSE.

Early short-term intensive cardiac rehabilitation induces positive results as long as one year after the acute coronary event: a prospective one-year controlled study.

AIMS: The one-year effects of early and short-term intensive cardiac rehabilitation programmes in patients after acute myocardial infarction or coronary artery bypass surgery (CABG) are not well established. METHODS AND RESULTS: One to four weeks after hospital discharge for acute myocardial infarction (n=55) or CABG (n=54), 109 patients were included in a multidisciplinary ambulatory cardiac rehabilitation programme, lasting 2 to 3 months and including a mean of 33 daily sessions. A complete cardiological assessment of the classical coronary risk factors was performed at entry into the study and again 12 months later, that is 9 to 10 months after the end of the rehabilitation programme. Major effects at one-year follow-up were a high rate of aspirin intake, a low rate of smoking (14% of the patients), a 15% increase in physical capacity, a 7 beats/min decrease in resting heart and a 4 mg/dl increase in the HDL-cholesterol. Body weight increased by 4.9 kg in the patients who stopped smoking; the modest increase in body weight in the other patients reflected a partial weight recovery in the CABG patients. Blood pressure levels also increased at the end of the study but our data in CABG patients and their extrapolation to the post MI patients strongly suggest a progressive return of blood pressure to the pre-acute event levels. In a control group matched for age, sex and type of coronary event, no significant modifications were observed after one year, except for an increase in body weight of 1.7 kg (P < 0.000). CONCLUSIONS: Cardiac rehabilitation which started early after an acute coronary event and regularly followed during 2 to 3 months induced beneficial effects which were still present 9 to 10 months later. Weight gain after smoking cessation was prevalent. The lack of changes in the control group reinforced the benefit of cardiac rehabilitation.

Felodipine-metoprolol combination tablet: a valuable option to initiate antihypertensive therapy?

The aim of the present study was to assess the efficacy and tolerability of a calcium antagonist/beta-blocker fixed combination tablet used as first-line antihypertesnive therapy in comparison with an angiotensin converting enzyme inhibitor and placebo. Patients with uncomplicated essential hypertension (diastolic blood pressure between 95 and 110 mm Hg at the end of a 4-week run-in period) were randomly allocated to a double-blind, 12-week treatment with either a combination tablet of felodipine and metoprolol (Logimax), 5/50 mg daily (n = 321), enalapril, 10 mg daily (n = 321), or placebo (n = 304), with the possibility of doubling the dose after 4 or 8 weeks of treatment if needed (diastolic blood pressure remaining >90 mm Hg). The combined felodipine-metoprolol treatment controlled blood pressure (diastolic < or =90 mm Hg 24 h after dose) in 72% of patients after 12 weeks, as compared with 49% for enalapril and 30% for placebo. A dose adjustment was required in 38% of patients receiving the combination, in 63% of patients allocated to placebo, and 61% of enalapril-treated patients. The overall incidence of adverse events was 54.5% during felodipine-metoprolol treatment; the corresponding values for enalapril and placebo were 51.7% and 47.4%, respectively. Withdrawal of treatment due to adverse events occurred in 18 patients treated with the combination, in 10 patients on enalapril, and 12 patients on placebo. No significant change in patients' well-being was observed in either of the three study groups. These results show that a fixed combination tablet of felodipine and metoprolol allows to normalize blood pressure in a substantially larger fraction of patients than enalapril given alone. This improved efficacy is obtained without impairing the tolerability. The fixed-dose combination of felodipine and metoprolol, therefore, may become a valuable option to initiate antihypertensive treatment.

Relation of exercise capacity to left ventricular systolic function and diastolic filling in idiopathic or ischemic dilated cardiomyopathy.

