EU-CaRE study: Could exercise-based cardiac telerehabilitation also be cost-effective in elderly?

BACKGROUND: The role of cardiac rehabilitation (CR) is well established in the secondary prevention of ischemic heart disease. Unfortunately, the participation rates across Europe remain low, especially in elderly. The EU-CaRE RCT investigated the effectiveness of a home-based mobile CR programme in elderly patients that were not willing to participate in centre-based CR. The initial study concluded that a 6-month home-based mobile CR programme was safe and beneficial in improving VO2peak when compared with no CR. OBJECTIVE: To assess whether a 6-month guided mobile CR programme is a cost-effective therapy for elderly patients who decline participation in CR. METHODS: Patients were enrolled in a multicentre randomised clinical trial from November 11, 2015, to January 3, 2018, and follow-up was completed on January 17, 2019, in a secondary care system with 6 cardiac institutions across 5 European countries. A total of 179 patients who declined participation in centre-based CR and met the inclusion criteria consented to participate in the European Study on Effectiveness and Sustainability of Current Cardiac Rehabilitation Programs in the Elderly trial. The data of patients (n = 17) that were lost in follow-up were excluded from this analysis. The intervention (n = 79) consisted of 6 months of mobile CR programme with telemonitoring, and coaching based on motivational interviewing to stimulate patients to reach exercise goals. Control patients did not receive any form of CR throughout the study period. The costs considered for the cost-effectiveness analysis of the RCT are direct costs 1) of the mobile CR programme, and 2) of the care utilisation recorded during the observation time from randomisation to the end of the study. Costs and outcomes (utilities) were compared by calculation of the incremental cost-effectiveness ratio. RESULTS: The healthcare utilisation costs (P = 0.802) were not significantly different between the two groups. However, the total costs were significantly higher in the intervention group (P = 0.040). The incremental cost-effectiveness ratio for the primary endpoint VO2peak at 6 months was €1085 per 1-unit [ml/kg/min] improvement in change VO2peak and at 12 months it was €1103 per 1 unit [ml/kg/min] improvement in change VO2peak. Big differences in the incremental cost-effectiveness ratios for the primary endpoint VO2peak at 6 months and 12 months were present between the adherent participants and the non-adherent participants. CONCLUSION: From a health-economic point of view the home-based mobile CR programme is an effective and cost-effective alternative for elderly cardiac patients who are not willing to participate in a regular rehabilitation programme to improve cardiorespiratory fitness. The change of QoL between the mobile CR was similar for both groups. Adherence to the mobile CR programme plays a significant role in the cost-effectiveness of the intervention. Future research should focus on the determinants of adherence, on increasing the adherence of patients and the implementation of comprehensive home-based mobile CR programmes in standard care.

MobileHeart, a mobile smartphone-based application that supports and monitors coronary artery disease patients during rehabilitation.

Conventional center-based cardiac rehabilitation adherence is poor, adversely affecting long-term efficacy. Innovative strategies such as telerehabilitation are perceived as promising alternatives to improve care delivery. This paper presents the results of prior and ongoing work on the design and development of MobileHeart, a telemedical smartphone-based application to be used in secondary prevention for ischemic heart disease patients. Its constituent components are discussed separately, the minimal necessary cardiovascular monitoring requirements are elaborated in more detail. The results are offered starting from a clinical perspective to stress its relevance in the establishment of scientifically/medically sound programs.

Ventilatory function during exercise in multiple sclerosis and impact of training intervention: cross-sectional and randomized controlled trial.

