Multidisciplinary interobserver agreement in the diagnosis of idiopathic pulmonary fibrosis

The purpose of the present study was to evaluate the accuracy of the diagnosis of idiopathic pulmonary fibrosis (IPF) by respiratory physicians in six European countries, and to calculate the interobserver agreement between high-resolution computed tomography reviewers and histology reviewers in IPF diagnosis. The diagnosis of usual interstitial pneumonia (UIP) was assessed by a local investigator, following the American Thoracic Society/European Respiratory Society consensus statement, and confirmed when a minimum of two out of three expert reviewers from each expert panel agreed with the diagnosis. The level of agreement between readers within each expert panel was calculated by weighted kappa. The diagnosis of UIP was confirmed by the expert panels in 87.2% of cases. A total of 179 thoracic high-resolution computed tomography scans were independently reviewed, and an interobserver agreement of 0.40 was found. Open or thoracoscopic lung biopsy was performed in 97 patients, 82 of whom could be reviewed by the expert committee. The weighted kappa between histology readers was 0.30. It is concluded that, although the level of agreement between the readers within each panel was only fair to moderate, the overall accuracy of a clinical diagnosis of idiopathic pulmonary fibrosis in expert centres is good (87.2%).

Effects of long-term cyclic iloprost therapy in systemic sclerosis with Raynaud's phenomenon. A randomized, controlled study

OBJECTIVE

Iloprost is a stable prostacyclin analogue which has been shown to be effective in the short-term symptomatic treatment of Raynaud's phenomenon (RP) secondary to systemic sclerosis (SSc). The aim of this study was to evaluate the effects of long-term cyclic therapy with iloprost in comparison with nifedipine on the skin score, pulmonary function and Raynaud's severity score in patients with SSc and RP.

METHODS

We conducted a 12-month prospective, randomised, parallel-group, blind-observer trial to compare the effects of intravenously infused iloprost (2 ng/kg/min on 5 consecutive days over a period of 8 hours/day and subsequently for 8 hours on one day every 6 weeks) with those of conventional vasodilating therapy with nifedipine (40 mg/day for os) in 46 patients with SSc and RP.

RESULTS

At 12 months, iloprost but not nifedipine reduced the skin score (iloprost: from 13.26 +/- 2.05 to 9.26 +/- 1.32, p = 0.002; nifedipine: from 10.83 +/- 2.09 to 12.17 +/- 3.02, p = n.s.; iloprost vs nifedipine: p = 0.016) and the RP severity score (iloprost: from 2.17 +/- 0.2 to 1.22 +/- 0.13, p = 0.02 vs baseline; nifedipine: from 2.08 +/- 0.34 to 1.33 +/- 0.22, p = n.s.). Carbon monoxide diffusing capacity (DLCO), expressed as % of the predicted normal value, worsened significantly in the nifedipine group (from 69.6 +/- 7.4% to 61.5 +/- 6.5%, p = 0.044) and remained stable in patients treated with iloprost (from 53.2 +/- 4.8 to 56.0 +/- 4.6%, iloprost vs nifedipine: p = 0.026).

CONCLUSION

In SSc patients, cyclic intravenous iloprost infusion is able to control vasospastic disease. Our results suggest that it might also act as a disease-modifying agent, as it seems to improve the course of the disease. Further studies principally focused on organ involvement and the natural history of the disease are needed to confirm our results.

Randomized trial of the effects of low-dose calcium-heparin in patients with peripheral arterial disease and claudication. Italian CAP Study Group

PURPOSE

We performed a long-term, multicenter, randomized, double-blind trial to evaluate the efficacy and tolerability of low-dose, subcutaneous calcium-heparin (12,500 IU/day) in comparison with placebo in patients with stable peripheral arterial disease of the lower extremities.

PATIENTS AND METHODS

At the end of a 2-week washout period, during which aspirin placebo was given, 201 patients were randomly assigned to receive either subcutaneous calcium-heparin or placebo for two 3-month treatment periods, each of which was followed by a 6-month period of observation. All of the patients were given low-dose aspirin (50 mg/day) throughout the 18-month study. The main efficacy variables were pain-free and maximum walking time (by standard treadmill test). Patients answered a questionnaire about pain and the limitation of daily activities. Results were analyzed by intention-to-treat.

