Prognostic implications of cardiac 82-rubidium positron emission tomography in angina patients with no perfusion defects

Background

Myocardial perfusion imaging with 82-Rubidium positron emission tomography (82Rb-PET) is increasingly used in the assessment of stable coronary artery disease (CAD). Among other variables, it provides quantitative measures of myocardial blood flow (MBF) which has shown the prognostic significance of coronary microvascular dysfunction (CMD), also in patients without perfusion defects. However, other 82Rb-PET variables may also be of prognostic significance in these patients.

Purpose

The purpose of this study was to evaluate the prognostic value of 82Rb-PET in patients with symptoms suggestive of CAD but no perfusion defects.

Methods

A study was conducted with 3726 consecutive patients who underwent 82Rb-PET on the suspicion of stable CAD between January 2018 and August 2020. After exclusion of patients with regional perfusion defects, we examined the association of 82Rb-PET derived parameters with a composite endpoint: all-cause mortality, hospitalization for unstable angina pectoris, acute myocardial infarction, heart failure or ischemic stroke in 2175 patients. CMD was defined as myocardial blood flow reserve (MBFR) <2. Analyses were further stratified to assess differences across gender.

Results

Resting and stress MBF were higher in women, while MBFR was lower and CMD more prevalent (30.5% among women versus 25.3% among men, p=0.008). Over a median follow-up of 1.7 years (IQR 1.1–2.5 years) a total of 148 events were observed. In unadjusted analyses, MBF during stress, MBFR, left ventricular ejection fraction (LVEF), LVEF-reserve, heart rate reserve and Ca-score were associated with adverse outcomes in both genders (Figure 1). A joint multivariable Cox model, for both genders, adjusted for patient characteristics, cardiovascular risk factors and 82Rb-PET variables showed reduced MBFR <2 (HR 1.75, 95% CI 1.24–2.48), resting LVEF (HR 1.38 per 10% decrease, 95% CI 1.24–1.54) and LVEF-reserve (HR 1.19 per 5% decrease, 95% CI 1.07–1.31) to be significant predictors of outcomes (Figure 2). Results were consistent in subgroups defined by gender, previous history of ischemic heart disease (IHD), reduced LVEF and atrial fibrillation.

Conclusion

MBFR, LVEF and LVEF-reserve derived from 82Rb-PET are predictors of adverse outcome and provide prognostic information in patients with no perfusion defects. This may aid in identifying patients at risk and provide opportunity of prevention.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): Department of Cardiology, Bispebjerg Frederiksberg Hospital, Copenhagen

Study rationale and design of the CIMT trial: the Copenhagen Insulin and Metformin Therapy trial

BACKGROUND

Patients with type 2 diabetes (T2DM) have an increased mortality rate primarily because of macrovascular disease. Where T2DM patients cannot be managed sufficiently through diet, exercise and peroral antidiabetic drugs, that is when haemoglobin A1c (HbA1c) is above 7.0%, it is yet unknown whether a combination of metformin and insulin analogues is superior to insulin analogues alone. Nor is it known which insulin analogue regimen is the optimal.

OBJECTIVE

The primary objective of this trial is to evaluate the effect of an 18-month treatment with metformin vs. placebo in combination with one of three insulin analogue regimens, the primary outcome measure being carotid intima-media thickness (CIMT) in T2DM patients.

DESIGN

A randomized, stratified, multicentre trial having a 2 x 3 factorial design. The metformin part is double masked and placebo controlled. The insulin treatment is open. The intervention period is 18 months.

PATIENT POPULATION

Nine hundred and fifty patients with T2DM and HbA1c > or = 7.5% on treatment with oral hypoglycaemic agents or on insulin treatment and deemed able, by the investigator, to manage once-daily insulin therapy with a long-acting insulin analogue.

RANDOMIZATION

Central randomization stratified for age (above 65 years), previous insulin treatment and treatment centre.

INTERVENTIONS

Metformin 1 g x two times daily vs. placebo (approximately 475 patients vs. 475 patients) in combination with insulin detemir before bedtime (approximately 315 patients) or biphasic insulin aspart 30 before dinner with the possibility to increase to two or three injections daily (approximately 315 patients) or insulin aspart before the main meals (three times daily) and insulin detemir before bedtime (approximately 315 patients). Intervention follows a treat-to-target principle in all six arms aiming for an HbA1c < or = 7.0%.

