Cardiopulmonary Exercise Testing Performance Research Articles

Abstract 476: Exercise Induced Pulmonary Hypertension in Patient Presenting With Acute Cardiac Symptoms

Introduction: Patients presenting with symptoms of angina, dyspnea, and fatigue with negative cardiac and pulmonary test findings are often investigated with exercise right heart catheterization. Patients displaying pulmonary hypertension or exercise-induced pulmonary hypertension (EIPH) were isolated and studied further to elaborate upon similarities and differences with patients with normal pressures. Hypothesis: EIPH may be an under-recognized cause of cardiac complaints. Methods: Clinical data was obtained from 172 randomly and retrospectively selected patients including data on hemodynamics, cardiopulmonary exercise testing (CPET), and echocardiogram findings. Patients with EIPH had a resting mean pulmonary arterial pressure below 25 mmHg and on exercise above 25 mmHg. Patients with resting pulmonary hypertension were stratified into WHO group 1 (pulmonary arterial) and WHO group 2 (due to left heart). Prior response to treatment with long-acting nitrates was also reviewed. Results: 27 patients had EIPH, 24 had WHO group 1 pulmonary hypertension, 37 had WHO group 2 pulmonary hypertension, 54 did not have pulmonary hypertension, and 30 did not have any exercise data. No significant differences were found across any groups in resting or exercise CPET performance. The mean age of those with pulmonary hypertension was 71.67 years and 58.89 for those without (p<0.01). Both had a mean left ventricular ejection fraction between 53-57%. The mean VO2 max for those with resting pulmonary hypertension or EIPH was below 20 ml/kg/min. For every 1-year increase in age the odds of developing EIPH increased by 1.08. The use of long-acting nitrate was associated with improvement of symptoms in symptomatic patients. Most of the EIPH patients were noted to have exercise-induced diastolic dysfunction and many also had concomitant chronotropic incompetance. Conclusions: EIPH represents those who have negative left-heart stress cardiac findings yet have underlying abnormalities significant enough to require symptomatic treatment during exercise. This includes diastolic dysfunction and chronotropic incompetency. Cardiovascular performance was found to be equally poor in patients with EIPH as compared to those with resting pulmonary hypertension.

Relationship Between Habitual Exercise and Performance on Cardiopulmonary Exercise Testing Differs Between Children With Single and Biventricular Circulations.

Increasing habitual exercise has been associated with improved cardiopulmonary exercise testing (CPET) performance, specifically maximal oxygen consumption in children with operatively corrected congenital heart disease. This has not been studied in children following Fontan palliation, a population in whom CPET performance is dramatically diminished. A single-center cross-sectional study with prospective and retrospective data collection was performed that assessed habitual exercise preceding a clinically indicated CPET in children and adolescents with Fontan palliation, transposition of the great arteries following arterial switch operation (TGA), and normal cardiac anatomy without prior operation. Data from contemporaneous clinical reports and imaging studies were collected. The association between percent predicted VO2max and habitual exercise duration adjusted for known covariates was tested. A total of 175 subjects (75 post-Fontan, 20 with TGA, and 80 with normal cardiac anatomy) were enrolled. VO2max was lower in the Fontan group than patients with normal cardiac anatomy (p<0.0001) or TGA (p<0.0001). In Fontan subjects, both univariate and multivariate analysis failed to demonstrate a significant association between habitual exercise and VO2max (p=0.6), in sharp contrast to cardiac normal subjects. In multivariate analysis, increasing age was the only independent risk factor associated with decreasing VO2max in the Fontan group (p=0.003). Habitual exercise was not associated with VO2max in subjects with a Fontan as compared to biventricular circulation. Further research is necessary to understand why their habitual exercise is ineffective and/or what aspects of the Fontan circulation disrupt this association.

Cardiorespiratory fitness, pulmonary function and C-reactive protein levels in nonsmoking individuals with diabetes.

