Echocardiography combined with cardiopulmonary exercise testing for the prediction of outcome in idiopathic pulmonary arterial hypertension

BACKGROUND: Right ventricular (RV) function is a major determinant of exercise intolerance and outcome in idiopathic pulmonary arterial hypertension (IPAH). The aim of the study was to evaluate the incremental prognostic value of echocardiography of the RV and cardiopulmonary exercise testing (CPET) on long-term prognosis in these patients. METHODS: One hundred-thirty treatment-naïve IPAH patients were enrolled and prospectively followed. Clinical worsening (CW) was defined by a reduction in 6-minute walk distance plus an increase in functional class, or non elective hospitalization for PAH, or death. Baseline evaluation included clinical, hemodynamic, echocardiographic and CPET variables. Cox regression modeling with c-statistic and bootstrapping validation methods were done. RESULTS: During a mean period of 528 ± 304 days, 54 patients experienced CW (53%). Among demographic, clinical and hemodynamic variables at catheterization, functional class and cardiac index were independent predictors of CW (Model-1). With addition of echocardiographic and CPET variables (Model-2), peak O2 pulse (peak VO2/heart rate) and RV fractional area change (RVFAC) independently improved the power of the prognostic model (AUC: 0.81 vs 0.66, respectively; p=0.005). Patients with low RVFAC and low O2 pulse (low RVFAC + low O2 pulse) and high RVFAC+low O2 pulse showed 99.8 and 29.4 increase in the hazard ratio, respectively (relative risk -RR- of 41.1 and 25.3, respectively), compared with high RVFAC+high O2 pulse (p=0.0001). CONCLUSIONS: Echocardiography combined with CPET provides relevant clinical and prognostic information. A combination of low RVFAC and low O2 pulse identifies patients at a particularly high risk of clinical deterioration

Healthcare professional’s guide to cardiopulmonary exercise testing

Cardiopulmonary exercise testing (CPEX) is a valuable clinical tool that has proven indications within the fields of cardiovascular, respiratory and pre-operative medical care. Validated uses include investigation of the underlying mechanism in patients with breathlessness, monitoring functional status in patients with known cardiovascular disease and pre-operative functional state assessment. An understanding of the underlying physiology of exercise, and the perturbations associated with pathological states, is essential for healthcare professionals to provide optimal patient care. Healthcare professionals may find performing CPEX to be daunting, yet this is often due to a lack of local expertise and guidance with testing. We outline the indications for CPEX within the clinical setting, present a typical protocol that is easy to implement, explain the key underlying physiological changes assessed by CPEX, and review the evidence behind its use in routine clinical practice. There is mounting evidence for the use of CPEX clinically, and an ever-growing utilisation of the test within research fields; a sound knowledge of CPEX is essential for healthcare professionals involved in routine patient care

Early prediction of the highest workload in incremental cardiopulmonary tests

Incremental tests are widely used in cardiopulmonary exercise testing, both in the clinical domain and in sport sciences. The highest workload (denoted Wpeak) reached in the test is key information for assessing the individual body response to the test and for analyzing possible cardiac failures and planning rehabilitation, and training sessions. Being physically very demanding, incremental tests can significantly increase the body stress on monitored individuals and may cause cardiopulmonary overload. This article presents a new approach to cardiopulmonary testing that addresses these drawbacks. During the test, our approach analyzes the individual body response to the exercise and predicts the Wpeak value that will be reached in the test and an evaluation of its accuracy. When the accuracy of the prediction becomes satisfactory, the test can be prematurely stopped, thus avoiding its entire execution. To predict Wpeak, we introduce a new index, the CardioPulmonary Efficiency Index (CPE), summarizing the cardiopulmonary response of the individual to the test. Our approach analyzes the CPE trend during the test, together with the characteristics of the individual, and predicts Wpeak. A K-nearest-neighbor-based classifier and an ANN-based classier are exploited for the prediction. The experimental evaluation showed that the Wpeak value can be predicted with a limited error from the first steps of the tes

Rowing-ramp protocol as a cardiopulmonary exercise test for hemiparetic stroke survivors

Cardiopulmonary capacity should be evaluated accurately to determine exercise intolerance and training intensity of stroke survivors before an exercise rehabilitation programme is prescribed. However, no cardiopulmonary exercise test (CPET) is suitable because of the stroke victims’ physical impairment. The aim of this study was to develop and validate a new rowing-ramp protocol as a CPET for stroke survivors. Eleven stroke patients (6 male; 5 female; age, 45 + 16.01 years, performed two incremental exercise tests on a Concept II rowing ergometer to determine the peak oxygen consumption (VO2 peak). Test-retest reliability for VO2 peak, measured 1-week apart, resulted in an intra-class correlation of 0.97 and 0.95, respectively. A linear regression equation was developed to predict the VO2 peak from final stage stroke power. Validity and reliability of the prediction equation were established. The regression equation for predicted VO2 peak was VO2 peak=11.429±+ 0.232 (Final Stage Stroke Power) + 12.63 (F=25.326, p<0.01; R=0.859, R2=0.738). Limits of agreement between predicted and measured VO2 peak were acceptable, with a mean bias of 0.37 ml/kg/min. The validity coefficient (R) was 0.83 (p<0.01) and 0.81 (p<0.01) in both trials. Test-Retest reliability coefficient for predicted VO2 peak 0.95 (p<0.01). The positive relationship between Final Stage Stroke Power and VO2 peak suggests that the Rowing-Ramp protocol could be used to measure VO2 peak of stroke survivors. Additional studies are needed to cross-validate the regression equation using larger sample size, different type and severity of stroke