OUTCOME MEASURES

Primary outcome measure is the change in CIMT from baseline to 18 months. Secondary outcome measures comprises the composite outcome of death, acute myocardial infarction, stroke or amputation assessed by an adjudication committee blinded to intervention, other cardiovascular clinical outcomes, average postprandial glucose increment from 0 to 18 months, hypoglycaemia and any inadvertent medical episodes. In addition, change in plaque formation in the carotids, HbA1c, cardiovascular biomarkers, body composition, progression of microvascular complications and quality of life will be assessed as tertiary outcome measures. TIME SCHEDULE: Patient enrolment started May 2008. Follow-up is expected to finish in March 2011.

CONCLUSION

CIMT is designed to provide evidence as to whether metformin is advantageous even during insulin treatment and to provide evidence regarding which insulin analogue regimen is most advantageous with regard to cardiovascular disease.

Soya isoflavone-enriched cereal bars affect markers of endothelial function in postmenopausal women

Soya isoflavones are thought to be cardioprotective due to their structural similarity to oestrogen. In order to investigate the effect of soya isoflavones on markers of endothelial function we conducted a randomised, double-blind, placebo-controlled, cross-over study with thirty healthy postmenopausal women. The women consumed cereal bars, with or without soya isoflavones (50 mg/d), for 8 weeks, separated by an 8-week washout period. Systemic arterial compliance (SAC), isobaric arterial compliance (IAC), flow-mediated endothelium-dependent vasodilation (FMD) and nitroglycerine-mediated endothelium-independent vasodilation (NMD) were measured at the beginning of the study and after each intervention period. Blood pressure (BP) and plasma concentrations of nitrite and nitrate (NOx) and endothelin-1 (ET-1) were measured at the beginning and end of each intervention period. NMD was 13.4 (SEM 2.0)% at baseline and 15.5 (SEM 1.1) % after isoflavone treatment compared with 12.4 (SEM 1.0)% after placebo treatment (P=0.03). NOx increased from 27.7 (SEM 2.7) to 31.1 (SEM 3.2) microM after isoflavones treatment compared with 25.4 (SEM 1.5) to 20.4 (SEM 1.1) microM after placebo treatment (P=0.003) and a significant increase in the NOx:ET-1 ratio (P=0.005) was observed after the isoflavone treatment compared with placebo. A significant difference in SAC after the isoflavone and placebo treatment was observed (P=0.04). No significant difference was found in FMD, IAC, BP and ET-1. In conclusion, 8 weeks' consumption of cereals bars enriched with 50 mg soya isoflavones/d increased plasma NOx concentrations and improved endothelium-independent vasodilation in healthy postmenopausal women.

Markers of collagen synthesis is related to blood pressure and vascular hypertrophy: a LIFE substudy

Cardiac fibrosis and high levels of circulating collagen markers has been associated with left ventricular (LV) hypertrophy. However, the relationship to vascular hypertrophy and blood pressure (BP) load is unclear. In 204 patients with essential hypertension and electrocardiographic LV hypertrophy, we measured sitting BP, serum collagen type I carboxy-terminal telopeptide (ICTP) reflecting degradation, procollagen type I carboxy-terminal propeptide (PICP) reflecting synthesis and LV mass by echocardiography after 2 weeks of placebo treatment and after 1 year of antihypertensive treatment with a losartan- or an atenolol-based regimen. Furthermore, we measured intima-media thickness of the common carotid arteries (IMT), minimal forearm vascular resistance (MFVR) by plethysmography and ambulatory 24-h BP in around half of the patients. At baseline, PICP/ICTP was positively related to IMT (r=0.24, P<0.05), MFVR(men) (r=0.35, P<0.01), 24-h systolic BP (r=0.24, P<0.05) and 24-h diastolic BP (r=0.22, P<0.05), but not to LV mass. After 1 year of treatment with reduction in systolic BP (175+/-15 vs 151+/-17 mmHg, P<0.001) and diastolic BP (99+/-8 vs 88+/-9 mmHg, P<0.001), ICTP was unchanged (3.7+/-1.4 vs 3.8+/-1.4 microg/l, NS) while PICP (121+/-39 vs 102+/-29 microg/l, P<0.001) decreased. The reduction in PICP/ICTP was related to the reduction in sitting diastolic BP (r=0.31, P<0.01) and regression of IMT (r=0.37, P<0.05) in patients receiving atenolol and to reduction in heart rate in patients receiving losartan (r=0.30, P<0.01). In conclusion, collagen markers reflecting net synthesis of type I collagen were positively related to vascular hypertrophy and BP load, suggesting that collagen synthesis in the vascular wall is increased in relation to high haemodynamic load in a reversible manner.

