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Deleterious effects of beta-blockers on exercise capacity and hemodynamics in patients with portopulmonary hypertension.

BACKGROUND & AIMS: It has been suggested that beta-blockers might be harmful in pulmonary arterial hypertension. However, no study has evaluated the effect of beta-blockers in these patients. The aim of this study was to investigate the effect of beta-blockers on exercise capacity and pulmonary hemodynamics in patients with portopulmonary hypertension receiving beta-blockers for the prophylaxis of variceal bleeding. METHODS: Ten consecutive patients with moderate to severe portopulmonary hypertension (mean pulmonary artery pressure of 52 [10] mm Hg) underwent a 6-minute walk test and a right heart catheterization at baseline and 2 (1) months after beta-blocker withdrawal. RESULTS: Following beta-blocker withdrawal, 9 of 10 patients increased their 6-minute walked distance with a mean increase in the whole group of 79 (78) meters (P = .01). Cardiac output increased by 28% (P < .01) with no change in mean pulmonary artery pressure, resulting in a 19% decrease in pulmonary vascular resistance (P < .01). Increases in cardiac output were related to a 25% increase in heart rate (P < .01), whereas stroke volume was unchanged (P = .65). The improvements in exercise tolerance were associated with increases in chronotropic response (maximal heart rate minus resting heart rate) from 18 (9) to 34 (12) beats/min (P < .01) during the 6-minute walk test. CONCLUSIONS: In patients with moderate to severe portopulmonary hypertension, beta-blockers are associated with significant worsening in exercise capacity and pulmonary hemodynamics. These deleterious effects support the contraindication of beta-blockers in patients with portopulmonary hypertension.

Adrenergic beta-Antagonists↗

Value of Doppler index combining systolic and diastolic myocardial performance in predicting cardiopulmonary exercise capacity in patients with congestive heart failure: effects of dobutamine.

STUDY OBJECTIVE: Doppler-derived myocardial performance index (MPI), a measure of combined systolic and diastolic myocardial performance, was assessed at rest and after low-dose dobutamine administration in patients with idiopathic or ischemic dilated cardiomyopathy. MPI also was correlated with other conventional echocardiographic indexes of left ventricular (LV) function, and its ability to assess cardiopulmonary exercise capacity in those patients was investigated. SETTINGS: A tertiary-care, university heart failure clinic. PATIENTS: Forty-two consecutive patients (27 men; mean [+/- SD] age, 57 +/- 10 years) with heart failure (New York Heart Association [NYHA] class, II to IV) who had received echocardiographic diagnoses of dilated cardiomyopathy. Coronary angiography distinguished the cause of dilated cardiomyopathy. INTERVENTIONS: Low-dose IV dobutamine was infused after patients underwent a baseline echocardiographic study. All patients also underwent a cardiopulmonary exercise test using a modified Naughton protocol. RESULTS: Advanced NYHA class and restrictive LV filling pattern were associated with higher index values. A negative correlation was found between MPI and LV stroke volume, cardiac output, early filling/late filling velocity ratio, and late LV filling velocity, as well as oxygen uptake at peak exercise (r = -0.550; p < 0.001) and at the anaerobic threshold (r = -0.490; p = 0.002). Dobutamine administration produced an improvement in MPI, reducing its value and decreasing the isovolumic relaxation and contraction times. Stepwise regression analysis revealed that the rest index and the late LV filling velocity were the only independent predictors of cardiopulmonary exercise capacity. CONCLUSION: MPI correlates inversely with LV performance, reflects disease severity, and is a useful complimentary variable in the assessment of cardiopulmonary exercise performance in patients with heart failure.

Adrenergic beta-Agonists↗

Normalization of right ventricular performance and remodeling evaluated by magnetic resonance imaging at late follow-up of heart transplantation: relationship between function, exercise capacity and pulmonary vascular resistance.

