Aerobic capacity in adults with tetralogy of Fallot

BACKGROUND

We investigated the aerobic capacity of 168 adult patients who had undergone successful surgical repair of retralogy of Fallot at the University of Toronto Congenital Cardiac Centre for Adults.

METHODS

We compared values of peak uptake of oxygen, peak heart rate, forced vital capacity, and forced expiratory volume in 1 second to predicted values for their age groups.

RESULTS

The patients who had undergone surgical repair of tetralogy of Fallot demonstrated an overall diminished peak uptake of oxygen, at 51%,and peak heart rate, at 79%, compared to predicted values. No difference in peak aerobic capacity was found according to the initial surgical strategy of palliation or repair.

CONCLUSIONS

Adult patients who have undergone surgical repair of tetralogy of Fallot have lower peak uptake of oxygen, and peak heart rate, compared to predicted values. The reduction in the peak heart rate may affect their exercise capacity. The peak uptake of oxygen also decreased with increasing age at the time of testing, and the age at surgical repair.

A pharmacoeconomic evaluation of results from the Coronary Angioplasty Amlodipine Restenosis Study (CAPARES) in Norway and Canada

INTRODUCTION

The objective of this analysis was to evaluate the health economic benefits of using amlodipine in patients undergoing angioplasty procedures in Canada and Norway.

METHODS

A decision tree model was constructed to find the total expected cost per patient for a 4-month time period following an initial angioplasty. The model used clinical data from the Coronary Angioplasty Amlodipine Restenosis Study (CAPARES), a prospective, randomized, double blind, placebo-controlled trial conducted to investigate the effects of amlodipine on restenosis and clinical events in patients undergoing percutaneous transluminal coronary angioplasty (PTCA). Outcomes of interest to this analysis included MI, repeat PTCA, CABG, and all-cause mortality. Clinical experts from Canada and Norway were enlisted and a modified Delphi study approach was used to quantify healthcare resources consumed for each clinical outcome.

RESULTS

The use of amlodipine decreased the rates of MI, PTCA, and CABG by 2.0, 4.7, and 2.7%, respectively. The total expected cost per patient using amlodipine was $6,398.30 (US$4,323) in Canada and kr 59,993.27 (US$6,846) in Norway. The total expected cost per patient not using amlodipine was $6,519.37 (US$4,405) in Canada and kr 64,292.17 (US$7,337) in Norway. The model demonstrated potential cost-savings over a 4-month follow up period resulting from the improved clinical outcomes for patients using amlodipine with PTCA--$121,071 (US$81,844) per 1000 patients in Canada and kr 4,298,899 (US$490,074) per 1000 patients in Norway.

CONCLUSIONS

The adjunctive use of amlodipine is a cost-effective therapeutic strategy to achieve more favorable clinical outcomes in patients undergoing PTCAs in Canada and Norway.

Supine and exercise systolic blood pressure predict cardiovascular death in middle-aged men

AIM AND METHODS

The outcome of 1999 apparently healthy men, aged 40-59 years, initially investigated in the period 1972-1975, has previously been ascertained at 7 and 16 year follow-ups. This has now been repeated after 21 years, to determine whether seated systolic blood pressure (BP) during a bicycle ergometer exercise test adds prognostic information on cardiovascular (CV) mortality beyond that of systolic BP measured after 5 min of supine rest.

RESULTS

After 21 years, 41 979 years of observation, 470 patients had died, 255 from CV causes. Supine systolic BP [2 SD increase: relative risk (RR) 1.6, 95% confidence interval (CI) 1.3-2.0, P < 0.0001], 6 min exercise systolic BP (2 SD increase: RR 1.6, 95% CI 1.3-2.0, P < 0.0001) on the starting workload of 600 kpm/min (approximately 100 W, 5880 J/min) and maximal systolic BP (2 SD increase: RR 1.5, 95% CI 1.2-1.9, P = 0.0005) during work were all related to CV mortality when adjusting for a large number of variables measured in the present study including age, exercise capacity, heart rates, smoking habits, glucose tolerance and serum cholesterol. When including other systolic BPs in the continuous multivariate analysis, supine systolic BP (2 SD increase: RR 1.4, 95% CI 1.04-1.9, P = 0.029) and 6 min systolic BP at 600 kpm/min (2 SD increase: RR 1.4, 95% CI 1.06-1.9, P = 0.017) were independent predictors of CV death but not maximal systolic BP during exercise (2 SD increase: RR 1.0, 95% CI 0.7-1.2, P = 0.95).