The objective of this study was to evaluate cardiorespiratory fitness and pulmonary function and the relationship with metabolic variables and C-reactive protein (CRP) plasma levels in individuals with diabetes mellitus (DM). Nineteen men with diabetes and 19 age- and gender-matched control subjects were studied. All individuals were given incremental cardiopulmonary exercise and pulmonary function tests. In the exercise test, maximal workload (158.3±22.3 vs 135.1±25.2, P=0.005), peak heart rate (HRpeak: 149±12 vs 139±10, P=0.009), peak oxygen uptake (VO2peak: 24.2±3.2 vs 18.9±2.8, P<0.001), and anaerobic threshold (VO2VT: 14.1±3.4 vs 12.2±2.2, P=0.04) were significantly lower in individuals with diabetes than in control subjects. Pulmonary function test parameters, blood pressure, lipid profile (triglycerides, HDL, LDL, and total cholesterol), and CRP plasma levels were not different in control subjects and individuals with DM. No correlations were observed between hemoglobin A1C (HbA1c), CRP and pulmonary function test and cardiopulmonary exercise test performance. In conclusion, the results demonstrate that nonsmoking individuals with DM have decreased cardiorespiratory fitness that is not correlated with resting pulmonary function parameters, HbA1c, and CRP plasma levels.

Exercise tolerance in Gulf War veterans and relationship to deployment exposures (884.22)

Exercise intolerance and post‐exertional malaise are common findings that persist in veterans of the 1990 ‐ 1991 Gulf War. Previous work has suggested that these symptoms are related to exposure to airborne hazards during deployment. The objective of this study was to examine the relationship between self‐report measures of exposure and fatigue with cardiopulmonary exercise testing (CPET) performance. Ten male veterans (51.0±3.8 yrs; BMI: 30.0±5.1) completed health, exposure and fatigue questionnaires prior to a maximal exercise test to exhaustion on cycle ergometer. Exercise capacity was significantly reduced in this group and 40% had ventilatory limitations to exercise (i.e. ventilatory reserve &lt; 30%). Exposure intensity was significantly associated with oxygen pulse (r = ‐0.69, p = 0.04), fatigue severity (r = 0.71, p = 0.03), and trends were observed for peak oxygen consumption (VO2) and uptake kinetics (p = 0.08). However, when categorized into low and high exposure groups, VO2 peak and uptake kinetics were significantly greater (p&lt;0.05) in the low exposure group. Our preliminary findings in a small group of Gulf War veterans suggest that higher deployment‐related exposures may be associated with greater fatigue, reduced exercise capacity and slower VO2 kinetics. Future studies are necessary to better understand the health effects of airborne hazards exposures on cardiorespiratory function.Grant Funding Source: VA Grants 1I21RX001079‐01, 1I21CX000797‐01

Clinical predictors of response to anakinra in patients with heart failure

Clinical predictors of response to anakinra in patients with heart failure

Determinants of Cardiopulmonary Exercise Testing Performance in Severely Obstructive Hypertrophic Cardiomyopathy

Patients with hypertrophic obstructive cardiomyopathy (HOCM) suffer functional limitation demonstrated by cardiopulmonary study (CPX). It is unclear whether left ventricular outflow tract (LVOT) obstruction is the primary determinant of exercise capacity. We aimed to establish the determinants of peak oxygen consumption (pVO2) and ventilatory efficiency (VE/VCO2) in patients with severe HOCM referred for septal ethanol ablation.

Decreased Fitness Is Associated with Abnormal Cardiopulmonary Response to Maximal Exercise in Pediatric Sickle Cell Anemia.