BACKGROUND: Right ventricular (RV) dysfunction remains one of the most prominent complications during the period immediately after heart transplantation (HT); however, late adaptation of the RV has not been well described. The aim of our study was to evaluate RV function and remodeling using magnetic resonance imaging (MRI) and to correlate it with exercise capacity and also with hemodynamic data obtained before HT. METHODS: We prospectively evaluated RV function of 25 heart-transplanted patients, without cardiac allograft vasculopathy, who were documented by negative dobutamine stress echocardiography during late follow-up (Group 1, 6 +/- 4.3 years) using MRI. We then compared Group 1 with a control group consisting of 10 patients, who were < or =1 year post-HT (Group 2), hemodynamically stable, and with the same pre-operative hemodynamic features as Group 1. Their pulmonary arterial systolic blood pressure (PSBP) varied from 17 to 67 mm Hg (43.2 +/- 15.3) and pulmonary vascular resistance (PVR) from 1.0 to 5.4 Wood units (2.5 +/- 1.12). The following parameters were studied: RV end-diastolic volume (EDV) and systolic volume (ESV); stroke volume (SV); ejection fraction (EF); and mass (M). We also evaluated the VO2 peak and slope VE/VCO2 values during a treadmill test. Data were analyzed and correlated with the hemodynamic values of PVR and PSBP obtained pre-HT. RESULTS: In Group 1, treadmill evaluation data showed exercise VO2 peak (19.9 +/- 3.19 ml/kg/min) and slope VE/VCO2 (36.9 +/- 4.5) values comparable to those of sedentary individuals; RV variables according to MRI were within normal ranges, with the following mean values for Groups 1 and 2, respectively: RVEDV, 99.6 +/- 4.0 ml vs 127 +/- 16 ml (p = 0.03); RVESV, 42 +/- 2 ml vs 58.5 +/- 9 ml (p = 0.01); RVSV, 57 +/- 3 ml vs 71 +/- 10 ml (p = 0.1); RVEF, 58 +/- 1.4% vs 54 +/- 3.8% (p = 0.29); and RVM, 43.4 +/- 1.9 g vs 74 +/- 8.8 g (p = 0.001). There was no correlation between hemodynamic pulmonary values before HT or any other index of late RV performance, including RV remodeling and hypertrophy, in our study population (p = not significant). CONCLUSIONS: In contrast to what we would expect for heart transplant patients at late follow-up, the RV may adapt to pulmonary pressure and resistance, with reverse remodeling characterized by volume and mass reduction, leading to normalization of RV function despite abnormal hemodynamic pulmonary values being measured before HT. There was no influence on the low exercise capacity observed in these patients, in the absence of cardiac allograft vasculopathy.

Adult↗

Effects of bisoprolol fumarate on left ventricular size, function, and exercise capacity in patients with heart failure: analysis with magnetic resonance myocardial tagging.

BACKGROUND: Recent data suggest that beta-blockers can be beneficial in subgroups of patients with chronic heart failure (CHF). For metoprolol and carvedilol, an increase in ejection fraction has been shown and favorable effects on the myocardial remodeling process have been reported in some studies. We examined the effects of bisoprolol fumarate on exercise capacity and left ventricular volume with magnetic resonance imaging (MRI) and applied a novel high-resolution MRI tagging technique to determine myocardial rotation and relaxation velocity. METHODS: Twenty-eight patients (mean age, 57 +/- 11 years; mean ejection fraction, 26 +/- 6%) were randomized to bisoprolol fumarate (n = 13) or to placebo therapy (n = 15). The dosage of the drugs was titrated to match that of the the Cardiac Insufficiency Bisoprolol Study protocol. Hemodynamic and gas exchange responses to exercise, MRI measurements of left ventricular end-systolic and end-diastolic volumes and ejection fraction, and left ventricular rotation and relaxation velocities were measured before the administration of the drug and 6 and 12 months later. RESULTS: After 1 year, heart rate was reduced in the bisoprolol fumarate group both at rest (81 +/- 12 before therapy versus 61 +/- 11 after therapy; P <.01) and peak exercise (144 +/- 20 before therapy versus 127 +/- 17 after therapy; P <.01), which indicated a reduction in sympathetic drive. No differences were observed in heart rate responses in the placebo group. No differences were observed within or between groups in peak oxygen uptake, although work rate achieved was higher (117.9 +/- 36 watts versus 146.1 +/- 33 watts; P <.05) and exercise time tended to be higher (9.1 +/- 1.7 minutes versus 11.4 +/- 2.8 minutes; P =.06) in the bisoprolol fumarate group. A trend for a reduction in left ventricular end-diastolic volume (-54 mL) and left ventricular end-systolic volume (-62 mL) in the bisoprolol fumarate group occurred after 1 year. Ejection fraction was higher in the bisoprolol fumarate group (25.0 +/- 7 versus 36.2 +/- 9%; P <.05), and the placebo group remained unchanged. Most changes in volume and ejection fraction occurred during the latter 6 months of treatment. With myocardial tagging, insignificant reductions in left ventricular rotation velocity were observed in both groups, whereas relaxation velocity was reduced only after bisoprolol fumarate therapy (by 39%; P <.05). CONCLUSION: One year of bisoprolol fumarate therapy resulted in an improvement in exercise capacity, showed trends for reductions in end-diastolic and end-systolic volumes, increased ejection fraction, and significantly reduced relaxation velocity. Although these results generally confirm the beneficial effects of beta-blockade in patients with chronic heart failure, they show differential effects on systolic and diastolic function.