CONCLUSION

These results are different from the mortality data at 16 years, when the independent predictive effect of supine systolic BP was cancelled out by 6 min exercise systolic BP at 600 kpm/min. Twenty-one years of follow-up of 1999 apparently healthy men disclose independently predictive information on CV death, of both supine systolic BP and 6 min exercise systolic BP taken at an early moderate workload. The influence of maximal exercise systolic BP on CV death is however cancelled out by the two other systolic BPs.

Prediction of Type 2 diabetes in healthy middle-aged men with special emphasis on glucose homeostasis. Results from 22.5 years' follow-up

AIMS

To study the glucose disappearance rate and fasting blood glucose as predictors of Type 2 diabetes in a 22.5-year prospective follow-up of 1947 healthy non-diabetic men.

SUBJECTS AND METHODS

Of a cohort of 2014 Caucasian men, the 1947 who had both fasting blood glucose < 110 mg/dl and an intravenous glucose tolerance test were included. A number of other physiological parameters were also determined at baseline. Multivariate Cox regression analyses were used to investigate the possible significance of the glucose disappearance rate and fasting blood glucose as predictors of Type 2 diabetes.

RESULTS

After 22.5 years' follow-up, 143 cases of Type 2 diabetes had developed. Glucose disappearance rate and fasting blood glucose were moderately correlated (r = -0.32). Men in the lowest quartile of glucose disappearance rate and highest quartile of fasting blood glucose had markedly higher diabetes rates than all other men (P < 0.0001). After adjusting for each other, age, diabetes heredity, body mass index, physical fitness, triglycerides, cholesterol and blood pressure (Cox model), both glucose disappearance rate and fasting blood glucose remained major predictors of diabetes

CONCLUSIONS

Glucose disappearance rate and fasting blood glucose are, in spite of low intercorrelation, major long-term predictors of Type 2 diabetes in healthy non-diabetic Caucasian men.

Aerobic capacity in adults with various congenital heart diseases

As an increasing number of patients with congenital heart disease reach adulthood, more information is needed regarding outcomes. The first signs of impaired heart function may appear during exercise testing. The aim of the present study was to establish mean values for maximal oxygen uptake in adults with various congenital heart diseases. Patients from 6 major diagnostic groups were identified, including patients with atrial septal defect (ASD, n = 93), transposition of the great arteries corrected with the Mustard procedure (n = 84), congenitally corrected transposition of the great arteries (CCTGA, n = 41), Tetralogy of Fallot (n = 168), Ebstein's anomaly (n = 37), and Modified Fontan procedure (n = 52). Diminished maximal oxygen uptake was found in all diagnostic groups across age compared with healthy subjects. A significant decrease in maximal oxygen uptake with aging was found in those with ASD (p <0.0001), CCTGA (p = 0.01), and Tetralogy of Fallot (p <0.0001). There was no significant decline, however, in Ebstein's anomaly (p = 0.270), Fontan procedure (p = 0.182), and in the Mustard patients (p = 0.188). All patients achieved significantly lower heart rates than predicted (mean for all groups, p <0.0001). Forced vital capacity values (3.51 L, mean SD +/- 1.02) were lower than predicted values (4.10 L, mean SD +/- 0.90, p <0.0001) for all patients groups except those with ASD. Mean values, however, were within the accepted 20% range of variance. This study showed diminished aerobic capacity in all diagnostic groups when compared with a healthy population. The maximal oxygen uptake values across age groups can be used as reference values in patients with similar diagnoses and as the basis for further research.