Cardiopulmonary exercise test responses to the BSU/Bruce Ramp protocol

Purpose: The purpose of this study was to evaluate known correlates of VO2max including subject characteristics and exercise test data to develop an equation to estimate VO2max for the BSU/Bruce Ramp protocol. Methods: 1913 cardiopulmonary exercise tests (CPX) were performed by adults aged 48 ± 13 years (range 18-82 years, 54% male). Linear regression analysis was performed to predict VO2max using 946 CPX with the remaining 967 used for crossvalidation. Exclusion criteria applied were RER <1.0, < 18 years old, abnormal test termination, and CPX from the same subject repeated within one month. Results: Total test time had the strongest correlation (r=0.82) with VO2max. Two separate equations were developed to predict VO2max. Total test time alone predicted VO2max with a standard error of 5.5 ml.kg-1.min-1. Addition of age, gender, physical activity status, and body weight improved the prediction to account for 77% of the variance in VO2max with a standard error of 4.6 ml.kg-1.min-1 . Conclusion: Of the exercise testing variables examined, the same predictors as previous analysis of test time, age, gender, body weight, and activity status provided the strongest prediction of VO2max. Additional variables of fat free mass and 1-minute heart rate recovery did not improve upon the prediction. Researchers and clinicians need to determine if the accuracy limits of ± 1 MET for predicted VO2max are acceptable in clinical practice. When greater accuracy is required, measured VO2max should be obtained.Thesis (M.S.)School of Physical Education, Sport, and Exercise Scienc

Prediction of exercise capacity and training prescription from the 6-minute walk test and rating of perceived exertion

Walking tests, such as the 6-min walk test (6MWT), are popular methods of estimating peak oxygen uptake (VO(2)peak) in clinical populations. However, the strength of the distance vs. VO(2)peak relationship is not strong, and there are no equations for estimating ventilatory threshold (VT), which is important for training prescription and prognosis. Since the 6MWT is often limited by walking mechanics, prediction equations that include simple additional predictors, such as the terminal rating of perceived exertion (RPE), hold the potential for improving the prediction of VO(2)max and VT. Therefore, this study was designed to develop equations for predicting VO(2)peak and VT from performance during the 6MWT, on the basis of walking performance and terminal RPE. Clinically stable patients in a cardiac rehabilitation program (N = 63) performed the 6MWT according to the American Thoracic Society guidelines. At the end of each walk, the subject provided their terminal RPE on a 6–20 Borg scale. Each patient also performed a maximal incremental treadmill test with respiratory gas exchange to measure VO(2)peak and VT. There was a good correlation between VO(2)peak and 6MWT distance (r = 0.80) which was improved by adding the terminal RPE in a multiple regression formula (6MWT + RPE, R(2) = 0.71, standard error of estimate, SEE = 1.3 Metabolic Equivalents (METs). The VT was also well correlated with walking performance, 6MWT distance (r = 0.80), and was improved by the addition of terminal RPE (6MWT + RPE, R(2) = 0.69, SEE = 0.95 METs). The addition of terminal RPE to 6MWT distance improved the prediction of maximal METs and METs at VT, which may have practical applications for exercise prescription

Influence of combined aerobic and resistance training on metabolic control, cardiovascular fitness and quality of life in adolescents with type 1 diabetes: a randomized controlled trial

OBJECTIVE: To evaluate the effect of combined exercise training on metabolic control, physical fitness and quality of life in adolescents with type 1 diabetes. DESIGN: A double-blind randomized controlled trial with patients receiving combined aerobic and strength or no training. SETTING: University Hospital Ghent (Belgium). SUBJECTS: Sixteen children with type 1 diabetes were randomized into a control group (n = 8) and an intervention group (n = 8). INTERVENTIONS: Patients participated twice a week for 20 weeks in the combined aerobic and strength group. The control group continued their normal daily activities. MAIN MEASURES: Before and after the intervention anthropometric variables (weight, length, BMI, body composition), metabolic control (glycaemia, HbA1c, daily insulin injected), aerobic capacity (peak Vo(2), peak power, peak heart rate, 6-minute walk distance), strength (1 repetition maximum of upper and lower limb, hand grip strength, muscle fatigue resistance, sit-to-stand) and quality of life (SF-36) were assessed. RESULTS: At baseline, none of the measured parameters differed significantly between the two groups. There was no significant evolution in the groups concerning anthropometric indices, glycaemia and HbA1c. However, the daily doses of insulin injected were significantly lowered in the training group (0.96 IU/kg.day pre versus 0.90 IU/kg.day post; P < 0,05), while it was increased in the control group. Physical fitness increased significantly in the training group. General health, vitality and role emotional had a tendency to improve. CONCLUSION: Combined exercise training seemed to lower daily insulin requirement and improve physical fitness, together with better well-being