Although exercise intolerance is a cardinal symptom of patients with dilated cardiomyopathy (DC) and heart failure, the factors that limit exercise capacity in these patients remain a matter of debate. To assess the contribution of left ventricular (LV) diastolic filling to the variable exercise capacity of patients with DC, we studied 47 patients (60 +/- 12 years) with DC in stable mild-to-moderate heart failure with a mean LV ejection fraction of 28%. Exercise capacity was measured as total body peak oxygen consumption (VO2) during symptom-limited bicycle (10 W/min) and treadmill (modified Bruce protocol) exercise. LV systolic function and diastolic filling were assessed at rest before each exercise by M-mode, Doppler echocardiography, and radionuclide ventriculography. As expected, treadmill exercise always yielded higher peak VO2 than bicycle exercise (21 +/- 6 vs 18 +/- 5 ml/kg/min, range 12 to 35 and 7 to 30 ml/kg/min, respectively, p <0.001). Both of these VO2 measurements were highly reproducible (R = 0.98). With univariate analysis, close correlations were found between peak VO2 (with either exercise modalities) and Doppler indexes of LV diastolic filling, as well as with the radionuclide LV ejection fraction. Stepwise multiple regression analysis identified 3 nonexercise variables as independent correlates of peak VO2, of which the most powerful was the E/A ratio (multiple r2 = 0.38, p <0.0001), followed by peak A velocity (r2 = 0.54, p <0.0001) and mitral regurgitation grade (r2 = 0.58, p = 0.024). In conclusion, our data indicate that in patients with DC, peak VO2 is better correlated to diastolic filling rather than systolic LV function.

Risk stratification in patients with dilated cardiomyopathy: contribution of Doppler-derived left ventricular filling.

Dilated cardiomyopathy (DCM) is a major cause of mortality among patients with heart failure. The aim of the present study was to investigate the independent contribution of Doppler-derived left ventricular (LV) filling to the prediction of survival in patients with DCM, of either ischemic or nonischemic origin, and to derive a simple risk stratification score based on easily available clinical and echocardiographic parameters. We followed 197 consecutive patients (159 men, mean age 60+/-13 years) with an echocardiographic diagnosis of DCM (LV end-diastolic dimension >60 mm, fractional shortening <25%) over an average period of 62+/-13 months. The presumed etiology of DCM was ischemic in 52% of the patients. During follow up, 69 patients died of cardiac causes and 41 required transplantation. At 5 years, overall cardiac event-free survival was 55% and freedom from death or heart transplantation was 43% (compared with 86% for the 5-year age- and sex-adjusted survival rate in our country). Kaplan-Meier survival curves generated for different thresholds of the peak E velocity and the E/A ratio indicated significant worsening of prognosis with increasing values of these parameters in both ischemic and nonischemic patients. Using Cox stepwise regression analyses, age (chi-square to remove 24.4; p <0.001), peak E velocity (chi-square to remove=18.9; p <0.001), LV ejection fraction (chi-square to remove 6.4; p <0.011), and systolic blood pressure (chi-square to remove 4.5; p=0.034) independently predicted cardiac deaths, whereas New York Heart Association (NYHA) functional class (chi-square to remove 48.5; p < 0.001), LV ejection fraction (chi-square to remove 19.1; p <0.001), E/A ratio (chi-square to remove 10.8; p <0.001), and systolic blood pressure (chi-square to remove 5.8; p <0.016) were independently associated with cardiac death or need for transplantation. Based on these parameters, a risk score was elaborated, which allowed appropriate classification of each individual patient into low- (5-year survival rate of 72%), intermediate- (46% survival rate), and high-risk groups (11% survival rate). In conclusion, our data show that among the noninvasive parameters commonly available in patients with either ischemic or nonischemic DCM, age, the NYHA functional class, the LV ejection fraction, the systolic blood pressure, the peak E velocity, and the E/A ratio provide relevant and independent information regarding the risk of cardiac death or the need for heart transplantation.

The relationship between parasite counts, lesions, antibody titres and daily weight gains in Psoroptes ovis infested cattle.