Plasma levels of natriuretic peptides and hemodynamic assessment of patent ductus arteriosus in preterm infants

The main purpose of this study was to investigate whether circulating natriuretic peptides in premature infants reflect the hemodynamic significance of a patent ductus arteriosus (PDA). The study comprises 120 examinations in 55 premature infants with a mean gestational age of 27.2 wk and a mean birthweight of 933 g. Based on clinical and echocardiographic findings, the hemodynamic influence of ductal shunting was classified as small, moderate or large. Blood samples for N-terminal proatrial natriuretic peptide (Nt-proANP) and brain natriuretic peptide (BNP) were analysed after completion of the clinical part of the study. Linear regression indicated a very strong association between Nt-proANP and BNP (adjusted R = 0.89). The mean levels of Nt-proANP and BNP increased with the size of the shunt through a PDA, and peptide values followed hemodynamic alterations. The size of PDA accounted for 50% and 47% of the total variation in the plasma values of Nt-proANP and BNP, respectively. In detecting an echocardiographically significant PDA, the area under a ROC curve was 0.94 for Nt-proANP and 0.90 for BNP.

CONCLUSION

The magnitude of shunting through a PDA is the main determinant of plasma levels of natriuretic peptides in premature infants. Nt-proANP and BNP seem to have the same pattern of secretion. Our findings indicate that measurements of natriuretic peptides may provide clinically relevant information in the hemodynamic assessment of premature infants.

Residual pulmonary hypertension in children after treatment with inhaled nitric oxide: a follow-up study regarding cardiopulmonary and neurological symptoms

Inhaled nitric oxide is a potent vasodilator in acute severe pulmonary hypertension and is increasingly used as rescue treatment in intensive care algorithms aiming at reducing severe hypoxaemia in neonates and children. Although the immediate effects may seem impressive, long-term outcome regarding residual pulmonary hypertension and other sequelae has been studied in only a very few patients. The aim of the present study was to evaluate residual pulmonary hypertension, cardiopulmonary or neurological symptoms in children after treatment with inhaled nitric oxide in severely hypoxaemic and/or pulmonary hypertensive mechanically ventilated children. The study was performed in four paediatric intensive care units in university hospitals in Sweden, Norway and Australia. Patients who had received inhaled nitric oxide as part of their intensive care treatment for severe hypoxaemia and/or pulmonary hypertension, and in whom 6 mo had elapsed since treatment, were included for evaluation. Thus 36 paediatric or neonatal patients were examined for circulatory, respiratory or neurological disorders with clinical examination, echocardiography, chest X-ray and a capillary blood sample. Four patients with congenital heart disease had residual pulmonary hypertension. Nine patients were receiving bronchodilators. Sixteen patients had minor (n = 15) or moderate (n = 1) changes on a chest X-ray. One patient had a possible delay in psychomotor development.

CONCLUSIONS

In spite of the severity of their primary illness, we found that the overwhelming majority of the surviving children were asymptomatic and doing well. The few residual circulatory and respiratory symptoms could be related to the initial condition.

Cardiac surgery in a girl with trisomy 13

We describe a profoundly retarded infant girl with multiple anomalies caused by trisomy 13. Due to heart failure, which was resistant to medical treatment, we closed successfully a ventricular septal defect at three months of age. She died at 10 months of age. Despite the short survival, we believe that the patient benefitted significantly from the surgical repair of her cardiac defect.

Erythrocyte sedimentation rate: a possible marker of atherosclerosis and a strong predictor of coronary heart disease mortality

AIMS

Since atherosclerosis is a chronic inflammation and the erythrocyte sedimentation rate is an appropriate test for monitoring chronic inflammatory responses, we wanted to investigate whether the erythrocyte sedimentation rate might carry prognostic information on the risk of sustaining coronary heart disease events.

METHOD

The erythrocyte sedimentation rate was determined in 2014 apparently healthy men aged 40-60 years during an extensive cardiovascular survey in 1972-75, and the test was repeated in an identical follow-up examination 7 years later. Cause-specific mortality and rates of non-fatal myocardial infarction were followed for 23 years.