RESULTS

At the end of the study, the estimated increase in pain-free walking time was 39% in the heparin group and 23% in the placebo group (P = 0.09). The estimated increase in maximum walking time was 40% in the heparin group and 16% in the placebo group (P = 0.05). Patients treated with heparin also reported that they had to stop walking because of leg pain, or had daily activities limited by leg pain, less frequently than the placebo group (P <0.01).

CONCLUSIONS

Treatment with low-dose subcutaneous calcium-heparin is safe and effective in improving walking performance and reducing physical disability in patients with stable peripheral arterial disease and claudication.

Is it possible to develop drugs that act more selectively on large arteries?

BACKGROUND

Patients with high pulse pressures have an increased risk for cardiovascular events. Drugs that selectively decrease high pulse pressure may be of interest for these patients. Such drugs have a more pronounced effect on large arteries than on resistance vessels.

OBJECTIVE

To compare the selectivity to large arteries of the new nitric oxide donor sinitrodil with the classic nitrate isosorbide dinitrate in healthy young men in order to investigate whether it is possible to develop drugs that act more selectively on large arteries.

DESIGN

The study had a double-blind, 5-way cross-over design. In randomized order, subjects received a single oral dose of 10 mg sinitrodil, 20 mg sinitrodil, 40 mg sinitrodil, isosorbide dinitrate and placebo. Measurements were performed before and 45 min after administration of the drugs. Between each drug administration, at least 3 days of wash-out was allowed.

METHODS

The effects of the drugs on large arteries and resistance vessels were assessed by their effects on brachial artery compliance and total peripheral resistance, respectively.

RESULTS

Brachial artery compliance increased gradually with increasing doses of sinitrodil (by 10, 20 and 27% with 10, 20 and 40 mg sinitrodil, respectively). Total peripheral resistance index decreased with isosorbide dinitrate (by 11%) and 40 mg sinitrodil (by 7%), while it remained unchanged with 10 mg and 20 mg sinitrodil.

CONCLUSIONS

The results of this study show that it may be possible to develop drugs with a higher selectivity for large arteries. Such drugs may be good candidates to decrease high pulse pressure without substantially decreasing mean and diastolic blood pressures.

Pharmacokinetics of ITF 296 (Sinitrodil) a novel organic nitrate, in healthy volunteers

ITF 296 is a new orally active nitrate acting selectively on large arterial vessels over a wide range of doses. In healthy volunteers it causes less reduction in vascular resistance and less venodilatation than classic nitrates. Its pharmacokinetic profile was evaluated after intravenous infusion and oral (solution and immediate-release tablet) administration in a randomised cross-over design on 11 healthy volunteers. The plasma levels of ITF 296 and its metabolite ITF 1124 were determined by a HPLC method. The drug is rapidly distributed (mean steady-state distribution volume 53+/-17 liters) and eliminated (half-life of about 25 minutes) both after intravenous and oral administration. The total clearance is 2. 31+/-0.46 l/min. The oral solution of ITF 296 is well absorbed (Cmax=0.057 microg/ml, tmax=30 min) but it undergoes a first-pass effect (F=25%). The tablet, developed only for Phase 1 clinical studies, is characterised by an immediate release (Cmax=0.057 microg/ml, tmax=30 min). The extent of its absolute and relative bioavailability is about 14% and 53% respectively.