24-h Ambulatory blood pressure in patients with ECG-determined left ventricular hypertrophy: left ventricular geometry and urinary albumin excretion—a LIFE substudy

This study was undertaken to evaluate the relationships among left ventricular (LV) geometric patterns and urinary albumin excretion in patients with hypertension and electrocardiographic (ECG) LV hypertrophy. In 143 patients with stage II-III hypertension, 24-h ambulatory blood pressure (BP) monitoring, single urine albumin determination, and echocardiography were performed after 14 days of placebo treatment. Mean age was 68+/-7 years, 35% were women, body mass index was 28+/-5 kg/m(2), LV mass index (LVMI) was 125+/-26 g/m(2), and 24% had microalbuminuria. The mean office BP was 176+/-15/99+/-8 mmHg and the mean daytime ambulatory BP was 161+/-18/92+/-12 mmHg. Ambulatory BP, but not office BP, was higher among albuminuric compared to normoalbuminuric patients. In patients with established hypertension, daytime pulse pressure and office BP were different in the four patterns of LV geometry, with the highest pressure in those with abnormal geometry. Furthermore, microalbuminuria was more frequent in hypertensive patients with LV hypertrophy than in those with either normal geometry or concentric remodelling. White coat hypertensives (10%) showed lower LVMI and no microalbuminuria compared to patients with established hypertension. There were no differences in the prevalence of nondippers (26%) among the four LV geometric patterns or in microalbuminuria. In conclusion, increased daytime pulse pressure and office BP were associated with increased prevalence of abnormal LV geometry. Microalbuminuria was more frequent in groups with concentric and eccentric LV hypertrophy. Ambulatory BP, but not office BP, was higher in albuminuric than normoalbuminuric patients. With regard to the relationship among BP, LV geometric patterns, and urine albumin excretion in this population, 24-h ambulatory BP did not provide additional information beyond the office BP.

Sympathetic dysfunction of central origin in patients with ALS

Amyotrophic lateral sclerosis (ALS) is a severe, progressive disease affecting both the central and peripheral parts of the motor nervous system. Some studies have shown unequivocal indications of a more disseminated disease also affecting the autonomic nervous system. We therefore evaluated the centrally and peripherally mediated autonomic vascular reflexes by (i) the local 133-Xenon washout technique, and (ii) the head-up tilt table test. The results correlated to clinical scores. We examined nine ALS patients and 15 age-matched controls. The 133-Xenon washout test showed a significant reduction in the centrally mediated sympathetic vasoconstrictor response, but a preserved locally mediated response in the patients. In the head-up tilt table test, the patients had a significantly higher mean arterial blood pressure (MAP) compared with controls, probably due to a general increase in vascular resistance. There were no correlations between the ALS Severity Scores and blood flow changes, diastolic blood pressure or MAP. Our study supports previous results, but indicates abnormalities consistent with a solely centrally located sympathetic dysfunction in ALS, independent of the stage of the disease.

Effects of a Ginkgo biloba extract on forearm haemodynamics in healthy volunteers

The aim was to validate possible vasodilating effects of a Ginkgo biloba extract with a secondary aim of finding a pharmacodynamic signal relating to the active component of these extracts. We studied the effect of G. biloba extract on forearm haemodynamics in 16 healthy subjects (nine females, seven males) with a median age of 32 years (range: 21-47). The study was conducted as a randomized, double-blinded cross-over design using oral treatment with G. biloba extract (Gibidyl Forte(R) t.i.d. or placebo for 6 weeks. Forearm blood flow and venous capacity were measured by strain-gauge plethysmography. Blood pressure was measured by standard sphygmomanometry, and forearm vascular resistance (FVR) was derived. Measurements were made at baseline and after 3, 6, 9 and 12 weeks of treatment. Forearm blood flow was significantly higher during active treatment after 3 and 6 weeks as compared with placebo treatment for 3 and 6 weeks (P<0.05). Mean arterial blood pressure was unchanged, making the calculated FVR significantly lower during active treatment (P<0.02). It is concluded that oral treatment with a G. biloba extract (Gibidyl Forte(R)) is able to dilate forearm blood vessels causing increments in regional blood flow without changing blood pressure levels in healthy subjects. The increments in blood flow may be used as a biological signal for pharmacokinetic studies.