RESULTS

The erythrocyte sedimentation rate was strongly correlated with age, haemoglobin level, smoking status, total cholesterol level and systolic blood pressure. After adjusting for all these associations in multivariate Cox regression analyses, the erythrocyte sedimentation rate emerged as a strong short- and long-term predictor of coronary heart disease mortality, particularly in men who had developed angina pectoris and/or had a positive exercise ECG test at the second survey. Increases in non-coronary heart disease deaths and in non-fatal myocardial infarctions were only seen in the upper erythrocyte sedimentation rate range.

CONCLUSIONS

The erythrocyte sedimentation rate is a strong predictor of coronary heart disease mortality, and appears to be a marker of aggressive forms of coronary heart disease. The erythrocyte sedimentation rate probably gives substantial information in addition to that given by fibrinogen on the risk of coronary heart disease death.

Hypothesis: the recent decline in coronary heart disease mortality--mainly a shift from fatal to non-fatal events?

OBJECTIVES

A marked, sequential decline in coronary heart disease (CHD) mortality is established, but not its causes. Does it reflect modern treatment effects or a spinoff of primary prevention? The aim of this study was to explore this issue using a prospective cohort follow-up design.

DESIGN

In 1972-1975 and 1980-1982 Cohorts 1 (n = 613) and 2 (n = 667) of identical age (males, mean 56 years) were examined, and thereafter followed closely for 14 years. CHD risk- and treatment patterns, incidence of non-fatal myocardial infarctions (MIs) and total-, cardiovascular and CHD mortality rates were studied.

RESULTS

CHD risk factors were more favourable, medical treatment more aggressive and 14-years CHD mortality, as expected, lower in Cohort 2 (7.7%/4.8%, p = 0.032). However, hospital- and prospective ECG data revealed opposite trends in non-fatal cohort CHD incidence, and aggregated numbers of CHD deaths and non-fatal MI cases were 16.7%/16.0% in Cohort 1/2 (p = 0.90).

CONCLUSIONS

A marked, sequential reduction in CHD mortality was followed by a reciprocal increase in non-fatal MIs. This phenomenon may prevail in low CHD-endemic areas, and may call for altered primary preventive measures for reduction in total CHD incidence.

Type 2 diabetes and maternal family history: an impact beyond slow glucose removal rate and fasting hyperglycemia in low-risk individuals? Results from 22.5 years of follow-up of healthy nondiabetic men

OBJECTIVE

Although an excess transmission of type 2 diabetes from mothers has been documented, whether this is an independent trait or whether the effect can be detected early through risk factors for type 2 diabetes remains to be elucidated. The objective of this study was to investigate the prevalence of and the possible prospective effect of family history on type 2 diabetes incidence adjusted for multiple diabetes risk factors in a 22.5-year follow-up study of healthy men.

RESEARCH DESIGN AND METHODS

A total of 1,947 apparently healthy nondiabetic men with fasting blood glucose (FBG) levels <110 mg/dl at baseline, in whom an intravenous glucose tolerance test (IVGTT) was administered and several conventional risk factors were measured, were followed for 22.5 years. Family history data were obtained at the baseline examination, and morbidity data were obtained from repeated investigations, hospital records, and death certificates.

RESULTS

A total of 131 men reported maternal diabetes family history only, 65 men reported paternal diabetes family history only and 10 men reported both maternal and paternal diabetes family history. Among the 1,947 men, 143 cases of type 2 diabetes developed during 22.5 years of observation. Maternal family history and combined maternal and paternal family history predisposed to future type 2 diabetes both in univariate Cox analysis and in multivariate Cox regression analysis after adjusting for glucose disappearance rate (Rd) during an IVGTT, FBG level, BMI, physical fitness, triglyceride level, and age. Maternal family history showed a relative risk (RR) of 2.51 (95% CI 1.55-4.07), combined maternal and paternal family history showed an RR of 3.96 (1.22-12.9), and paternal family history showed an RR of 1.41 (0.657-3.05) in multivariate analysis.

CONCLUSIONS

Maternal family history appears to be an important risk factor for type 2 diabetes independent of prediabetic Rd, FBG, BMI, and physical fitness levels.