Psoroptes ovis counts, extent of lesions (clinical index: ClinI), daily weight gains (DWGs) and anti-P. cuniculi antibody titres in ELISA were recorded during seven therapeutic field trials. Relationship between these different data were studied. The differences between the mean DWG of treated and untreated control animals of the different trials ranged from 39 to 1206 g/day. Data were pooled for statistical analysis and the influence of trial conditions (management of the herd, farm, treatment) was extracted from each individual data by subtracting, from the DWG of each animal, the mean DWG of its trial. Such data were called daily weight gain over the trial mean (DWG/TM). Multiple regression of DWG/TM, calculated over the period between the clinical examinations in control animals (n = 40), on clinical indices and sex demonstrated a significant DWG/TM reduction per percentage of affected body surface according to the following equation: DWG/TM (in g/day)= 135-22 ClinI(0)-13 ClinI(28/35)-70 (if male) (R2 adjusted = 0.39), where ClinI(0) and ClinI(28/35) are the clinical indices recorded respectively at the beginning (day 0) and at the end (day 28 or 35) of the experimental period during which the animals were left untreated. A nonsignificant relationship (R2 adjusted = 0.07) was found between the antibody titres on day 28 or 35 and the individual DWG/TM This would suggest that serology could be used to estimate the prevalence of the disease on a local or national basis but not to calculate its economic impact.

Pathophysiologic mechanisms underlying dobutamine- and exercise-induced wall motion abnormalities.

BACKGROUND: Dobutamine and exercise echocardiography are accepted as tests of comparable efficacy for the diagnosis of coronary artery disease. Although dobutamine has been classified as "exercise simulating," the mechanisms of ischemia with dobutamine and exercise have not been well studied. This study sought to compare the determinants of myocardial oxygen consumption. METHODS AND RESULTS: We studied 54 patients with coronary artery disease undergoing dobutamine and exercise stress. A subgroup of 13 patients with comparable degrees of wall motion abnormalities and ST-segment changes during both stresses were selected to compare the determinants of ischemia in comparable circumstances. Dobutamine was infused to a mean maximal dose of 32+/-8 microg/kg/min, and exercise was stopped at an average of 135+/-25 W. The mean regional wall motion score was not statistically different between the two protocols (p = 0.27). At the onset of wall motion abnormalities and peak stress, the heart rate increased significantly less during dobutamine than during exercise (106+/-23 vs 126+/-19 beats/min, p < 0.001). The same was true of systolic blood pressure (155+/-21 vs 205+/-24 mm Hg, p < 0.001) and the rate-pressure product (16.5+/-4.6 vs 25.9+/-5, p < 0.001). Cardiac volumes were similar during both tests. CONCLUSIONS: Ischemia occurs at a lower level of external cardiac work during dobutamine than during exercise stress. We suspect that additional mechanisms, such as the oxygen wasting effect of dobutamine, may be responsible for this observation.

Effects of spironolactone-altizide on left ventricular hypertrophy.

OBJECTIVE: To investigate the effects of the association spironolactone (25 mg)/altizide (15 mg) as monotherapy on left ventricular hypertrophy (LVH) in patients with mild to moderate hypertension. Additionally, to study the correlation between left ventricular mass (LVM) index and electrocardiographic (ECG) criteria for LVH. METHODS AND RESULTS: This was an open, prospective study of 6 months. Patients with mild to moderate essential hypertension were treated with spironolactone/altizide for two months and were included in the study if their blood pressure (BP) at the end of this first treatment period was normalised according to protocol criteria (systolic BP < 160 mm Hg and diastolic BP < 95 mm Hg). Patients then entered a second 4-month treatment period. LVM was determined by echocardiography performed at the beginning of treatment and after 6 months. LVH was defined as LVM > or = 100 g/m2 in women and LVM > or = 131 g/m2 in men. Echocardiograms were interpreted blindly by two echocardiography reading laboratories. Seventy-one patients with a normalised BP after two months of treatment, were enrolled in the study. Changes in LVM index were studied in 31/71 patients with LVH (25 women and 6 men, mean LVM index +/- (SD) 119.9 +/- 16.4 g/m2 in women and 147.8 +/- 10.9 g/m2 in men). Spironolactone/altizide significantly reduced LVM index by 10%, from 125.3 +/- 22.5 to 114.2 +/- 25.1 g/m2 (p < 0.005). Posterior and septal wall thickness decreased by 4% (p = 0.06) and 5% (p = 0.026), respectively. End-diastolic dimension was reduced by 3%, from 50.3 +/- 3.3 to 48.9 +/- 3.4 mm (p = 0.006). The posterior wall thickness to end-diastolic dimension ratio remained unchanged. Complete regression of LVH according to mass criteria occurred in 11 patients out of 31 (34.5%). The observed changes in ECG voltage criteria were in accordance with a decrease of LVM index. CONCLUSION: In this open study, the potassium-sparing diuretic spironolactone/altizide decreases LVM index in hypertensive patients, who were selected for follow-up because they had echocardiographic LVH and because their BP had normalised during an initial 2-month treatment period.