BACKGROUND: Patients with MS (pwMS) often experience resting ventilatory anomalies. Ventilatory function during exercise and impact of long-term training intervention remains however uncertain. AIM: The aim of this study was to examine the ventilatory function during exercise and impact of a 6-month training intervention in pwMS. DESIGN: Combination of a cross-sectional (part 1) and randomized controlled trial (part 2). SETTING: University rehabilitation facility. POPULATION: Caucasian patients with MS and healthy controls. METHODS: In part 1, the ventilatory function during submaximal endurance exercise was compared between pwMS (N.=37) and healthy participants (N.=15). In part 2, pwMS were then randomly assigned to a 6-month training intervention (N.=16) or usual care (N.=11). Following training intervention, ventilatory function during exercise was re-evaluated. RESULTS: Despite comparable relative exercise testing intensities between groups in part 1, significantly elevated steady-state exercise dead space/tidal volume ratio, O2 uptake and CO2 output equivalent, end-tidal O2 pressure, ratings of perceived exertion and lowered end-tidal CO2 pressure and O2 pulse was observed in pwMS (P<0.05). The degree of ventilatory dysfunction during exercise correlated significantly with ratings of perceived exertion and blood lactate content (P<0.05). In part 2, despite an improved exercise tolerance (based on reductions in heart rate, blood lactate content and ratings of perceived exertion during exercise at similar workload) after a 6-month training intervention, ventilatory dysfunction remained present during endurance exercise (P>0.05). CONCLUSION: Patients with MS experience a ventilatory dysfunction during endurance exercise, which is related to worse exercise tolerance. This ventilatory anomaly remains present after long-term training intervention. CLINICAL REHABILITATION IMPACT: Patients with MS experience ventilatory dysfunction during exercise. This dysfunction is related to exercise tolerance and ratings of perceived exertion. Long-term exercise training did not remediate this ventilatory dysfunction. The systematic examination of the pulmonary/cardiovascular system at rest and during exercise is recommended in MS.

Is long-term exercise intervention effective to improve cardiac autonomic control during exercise in subjects with multiple sclerosis? A randomized controlled trial.

BACKGROUND: Patients with multiple sclerosis (MS) suffer from a disturbed cardiac autonomic control during exercise (based on heart rate (HR) changes during exercise), which affects exercise tolerance. Whether long-term exercise intervention improves HR changes during exercise in patients with MS remains unknown. AIM: To examine whether long-term exercise intervention improves HR changes during exercise, and correlates with improvements in exercise tolerance, in patients with MS. DESIGN: Randomized controlled trial. SETTING: University rehabilitation facility. POPULATION: Twenty-three patients with MS were randomly assigned to six months of follow-up (n=9) or six months of exercise training (n=14, 54-60 training sessions). METHODS: At baseline and after three and six months of follow-up, exercise-onset (first 20 and 60 seconds) and -offset (1-minute recovery) heart rate (HR) change was determined during a constant-load exercise test: these data reflect the (re)activation of the (para)sympathetic nervous system at initiation and/or cessation of exercise. Blood lactate, HR, oxygen uptake, expiratory volume and ratings of perceived exertion (RPE) were assessed during exercise as indicators for exercise tolerance. RESULTS: Exercise-onset and -offset HR and exercise tolerance did not change during follow-up in the control group (P>0.05). In the exercise intervention group, blood lactate content and RPE during exercise decreased significantly (group/time interaction effect P<0.05), but exercise-onset and -offset HR did not change (P>0.05). No correlations were found between changes in exercise tolerance and changes in exercise-onset and -offset HR (P>0.05). CONCLUSION: In patients with MS, long-term exercise intervention does not improve HR changes during exercise, despite improvements in exercise tolerance, indicating that cardiac autonomic control during exercise is not easily improved by exercise intervention in patients with MS. CLINICAL REHABILITATION IMPACT: This study indicates that patients with MS suffer from a disturbed cardiac autonomic control during exercise, based on heart rate changes, which is not easily remediated by exercise intervention. Because a disturbed cardiac autonomic control is related to exercise intolerance in MS, it should further be explored how to remediate this anomaly through exercise intervention or other approaches.

Suppressed increase in blood endothelial progenitor cell content as result of single exhaustive exercise bout in male revascularised coronary artery disease patients.