Results and clinical implications of the CAPARES trial

The Coronary AngioPlasty Amlodipine REStenosis Study (CAPARES) is a multicentre, double-blind, placebo controlled restenosis trial investigating the effect of amlodipine on angiographic and clinical endpoints in patients undergoing routine percutaneous transluminal coronary angioplasty (PTCA) for stable angina pectoris. A total of 635 patients were randomized to amlodipine or placebo two weeks before PTCA and were followed for four months after PTCA. There were 451 nonstented patients who completed the study with angiographic follow-up. Quantitative coronary angiography revealed that the loss in minimal luminal diameter from immediately after PTCA to the four-month follow-up was unaffected by amlodipine treatment. However, the incidence of repeat PTCA and composite clinical events were significantly lower in patients treated with amlodipine.

Plasma levels of N-terminal proatrial natriuretic peptide in children are dependent on renal function and age

Plasma levels of natriuretic peptides are used as diagnostic markers of heart failure. The aim of this study was to analyse the relation between plasma levels of N-terminal proatrial natriuretic peptide (Nt-proANP) and renal function, and to develop reference values in children. Nt-proANP was measured in the plasma of 86 patients whose glomerular filtration rate (GFR) was determined by use of the X-ray contrast medium iohexol and a fluorescence technique. Blood samples for Nt-proANP were also collected in 399 reference children, aged 0 - 15 years. The relationship between Nt-proANP and GFR was examined using a multiple regression analysis. The mean value of Nt-proANP was markedly higher in children with heart failure than in children with malignant or urologic diseases (p<0.001). The variability in plasma levels of Nt-proANP was mainly (adjusted R2=0.81) explained by the following four variables: presence of heart failure, GFR, age and previous treatment with anthracyclins. Plasma levels of the peptide are raised at birth, but fall rapidly to adult levels. We conclude that the plasma levels of Nt-proANP are age-dependent. Moderately elevated values were registered in children with severe renal impairment. Heart failure is regularly associated with excessive elevation of Nt-proANP in plasma. Our findings suggest that the influence of heart failure on levels of this peptide in children greatly exceeds the influence of renal dysfunction.

[Catheter closure of open ductus arteriosus--the first 100 patients]

BACKGROUND

Patent ductus arteriosus is increasingly treated with catheter based techniques. We present our results as by the end of 1998 of the first 100 patients given such treatment.

MATERIAL AND METHODS

The 100 patients between 0.6 and 31.4 years were initially treated with one of these devices: The Rashkind umbrella (60 patients), Cook PDA coils (31 patients) or Amplatzer ductal occluders (ten patients). Seven umbrella patients were treated twice, one with an additional umbrella, six with coils; two coil patients twice, one with another coil and one--after embolisation--with a peg.

RESULTS

The overall complete closure rate for all groups was 90% after nine patients had been treated a second time. The primary complete closure rate in pegs was 100%, after reintervention 85% in umbrella and 97% in coil patients. Neither umbrellas nor pegs have embolised. One coil embolised in the course of implantation of 40 coils (2.5%). No other complication has occurred.

INTERPRETATION

The closure of the arterial duct with catheter techniques compares favorably with surgery and is now established as the method of choice. Following the investigational introduction of pegs there is no longer an upper limit in the size of ducts suitable for such treatment.

Restenosis and clinical outcome in patients treated with amlodipine after angioplasty: results from the Coronary AngioPlasty Amlodipine REStenosis Study (CAPARES)

OBJECTIVES

Our intent was to investigate the effect of the dihydropyridine calcium channel blocker amlodipine on restenosis and clinical outcome in patients undergoing percutaneous transluminal coronary angioplasty (PTCA).

BACKGROUND

Amlodipine has sustained vasodilatory effects and relieves coronary spasm, which may reduce luminal loss and clinical complications after PTCA.

METHODS

In a prospective, double-blind design, 635 patients were randomized to 10 mg of amlodipine or placebo. Pretreatment with the study drug started two weeks before PTCA and continued until four months after PTCA. The primary angiographic end point was loss in minimal lumen diameter (MLD) from post-PTCA to follow-up, as assessed by quantitative coronary angiography (QCA). Clinical end points were death, myocardial infarction, coronary artery bypass graft surgery and repeat PTCA (major adverse clinical events).