Hemodynamic changes after levothyroxine treatment in subclinical hypothyroidism

In hypothyroidism, lack of thyroid hormones results in reduced cardiac function (cardiac output [CO]), and an increase of systemic vascular resistance (SVR). We speculated whether hemodynamic regulation in subjects with subclinical hypothyroidism (SH) (defined as mildly elevated thyrotropin [TSH] despite free thyroxine [T(4)] and triiodothyronine [T(3)] estimates within reference range) would benefit from levothyroxine (LT(4)) substitution. CO was measured by impedance cardiography, which is an observer independent method with high precision, and mean arterial pressure (MAP) by oscillometry. SVR was then calculated as MAP/CO. Measurements were performed before and after 60 degrees head-up tilting, and before and after LT(4) substitution. Plasma levels of catecholamines were also measured. In 16 otherwise healthy women with SH (ages 44-74 years; serum TSH in mean 17.1 mU/L (range, 6.8-27), and normal free T(4) and T(3) estimates) LT(4) treatment resulted in 6% reduction in supine MAP (p < 0.01), 14% increase in upright CO (p < 0.05), and 13%-20% decrease in SVR (supine and upright position, respectively) (p < 0.05). Plasma norepinephrine as well as epinephrine decreased during LT(4) treatment (p < 0.05). These changes were qualitatively similar but quantitatively less pronounced than in 15 women with overt hypothyroidism, also studied. Taking the two groups together (n = 31), pretreatment thyroid function (expressed as either TSH or free T(4) estimate) correlated to CO and SVR as well as the changes induced by LT(4) (p < 0.05), i.e., the lower the thyroid function the lower the CO and the higher the SVR, and the greater the response to LT(4). We conclude, that LT(4) treatment in SH results in changes in hemodynamic parameters of potentially beneficial character. SH and overt hypothyroidism should be regarded as a continuum, and our data favor earlier and more aggressive treatment of SH.

Haemodynamic changes following treatment of subclinical and overt hyperthyroidism

OBJECTIVE

Hyperthyroidism has profound effects on the cardiovascular system, including reduced systemic vascular resistance (SVR) due to relaxation of vascular smooth muscle cells, enhanced heart rate (HR) and cardiac output (CO) due to an increase in cardiac diastolic relaxation, contractility and heart rate. Subclinical hyperthyroidism is characterised by reduced serum TSH levels despite free thyroxine (T4) and tri-iodothyronine (T3) estimates within the reference range, in subjects with no obvious symptoms of hyperthyroidism. We measured haemodynamic changes (using impedance cardiography) in subjects with endogenous subclinical hyperthyroidism in order to elucidate whether these patients had signs of excess thyroid hormone at the tissue level.

DESIGN

The patients were otherwise healthy women with a multinodular goitre (n=6; age 47-81 years; serum TSH 0.006-0.090 mU/l and normal free T4 and T3 estimates), studied before and after normalisation of TSH (0.280-1.120 mU/l) by means of radioiodine treatment, and they were compared with 9 overt hyperthyroid patients (2 with multinodular goitre and 7 with Graves' disease) in the untreated state and after euthyroidism had been obtained.

RESULTS

Treatment of the subclinical hyperthyroid women resulted in 11% reduction in HR (P<0.02), 19% reduction in CO from (means+/-s.d.) 6.93+/-2.15 l/min to 5.58+/-1.94 l/min (P<0.05), and 30% increase in SVR (P<0.02). Similar but more pronounced changes were seen in the hyperthyroid group: 17% reduction in HR, 25% reduction in CO and 46% increase in SVR (all at least P<0.05). Taking all 15 patients together, thyroid function (as measured by free T3 index (FT3I) or TSH) correlated significantly to the haemodynamic parameters as follows: the higher the thyroid function the lower the mean arterial pressure and SVR, and the higher the CO and central aortic compliance (stroke volume/pulse pressure) (P<0.05). Plasma norepinephrine increased significantly after treatment of the overt hyperthyroid patients, whereas epinephrine did not change, and no changes were seen among subclinical hyperthyroid patients.

CONCLUSION

Treatment of endogenous subclinical hyperthyroidism resulted in significant changes in several haemodynamic parameters regarding the heart and the vascular system, compatible with some degree of excess tissue exposure to thyroid hormones in the untreated state. Our data favour more aggressive treatment of these patients, and endogenous subclinical hyperthyroidism might be regarded as a mild form of hyperthyroidism.