The pathophysiology of myocardial ischaemia.

In this review paper on the pathophysiology of myocardial ischaemia, the recent concepts of the ischaemic cascade, as well as the concepts of stunning and hibernating myocardium, are discussed. It is clear that painful ischaemia is the final phenomenon in the ischaemic cascade and that it is preceded by biochemical disturbances, diastolic and systolic dysfunction and electrocardiographic abnormalities. Silent ischaemia remains a difficult research field.

Permutation distribution estimation applied to the comparison of the profile of the activity of two antianginal drugs.

The comparison of the anti-ischemic activity of trimetazidine and propranolol was evaluated by multiple end points (clinical, exercise test, and ambulatory electrocardiogram [ECG] monitoring criteria) in 149 male patients with effort angina who received either trimetazidine 20 mg tid or propranolol 40 mg tid during a period of 3 months. The distribution of the standardized differences between the two treatments for each variable was obtained by a permutation method. The medians (estimation of the actual difference between the two treatments) and the 5, 25, 75 and 95% quantiles were represented on the same diagram for all end points. The pattern of the standardized distribution of the differences showed a similar activity of both drugs on symptoms and nitrates consumption, on exercise tolerance and increase in ischemic threshold at exercise, and on ischemia recorded at ambulatory ECG monitoring. Conversely, only propranolol decreased heart rate and rate pressure product at rest as well as at exercise, underlining the difference in the mode of action of the two drugs. This descriptive technique is an attractive method to evaluate the differences between drugs considering multiple criteria favouring the estimation of these differences together with their variability.

Improved identification of coronary artery disease in patients with left bundle branch block by use of dobutamine stress echocardiography and comparison with myocardial perfusion tomography.

This study compared the efficacy of dobutamine stress testing using 2-dimensional echocardiography and perfusion tomography for the noninvasive identification of coronary artery disease (CAD) in patients with left bundle branch block (LBBB). Twenty-four patients with permanent, complete LBBB (11 with previous myocardial infarction) were studied prospectively with dobutamine echocardiography and perfusion tomography. The presence of > 50% luminal diameter coronary stenosis was compared with the presence of dobutamine-induced fixed or reversible perfusion defects, and with resting or dobutamine-induced abnormalities of wall thickening. For each test, the left anterior coronary artery territory was compared with the circumflex and/or right coronary artery. Significant CAD was found in the left anterior descending coronary artery in 12 patients; all (100%) were identified by perfusion imaging, and 10 (83%, p = NS) by 2-dimensional stress echocardiography. In the 12 patients without left anterior descending CAD, scintigraphy was also positive in all (specificity: 0%), and echocardiography in only 1 (specificity: 92%, p < 0.01). The diagnostic accuracy was 50% and 87% (p < 0.05), respectively. This low specificity of perfusion tomography was improved by requiring an associated apical defect to indicate left anterior descending CAD and was corrected by restricting the diagnosis of coronary disease to those patients with partially reversible defects. In the circumflex and/or right coronary artery territory, sensitivity and specificity were similar using both techniques. We conclude that dobutamine-stress echocardiography is a specific and accurate test for the noninvasive identification of CAD, even in the left anterior descending artery territory of patients with LBBB.

Trimetazidine European Multicenter Study versus propranolol in stable angina pectoris: contribution of Holter electrocardiographic ambulatory monitoring.