Endothelial progenitor cells (EPCs) significantly affect endothelial repair capacity and, hence, cardiovascular disease incidence. In healthy subjects, blood EPC content increases significantly as result of a single maximal exercise test, hereby stimulating endothelial repair capacity. It remains to be shown whether a single exercise positively affects blood EPCs in revascularised coronary artery disease (CAD) patients. From male revascularised CAD patients (n = 60) and healthy volunteers (n = 25) blood samples were collected before and immediately after a maximal cardiopulmonary exercise test. Blood samples were analyzed by optimised flow cytometry methodology for EPC content (CD34+, CD34+ CD133+, CD34+VEGFR2+, CD34+CD133+VEGFR2+, and CD34+CD133-VEGFR2+ cells) and compared between groups. CFU-Hill colonies were additionally assessed. As a result of a maximal exercise test, blood CD34+, CD34+VEGFR2+ (all EPCs), CD34+CD133+, and CD34+ CD133-VEGFR2+ (mature EPCs) cells increased significantly in CAD patients (p < 0.05), but less than in healthy subjects (p < 0.05, and p = 0.06 for CD34+VEGFR2+). CD34+CD133+VEGFR2+ cells (immature EPCs) did not change as result of exercise (p > 0.05). No changes in CFU-Hill colonies as result of exercise were observed. This study shows that blood mature EPCs (CD34+CD133-VEGFR2+) increase significantly as result of a single exercise bout in revascularised CAD patients, but with smaller magnitude compared to healthy subjects. Blood immature EPCs (CD34+CD133+VEGFR2+) did not change significantly as result of exercise.

Prolonged exercise training increases intramuscular lipid content and perilipin 2 expression in type I muscle fibers of patients with type 2 diabetes.

The aim of the present study was to investigate changes in intramuscular triglyceride (IMTG) content and perilipin 2 expression in skeletal muscle tissue following 6 mo of endurance-type exercise training in type 2 diabetes patients. Ten obese male type 2 diabetes patients (age 62 ± 1 yr, body mass index BMI 31 ± 1 kg/m²) completed three exercise sessions/week consisting of 40 min of continuous endurance-type exercise at 75% V(O2 peak) for a period of 6 mo. Muscle biopsies collected at baseline and after 2 and 6 mo of intervention were analyzed for IMTG content and perilipin 2 expression using fiber type-specific immunofluorescence microscopy. Endurance-type exercise training reduced trunk body fat by 6 ± 2% and increased whole body oxygen uptake capacity by 13 ± 7% (P < 0.05). IMTG content increased twofold in response to the 6 mo of exercise training in both type I and type II muscle fibers (P < 0.05). A threefold increase in perilipin 2 expression was observed from baseline to 2 and 6 mo of intervention in the type I muscle fibers only (1.1 ± 0.3, 3.4 ± 0.6, and 3.6 ± 0.6% of fibers stained, respectively, P < 0.05). Exercise training induced a 1.6-fold increase in mitochondrial content after 6 mo of training in both type I and type II muscle fibers (P < 0.05). In conclusion, this is the first study to report that prolonged endurance-type exercise training increases the expression of perilipin 2 alongside increases in IMTG content in a type I muscle fiber-type specific manner in type 2 diabetes patients.

Effect of a tailored behavior change program on a composite lifestyle change score: a randomized controlled trial.

To evaluate the effect of a tailored behavior change program on a composite lifestyle change score. A randomized controlled trial conducted in Belgium in 2007-08 with 314 participants allocated to a control and an intervention condition. The intervention was a tailored behavior change program (web-based and individual coaching). The dose of the coaching was chosen by the participants and registered. Outcome measures were weight, saturated fat intake, fruit and vegetable intake, physical activity, smoking status and a composite lifestyle change score. Mann-Whitney U-tests, Kruskal-Wallis tests, t-tests and one-way analyses of variance were used to compare the study conditions and three intervention dose groups (no/low, medium and high intervention dose). There were no significant differences between the study conditions or between the intervention dose groups for the individual lifestyle factors. The composite lifestyle change score was significantly higher in the high intervention dose group compared with the no/low intervention dose group (P = 0.009). The composite lifestyle change score was positively related to the intervention dose, while the individual lifestyle factors were not. Behavior change programs that target multiple lifestyle factors could be evaluated by using a composite lifestyle change score taking into account the intervention dose.

Continuous low- to moderate-intensity exercise training is as effective as moderate- to high-intensity exercise training at lowering blood HbA(1c) in obese type 2 diabetes patients.