Adrenergic beta-Antagonists↗

Effects of nisoldipine and/or enalapril on left ventricular function and exercise capacity in patients with recent anterior myocardial infarction and mild cardiac dysfunction.

Treatment of abnormal remodeling and dysfunction of left ventricle after myocardial infarction is one of the major goals of recent therapeutic interventions. The current study, the Nisoldipine Enalapril Anterior Myocardial infarction Study pilot investigation, was designed to investigate the effects of 12 weeks of treatment with enalapril or nisoldipine or their combination on left ventricular (LV) function and exercise capacity in patients with recent (< 1 month) anterior myocardial infarction and mild LV dysfunction (LV ejection fraction [EF] 38% to 48%). Forty-six patients were studied and received, by random assignment, enalapril (5 mg once per day) plus placebo (n = 14) or nisoldipine (10 mg two times per day) plus placebo (n = 18) or enalapril (5 mg once per day) plus nisoldipine (10 mg two times per day) (n = 14). All patients received aspirin (325 mg) throughout the study. Data on LV EF and peak filling rate at rest and LV EF during exercise were collected during radionuclide ventriculography. In addition, the product of heart rate and systolic blood pressure (rate-pressure product) and exercise time were determined during exercise stress testing. The analyzed parameters were not significantly modified after treatment with enalapril or with nisoldipine. In contrast, the combination of enalapril and nisoldipine significantly raised LV EF at rest (from 43% +/- 3% to 48% +/- 6%, p < 0.01) and during exercise (from 45% +/- 8% to 50% +/- 9%, p < 0.01) and raised peak filling rate at rest (fraction of end-diastolic volume per second) from 1.57 +/- 0.3 to 1.67 +/- 0.3 (p < 0.05). In addition, the combined administration of the two drugs increased the rate-pressure product (values x 10(3)) (from 20.7 +/- 5 to 22.7 +/- 4, p < 0.05) and increased exercise time (from 573 +/- 173 seconds to 668 +/- 178 seconds, p < 0.05). These results show that in patients with recent anterior myocardial infarction and mild LV dysfunction, the combination of the angiotensin-converting enzyme inhibitor enalapril and the dihydropyridine nisoldipine improves resting LV systolic and diastolic function and exercise LV systolic function and exercise capacity.

Adult↗

Effect of a cardiac rehabilitation program on left ventricular diastolic function and its relationship to exercise capacity in patients with coronary heart disease: experience from a randomized, controlled study.

BACKGROUND: A cardiac rehabilitation and prevention program (CRPP) is a recognized nonpharmacological modality in the management of coronary heart disease (CHD). However, the effect of a CRPP on systolic function of the heart is controversial, and no data exists on diastolic function in CHD. A randomized, controlled study was conducted to address these issues. METHODS: Patients (n = 269) with recent acute myocardial infarction (n = 193) or after percutaneous coronary intervention (PCI) (n = 76) were randomized to either CRPP (2-hour twice-weekly exercise program for 8 weeks) or conventional therapy (control group). Serial treadmill exercise testing and at-rest echocardiography were performed during phases 1 (baseline), 2 (post-exercise training), and 3 (8-month follow up). RESULTS: The prevalence of left ventricular (LV) abnormal relaxation pattern (ARP) of diastolic dysfunction was increased in the control group only in phase 3 (65% vs 88%, chi2 = 7.6, P <.01). Significant improvement of individual LV diastolic parameters towards less severe delayed relaxation was also observed in the CRPP group, especially in those with recent acute myocardial infarction or ARP. The gain in exercise capacity was faster and more substantial in the CRPP than the control group (P <.001 for phase 2, P <.05 for phase 3), and was significantly correlated with LV diastolic indices in those with ARP. Exercise training had neutral effects on LV systolic function and rate-pressure product. CONCLUSIONS: In patients with CHD, CRPP prevented the progression of resting LV diastolic dysfunction, without affecting systolic function. In those with ARP, the improvement of diastolic function predicted the gain in exercise capacity.