Safety, tolerability, and antiischaemic efficacy of ITF-296, a nitric oxide donor, in patients with chronic stable angina

A double-blind, placebo-controlled, parallel-group, dose-escalation study was performed to evaluate ITF-296, a new nitric oxide donor, in chronic stable angina. Twenty-four male patients underwent exercise electrocardiography in conjunction with echocardiography on three separate occasions within 2 weeks. After two reproducibility tests, the third exercise test was immediately preceded by a 30-min intravenous infusion of either placebo or 0.3, 1.0, or 3.0 microg/kg/min of ITF-296, with six patients in each treatment group. During ITF-296 infusion, systolic blood pressure decreased by a mean of 12 mm Hg compared with a 2 mm Hg increase in the placebo group [difference, -14; 95% confidence interval (CI), -23 to -6 mm Hg]. ITF-296 administration was followed by consistent increases in total exercise time, time to angina threshold, and time to 1-mm ST-segment depression. The mean change in total exercise time was 39 s on placebo and 94 s on ITF-296 (mean difference, 54 s; 95% CI, -48 to 157 mm Hg). The 1.0- and 3.0-microg/kg/min doses increased exercise time by >2 min with no important change in peak rate-pressure product compared with baseline. The trends exhibited in this small preliminary study were consistently pharmacologically plausible and indicate that ITF-296 shows potential antiischaemic efficacy in patients with chronic stable angina.

Clinical and circulatory effects of Iloprost either administered for 1 week or 4 weeks in patients with peripheral obstructive arterial disease at Leriche-Fontaine stage III

BACKGROUND

Iloprost therapy for severe peripheral obstructive arterial disease (POAD) has demonstrated to be effective in reducing the need for amputation. However the feasibility of a 28-day infusion regimen in less severe stages of the disease is poor due to the length in hospital stay. A randomized, controlled, parallel-group pilot study was carried out with the aim to evaluate clinical and circulatory effects of Iloprost, a stable prostacyclin analogue, administered with two different infusion schedules to patients with POAD at Leriche Fontaine stage III.

METHODS

Twenty patients 16 males and 4 females, mean age 66 +/- 6 years) with objective signs of POAD, rest pain for at least two weeks and posterior tibial artery pressure > 50 mmHg, were randomized to either Iloprost i.v. infusion up to 2 ng/Kg/min for 6/h/day for 28 days (Group A) or to Iloprost i.v. infusion up to 1.5 ng/Kg/min for 16/h/day for 7 days (Group B). At baseline (before starting first infusion) after 7 days (for group B only, end of therapy) and after 28 days (end of therapy for Group A, end of study for Group B) the following parameters were evaluated: walking distance, rest pain and analgesic consumption, plethysmographyc parameters (first flow, peak flow and peak flow time) and laser Doppler parameters (rest flow, post ischemic flow).

RESULTS

After 28 days, both Iloprost infusion schedules increased walking capacity (maximum walking distance/pain free walking distance +119/+84% +199/+85% respectively, for Group A and B respectively) reduced ischemic pain (-45% and -48% respectively for Group A and B) and analgesic consumption and improved plethysmographyc and laser Doppler parameters. Tolerability seemed to be better in Group B, suggesting that the lower dose and the shorter duration of the therapy period might result in reduced incidence of headache thus, in principle, increasing patient acceptability.

CONCLUSIONS

The results of this pilot study, if confirmed by larger trials, could have important positive implications in terms of costs, patient comfort and management.

Pharmacokinetics of isosorbide dinitrate in healthy volunteers after 24-hour intravenous infusion

No studies have examined the pharmacokinetics of isosorbide dinitrate (ISDN) after infusion of long duration, even though such infusions are used in patients. We therefore measured ISDN and its active metabolites, isosorbide-5-mononitrate (IS5MN) and isosorbide-2-mononitrate (IS2MN), in plasma of 9 healthy volunteers who received a continuous intravenous infusion of ISDN for 24 hours at a dose rate that lowered diastolic blood pressure by 10% during the first 30 minutes of infusion. All subjects tolerated the infusion except one who experienced intolerable headache. Five subjects received 1 microgram.min-1.kg-1, one 2 micrograms.min-1.kg-1, and two 4 micrograms.min-1.kg-1 ISDN, whereas the full rate of 6 micrograms.min-1.kg-1 was used continuously in one subject. At all infusion rates the plasma concentrations of ISDN were higher at 24 hours than at earlier times, suggesting that a steady-state condition had not been reached at that time. The same was true for the mononitrate metabolites, which reached higher plasma concentrations and were cleared more slowly than the parent compound after the end of the infusion. Apparent elimination half-lives of ISDN, IS2MN, and IS5MN were 67 +/- 10 minutes, 115 +/- 13 minutes, and 272 +/- 38 minutes, respectively. Comparison of low-rate infusions (1 and 2 micrograms.min-1.kg-1) with high-rate infusions (4 and 6 micrograms.min-1.kg-1) showed that the plasma concentration ratios at 24 hours of mononitrate metabolites to parent drug and apparent plasma clearance of ISDN were almost halved at the higher infusion rates.