The major objective of the Trimetazidine European Multicenter Study (TEMS) was to compare in a double-blind trial the anti-ischemic effects of trimetazidine (20 mg 3 times daily) with those of propranolol (40 mg 3 times daily). The inclusion criteria were based on an abnormal response to a multistage exercise test. After 3 months of treatment the improvements noted in all exercise testing data were similar in the trimetazidine and propranolol groups; similar data were obtained for the grades and severity of anginal attacks during daily life (from patient diaries). A 24-hour Holter monitoring was performed at entry and at the end of the study, but an abnormal Holter monitoring (1-mm ST-segment depression during at least 1 minute) was not an inclusion criterion. This explains why at entry only 50% of the patients in both groups had an abnormal Holter recording. After 3 months of treatment, there were no significant differences between the 2 groups, but we observed a trend toward a decrease in ambulatory ischemia in the trimetazidine group and a trend toward an increase in ambulatory ischemia in the propranolol group. These data in the propranolol group are in total disagreement with the available literature on beta blockers, which was due to a totally erratic behavior pattern in 2 patients in the propranolol group. When we excluded these 2 erratic cases from the propranolol group and extended our analysis to all available paired comparisons (day -14 to day 30 and day 0 to day 90), we were able to compare 44 and 60 observations, both off therapy and on either propranolol or trimetazidine, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of a fermented infant formula containing viable bifidobacteria on the fecal flora composition and pH of healthy full-term infants.

We assessed the growth, tolerance, and acceptability as well as fecal flora composition and stool pH of 20 healthy full-term infants fed with a fermented whey-adapted infant formula containing viable bifidobacteria (10(6)/g of powder) during the first 2 months of life. This fermented infant formula, first biologically acidified by Streptococcus thermophilus and Lactobacillus helveticus, was compared to a whey-adapted, nonacidified, low-phosphate infant formula in a double-blind, randomized controlled study. The results were compared to a control group (n = 14) of fully breast-fed infants. The fermented whey-adapted formula containing viable bifidobacteria induced a prevalence of colonization with bifidobacteria at 1 month of age similar to that of breast-fed infants (12/20 versus 8/14) but significantly higher than in the group fed the standard infant formula (4/20). The mean bacterial count of bifidobacteria was similar in all colonized infants; however, fecal pH was significantly lower in the breast-fed infants than in the nonacidified bottle-fed infants. This kind of infant formula was well tolerated and promoted a normal growth during the first 2 months.

Patient compliance and therapeutic coverage: comparison of amlodipine and slow release nifedipine in the treatment of hypertension. The Belgian Collaborative Study Group.

To study patient compliance in hypertensive outpatients amlodipine (5 mg once daily) and slow release nifedipine (20 mg twice daily) were compared in an open, crossover study in general practices. Four methods of assessment for patient compliance (pill count, taking compliance, days with correct dosing, timing compliance) were used in both study arms. For the latter three assessment a special device, the medication event monitoring system, was used to record the time and date of each opening and closure of the container. The compliance of the 320 hypertensive patients with once-daily amlodipine was markedly superior to twice-daily slow release nifedipine. Therapeutic coverage was also significantly better for amlodipine in the hypertensive patients. Amlodipine was better tolerated than nifedipine slow release. Patient compliance and therapeutic coverage with the calcium antagonist amlodipine given once daily was superior to slow release nifedipine b.d. in hypertensive outpatients recruited in general practice.

Amlodipine reduces transient myocardial ischemia in patients with coronary artery disease: double-blind Circadian Anti-Ischemia Program in Europe (CAPE Trial).

OBJECTIVES: This study was carried out to determine the effect of the once-daily calcium channel blocking agent amlodipine (half-life 35 to 50 h) on the circadian pattern of myocardial ischemia in patients with chronic stable angina. BACKGROUND: Myocardial ischemia during normal daily life, both symptomatic and asymptomatic, has been associated with increased risk of cardiovascular morbidity and mortality, and the circadian pattern parallels that for myocardial infarction and sudden death. METHODS: The Circadian Anti-Ischemia Program in Europe (CAPE) was a large, 10-week international (63 sites), double-blind, parallel study. After a 2-week, single-blind placebo phase, during which stable doses of antianginal treatment were maintained (beta-adrenergic blocking agents in 65% of patients), patients with chronic stable angina with at least three attacks of angina per week, with at least four ischemic episodes or > or = 20 min of ST segment depression in 48 h of Holter monitoring, were randomized to receive treatment with either 5 mg/day of amlodipine or placebo (2:1 randomization). The dose was increased to 10 mg/day after 4 weeks. During week 7 of treatment, 48-h ambulatory ECG monitoring was repeated. RESULTS: Three hundred fifteen of 1,160 patients screened were eligible, and 250 had complete evaluable data. Compared with placebo, amlodipine significantly reduced both the frequency of ST segment depression episodes (60% for amlodipine vs. 44% for placebo, p = 0.025) and total integrated ST ischemic area (62% mm-min vs. 50% mm-min, p = 0.042). Amlodipine reduced ischemia over the 24 h with the intrinsic circadian pattern maintained. In addition, diary data showed a significant reduction in angina (70% for amlodipine vs. 44% for placebo, p = 0.0001) and in nitroglycerin consumption (67% vs. 22%, respectively, p = 0.0006). Amlodipine and placebo demonstrated similar safety profiles (adverse events 17.3% for amlodipine and 13.3% for placebo; discontinuation rates due to adverse events were 2% vs. 4.4%, respectively). CONCLUSIONS: Once-daily amlodipine, when added to background treatment, significantly reduced both symptomatic and asymptomatic ischemic events over 24 h in patients with chronic stable angina.