RESULTS

Angioplasty was performed in 585 patients (92.1%); 91 patients (15.6%) had coronary stents implanted. Follow-up angiography suitable for QCA analysis was done in 236 patients in the amlodipine group and 215 patients in the placebo group (per-protocol group). The mean loss in MLD was 0.30 +/- 0.45 mm in the amlodipine group versus 0.29 +/- 0.49 mm in the placebo group (p = 0.84). The need for repeat PTCA was significantly lower in the amlodipine versus the placebo group (10 [3.1%] vs. 23 patients [7.3%], p = 0.02, relative risk ratio [RR]: 0.45, 95% confidence interval [CI]: 0.22 to 0.91), and the composite incidence of clinical events (30 [9.4%] vs. 46 patients (14.5%), p = 0.049, RR: 0.65, CI: 0.43 to 0.99) within the four months follow-up period (intention-to-treat analysis).

CONCLUSIONS

Amlodipine therapy starting two weeks before PTCA did not reduce luminal loss, but the incidence of repeat PTCA and the composite major adverse clinical events were significantly reduced during the four-month follow-up period after PTCA with amlodipine as compared with placebo.

Effect of physical training in children and adolescents with congenital heart disease

In order to test the effect of systematic supervised physical training, we divided a total of 129 children and adolescents with congenital heart disease into a group undergoing intervention and a control group. All patients underwent exercise tests, measurements of physical activity, and a survey of psychosocial factors. An improvement in uptake of peak level of oxygen was observed after intervention. There was also an improvement in physical activity in both groups measured by a monitor, although this was significant only in those with intervention. The psychosocial scales measured by the Child Behavior Checklist showed a decrease in internalizing scores for those subjected to intervention. This was decreased due to decreased withdrawal and somatic complaints. In conclusion, we recommend systematic supervised training, including testing of routine follow-ups, in patients with congenital heart disease.

Physical activity in children and adolescents with congenital heart disease. Aspects of measurements with an activity monitor

The aim of the present study was to evaluate different aspects of a device designed to monitor physical activity. Measurements of different axes and placement of the monitor were tested using a treadmill with ranging increments in incline or speed. The monitor was also used to assess the level of physical activity among children and adolescents with congenital heart disease and in healthy controls at the same age. The results indicate that the monitor is a valid and reproducible instrument for measurements of physical activity. The study revealed that the level of activity was higher for healthy boys than healthy girls (p<0.0001). Boys with congenital heart disease also displayed higher values compared to girls with congenital heart disease, although the difference was not significant (p=0.067). Healthy boys revealed a significantly higher level of activity than did boys with congenital heart disease (p=0.003), but no such difference was found in girls (p=0.757). Nor were any differences found between younger and older individuals among patients with congenital heart disease. Young healthy controls, however, showed significantly higher levels of activity than their older counterparts. There were differences in activity monitored during the week, with lower activity in the weekends, but the activity on the same day in different weeks seemed stable. Neither were there any differences between measurements over whole weeks. The results indicate that the Computer Science & Application monitor is a valid instrument for assessing physical activity. The monitor may also be used, therefore, to validate the levels of physical activity level in children with congenital heart disease after medical and surgical treatment.

Physiologic response to gain and loss in coronary minimal luminal diameter in patients treated with coronary angioplasty: prediction of restenosis on the basis of exercise capacity

BACKGROUND

The effect of percutaneous transluminal coronary angioplasty (PTCA) on physiologic measurements has previously been shown, but the relation between physiologic response and degree of change in coronary luminal diameter is not known. We studied the relation between exercise capacity and minimal luminal diameter before and after PTCA. We also explored the usefulness of measurement of attenuation in exercise capacity after PTCA to predict the likelihood of restenosis.

METHODS

Bicycle exercise testing was performed 2 weeks before and 2 and 20 weeks after PTCA in 395 consecutively enrolled patients. Angiograms obtained before and after PTCA and 20 weeks afterward were analyzed by quantitative coronary angiography. Restenosis was defined as both angiographic (>/=50% diameter stenosis at follow-up angiography) and clinical (target-vessel revascularization), after successful PTCA. Exercise capacity was defined as the cumulative work performed divided by body weight (watt x minutes x kilograms(-1)).