Diagnostic value of the Nycocard, Nycomed D-dimer assay for the diagnosis of deep venous thrombosis and pulmonary embolism: a retrospective study

The relatively new D-dimer assay from Nycomed Pharma (Nycocard), which has shown both high sensitivity and specificity in diagnosing deep venous thrombosis (DVT) and pulmonary embolism (PE) in earlier studies, was re-evaluated retrospectively. The diagnostic value of the D-dimer assay for DVT was evaluated with contrast venography as reference. The diagnostic value of the D-dimer assay for PE was evaluated with pulmonary scintigraphy as reference. D-dimer tests were examined from 54 consecutive patients. The D-dimer assay was found to have a sensitivity and specificity of 50% and 58%, respectively, for the diagnosis of DVT, with a positive predictive value (PPV) and negative predictive value (NPV) of 55% and 54%, respectively. Using reference diagnostic results of high probability and low probability for the diagnosis of PE, the D-dimer test sensitivity and specificity was found to be 40% and 94%, respectively (PPV: 86%, NPV: 64%). The diagnostic value of the Nycocard(R) assay appears to be very limited for the diagnosis of DVT and PE. This retrospective study suggests that it is unsuitable as a screening method. Further re-evaluation of D-dimer assays is recommended prior to routine clinical use.

Measurement of arterial compliance in vivo

Measurement of arterial compliance is of interest in evaluating patients with atherosclerosis and other diseases which affect the vessels. Arterial compliance is the relation between changes in transmural pressure and volume of an arterial segment, where a high compliance signifies large changes in volume per change in transmural pressure. The relation between changes in transmural pressure and volume is far from linear as compliance increases progressively with decreases in blood pressure. A change in compliance could indicate static changes in arterial wall composition, i.e. the relation between elastic and collagen fibres and accumulation of disease related deposits or dynamic changes caused by alterations in muscular tone. The most used method reflecting arterial compliance is the measurement of pulse wave velocity. However, the pulse wave velocity method measures compliance at ambient transmural pressures and is affected both by the actual blood pressure and the rate of pressure change. Another commonly used method employs the echo-tracking technique to measure the arterial diameter simultaneously with continuous blood pressure monitoring. By this method it is possible to calculate arterial compliance for continuous pressure values between the diastole and the systole. The volume-oscillometry method is based on the fact that the artery can be made to collapse at the end of the diastole by an occlusive cuff while it remains open in a pressure dependent manner during the rest of the cardiac cycle. Changes in the arterial volume is transmitted to the cuff, where it induces a measurable change in pressure, and hence the volume of the artery can be calculated at different values of transmural pressures. Using this method on normal subjects has shown that the arterial compliance decreases with increasing age and that females have lower compliance than males primarily due to a smaller diameter of their arteries. It has also been shown that patients with essential (diastolic) hypertension have compliances which are higher or equal to those of normal subjects, and that patients with systolic hypertension have lower arterial compliances than normal subjects. The former finding is in contrast with pulse wave velocity measurements, where diastolic hypertension was associated with low arterial compliance.

[Ambulatory 24-hour blood pressure monitoring. A comparative study of oscillometric and auscultatory blood pressure measurement]

The purpose of this study was to investigate the compatibility between oscillometric and auscultatory methods, and to determine whether one is preferable to the other for ambulatory 24 h blood pressure monitoring. We used an A & D TM 2421 blood pressure monitoring device. Our investigation included 281 patients with suspected hypertension or undergoing treatment for hypertension. We were able to compare 18,790 paired measurements. The difference (auscultatoric--oscillometric) in paired single readings between the two methods was 1.4 +/- 19 mmHg (mean +/- SD) for systolic and -2.4 +/- 18 mmHg for diastolic readings. The difference for 24 h monitoring amounted to 0.7 +/- 4 mmHg for systolic and -2.2 +/- 6 mmHg for diastolic measurements. The auscultatory method showed a uniformed distribution of errors throughout the 24 h, whereas the oscillometric method had fewer errors in the evenings, but more during working hours. A weak correlation between the difference and systolic blood pressure levels, age and pulse pressure was found. Difference in diastolic blood pressure correlated only weakly with the level of pulse pressure. Although we found a considerable SD on single readings, there was a good agreement between the mean values for the 24 h monitoring for the two methods. The findings suggest that, for this equipment, the oscillometric method is preferable for 24 h ambulatory blood pressure monitoring because it provides a much higher rate of successful readings.