AIMS/HYPOTHESIS: Exercise represents an effective interventional strategy to improve glycaemic control in type 2 diabetes patients. However, the impact of exercise intensity on the benefits of exercise training remains to be established. In the present study, we compared the clinical benefits of 6 months of continuous low- to moderate-intensity exercise training with those of continuous moderate- to high-intensity exercise training, matched for energy expenditure, in obese type 2 diabetes patients. METHODS: Fifty male obese type 2 diabetes patients (age 59 +/- 8 years, BMI 32 +/- 4 kg/m(2)) participated in a 6 month continuous endurance-type exercise training programme. All participants performed three supervised exercise sessions per week, either 55 min at 50% of whole body peak oxygen uptake (VO(2)peak (low to moderate intensity) or 40 min at 75% of VO(2)peak (moderate to high intensity). Oral glucose tolerance, blood glycated haemoglobin, lipid profile, body composition, maximal workload capacity, whole body and skeletal muscle oxidative capacity and skeletal muscle fibre type composition were assessed before and after 2 and 6 months of intervention. RESULTS: The entire 6 month intervention programme was completed by 37 participants. Continuous endurance-type exercise training reduced blood glycated haemoglobin levels, LDL-cholesterol concentrations, body weight and leg fat mass, and increased VO(2)peak, lean muscle mass and skeletal muscle cytochrome c oxidase and citrate synthase activity (p < 0.05). No differences were observed between the groups training at low to moderate or moderate to high intensity. CONCLUSIONS/INTERPRETATION: When matched for energy cost, prolonged continuous low- to moderate-intensity endurance-type exercise training is equally effective as continuous moderate- to high-intensity training in lowering blood glycated haemoglobin and increasing whole body and skeletal muscle oxidative capacity in obese type 2 diabetes patients. TRIAL REGISTRATION: ISRCTN32206301 FUNDING: None.

[Guidelines on cardiovascular disease prevention in clinical practice. Belgian Working Group on Cardiovascular Prevention and Rehabilitation]. / Recommandations relatives a la prévention des maladies cardiovasculaires en pratique clinique. Groupe de travail belge de prévention des maladies cardiovasculaires.

Since more than 15 years, expert groups and various European Scientific Societies have written Guidelines on Cardiovascular Disease Prevention. Because of the rapid evolution of science, it is necessary to adapt regularly these guidelines. The last version dates from 2007 and has been written by the " Fourth Joint Task Force of European and other Societies on Cardiovascular Disease Prevention in Clinical Practice ". In this issue, the more recent Guidelines are summarised and we focus on highlighting the aspects of these Guidelines that have changed since the previous version published in this journal in 2005.

Type of exercise alters VE/VCO2slope in CAD patients.

The exercise carbon dioxide equivalent slope predicts prognosis in coronary artery disease patients. However, no study examined whether the carbon dioxide equivalent slope in coronary artery disease patients is dependent on the type of exercise. Twenty-nine coronary artery disease patients performed maximal cardiopulmonary exercise tests on bike, treadmill and arm cycle, with assessment of oxygen uptake, carbon dioxide output, and expiratory volume. The carbon dioxide equivalent slope was calculated from rest till peak exercise. The carbon dioxide equivalent slope was significantly different between walking, cycling, and arm cranking exercises (P<0.05), i.e. the carbon dioxide equivalent slope was the lowest during walking and the highest during arm cranking. Bland-Altman plots revealed that the difference of the carbon dioxide equivalent slope between exercises was greater in the case of a higher averaged carbon dioxide equivalent slope and overall peak oxygen uptake. In conclusion, the carbon dioxide equivalent slope is significantly dependent on the type of exercise in coronary artery disease patients. Additionally, the averaged carbon dioxide equivalent slope and peak oxygen uptake affect the difference of the carbon dioxide equivalent slopes between exercises.

Association between leisure time physical activity and markers of chronic inflammation related to coronary heart disease.