Adult↗

Aerobic group training improves exercise capacity and heart rate variability in elderly patients with a recent coronary event. A randomized controlled study.

AIMS: Reduced heart rate variability is associated with an unfavourable prognosis in patients with ischaemic heart disease. Whether physical training can modify this risk factor is not definitely proven. Our hypothesis was that training might increase both physical capacity and heart rate variability in elderly patients recovering from an acute coronary event, i.e. acute myocardial infarction (n=38) or an episode of unstable angina (n=27). METHODS AND RESULTS: 24 h ambulatory ECG recordings were obtained from 65 patients randomized to either a 3 months supervised outpatient group training programme 50 min three times a week (n=29) or to a control group (n=36). The two groups were well balanced as regards demographic data and pharmacological treatment at the time of randomization. Body mass index and pharmacological therapy remained unchanged during the study. Heart rate variability was analysed in the time and frequency domains. At the 3 month follow-up, exercise tolerance had increased from 103 to 120 W in the training group (P<0.001), and from 102 to 106 W in the control group (ns). The time-domain heart rate variability measures SDNN (standard deviation of all filtered RR intervals over the analysed time period) and SDANN (standard deviation of the means of all filtered RR intervals for all 5 min epochs of the analysed time period) increased significantly during the daytime in the training group (P<0.01 and P<0.05, respectively), but not in the control group. A significant improvement in night-time heart rate variability was observed among controls. There was a statistically significant correlation (P<0.05) between changes in 24 h overall power (frequency domain measure) and changes in maximal exercise capacity in the training group. CONCLUSION: A regular aerobic group training programme after an acute coronary event can significantly improve exercise capacity and modify heart rate variability in a prognostically favourable direction in elderly low-to-intermediate risk patients, recovering from an acute coronary event.

Aged↗

The 6-minute walk: a new measure of exercise capacity in patients with chronic heart failure.

Cycle and treadmill exercise tests are unsuitable for elderly, frail and severely limited patients with heart failure and may not reflect capacity to undertake day-to-day activities. Walking tests have proved useful as measures of outcome for patients with chronic lung disease. To investigate the potential value of the 6-minute walk as an objective measure of exercise capacity in patients with chronic heart failure, the test was administered six times over 12 weeks to 18 patients with chronic heart failure and 25 with chronic lung disease. The subjects also underwent cycle ergometer testing, and their functional status was evaluated by means of conventional measures. The walking test proved highly acceptable to the patients, and stable, reproducible results were achieved after the first two walks. The results correlated with the conventional measures of functional status and exercise capacity. The authors conclude that the 6-minute walk is a useful measure of functional exercise capacity and a suitable measure of outcome for clinical trials in patients with chronic heart failure.

Aged↗

Nitroglycerin prophylaxis in angina pectoris. Effect of sustained release nitroglycerin capsules on anginal frequency and exercise capacity.

Since the pharmacological effects of sublingual nitroglycerin are of short duration, attempts have been made over a number of years to prolong the activity of nitroglycerin by various means, viz. : (1) topical applications of nitroglycerin ointments, relying upon percutaneous absorption; (2) changes in chemical structure leading to such derivatives as isosorbide dinitrate or pentaerythritol tetranitrate; and (3) development of pharmaceutical preparations devised to disintegrate slowly, thus releasing the active substance over a long period. The purpose of the present study was to determine the effects of such a sustained-release nitroglycerin preparation on the frequency of painful paroxysms and on exercise capacity in patients with angina pectoris. In a double-blind trial comparing the preparation with a placebo 25 patients were observed during 24 weeks. The active substance significantly reduced the number of anginal attacks and increased exercise capacity in all cases. It would therefore seem that sustained-release nitroglycerin capsules deserve to have a place in the treatment of angor pectoris. However, further studies involving a larger number of patients are required to support these conclusions.