Smoking related to 24-h ambulatory blood pressure and heart rate: a study in 352 normotensive Danish subjects

This study shows the association between smoking and both office and ambulatory blood pressure. By means of stratification, a uniform number of subjects of both sexes and spanning 6 decades (aged 20 to 79 years) were recruited randomly from the local community register. A total of 352 subjects participated, including 161 smokers. Smokers (both sexes and all age groups summed), as compared with nonsmokers had statistically significant lower office blood pressure as follows (mean systolic +/- SED/mean diastolic +/- SED): (systolic and diastolic, -6.8 +/- 2.1/-3.9 +/- 1.3); day ambulatory blood pressure (diastolic, /-2.8 +/- 1.0); and night ambulatory blood pressure (systolic and diastolic, -4.2 +/- 1.8/-3.9 +/- 1.1). The intraperson variability of the day ambulatory blood pressure (as measured every 15 min) was identical for the smokers and the nonsmokers. Smokers were found to have a diminished "white coat" effect; this diminished white coat effect has not previously been described. The major white coat effect was seen in the older nonsmokers, whereas the diminished white coat effect was most pronounced in the older male smokers and in the younger female smokers. Smokers seem to have a diminished white coat effect, as well as a lower ambulatory blood pressure throughout the day (diastolic) and at night (systolic and diastolic). The similar intraperson variability found in the smokers' and nonsmokers' blood pressure further speaks for a consistently lower blood pressure in smokers as compared with nonsmokers.

[Round-the-clock blood pressure measurements in 352 persons--a reference material]

The aim of this study was to establish reference values for 24-hour ambulatory blood pressure in a Danish population stratified for gender and age in the decades from 20 to 79 years of age. A sample of 352 persons, 179 men and 173 women randomly selected from the local community register, age 20-79 years underwent 24-h ambulatory blood pressure monitoring. For men age < 50 daytime ambulatory blood pressure (median) was 125/79 mmHg and night time was 106/65 mmHg, for women the respective pressures were 113/77 mmHg and 97/64 mmHg. For men age > or = 50 daytime ambulatory blood pressure was 133/83 mmHg and night time was 124/86 mmHg, for women the respective pressures were 122/83 mmHg and 105/65 mmHg. Presently, we can only relate cardiovascular risk to clinic blood pressure. Therefore we have calculated corresponding ambulatory blood pressure values to WHO's upper limit 160/90 mmHg for normal blood pressure in the clinic and found 154/87 mmHg for daytime and 134/74 mmHg at night. For a clinic pressure of 95 mmHg the corresponding daytime value was 91 mmHg, for 100 mmHg it was 95 mmHg.

[Determination of diurnal blood pressure variations in cirrhosis]

Cirrhotic patients have disturbed systemic haemodynamics with reduced arterial blood pressure, but this has not been investigated during daily activity and sleep. Systolic (SBP), diastolic (DBP), and man arterial blood pressure (MAP), and heart rate (HR) were measured by an automatic ambulatory device for monitoring blood pressure in 35 patients with cirrhosis and 35 healthy matched controls. During the day-time, SBP, DBP and MAP were significantly lower in the patients than in the controls (median 118 vs 127; 70 vs 78; 86 vs 94 mmHg, p < 0.0001 to p < 0.05). The night-time blood pressures were almost similar in the two groups (108 vs 110; 65 vs 67; 78 vs 82 mmHg, NS). Conversely, HR was significantly higher in the patients both in the day-time (86 vs 72 min-1, p < 0.0001) and night (80 vs 64 min-1, p < 0.0001). Consequently, the reduction in blood pressure and HR from day-time to night-time was significantly lower in the patients than in the controls (p < 0.0001 to p < 0.01). Multiple regression analysis revealed HR, serum albumin, serum sodium, and clotting factors 2, 7 and 10 as significant independent predictors of SBP in cirrhosis. In conclusion, cirrhotic patients have elevated HR, but surprisingly normal arterial blood pressure during the night-time, and the circadian variation in blood pressure and HR is diminished probably due to an almost unaltered cardiac output during the 24 hours. These results may reflect a major defect in the ability of optimal regulation of blood pressure in cirrhotic patients.

24-h ambulatory blood pressure in 352 normal Danish subjects, related to age and gender

The study was conducted to determine age and sex stratified normal values for 24-h ambulatory blood pressure. A sample of 352 healthy subjects (all white) were randomly selected from the community register and stratified by sex and age groups in decades from 20 to 79 years of age. Persons with a history of hypertension, cerebral apoplexy, diabetes, myocardial or renal disease, and who were taking blood pressure-influencing medication were excluded. Ambulatory blood pressure was recorded over 24 h, with measurements taken every 15 min from 07:00 to 22:59, and every 30 min from 23:00 to 6:59. Systolic blood pressure increased only slightly with age and was significantly higher in men than in women. The diastolic blood pressure increased only slightly with age in both sexes until the 50 to 59 years age group and declined thereafter. The diastolic blood pressure was not different for the two sexes. Both systolic and diastolic blood pressure were approximately 15% lower during the night regardless of age or sex. Ambulatory blood pressure during the daytime was on an average of 5 mm Hg lower than office blood pressure, but the mean difference between the two measurements increased with age. The variability of the difference also increased with age.