Cryptosporidium parvum in children with diarrhea in Zulia State, Venezuela

The prevalence and importance of Cryptosporidium parvum as a causal agent of acute diarrhea among pediatric patients from Zulia State, Venezuela was assessed. Single stool specimens were collected from 310 children 0-60 months of age with acute diarrheal disease who were admitted to three public hospitals and from 150 comparable control children without gastrointestinal symptoms who were seen as outpatients. Cryptosporidium parvum oocysts were identified in 35 (11.2%) of 310 children with diarrhea and the coccidium was the single detectable pathogen in only 12 (34.2%). Other potential pathogenic parasites were present in most of the patients shedding oocysts (23 of 35, 65%). In nondiarrheal control children, oocysts were identified in nine (6%) of 150. The data suggest that C. parvum is relatively highly endemic in children 0-60 months of age in Zulia State and that although C. parvum may be an important pathogen associated with diarrhea, it may be a cause of only a small proportion of diarrheal episodes.

Thrombin and platelet inhibition with low-dose calcium-heparin in comparison with ASA in patients with peripheral arterial occlusive disease at Leriche-Fontaine IIb class

Sixty patients with a mean age of 64 years (range 57-77 years), 55 males and 5 females, with peripheral arterial occlusive disease (PAOD) at Leriche-Fontaine IIb class were randomly allocated to receive either subcutaneous calcium-heparin (12,500 IU once daily) or oral acetylsalicylic acid (ASA) (300 mg twice daily), each given for 3 months, followed by a 6-month follow-up period during which no treatment was given. The following parameters were evaluated before randomization, after 1 and 3 months of therapy and after 1, 3 and 6 months of follow-up: pain-free walking distance (PWD), maximum walking distance (WDmax), systolic and diastolic blood pressure, posterior tibial arterial pressure and ankle/arm index at rest and after exercise (treadmill), transcutaneous gas analysis at rest (TcPO2). Under both treatments a statistically significant increase (p < 0.01) in PWD/WDmax was observed after 3 months of therapy. Calcium-heparin was slightly but significantly more effective than ASA in prolonging WDmax (p < 0.05) after 3 months of therapy. Both treatment groups maintained the clinical improvement after 6 months of follow-up without any difference between each-other. Both treatments resulted in a statistically significant increase in TcPO2 and decrease in plasma fibrinogen but under calcium-heparin treatment these modifications were doubled in comparison with ASA (p < 0.01 and p < 0.05, respectively for TcPO2 and fibrinogen). The sustained effects on these parameters after 6 months of follow-up could suggest a more direct and multifactorial activity of calcium-heparin on microcirculation.(ABSTRACT TRUNCATED AT 250 WORDS)

Hemodynamic effects of cadralazine or chlorthalidone in verapamil-treated elderly hypertensives

Fourteen hypertensives aged > 66-77 years, whose diastolic blood pressure (DBP) was > or = 95 mmHg at the end of 1-month treatment with verapamil 240 mg SR, took part in this clinical-hemodynamic study. Patients were randomized to add the long-acting hydralazine derivative, cadralazine, 10 mg once daily, or chlorthalidone 25 mg once daily for 1 month each, to their previous verapamil regimen, according to a double-blind crossover design. Echo-Doppler hemodynamics were performed before starting verapamil, 1 month after verapamil and then after each phase of the crossover study. A significant reduction in DBP both in supine and upright position was observed with both drugs, while the reduction in systolic blood pressure was not significant. Criteria for a satisfactory response were DBP < or = 90 mmHg or a DBP reduction > or = 10 mmHg; this goal was achieved in 9 patients with cadralazine, 9 patients with chlorthalidone, 5 patients with both. The hemodynamic study in responders showed that both cadralazine and chlorthalidone acted through a reduction of peripheral resistances without inducing reflex tachycardia. Thus, cadralazine and chlorthalidone represent a suitable second-step treatment in elderly hypertensives insufficiently controlled by verapamil monotherapy: both drugs act through a reduction in total peripheral resistance (TPR).