Changes and prognostic value of cardiopulmonary exercise testing parameters in elderly patients undergoing cardiac rehabilitation: The EU-CaRE observational study

Objective We aimed 1) to test the applicability of the previously suggested prognostic value of CPET to elderly cardiac rehabilitation patients and 2) to explore the underlying mechanism of the greater improvement in exercise capacity (peak oxygen consumption, VO2) after CR in surgical compared to non-surgical cardiac patients. Methods Elderly patients (?65 years) commencing CR after coronary artery bypass grafting, surgical valve replacement (surgery-group), percutaneous coronary intervention, percutaneous valve replacement or without revascularisation (non-surgery group) were included in the prospective multi-center EU-CaRE study. CPETs were performed at start of CR, end of CR and 1-year-follow-up. Logistic models and receiver operating characteristics were used to determine prognostic values of CPET parameters for major adverse cardiac events (MACE). Linear models were performed for change in peak VO2 (start to follow-up) and parameters accounting for the difference between surgery and non-surgery patients were sought. Results 1421 out of 1633 EU-CaRE patients performed a valid CPET at start of CR (age 73±5.4, 81% male). No CPET parameter further improved the receiver operation characteristics significantly beyond the model with only clinical parameters. The higher improvement in peak VO2 (25% vs. 7%) in the surgical group disappeared when adjusted for changes in peak tidal volume and haemoglobin. Conclusion CPET did not improve the prediction of MACE in elderly CR patients. The higher improvement of exercise capacity in surgery patients was mainly driven by restoration of haemoglobin levels and improvement in respiratory function after sternotomy

Comparison of maximal heart rate using the prediction equations proposed by Karvonen and Tanaka

BACKGROUND: Equations for predicting maximal heart rate (HRmax) are widely used in exercise testing and for training prescription, but their efficacy remains controversial in the literature. OBJECTIVE: To compare maximal heart rate during cardiopulmonary exercise testing (CPET) using the prediction equations developed by Karvonen and Tanaka. METHODS: Of the 24,120 maximal treadmill graded exercise tests stored in the CEMAFE database from 1994 to 2006, 2047 HRmax values were analyzed, 1091 of which were from male and 956 from female sedentary subjects. These data were used as a gold standard to compare Karvonen's and Tanaka's prediction formulas. RESULTS: Mean measured maximal heart rates were 181.0 ± 14.0; 180.6 ± 13.0, and 180.8 ± 13.8 for men, women, and both genders combined, respectively. Likewise, mean values from Karvonen's equation were 182.0 ± 11.4; 183.7 ± 11.5, and 183.9 ± 11.7; and from Tanaka's, 182.0 ± 8.0; 182.6 ± 8.0, and 182.7 ± 8.2. Karvonen's and Tanaka's equations yielded the same correlation coefficients, as compared with measured maximal heart rate (r = 0.72). CONCLUSION: Karvonen's and Tanaka's equations are similar in predicting maximal heart rate and show good correlation with measured maximal heart rate.FUNDAMENTO: Fórmulas de predição da freqüência cardíaca máxima são amplamente utilizadas em serviços de ergometria e para prescrição de treinamento, contudo há controvérsia na literatura sobre a eficácia delas. OBJETIVO: Comparar a freqüência cardíaca máxima obtida pelo teste ergoespirométrico com as equações propostas por Karvonen e Tanaka. MÉTODOS: Dos 24.120 testes ergoespirométricos máximos, com protocolo de cargas crescentes, realizados em esteira rolante e armazenados no banco de dados do Cemafe, no período de 1994 a 2006, foram resgatados 1.091 resultados da freqüência cardíaca máxima de indivíduos sedentários do sexo masculino e 956 do feminino. Esses dados foram utilizados como padrão-ouro na comparação com as fórmulas de predição propostas por Karvonen e Tanaka. RESULTADOS: Os valores médios da freqüência cardíaca máxima medida foram: 181,0 ± 14,0, 180,6 ± 13,0 e 180,8 ± 13,8, para o sexo masculino, feminino e ambos os sexos, respectivamente. Seguindo o mesmo padrão, os valores para equação de Karvonen foram de 182,0 ± 11,4, 183,7 ± 11,5 e 183,9 ± 11,7; e os de Tanaka 182,0 ± 8,0, 182,6 ± 8,0 e 182,7 ± 8,2. A equação de Karvonen apresentou valores de correlação iguais à de Tanaka, quando comparadas com a freqüência cardíaca máxima medida, r = 0,72. CONCLUSÃO: As equações de Karvonen e Tanaka são semelhantes para predição da freqüência cardíaca máxima e apresentam boa correlação com a freqüência cardíaca máxima medida.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de MedicinaUniversidade Metodista de PiracicabaUniversidade Santo AmaroUNIFESP, EPMSciEL