BACKGROUND: Some markers of chronic inflammation have been recognized as predictors of cardiovascular risk in apparently healthy subjects and in patients with coronary heart disease (CHD). High sensitivity C-reactive protein (CRP) appears to be the most useful marker in clinical settings. Several studies reported associations between inflammatory markers and other cardiovascular risk factors, such as age, obesity, cholesterol levels, the presence of diabetes mellitus, physical activity, social level and smoking habits. We focussed on the association between C-reactive protein, serum amyloid A (SAA), fibrinogen and leisure time physical activity (LTPA). METHODS: This report deals with the results observed in a sub-sample of the BELSTRESS study. 892 male subjects, free from clinical CHD and major ECG abnormalities, working in the same environment, aged 35-59 years, were selected. A questionnaire was used to estimate the level of leisure time physical activity. Associations between CRP, SAA, fibrinogen and leisure time physical activity were evaluated through univariate and multivariate methods. Subjects taking statins or other lipid lowering medication were excluded from the study. RESULTS: Regular leisure time physical activity is associated with reductions of several cardiovascular risk factors, such as body mass index (BMI), waist hip ratio and the lipid profile. Smokers and low educated subjects had a lower physical activity status. Age adjustment did not alter the means of inflammatory parameters according to the levels of leisure time physical activity. After correction for personal characteristics (BMI, current smoking status, educational level, presence of diabetes and alcohol consumption) no significant relation was found between leisure time physical activity and levels of inflammatory markers. The differences of CRP and fibrinogen according to the level of physical activity, found in bivariate analysis, seem to be explained by linked differences in BMI, or related to current smoking habits. Leisure time physical activity, as reported in this study, is not significantly related to C-reactive protein, serum amyloid A or fibrinogen levels, after correction for other cardiovascular risk factors. CONCLUSION: These data indicate that leisure time physical activity, as reported in our study, is not an independent predictor of C-reactive protein, serum amyloid A or fibrinogen levels. Possible interactions of physical activity and other cardiovascular risk factors might explain the (indirect) relation we found in the bivariate analysis.

Magnetic resonance diagnosis of lipomatous hypertrophy of the atrioventricular grooves mimicking a tumour on echocardiography.

Echogenic structures in the atrioventricular grooves may cause diagnostic problems and may be misinterpreted as a tumour. Images of lipomatous hypertrophy of the atrioventricular grooves diagnosed by magnetic resonance but mimicking a tumour on echocardiography are presented.

Chronotropic incompetence: a case report.

Chronotropic incompetence is generally defined as an inadequate heart rate response to exercise, but manifestations can vary. The incidence depends on underlying cardiac pathology and, to a lesser degree, on the cut-off value of the predicted heart rate during exercise. Different pathologies induce chronotropic incompetence. Its presence indicates an adverse outcome and is strongly correlated with coronary artery disease. Treatment consists of rate-responsive pacemakers; dual-sensor, adaptive pacemakers are superior to single-sensor, rate-augmenting pacemakers. This case report illustrates the negative effect of chronotropic incompetence on daily activities and its amelioration by implantation of a rate-responsive pacemaker. (c)2001 by CHF, Inc.

Prediction of functional outcome by quantification of sestamibi and BMIPP after acute myocardial infarction.

Iodine-123 15-(p-iodophenyl)-3-R,S-methylpentadecanoic acid (BMIPP) can be used to image myocardial fatty acid regional distribution and utilisation with single-photon emission tomography (SPET). By visual analysis, a mismatching with regional uptake of BMIPP less than that of a perfusion tracer has been shown to predict myocardial viability and functional improvement after restoration of flow in patients with myocardial infarction. The current study aimed to evaluate a newly developed quantitative method of analysis of sestamibi and BMIPP uptake for the prediction of functional recovery after revascularization in patients with acute infarction. BMIPP and gated sestamibi SPET studies at rest were obtained before and >3 months after revascularization in 18 patients with recent infarction. A colour-coded polar map was generated from the comparison of sestamibi and BMIPP uptake. Depending on the relative distribution of the two tracers, different patterns of uptake were identified and their extent expressed as percentages of the surface of the whole left ventricle and of the three main coronary artery territories. At follow-up, recovery was defined as a > or =5% increase in ejection fraction compared with baseline. Receiver-operating characteristic curve analysis was performed to analyse the data. At baseline, significant correlations were found between ejection fraction and the % surface with decreased sestamibi or BMIPP uptake (r=-0.68, P= 0.001, and r=-0.72, P<0.0001, respectively). When combining both tracers, ejection fraction was significantly associated with the extent of myocardium showing decreased sestamibi uptake with lower BMIPP uptake (mismatching; r=-0.68, P=0.001). At follow-up, significant functional recovery was found in 13/18 patients. By ROC curve analysis, the optimal pattern of distribution predicting recovery was a mismatching with uptake of sestamibi <70% and uptake of BMIPP at least 10% lower. For this parameter, optimal cut-off of extent was 10% of the whole left ventricle surface (sensitivity 69%, specificity 80%, accuracy 72%) and 25% of the infarct-related arterial territory (sensitivity 77%, specificity 80%, accuracy 78%). The areas under the curve were 79% for the left ventricle surface and 72% for the individual arterial territories. These results suggest that in patients with acute infarction, quantitative analysis of sestamibi and BMIPP could offer an objective and reproducible method for estimating the severity of cardiac dysfunction and predicting the evolution of ejection fraction after revascularization.