Angina Pectoris↗

Disparity between improvement in left ventricular function and changes in clinical status and exercise capacity during chronic enoximone therapy.

Twenty patients with moderately severe congestive heart failure were randomized to chronic enoximone (n = 10) or placebo (n = 10) therapy in a double-blind manner and serially evaluated over a 16-week-period. The purpose of the study was to determine if the addition of standard doses (1 and 2 mg/kg) of this new phosphodiesterase inhibitor to conventional therapy (digitalis and diuretics) would alter the clinical and laboratory course of this patient population. Except for a transient improvement in the quality of life score, none of the symptomatology indicators were significantly affected by enoximone. Similarly, maximal exercise capacity was not altered. Enoximone did elicit a statistically significant augmentation of echocardiographic, radionuclide angiographic, and systolic time interval parameters of left ventricular function. These enoximone-induced effects were accompanied by a significant increase (7% to 11%) in resting heart rate. Enoximone is capable of improving ventricular function when added to digitalis-diuretic therapy in moderately severe congestive heart failure. While individual patients may benefit from enoximone, the ability of standard doses of this agent to improve symptoms and exercise capacity over a 16-week period appears somewhat limited in a moderately severe heart failure population as a whole. Furthermore, a disparity between improvement in ventricular function parameters and changes in clinical status and exercise performance is apparent in this heart failure population.

Adult↗

Selenium deficiency, endurance exercise capacity, and antioxidant status in rats.

Increased O2 metabolism imposed by physical exercise is likely to augment the production of active O2 species that have been shown to react with lipids, proteins, and DNA. Antioxidants and antioxidant enzymes, such as the selenium enzyme glutathione peroxidase, minimize or prevent such potentially toxic reactions. This study shows that selenium deficiency decreases glutathione peroxidase activity in liver and muscle (less than 80%, P less than 0.001), increases total glutathione in liver, muscle, and plasma (P less than 0.05) and increases muscle cytochrome oxidase activity, and ubiquinone content (P less than 0.05) but has no effect on endurance capacity. Exercise to exhaustion resulted in a significant (P less than 0.001) elevation of total and oxidized glutathione (GSSG) and a significant (P less than 0.05) decrease of vitamin E in plasma of control and selenium-deficient rats. Acute exercise also increased tissue GSSG levels in both control and selenium-deficient groups of rats. Hence, despite a large depletion of selenium-deficient glutathione peroxidase, pronounced oxidation of glutathione to GSSG can be produced by the increased oxidative metabolism during physical exercise. The results suggest that the residual glutathione peroxidase activity is sufficient to detoxify hydroperoxides in exercising selenium-deficient animals and to prevent the impairment of endurance capacity.

Animals↗

Insulin resistance, exercise capacity and body composition in subjects with two hypertensive parents.

OBJECTIVE: To study insulin resistance in subjects with strong genetic predisposition to essential hypertension, compared with non-disposed subjects. SUBJECTS: Thirty normotensive subjects aged 18-35 years whose parents both had essential hypertension, and 30 age- and sex matched subjects whose parents were both normotensive, were studied. Subjects or parents with diabetes and morbid obesity were excluded. METHODS: The study comprised (1) a frequent sampling oral glucose tolerance test; (2) an isoglycemic hyperinsulinemic clamp study; (3) an analysis of body composition by dual-energy X-ray absorptiometry; (4) an exercise test with gas exchange analysis; and (5) investigation of composition of usual diet by diet registration for 5 days. RESULTS: The 24-h diastolic blood pressure was higher in subjects predisposed to hypertension compared with the controls: 78.1 versus 74.0 mmHg (confidence interval for the difference between the means; -0.5; -7.9), but the insulin sensitivity index was similar: 312 versus 362 I(2) min(-1) pmol(-1) kg(-1) (28; -129). The two groups were similar in terms of body composition, exercise capacity and composition of usual diet. Resting and 24-h diastolic blood pressures were correlated to abdominal fat mass but not to insulin sensitivity. CONCLUSION: Subjects with a strong genetic predisposition to essential hypertension had increased diastolic blood pressure compared with subjects with normotensive parents, but they were not insulin resistant. This may be due to the subjects being highly selected as to confounding factors. The increased blood pressure in the hypertension prone subjects could not be attributed to differences in body composition, exercise capacity or dietary habits.