AbstractAbstract 2109▪▪This icon denotes a clinically relevant abstractThe clinical burden of sickle cell anemia (SCA) has a tremendous impact on physical functioning, including cardiopulmonary fitness, among affected individuals. However, the physiologic basis of exercise limitation remains poorly understood in this population. The objective of our study was to characterize the cardiopulmonary response to maximal exercise and to delineate the physiologic mechanisms responsible for decreased fitness among children and young adults with SCA. Methods:We prospectively performed maximal cardiopulmonary exercise testing (CPET) on 60 subjects with SCA (hemoglobin SS or S/β0 thalassemia) and 20 controls without SCA or sickle cell trait matched for race and gender. CPET was completed using a graded, symptom-limited cycle ergometry protocol with breath-by-breath, gas exchange analysis and pre/post spirometry. The primary outcome of fitness was defined by weight-adjusted, peak oxygen consumption (peak VO2). Slopes for determining oxygen uptake kinetics and ventilatory efficiency were calculated using 10-second averages of data points. We used the V-slope method to determine ventilatory threshold. Bivariate comparisons of continuous data were performed using Student’s t-test for independent samples (IBM, SPSS V20). We used multivariate analysis to derive a model for determining independent contributors to peak VO2 in subjects. Results:There was no difference in gender distribution among subjects and controls, but subjects were older (15.1 ± 3.44 vs. 13.2 ±2.9 years, p = 0.03) and had lower hemoglobin (8.8 ±1.3 vs. 12.8 ±1.5 g/dL, p < 0.0001). All subjects met criteria for a maximal test as defined by a respiratory exchange ratio (RER) ≥ 1.1, and in all, testing was terminated due to excessive fatigue. No major adverse events occurred during CPET in any subject. Only 1/60 (1.7%) subjects developed vaso-occlusive pain requiring hospitalization in the 2-week follow-up period after testing. Nearly all of the major indicators of CPET performance and gas exchange were adversely affected in our subjects. Compared to controls, subjects demonstrated significantly lower mean peak VO2 (26.9 ±6.9 vs. 40.6 ±8.2 mL/kg/min, p < 0.0001), even after adjustment for age and hemoglobin. Average total test time (5.6 ±1.3 vs. 7.8 ±2.2 min, p = 0.012) and peak work rate (108 ±37 vs. 151 ±57 watts, p = 0.011) were similarly reduced as was ventilatory threshold (1.01 ±0.29 vs. 1.34 ±0.34 L/min, p < 0.0001), indicating earlier transition to anaerobic metabolism during exercise. Heart rate reserve, the difference between achieved maximal and baseline heart rates, was significantly lower (99 ±14 vs. 111 ±15, p = 0.002) in subjects. Slopes calculated using minute ventilation (VE), expired CO2 (VCO2), VO2 and work rate also indicated significantly reduced ventilatory efficiency (ΔVE/ΔVCO2), oxygen delivery (ΔVO2/ΔWR) and oxygen uptake (ΔVO2/ΔVE) kinetics in subjects versus controls. To examine the physiologic contributors to peak VO2 in subjects with SCA alone, we developed a multivariate model that included age, baseline hemoglobin, heart rate reserve, maximal VE, pre-exercise forced expiratory volume in 1 second, and ventilatory threshold. This model explained 67% of the variability observed in peak VO2 in subjects, with age, maximal VE and ventilatory threshold retaining independent contributions to peak VO2 and ventilatory threshold making the largest contribution with an non-standardized β coefficient of 11.9 (SE ±3.2), p < 0.0001. Conclusions:Maximal CPET is safe in children and young adults with SCA, suggesting that acute exercise challenge is well tolerated in this population even at high levels of exercise intensity and physical exertion. When compared to their peers, children and young adults with SCA demonstrate significantly reduced fitness levels. Exercise limitation in SCA may be attributed to complex derangements in the cardiopulmonary and metabolic responses to exercise that are independent of anemia. Our findings highlight the need to develop targeted exercise training strategies aimed at improving fitness in this population and to assess its impact on overall disease severity. Disclosures:No relevant conflicts of interest to declare.

Associations between isokinetic muscle strength, high-level functional performance, and physiological parameters in patients with chronic obstructive pulmonary disease