Three-month therapy with calcium-heparin in comparison with ticlopidine in patients with peripheral arterial occlusive disease at Leriche-Fontaine IIb class

Forty patients with a mean age of 62.6 +/- 6 years, 36 men and 4 women, with peripheral arterial occlusive disease (PAOD) at Leriche-Fontaine IIb class, were randomly allocated to one of two treatment groups, receiving either 12,500 IU/day of subcutaneous (sc) calcium-heparin (CAE) or 250 mg/day of oral ticlopidine, each given for ninety days. The following parameters were evaluated before the start of the active treatment period and after thirty and ninety days of treatment: pain-free walking distance (PWD), maximum walking distance (WDmax), systolic and diastolic blood pressure (BP), posterior tibial arterial pressure and Winsor index at rest and after exercise (treadmill), transcutaneous oxygen and carbon dioxide pressures at rest (TcPO2 and TcPCO2 respectively), and time to 50% TcPO2 recovery after three-minute ischemia. Both treatments induced an improvement in PWD/WDmax, which, at the end of the study, were increased by 50.7/58.7% and 31.7/36.2%, respectively, for CAE and ticlopidine treatments, respectively.

Felodipine (once daily) versus nifedipine (four times daily) for Prinzmetal's angina pectoris

In 30 consecutive patients with Prinzmetal's angina pectoris, the antiischemic effect of felodipine, a new long-acting vasoselective calcium antagonist, administered at doses of 10 and 20 mg once daily was compared with that of the well-established therapeutic regimen with nifedipine administered at a dose of 20 mg 4 times daily. Twenty-four-hour Holter monitoring was performed during a 2-day placebo run-in and at the end of each of 3 consecutive 6-day periods during which the 3 active treatments were administered in randomized sequence. Three patients withdrew, whereas 27 completed the study. The therapeutic regimens tested proved to be similarly effective; primary end points (ischemic episodes recorded by Holter monitoring, and anginal attacks reported on diary cards) occurred in 5 patients (19%) during nifedipine treatment, and in 7 (26%) and 3 (11%) during felodipine treatment with 10 and 20 mg, respectively (p = not significant). The distribution of residual ischemic episodes demonstrated that treatment with felodipine once daily provides 24-hour antiischemic protection. Twenty-six patients were followed up with 20 mg of felodipine once daily for a mean of 6 +/- 5 months, and 21 of them (81%) remained free of symptoms and Holter-recorded ischemic attacks. It is concluded that for Prinzmetal's angina pectoris, 24-hour antiischemic protection may be achieved with administration of felodipine once daily. The availability of a simplified therapeutic approach may constitute a real advantage in terms of patient compliance and improving the quality of life.

Impedance cardiography for repeated determination of stroke volume in elderly hypertensives: correlation with pulsed Doppler echocardiography

In this double-blind, crossover study the authors have validated stroke volume determination by impedance cardiography against the pulsed Doppler echocardiographic method in elderly hypertensives. They found a good correlation between the stroke volume values obtained by the two methods over a range of values from 30 to 130 mL. The coefficient of linear regression was about .95 at each visit. The mean of the differences was -0.73 mL with a standard deviation of 8.46. Given that individual differences are normally distributed, the values corresponding to 2 standard deviations of the mean define a range covering 95% of the observed differences. From the distribution of the data around the mean plot it appears that, in comparison with pulsed Doppler, impedance cardiography tends to slightly underestimate stroke volumes of greater than 90 mL and to overestimate values of less than 50 mL. The results of this study indicate that impedance cardiography may represent a reliable alternative to pulsed Doppler echocardiography for the noninvasive estimation of cardiac output at rest in elderly patients.