Six months clinical, angiographic, and IVUS follow-up after PTFE graft stent implantation in native coronary arteries.

INTRODUCTION: Restenosis remains a problem even after stent implantation. An important breakthrough could be the use of graft stents, functioning as a mechanical barrier between the blood flow and the vessel wall, and possibly inducing less restenosis by more limited hyperplasia and minimal transgraft tissue penetration. OBJECTIVE: To assess the acute and 6 months clinical, angiographic and IVUS results of a new balloon expandable coronary polytetrafluoroethylene (PTFE) graft stent (Jomed). METHOD: Ten patients with a short (< or = 15 mm length) de novo proximal stenosis in a large (> or = 3 mm diameter) coronary artery were treated by elective implantation of a graft stent (19 mm stent, 15 mm graft). Clinical assessment, quantitative coronary angiography (QCA) and intracoronary ultrasound (IVUS) were performed before, immediately after and 6 months after implantation. A stress test was also done at 6 months. RESULTS: The coronary arteries treated were: RCA in 7 patients, LCX in 2 patients, LAD in 1 patient. Mean balloon size was 3.7 mm diameter, and mean inflation pressure was 18 atm (min. 12, max. 23). Additional stenting was needed in 3 patients. Two patients showed a minimal rise in CK (< 250 IU/l) and 1 patient needed a transfusion. No patient experienced a (sub)acute nor late thrombosis. As shown in the table, no restenosis was seen in the body of the graft stent. In 2 patients a restenosis was detected in the proximal and/or distal parts of the stent which are not covered by the graft. In 1 patient a restenosis was found outside the stent. All patients remained asymptomatic with a negative stress test at 6 months follow-up (FU). [table in text] CONCLUSIONS: A graft stent could indeed reduce the restenosis rate after stenting, in the part of the stent covered by the graft, but the uncovered distal and proximal parts are the weak points in this type of stent. For this reason, technical ameliorations in the construction of this graft stent are needed, e.g. a complete coverage of the stent by the PTFE graft and less rigidity of the stent causing reduced vessel trauma at the edges of the stent during implantation.

Effect of exercise induced hyperlactatemia on the biodistribution and metabolism of iodine-123-15(p-iodophenyl)-3-R,S-methyl pentadecanoic acid in normal volunteers.

We have evaluated the biodistribution and metabolism of iodine-123-15-(p-iodophenyl)-3-R,S-methyl pentadecanoic acid (BMIPP) in the presence of increased lactate levels induced by short-term heavy exercise. Five healthy male subjects received 159 MBq (+/- 13 MBq) 123I-BMIPP at rest and a week later after they performed a maximal exercise test using a bicycle ergometer. Planar and tomographic images were obtained with a dual-head gamma camera up to 4 h after administration of the tracer. Multiple blood samples were taken at different time points for blood clearance, substrate concentration measurements and for HPLC analysis of metabolites. The exercise test did not alter plasma glucose and non-esterified fatty acid concentrations, but blood lactate increased from 1.12 mmol/l at rest to 9.26 mmol/l with maximal exercise. After exercise, BMIPP showed a significantly faster plasma clearance than at rest and the production of PIPA, the end metabolite of BMIPP oxidation, was reduced. Activity in the heart was similar after exercise and at rest on planar images 15 min after injection (4.83 +/- 0.50% ID vs 4.80 +/- 0.43% ID, P = NS), although the myocardium-to-cavity activity ratio, as determined on the SPET images 20 min after tracer injection, was slightly increased after the exercise test (4.20 +/- 0.63 vs 3.78 +/- 1.34 at rest, P = NS). Significantly increased activity was observed in a leg muscle region of interest after exercise (4.98 +/- 0.50% ID vs 3.93 +/- 0.44% ID at rest, P = 0.02). Between early and late images, tracer washout from the myocardium increased from 20.72% at rest to 36.72% after exercise (P < 0.05), but was unchanged for liver and leg muscles. The metabolic and physiological alterations induced by exercise do not degrade image quality of BMIPP scintigraphy. On the contrary, exercise-induced hyperlactatemia seems to enhance myocardium-to-cavity activity ratios on SPET images, although this effect does not reach statistical significance in this small group of normal subjects. These findings further support the robustness of BMIPP SPET in varied metabolic environments.