IN CONCLUSION

Normal values for ambulatory blood pressure are presented in a randomly selected age- and gender-stratified population. Differences between office blood pressure and ambulatory blood pressure increased with age suggesting that the previously observed higher blood pressure seen in the elderly partly might be explained by a greater impact of white coat hypertension in older people.

Office and ambulatory blood pressure: a comparison between amlodipine and felodipine ER. Danish Multicentre Group

The anti-hypertensive efficacy and safety of extended-release (ER) felodipine (5, 10 or 20 mg) and amlodipine (5 or 10 mg) once daily were compared in patients with mild-to-moderate essential hypertension in a double-blind, double-dummy, randomised, comparative study. A total of 118 patients were allocated to a 12-week, double-blind treatment with either felodipine ER (n = 57) or amlodipine (n = 61). The anti-hypertensive effect was evaluated by measuring office blood pressure (BP) at baseline and after 4, 6, 8 and 12 weeks, together with 24 h ambulatory blood pressure monitoring (ABPM) at baseline, on day 1 of treatment and at the end of the study. The mean office BP changes from baseline to week 12 were -13.4 (+/- 15.7)/-11.8 (+/- 6.9) mmHg for felodipine ER (mean daily dose 11.2 mg) and -15.3 (+/- 17.0)/-12.9 (+/- 7.3) mm Hg for amlodipine (mean daily dose 7.4 mg). All BP reductions were significant (P < 0.01) with respect to time, but differences between treatment groups were not significant. The mean ambulatory BP changes from baseline to end of the study were -11.6 (+/- 5.2)/-10.0 (+/- 2.0) mmHg for felodipine ER and -16.3 (+/- 4.4)/-9.6 (+/- 3.0) mm Hg for amlodipine, both significant (P < 0.01). The fall in ambulatory SBP was significantly greater (P < 0.001) in the patients treated with amlodipine compared with felodipine ER whereas there was no difference between the groups with respect to ambulatory DBP. Both drgs were well tolerated with a withdrawl rate of 12% equally distributed.(ABSTRACT TRUNCATED AT 250 WORDS)

Noninvasive 24-hour ambulatory arterial blood pressure monitoring in cirrhosis

Cirrhotic patients have disturbed systemic hemodynamics with reduced arterial blood pressure, but this has not been investigated during daily activity and sleep. Systolic (SBP), diastolic (DBP), and mean arterial blood pressure (MAP), and heart rate (HR) were measured by an automatic ambulant device for monitoring blood pressure in 35 patients with cirrhosis and 35 healthy matched controls. During the daytime, SBP, DBP, and MAP were significantly lower in the patients than in the controls (median 118 vs. 127; 70 vs. 78; 86 vs. 94 mm Hg, P < .0001 to P < .05). The nighttime blood pressures were almost similar in the two groups (108 vs. 110; 65 vs. 67; 78 vs. 82 mm Hg, NS). Conversely, HR was significantly higher in the patients both in the daytime (86 vs. 72/min, P < .0001) and at night (80 vs. 64/min, P < .0001). Consequently, the reduction in blood pressure and HR from daytime to nighttime was significantly lower in the patients than in the controls (P < .0001 to P < .01). Multiple regression analysis showed HR, serum albumin, serum sodium, and clotting factors 2, 7, and 10 as significant independent predictors of SBP in cirrhosis. In conclusion, cirrhotic patients have elevated HR, but surprisingly normal arterial blood pressure during the nighttime, and the circadian variation in blood pressure and HR is diminished, probably because of an almost unaltered cardiac output during the 24 hours. These results may reflect a major defect in the ability of optimal regulation of blood pressure in cirrhotic patients.