Absorptiometry, Photon↗

Maximal exercise capacity of children with heart defects.

Maximal treadmill tests following the Bruce protocol were performed by 830 children with heart defects and the endurance times compared with normal values from 327 children seen in the same clinic because of normal murmurs and from 388 normal children randomly selected and tested in the schools. When values in the normal clinic children were used as the reference, only 21 percent of the patients with heart defects had endurance times below the 10th percentile line. This line was 14 percent higher in the normal school children, and 47 percent of the patient group had values below the 10th percentile when values in the school children were used as the reference. Maximal heart rate in children with heart defects was almost always in the normal range (180 to 210 beats/min) except in patients with cyanosis or severe valve disease and, when encouraged to continue exercising, even these children had a mean maximal heart rate of 175 beats/min. When comparing the exercise capacity of children with heart defects with that of normal children, the source of the normal children is important; body build needs to be considered, as well as physical activity habits. Clinic patients without heart defects probably serve as a better normal control group than children obtained from the school system. Maximal exercise tests do not necessarily distinguish between children with mild or severe heart disease. Only children with lesions causing cyanosis or children with obviously severe disease have consistent reductions in exercise capacity.

Adolescent↗

Improved exercise capacity and ischemia 6 and 12 months after transendocardial injection of autologous bone marrow mononuclear cells for ischemic cardiomyopathy.

BACKGROUND: We recently reported the safety and feasibility of autologous bone marrow mononuclear cell (ABMMNC) injection into areas of ischemic myocardium in patients with end-stage ischemic cardiomyopathy. The present study evaluated the safety and efficacy of this therapy at 6- and 12-month follow-up. METHODS AND RESULTS: Twenty patients with 6- and 12-month follow-up (11 treated subjects; 9 controls) were enrolled in this prospective, nonrandomized, open-label study. Complete clinical and laboratory evaluations as well as exercise stress (ramp treadmill), 2-dimensional Doppler echocardiography, single-photon emission computed tomography (SPECT) perfusion scanning, and 24-hour Holter monitoring were performed at baseline and follow-up. Transendocardial delivery of ABMMNCs was performed with the aid of electromechanical mapping to identify viable myocardium. Each patient received 15 ABMMNC injections of 0.2 mL each. At 6 and 12 months, total reversible defect, as measured by SPECT perfusion scanning, was significantly reduced in the treatment group as compared with the control group. At 12 months, exercise capacity was significantly improved in the treatment group. This improvement correlated well with monocyte, B-cell, hematopoietic progenitor cell, and early hemapoietic progenitor cell phenotypes. CONCLUSIONS: The 6- and 12-month follow-up data in this study suggest that transendocardial injection of ABMMNCs in patients with end-stage ischemic heart disease may produce a durable therapeutic effect and improve myocardial perfusion and exercise capacity.

Aged↗

Decreased lung function and exercise capacity in Fontan patients. A long-term follow-up.

OBJECTIVE: The haemodynamic situation for patients with Fontan circulation is characterized by a reduced, non-pulsatile pulmonary blood flow. To evaluate if this has any impact on lung function and exercise capacity, we studied the surviving 20 patients operated upon at our institution between 1980 and 1991. The median age was 17.5 years, the median follow-up time was 11.5 years. DESIGN: Lung volumes, flow-volume curves, the ventilatory distribution and the diffusion capacity for carbon monoxide were obtained using routine methods. The exercise tests were performed on a bicycle ergometer with determination of ventilation, oxygen uptake, carbon dioxide production, respiratory rate and heart rate. RESULTS: The lung volumes, maximal expiratory flows and diffusion capacity were significantly lower than expected. The median maximal oxygen uptake was 1.39 for the females and 1.63 l/min for the males, corresponding to 25.1 and 25.2 ml/kg/min, respectively. The maximal heart rates varied from 104 to 177 beats/min. All patients reached a respiratory exchange ratio above 1.0. CONCLUSION: Fontan patients have small lungs. They have a markedly reduced exercise capacity and a low maximal heart rate.