Venous pooling during nitrate-stimulated tilt testing in patients with vasovagal syncope.

AIMS: To investigate the importance of venous pooling and variation in venous tone during nitrate-stimulated tilt testing in patients. METHODS: Ten patients with a history of vasovagal syncope underwent an upright tilt test after an injection of 99mTc-labelled albumin. A gamma camera was positioned at the level of the lower legs. The patients were tilted to 90 degrees for 30 min or until symptoms developed. In those subjects who did not show any symptoms before the end of the 30-min period, isosorbide dinitrate (ISDN) 5 mg was given sublingually and the test was prolonged for a maximum of 15 min. RESULTS: Nine of 10 patients needed nitrate stimulation to develop symptoms, and one patient remained symptom free following ISDN administration. Measurement of radioactivity revealed no significant increase in calf volume after nitrate stimulation (the mean volume increase was 77% before ISDN stimulation and a further 0.9% afterwards). CONCLUSIONS: The higher sensitivity for vasovagal syncope during upright tilt testing after administration of sublingual ISDN is not due to an increase in venous pooling in the lower extremities.

Intravenous nitrates for pharmacological stimulation during head-up tilt testing in patients with suspected vasovagal syncope and healthy controls.

Nitrates may be used for pharmacological stimulation during tilt testing for the diagnosis of vasovagal syncope. In this study we assessed the diagnostic value of intravenous nitrates during tilt testing in patients with a typical history of vasovagal syncope. Twenty patients and 23 controls were tilted at 700 for a maximum duration of 30 minutes. After a 10-minute baseline supine phase, the test started with a continuous nitrate infusion at 1 microg/kg/min and increased every 5 minutes by 1 microg/kg/min, to a maximum of 6 microg/kg/min at the end of the test. The test was ended if the subjects developed a positive response (syncope or presyncope). Nineteen patients (95%) and 17 (74%) of the controls had a positive response. At test end sensitivity was 95%, but specificity was 26% and accuracy was 58%. Receiver operator characteristics (ROC) analysis revealed a maximum accuracy of 79% at 18 minutes, with a sensitivity of 80% and a specificity of 78%. Intravenous nitrates during tilt testing in patients with typical clinical criteria of vasovagal syncope is highly effective in provoking vasovagal syncope. Based on the ROC analysis, a maximum accuracy of 79% was attained at 18 minutes (at a dose of 4 microg/kg/min), suggesting a good diagnostic performance when tilt duration is limited to this point. A positive result requiring more than 18 minutes of stimulated tilting should be interpreted with caution, due to the accompanying considerable decrease of specificity.

Prinzmetal's variant angina: three case reports and a review of the literature.

Prinzmetal's variant angina is a rare entity. When angina-like symptoms occur at rest, mostly at a specific hour in the early morning, together with transient ST segment elevations and angiographically normal arteries, provocative tests with ergonovine or acetylcholine should be performed. Endothelial dysfunction, a strong thrombotic tendency, an increased platelet aggregation together with changes in autonomic tone can trigger coronary vasospasms. Once treated with calcium antagonists and nitrates the prognosis is excellent and severe complications such as arrhythmias, myocardial infarction or sudden death are extremely rare. Coronary stenting can be useful for refractory coronary spasm, CABG can be used for important coronary atherosclerosis. This review is illustrated with three typical presentations of variant angina: a myocardial infarction without significant organic coronary atherosclerosis, an ergonovine-induced coronary spasm with a non-significant coronary lesion and a multivessel spasm complicated by ventricular arrhythmia. All these three patients became asymptomatic after a treatment with calcium antagonists and nitrates.