Comparative effects of amlodipine and felodipine ER on office and ambulatory blood pressure in patients with mild to moderate hypertension. Danish Multicentre Group

The anti-hypertensive efficacy and safety of extended-release (ER) felodipine (5, 10 or 20 mg) and amlodipine (5 or 10 mg) once daily were compared in patients with mild to moderate essential hypertension in a double-blind, double-dummy, randomised, comparative study. One hundred and eighteen patients were randomised to receive either felodipine ER (n = 57) or amlodipine (n = 61) for 12 weeks. Efficacy was assessed by measuring office blood pressure (BP) at baseline and after 4, 6, 8 and 12 weeks, together with 24h ambulatory blood pressure monitoring (ABPM) at baseline, on day 1 of treatment and at the end of the study. The mean office BP changes from baseline to week 12 were -13.4/-11.8 mmHg for felodipine ER (mean daily dose 11.2 mg) and -15.3/-12.9 mm Hg for amlodipine (mean daily dose 7.4 mg). Changes in office BP between treatment groups were not significant. The mean 24h ambulatory BP changes from baseline to end of the study were -11.6/-10.0 mm Hg for felodipine ER and -16.3/-9.6 mm Hg for amlodipine, both significant (P < 0.01). The fall in systolic ambulatory BP was significantly greater (P < 0.001) in the amlodipine-compared with felodipine ER-treated patients but there was no difference between the groups with respect to diastolic ambulatory BP. Both drugs were well tolerated with only seven patients withdrawing because of side-effects, equally distributed between treatment groups. Headache and flushing were significantly (P < 0.05) more frequent in the felodipine ER group. Amlodipine appears to be more potent on a milligram to milligram basis and induces fewer side-effects than does felodipine ER.

Diurnal blood pressure profile in patients with severe congestive heart failure: dippers and non-dippers

Patients with severe congestive heart failure (CHF) have increased sympathetic nervous activity and altered baroreceptor function, which may influence the diurnal blood pressure rhythm. The 24-h blood pressure profile was measured in 25 patients with severe CHF (mean ejection fraction: 17%) and 25 control subjects. Systemic blood pressure was measured automatically at the arm by a non-invasive blood pressure monitoring system every 15 min. The mean +/- SD systolic blood pressure in CHF patients and controls was during day-time 105 +/- 10 and 130 +/- 11 mm Hg and night-time 97 +/- 10 and 112 +/- 10 mm Hg, i.e. the nocturnal decrease was 9 +/- 6 and 18 +/- 8 mm Hg, respectively (p < 0.0005 for all). The subjects could be divided into two groups: dippers and non-dippers, with and without a relative decrease in nocturnal systolic blood pressure > 10%. There was significantly more non-dipping CHF patients (16) than controls (5) (p < 0.01). Systolic blood pressure was in CHF dippers vs. non-dippers during day-time: 108 +/- 7 vs. 104 +/- 12 mm Hg (NS) and night-time: 92 +/- 7 vs. 99 +/- 11 mm Hg (p = 0.08). The nocturnal decrease was 16 +/- 3 vs. 5 +/- 4 mm Hg and the relative nocturnal decrease 15 +/- 3 vs. 5 +/- 3% (p < 0.00001 for both). It is concluded that patients with severe congestive heart failure can be divided into two groups: dippers and non-dippers, with and without a normal decrease in nocturnal blood pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

[Diurnal blood pressure. Practical, prognostic and therapeutic aspects]

Outpatient blood pressure monitoring is now feasible employing good equipment which is easy to handle. However, some major problems must be solved before outpatient measurement of blood pressure (AMBP) can be employed routinely in the treatment of hypertension. Normal measurements, a satisfactory description of the AMBP curve and more prognostic studies with and without treatment are necessary.

Accidental injuries and blood exposure to cardiothoracic surgical teams

A survey was undertaken over a 15-week period (62 working days) to find out the incidence and common mechanism of accidental injuries and blood exposure in cardiothoracic surgical teams. Two hundred and seventy events were reported: 70% glove penetrations, 18% skin punctures, 4% non-bleeding skin lesions and 8% lacerations with bleeding. Eye splashes occurred in 14% of the cases. The risk to the team was higher for cardiac surgery (1.6) than for thoracic surgery (0.5) and endoscopy (0.01). Most of the events were self-inflicted by experienced personnel. The surgeon's left index finger was most frequently injured, and the majority of the injuries were caused by needles followed by wire injuries during sternal closure. Prevention should be directed towards a safer technique for sternal closure, and protection of the surgeon's hands, especially his left index finger, should be found. Eye protection with goggles should become routine. This study demonstrates that open heart procedures carry a high risk of injury and frequent exposure to blood increasing the risk to the surgical team of acquiring viral infections (hepatitis-B and HIV) from the patients.