High-level activities are typically not performed by patients with chronic obstructive pulmonary disease (COPD), which results in reduced functional performance; however, the physiological parameters that contribute to this reduced performance are unknown. The aim of this study was to determine the relationships between high-level functional performance, leg muscle strength/power, aerobic power, and anaerobic power. Thirteen patients with COPD underwent an incremental maximal cardiopulmonary exercise test, quadriceps isokinetic dynamometry (isometric peak torque and rate of torque development; concentric isokinetic peak torque at 90°/sec, 180°/sec, and 270°/sec; and eccentric peak torque at 90°/sec), a steep ramp anaerobic test (SRAT) (increments of 25 watts every 10 seconds), and three functional measures (timed up and go [TUG], timed stair climb power [SCPT], and 30-second sit-to-stand test [STS]). TUG time correlated strongly (P < 0.05) with all muscle strength variables and with the SRAT. Isometric peak torque was the strongest determinant of TUG time (r = −0.92). SCPT and STS each correlated with all muscle strength variables except concentric at 270°/sec and with the SRAT. The SRAT was the strongest determinant of SCPT (r = 0.91), and eccentric peak torque at 90°/sec was most significantly associated with STS (r = 0.81). Performance on the SRAT (anaerobic power); slower-velocity concentric, eccentric, and isometric contractions; and rate of torque development are reflected in all functional tests, whereas cardiopulmonary exercise test performance (aerobic power) was not associated with any of the functional or muscle tests. High-level functional performance in patients with COPD is associated with physiological parameters that require high levels of muscle force and anaerobic work rates.

Increased Plasma Nitrite Enhances Exercise Performance in PAD:-A Nitric Oxide Effect?

Peripheral Arterial Disease is the manifestation of a failure to adequately supply blood flow and O2 to working tissues and presents as claudication pain during walking which subsides with rest. Any intervention that can improve tissue perfusion during exercise in PAD subjects is clinically significant. Nitric oxide (NO) bioavailability is essential for vascular health and function and is implicated in aerobic exercise performance. Dietary inorganic nitrate is absorbed in the gut, converted to nitrite (NO2-) by comensural bacteria in saliva and then reabsorbed to become concentrated in the blood. Plasma NO2- is a marker of vascular NO production but recent findings suggest it may also be a protected circulating "sink" that can be converted to NO during hypoxic conditions, possibly aiding perfusion. PURPOSE: To determine the effects of a dietary provision of plasma nitrate on plasma NO2- and subsequent cardiopulmonary graded exercise test (CPX) performance in PAD subjects. METHODS: This was a randomized open label cross-over study of a HIGH (beet juice) versus a LOW (orange juice) nitrate drink (7 days between tests). On each visit subjects (n=8) underwent resting blood draws, followed by 500ml of juice and subsequent blood draws at 2hr, 3hr (pre-CPX), immediately and 10 minutes post CPX. Measures of brachial artery endothelial function following reactive hyperemia and calf tissue oxygenation using near-infra red spectroscopy during the CPX were also performed. All blood samples were immediately treated, snap frozen and stored for later analysis for plasma NO2- and nitrate using reductive chemiluminescence. RESULTS: There were no changes from rest (180±60nM) in plasma NO2- following the LOW drink. The HIGH drink increased plasma NO2- levels after 3 hours (1139nM±815, p≥0.01). Subjects walked 18% longer before reporting the onset of claudication pain (COT) (183±84sec to 215±99sec, p≥0.01) and 14% longer before stopping (TTE) (467± 223sec to 533±233sec, p≥0.01) following the HIGH vs LOW beverage. Interestingly, DBP was lower in the HIGH group at rest and during CPX testing (p≥0.05). CONCLUSION: A high nitrate drink increased plasma NO2- at 3 hours post consumption. This was associated with an increase in exercise performance (COT and TTE) in PAD subjects. Supported by Wake Forest TSC & Duke Pepper OAIC grants to JDA

Comparison of 6-min walk test distance and cardiopulmonary exercise test performance in children with pulmonary hypertension

ObjectiveTo assess the relationship between 6-min walk test (6MWT) distance and variables of cardiopulmonary exercise testing (CPET) in children with pulmonary arterial hypertension (PAH).DesignRetrospective study.SettingTertiary hospital.PatientsChildren with PAH.InterventionsCPETs and 6MWTs.Main...

Exercise testing with concurrent beta-blocker usage: Is it useful? What do we learn?