How accurate is dobutamine stress electrocardiography for detection of coronary artery disease? Comparison with two-dimensional echocardiography and technetium-99m methoxyl isobutyl isonitrile (mibi) perfusion scintigraphy.

OBJECTIVES: This study was designed to establish the appropriate diagnostic criteria for positive dobutamine electrocardiographic (ECG) stress test results and to compare their accuracy with those of dobutamine two-dimensional echocardiography and perfusion scintigraphy. BACKGROUND: Conventional criteria for positive findings on ECG exercise testing may not be appropriate for use with dobutamine ECG stress testing. METHODS: One hundred twenty-nine consecutive patients with an interpretable ECG and without previous myocardial infarction were prospectively studied at the time of coronary arteriography. All completed a standard dobutamine protocol (5 to 40 micrograms/kg body weight per min in 3-min dose increments) without side effects. Significant coronary artery disease, defined as > 50% lumen diameter stenosis of a major epicardial coronary artery on coronary angiography, was present in 83 patients. Empiric receiver operating curves were generated for various ECG criteria derived from computer-averaged signals. RESULTS: The best ECG criterion, with a sensitivity of 42% and a specificity of 83%, was an ST segment shift, relative to baseline, of 0.5 mm 80 ms after the J point. The sensitivity of this criterion was greater than that of the conventional criterion of 1-mm ST segment depression 60 (23%) or 80 (18%) ms after the J point, was comparable to that of chest pain occurring during the test (44%, p = NS) but remained inferior to the sensitivities of technetium-99m methoxyl isobutyl isonitrile (mibi) perfusion (76%) or stress echocardiography (76%, p < 0.001, for both). The specificity of this criterion was not significantly different from that of technetium-99m mibi perfusion tomography (65%) or stress echocardiography (89%) but was superior to that of chest pain (59%, p < 0.025). CONCLUSIONS: We conclude that this new criterion for dobutamine electrocardiography is specific but that an imaging technique is still required to accurately predict coronary artery disease.

Patient compliance and therapeutic coverage: amlodipine versus nifedipine (slow-release) in the treatment of angina pectoris. Belgian Collaborative Group.

Patient compliance with therapy is often poor and overestimated by the treating physician; it is particularly important in cardiovascular diseases such as hypertension and angina pectoris. Compliance was studied in an open parallel study in out-patients with stable angina pectoris, given either amlodipine (5 mg, once daily) or slow-release nifedipine (20 mg, twice daily) for 12 weeks. Compliance was assessed using pill counting and using an electronic device, the medication event monitoring system, to record the time and date of each opening and closure of the pill container. There was no difference between the two groups in pill count or in 'taking compliance' (the percentage of prescribed doses taken as indicated by the monitoring system). Compliance was significantly better (P < 0.001) with amlodipine, however, for 'correct dosing' (the percentage of days on which the correct dose was taken) and for 'timing compliance' (the percentage of doses taken at the prescribed time interval after the last dose). 'Therapeutic coverage' (the estimated proportion of treatment time for which the drug was active) was also significantly better for amlodipine (P < 0.001). There was no difference in reported side-effects between the two therapies.