RESULTS

Exercise capacity increased 43% (P <.0001) from before PTCA to 2 weeks after PTCA (early increase) and decreased 4% (P =.01) from 2 to 20 weeks after PTCA (late decrease). The gain in minimal luminal diameter (Minimal luminal diameter after - Minimal luminal diameter before) was 0.92 +/- 0.46 mm. The loss in minimal luminal diameter (Minimal luminal diameter after PTCA - Minimal luminal diameter at follow-up examination) was 0.27 +/- 0.42 mm. Exercise capacity and minimal luminal diameter measured before PTCA were positively correlated (coefficient 3.3; R = 0.12; P =.01). Gain in minimal luminal diameter correlated with the early increase in exercise capacity (coefficient -3.8; R = 0.23; P <.0001). Loss in minimal luminal diameter correlated with the late decrease in exercise capacity (coefficient 3.3; R = 0.20; P <.0001). Multivariate logistic regression analysis revealed that the late decrease in exercise capacity was independently predictive of both angiographically (odds ratio 1.13; P <.0001) and clinically (odds ratio 1.12; P <.0001) defined restenosis.

CONCLUSIONS

The results demonstrated a linear relation between the severity of coronary stenosis and exercise capacity measured before PTCA. The degree of coronary luminal enlargement achieved with angioplasty and the luminal reduction that occurred between PTCA and follow-up evaluation correlated with increases and decreases in exercise capacity. Attenuation in exercise capacity was found to be a strong predictor of restenosis.

[Long-term follow-up of patients with congenital heart defects]

There are about 500 new cases of congenital heart disease per year in Norway. Modern diagnostic skills, surgical techniques and follow-up programs have contributed to higher survival rates among patients. Based on international experience, 85-90 per cent of these children will survive into adulthood. Half will suffer from conditions which should be followed up by cardiologists. This article is based upon recommendations on long-term follow-up of patients with congenital heart disease.

A comparison of VO2(peak) between patients with congenital heart disease and healthy subjects, all aged 8-17 years

The peak oxygen uptake (VO2(peak)) of 196 healthy children and adolescents aged 8-16 years, and 187 children and adolescents (in the same age range) with congenital heart disease (CHD), was measured using a graded treadmill test (Oslo-protocol). The healthy population was tested to assess the reference values that were to be used in the interpretation of the results obtained from patients with CHD. The results revealed that patients with CHD exhibited lower VO2(peak) values, with declining values for boys after the age of 12-13 years. When separated into different diagnostic groups, on average, patients with a chronic pressure overload of the left ventricle and patients with tetralogy of Fallot have lower VO2(peak) values, but make approximately the same progress with age as healthy subjects. Patients with transposition of the great arteries, however, displayed a marked decline in VO2(peak) after the age of 12-13 years. Whether exercise testing should be included in routine follow-up in patients with CHD, especially those between the ages of 10 and 16 years, when the condition of some patients deteriorates, requires special attention.

Luminal loss and restenosis after coronary angioplasty. The role of lipoproteins and lipids

AIMS

Lipoproteins and lipids, especially lipoprotein(a), have been studied as risk factors for restenosis after coronary angioplasty with conflicting results. We investigated the association between serum levels of lipoprotein(a) apolipoprotein A-1, apolipoprotein B-100, total-cholesterol, high density lipoprotein-cholesterol, triglycerides, and coronary luminal loss and restenosis after angioplasty.

METHODS

The lipoproteins and lipids were measured in 305 consecutive patients who underwent successful angioplasty and reangiography 20+/-3 weeks after angioplasty. Single-vessel dilatation was performed in 251 patients. Luminal loss was defined as minimal luminal diameter post-angioplasty minus minimal luminal diameter at follow-up, divided by the interpolated reference diameter of the vessel. Restenosis was defined according to three dichotomous categorical criteria: (1) >50% diameter stenosis at follow-up (2) loss of >50% of the gain achieved by angioplasty, (3) the need for target vessel revascularization.