Cardiopulmonary exercise testing (CPET) has been used for the assessment of severity of heart failure (HF), secondary to left ventricular systolic dysfunction. Initial studies determined that oxygen consumption (VO2) during exercise, as a measure of functional capacity, correlated well with the hemodynamic responses related to chronic HF. These studies led to the use of peak VO2 as a prognostic indicator in chronic HF. In addition, the use of several ventilatory parameters, eg, minute ventilation/carbon dioxide production during submaximal and peak exercise, were shown to have additive and (in some studies) superior prognostic value in patients with chronic HF. However, most of these studies were performed before beta-adrenergic blockade became the main focus of therapy in chronic HF. Unlike other drugs used in the treatment of HF, these drugs do not consistently improve exercise capacity as measured by peak VO2. Several retrospective studies and one prospective study have examined the effect of long-term beta-blocker therapy on the prognostic value of CPET in patients with chronic HF. These studies indicate that patients on beta-blockers have improved overall cardiovascular outcomes compared with patients not on these drugs. In addition, peak exercise VO2 still has prognostic value in beta-blocked patients; however, the thresholds for increased risk and need for transplantation have to be lower than in patients not on these drugs. There appears to be a real demand for a comprehensive survival score tool that includes the use of beta-blockade, along with CPET performance.

Early response of cardiopulmonary exercise test(CPET) in patients with locally advanced Non-Small Cell Lung cancer treated with radiation

Background : Patients with locally advanced non-small cell lung cancer are often treated with radiation alone or in combination with chemotherapy. Both modalities have a potentially damaging effect on pulmonary function. In order to examine changes in the cardiopulmonary exercise function of patients with locally advanced non-small cell lung cancer before and after conventional radiotherapy, we conducted a prospective study involving patients with such cancer, that had received radiation therapy. Method : Resting pulmonary function test, thoracic radiographic finding and cardiopulmonary exercise test(CPET) were assessed prior to and 4 weeks following radiation therapy in 11 male patients with locally advanced non-small cell lung cancer. Patient with endobronchial mass were excluded. Results : The forces vital capacity (FVC), forced expiratory volume in 1 second ( and maximal voluntary ventilation (MVV) did not decreased between before and 4 weeks after radiation but the diffusing capacity (DLCO) had decreased by 11% 4 weeks after radiation, which was not statistically significant. No changes in maximal oxygen consumption (max), carbon dioxide production (), exercise time and work load were attributed to radiation therapy. Follow up cardiopulmonary exercise testing revealed unchanged cardiovascular function, ventilatory function and gas exchange. No difference in cardiopulmonary exercise test performance was observed between pre- and post-radiation. Conclusion : Cardiopulmonary exercise function did not decrease within the short-term after the radiation of patients with locally advanced non-small cell lung cancer.

Relation between aerobic capacity and extent of myocardial ischemia in patients with normal cardiac function

Background The relation between aerobic capacity and extent of exercise-induced myocardial ischemia has not been investigated. Fifty patients with coronary artery disease (≥50% stenosis) without myocardial infarction underwent cardiopulmonary exercise testing followed by quantitative thallium perfusion imaging. Results were compared with those of age- and sex-matched healthy controls with a low likelihood of coronary artery disease. Patients with Q-wave infarction, pulmonary disease, and peripheral vascular disease were excluded. Cardiopulmonary exercise testing and thallium perfusion imaging parameters were correlated for extent of global ischemia, occurrence of increased pulmonary thallium uptake, and transient ventricular dilatation during exercise. Results Patients with global ischemia <20% (group 1, n = 25) had normal cardiopulmonary exercise testing results, similar to the control group, except for workload and maximal predicted heart rate, which were reduced. However, patients with ischemia ≥20% (group 2, n = 25) had poor cardiopulmonary exercise testing results compared with the controls. The ventilatory anaerobic threshold showed the most significant decrease of all cardiopulmonary exercise testing parameters (48% ± 6% vs 57% ± 6%, P < .0001), and it was the only parameter to correlate with extent of ischemia ( r = –0.5; P < .003) as well as frequency of increased pulmonary uptake and transient ventricular dilatation ( r = –0.33, P = .03). Conclusions Ventilatory anaerobic threshold is significantly related to extent of myocardial ischemia and signs of heart failure during exercise. However, patients with mild to moderate exercise-induced ischemia may have normal cardiopulmonary exercise testing performance. (Am Heart J 1999;138:1088-92.)