Beta-adrenergic receptors and reflex tachycardia after single and repeated felodipine administration in essential hypertension

To verify the possible contribution of beta-adrenergic receptor down-regulation to the reversal of reflex tachycardia during chronic treatment with a dihydropyridine calcium antagonist, 11 hypertensive patients were studied with noninvasive blood pressure (BP) and heart rate (HR) monitoring after a placebo period, and on the first and seventh day of felodipine administration, 5 mg twice daily. Plasma catecholamines and neutrophil beta-adrenergic receptors were measured on the first and seventh day of treatment, immediately before and 2 h after drug administration. The first administration of felodipine was followed by a significant drop in BP (peak reduction in mean BP 24 +/- 7 mm Hg), lasting 6 h and mirrored by reflex tachycardia (peak increase in HR 14 +/- 9 beats/min). On the morning of the seventh day, 12 h after the previous felodipine administration, mean BP (MBP) was 16 mm Hg lower than on the last placebo day, while HR was unchanged. The next administration of felodipine was followed by a smaller drop in BP (MBP - 15 +/- 7 mm Hg; NS vs. placebo), while reflex tachycardia was the same as after acute felodipine (HR 13 +/- 8 beats/min; p less than 0.05 vs. placebo, NS vs. acute administration). Plasma noradrenaline concentration increased after both acute and chronic administration (p less than 0.0001), and preadministration values were highest on day 7 (p less than 0.05). Neutrophil beta-adrenergic receptor density and affinity did not change either acutely or chronically. This study gives both indirect and direct evidence that beta-adrenoceptor down-regulation does not occur during repeated felodipine administration in hypertension. Reflex tachycardia is not abolished, but is reset to lower BP levels.

Effects of a cable car trip on blood pressure and cardiovascular hormones in lowlander and highlander normotensives

The effects of a cable car trip from 1370 m (4500 ft) to 3460 m (11350 ft) were studied in 6 lowlanders (3 men and 3 women, mean age 31 +/- 4 years, living at an altitude of less than 500 m) and in 10 highlanders (all males, mean age 37 +/- 12 years, ski teachers and cable car workers working for greater than or equal to 6 months/year at a greater than 3000 m). Cuff blood pressure (BP), heart rate, plasma catecholamines, serum renin, aldosterone, ACTH and cortisol were measured immediately before and 20 min after the trip, at rest and at the same air temperature. A handgrip test was also performed under the same conditions. At baseline, lowlanders and highlanders showed significant differences in diastolic BP (86 +/- 5 mmHg in lowlanders and 91 +/- 4 mmHg in highlanders, p = 0.05), plasma noradrenaline (323 +/- 114 pg/ml in lowlanders and 585 +/- 255 in highlanders, p less than 0.05), serum renin (10 +/- 6 pg/ml in lowlanders and 17 +/- 8 in highlanders, p less than 0.05), and serum cortisol (163 +/- 54 ng/ml in lowlanders and 120 +/- 25 in highlanders, p less than 0.01). The acute exposure to high altitude did not modify BP, heart rate or any of the measured cardiovascular hormones in either group. The handgrip test provoked a significant increase in systolic and diastolic BP in both lowlanders and highlanders (p less than 0.01), and this response was not modified by the change in altitude; however, highlanders showed significantly smaller increases in systolic BP than lowlanders at both altitudes (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Verapamil 240 SR versus verapamil 120 SR in arterial hypertension. A randomized double-blind, placebo-controlled study with 24-hour ambulatory blood pressure monitoring

Fifteen patients (6 males, 9 females), age range 36-70 years, were enrolled in a randomized, double-blind, placebo-controlled study according to a Latin-square design, with the aim of comparing 24-hour blood pressure profiles after three 15-day treatment periods with placebo, verapamil SR 120 mg (V120 SR) given twice daily (bid), and verapamil SR 240 mg (V240 SR) given once daily (od). All of the patients were diagnosed as mild or moderate essential hypertensives on the basis of standard casual recordings. Noninvasive 24-hour ambulatory blood pressure (BP) monitoring was performed with an ICR Spacelab 5200 automatic device. In comparison with placebo, a clinically and statistically significant reduction in both systolic and diastolic BP over 24 hours was obtained with both active treatments. Comparison of the two active treatments shows that V240 SR led to a greater reduction in systolic and diastolic BP than V120 SR. No changes in heart rate were observed. Both treatments were well tolerated. In conclusion, both verapamil regimens proved to be effective and safe in treating essential hypertensives, with V240 SR giving better 24-hour BP control.