RESULTS

There was no significant association between the serum levels of lipoproteins and lipids and luminal loss. Univariate analysis did not show any significant difference in the serum levels of any of the lipoproteins and lipids between the restenosis and no-restenosis groups. Multivariate analysis revealed that only the angiographic variables (luminal gain and post-angioplasty minimal luminal diameter) were associated with luminal loss and restenosis after angioplasty.

CONCLUSION

Lipoproteins and lipids were neither associated with luminal loss nor independent risk factors for restenosis after angioplasty.

[Measurements of N-terminal proatrial natriuretic factor in children]

Measurement of plasma levels of natriuretic peptides are now in clinical use in adult patients with heart failure. Experiences in adult medicine cannot be extended to paediatric cardiology due to important physiological differences between adults and children. The haemodynamic background of heart failure in children with congenital heart disease is diverse, and there is no relevant functional or echocardiographic grading system. The authors present results from published studies and summarizes the results of a research project concerning the clinical potential of N-terminal proatrial natriuretic peptide (Nt-proANP) in paediatric cardiology. Peptide levels in newborn children with or without disease are not fully clarified. In children above three months of age, an elevated Nt-proANP value strongly indicates haemodynamic imbalance. This may be important in the follow-up of children with congenital heart disease. A normal value does not exclude the presence of heart disease. A case report illustrates the clinical use of Nt-proANP, and peptide levels in different haemodynamic situations are discussed.

Pharmacologic effects of calcium channel blockers on restenosis

The understanding and control of the healing process after percutaneous transluminal coronary angioplasty (PTCA) and of the pathogenesis of restenosis are incomplete. To date, only stent implantation has been shown to successfully reduce the rate of restenosis. Calcium channel blockers have positive effects on a number of processes that may be associated with restenosis, including reduction of platelet aggregation, minimization of vasospasm, and inhibition of mitogens. Clinical trials have therefore been performed to assess the effect of calcium channel blockers on restenosis and ischemia. A meta-analysis of five restenosis trials investigating calcium channel blockers demonstrated a 30% reduction in the risk for restenosis. The Coronary Angioplasty Amlodipine Restenosis Study (CAPARES) is therefore assessing the effect of amlodipine, a long-acting, third-generation calcium channel blocker in angioplasty patients. Therapy (amlodipine 5 mg with a forced titration to 10 mg once daily, or placebo), is begun 2 weeks before angioplasty and is continued for 4 months after the procedure. The rationale of CAPARES is that amlodipine may offer anti-ischemic protection before, during, and after angioplasty, may have more beneficial effects on restenosis and various clinical end points than calcium channel blockers used in previous trials, and may improve the long-term outcome of PTCA therapy.

Elevation of atrial natriuretic peptide prohormone. Hemodynamic background of the elevation of N-terminal natriuretic peptide prohormone in children with congenital heart disease

We postulated previously that variables related to pulmonary flow are independent predictors of levels of atrial natriuretic peptide in children with congenital heart disease. The aim of this study was to test this hypothesis in relation to other hemodynamic and clinical variables. During catheterization we measured the levels of plasma N-terminal atrial natriuretic peptide prohormone in the plasma of 68 children with congenital heart disease. All had undergone complete clinical, echocardiographic and invasive hemodynamic investigations. The influence on the prohormone was analyzed for 10 different variables in a multiple linear regression model. The variability could be explained in large parts (adjusted R2 =77.2%) by variations in atrial pressures or sizes, together with the degree of excessive pulmonary blood flow and signs of heart failure. A value for atrial natriuretic peptide prohormone above 800 pmol/l predicted hemodynamic imbalance (defined as elevated pressures in left or right atrium or the pulmonary arteries, and/or Qp/Qs > 1.5) with a specificity of 94%, a sensitivity of 73%, a positive likelihood ratio of 12.2, and a negative likelihood ratio of 0.29. In conclusion, variables related to pulmonary blood flow are influential determinants of the levels of atrial natriureic peptide in children with congenital heart disease. Atrial pressures, and symptoms of heart failure are also of major importance.