Adolescent↗

Correlation of exercise capacity with high-sensitive C-reactive protein in patients with stable coronary artery disease.

BACKGROUND: There is growing evidence for the association between physical activity and systemic inflammatory markers in healthy individuals and populations with a low prevalence of coronary artery disease (CAD). However, the association between fitness and CRP in patients with stable CAD treated with medications known to influence the inflammatory response, such as statins and aspirin, is not well known. METHODS: We prospectively enrolled 209 patients with angiographically documented CAD (161 men; age 63 +/- 10 years; 1-/2-/3-vessel disease in 42%, 34%, and 24% of patients, respectively; left ventricular ejection fraction 60% +/- 13%). Fitness level was assessed by maximal exercise testing. CRP was measured in all patients using high-sensitivity immunoassay. RESULTS: Fitness level was inversely correlated with natural log-transformed CRP level (r = -0.28, P < .001). After multivariate linear regression adjustment for age, sex, body mass index, waist circumference, smoking status, educational level, diabetes, hypertension, modality of exercise testing, exercise-induced ischemia, extent of CAD, medication use, leukocyte count, hemoglobin, renal function, glucose level, and cholesterol level, exercise capacity remained inversely correlated with CRP level (beta = -.226, P = .001). Other covariates associated with CRP remaining in the final model were leukocyte count (beta = .348), pack-years of smoking (beta = .185), diabetes status (beta = -.201), hemoglobin concentration (beta = -.187), and high-density lipoprotein cholesterol level (beta = -.149). CONCLUSIONS: These results indicate that exercise capacity is inversely correlated with CRP level in patients with known stable CAD irrespective of extent of CAD and standard medication for secondary prevention.

Aged↗

[Sports medical aspects in cardiac risk stratification--heart rate variability and exercise capacity].

The present study investigates the association of the predicted CHD-risk (PROCAM) with the individual endurance capacity and heart rate variability (HRV) in a population-based sample of sedentary elderly. After stratification, in 57 men (48.1+/-9.5 yrs.) with an overall PROCAM-risk <10% (28.7+/-10.9 points) and 22 men (54.5+/-7.7 yrs.) with a coronary 10-year risk > or =10% (50.8+/-5.6 points) cycle ergometries and short-term HRV analysis of time (RRMEAN, SDNN, RMSSD) and frequency domain parameters (LF, HF, TP, LF/HF) were conducted. Additionally the autonomic stress index (SI) was calculated. Nonparametric tests were used for statistical correlation analysis (Spearman rho) and group comparisons (Mann-Whitney). For endurance capacity [W/kg] (r=-0.469, p<0.001), SDNN (r=-0.302, p<0.05), RMSSD (r= -0.311, p<0.05), LF (r=-0.325, p<0.05), HF (r= -0.311, p<0.05) and TP (r= -0.307, p<0.05) negative monotone correlations with the coronary score-risk were determined. Significant positive correlations were calculated for SI (r=0.476, p<0.001). Except for RRMEAN and LF/HF significant group differences (p<0.05) were computed for SDNN (30.0+/-20.0 vs 20.0+/-10.0 ms), RMSSD (22.2+/-18.3 vs 18.0+/-8.7 ms), LF (90.9+/-241.5 vs 41.35+/-81.1 ms(2)), HF (43.0+/-105.1 vs 18.0+/-27.0 ms(2)) and TP (189.0+/-457.1 vs 100.0+/-157.6 ms(2)). Significant differences (p<0.01) were evaluated for exercise capacity (2.4+/-0.5 vs 1.8+/-0.3 W/kg) and SI (90+/-183 vs 322+/-291). The results underline the predictive value of HRV analysis in risk stratification and outline the interrelation of a decreased exercise capacity and autonomic function with a raised individual 10-year cardiac risk. As an independent parameter of the vegetative regulatory state the stress index may contribute to an increased practical relevance of short-time HRV analysis.

Adult↗