Benazepril at incremental doses in essential hypertension

The antihypertensive effect of the new non-sulphydryl ACE-inhibitor benzepril was studied in 30 patients (16 men, 14 women; mean age 50 +/- 7 years) with essential hypertension at WHO stage I or II. After a 2-week placebo treatment, patients with lying diastolic blood pressure (DBP) greater than or equal to 95 mmHg were given benzepril 10 mg once daily for 2 weeks. At the end of this period, patients with lying DBP less than 95 mmHg continued with the same dosage, while those with lying DBP greater than or equal to 95 mmHg were blindly up-titrated to benazepril 20 mg once daily. In both cases treatment was continued for further 4 weeks. BP was measured every two weeks 24-26 h after last drug administration. After the run-in period, mean group lying BP was 160/104 +/- 8/5 mmHg. Benazepril significantly reduced systolic blood pressure (SBP) and DBP, both supine and standing (p less than 0.01), while heart rate (HR) did not change. After the first 2 weeks, 13 patients (43%) had lying DBP less than 95 mmHg ("fast responders"), while 17 patients (57%) had DBP greater than or equal to 95 mmHg. By increasing the dosage to 20 mg, a further 5 patients became responder and mean group blood pressure in patients up-titrated with benazepril dropped significantly (-16/-10 mmHg from baseline; p less than 0.01, "slow responders"). Fast responders were younger (47 +/- 5 vs 54 +/- 8 years), had lower baseline BP (160/99 +/- 4/3 vs 173/107 +/- 7/3) and had shorter duration of hypertension (20 +/- 14 vs 61 +/- 27 months) than "slow responders".(ABSTRACT TRUNCATED AT 250 WORDS)

Role of the Frank-Starling mechanism in maintaining cardiac output during increasing levels of treadmill exercise in beta-blocked normal men

To determine the effects of beta blockade on hemodynamics during increasing levels of treadmill exercise, 10 healthy volunteers were studied after 1 week of placebo, and then after 1 week of treatment with oral propranolol, 80 mg twice daily, or dilevalol, 400 mg once daily. The study was randomized and double-blind, with a crossover sequence. Hemodynamics were measured by CO2 rebreathing at rest and at 25, 50, 75 and 100% of VO2 max. After placebo, cardiac output increased from 5.8 +/- 2.1 (rest), to 19.4 +/- 6.4 liters/min (100% VO2 max), mainly due to an increase in heart rate from 84 +/- 6 to 169 +/- 15 beats/min. Stroke volume increased from 70 +/- 27 (rest), to 137 +/- 65 ml (25% VO2 max), and then leveled off to 116 +/- 41 at 100% VO2 max. After both beta blockers, exercise cardiac output was maintained at 100% VO2 max: 20.1 +/- 9.3 liters/min with propranolol and 19.1 +/- 8.6 with dilevalol. However, a significant reduction versus placebo values was observed for cardiac output at 25% VO2 max, from 13.7 +/- 5.9 during placebo, to 9.4 +/- 2.5 during propranolol, and to 9.6 +/- 2.3 during dilevalol (both p less than 0.01 vs placebo). Maintenance of cardiac output with both beta blockers at higher levels of exercise came from an increased stroke volume (p less than 0.05 vs placebo), while heart rate (in beats/min) was greatly reduced (propranolol 61.6 +/- 9.4 rest, 90.1 +/- 10.7 at 100% VO2 max; dilevalol 70.8 +/- 6.4 rest, 99.2 +/- 11.8 at 100% VO2 max, p less than 0.01 vs placebo for each).(ABSTRACT TRUNCATED AT 250 WORDS)