ABSTRACT
Abstract Objectives Refractory angina (RA) is a chronic condition clinically characterized by low effort tolerance; therefore, physical stress testing is not usually requested for these patients. Cardiopulmonary exercise testing (CPET) is considered a gold standard examination for functional capacity evaluation, even in submaximal tests, and it has gained great prominence in detecting ischemia. The authors aimed to determine cardiorespiratory capacity by using the oxygen consumption efficiency slope (OUES) in patients with refractory angina. The authors also studied the O2 pulse response by CPET and the association of ischemic changes with contractile modifications by exercise stress echocardiography (ESE). Methods Thirty-one patients of both sexes, aged 45 to 75 years, with symptomatic (Canadian Cardiovascular Society class II to IV) angina who underwent CPET on a treadmill and exercise stress echocardiography on a lower limb cycle ergometer were studied. ClinicalTrials.gov: NCT03218891. Results The patients had low cardiorespiratory capacity (OUES of 1.74 ± 0.4 L/min; 63.9±14.7% of predicted), and 77% of patients had a flattening or drop in O2 pulse response. There was a direct association between Heart Rate (HR) at the onset of myocardial ischemia detected by ESE and HR at the onset of flattening or drop in oxygen pulse response detected by CPET (R = 0.48; p = 0.019). Conclusion Patients with refractory angina demonstrate low cardiorespiratory capacity. CPET shows good sensitivity for detecting abnormal cardiovascular response in these patients with a significant relationship between flattening O2 pulse response during CEPT and contractile alterations detected by exercise stress echocardiography. Highlights OUES analysis is useful for assessing functional capacity in refractory angina. O2 pulse curve is correlated with contractile alterations in exercise echocardiogram. Cardiopulmonary exercise test is useful toll in patients with refractory angina.
ABSTRACT
Objective To investigate clinical significance and the correlation between oxygen uptake efficiency slope(OUES) measured by the cardiopulmonary exercise test(CPET) and echocardiographic left ventricular function in elderly patients with coronary heart diseases after the percutaneous coronary intervention.Methods Patients aged 65 years and over after PCI and CPET were enrolled to collect relevant parameters including the peak oxygen consumption(VO2peak),oxygen pulse(VO2/HR),OUES and cardiorespiratory fitness(CRF) index,also mitral annulus systolic peak speed(Sm),early diastolic mitral flow velocity Em and mitral annular early diastolic peak velocity Em ratio(E/Em) using the echocardiography.Patients with systolic velocity of mitral annulus(Sm)≥8 cm/s were assigned to the normal Sm group,while the rest were selected into the lower Sm group.The correlation between the cardiopulmonary fitness and cardiac function was analyzed.Results Four hundred and two patients were enrolled,with an average age of 71 ± 5 years,283 males(70.40％),and 119 females(29.60％).Among them,111 (27.61％) were 75 years of age or older,202(50.25％) ranging from 65 to 69 and 89 (22.14％) between 70 and 74.Totally 227 patients were diagnosed as angina pectoris(56.47％),62 as acute myocardial infarction (15.42％),and 113 patients with old myocardial infarction (28.11％).It was found that the heart systolic function was associated with CRF:Sm and OUES were positively correlated independently(r=29.220,P=0.001);Em was positively related to VO2peak(r=0.176,P＜0.001) andOUES (r=0.151,P=0.003).However,E/Em was negatively correlated with VO2peak (r=-0.199,P＜0.001),VO2/HR (r=-0.118,P=0.018) and OUES (r=-0.201,P＜0.001).The left atrial pressure was negatively correlated with VO2peak (r=-0.187,P＜0.001),VO2/HR (r=-0.108,P=0.030) and OUES (r=-0.185,P＜ 0.001).Left ventricular ejection fraction and left ventricular end diastolic diameter were not found to be related to cardiorespiratory fitness parameters (P＞0.05).Conclusion The cardiopulmonary exercise test can be used as a practical method to evaluate and guide the rehabilitation exercises.The CRF parameters can evaluate the heart function exercise and is significantly correlated to the resting cardiac systolic and diastolic function parameters.
ABSTRACT
Objectives: To explore weather oxygen uptake efficiency slope (OUES) may predict the prognosis in patients with idiopathic pulmonary arterial hypertension (IPAH). Methods: The consecutive newly diagnosed IPAH patients in our hospital from 2010-11 to 2015-06 were prospectively enrolled and regular follow-up study was conducted to record cardiovascular events (death and lung transplantation). Kaplan–Meier curve, uni- and multivariate Cox regression analysis were performed to assess the survival rate in relevant patients. Results: A total of 210 IPAH patients at the mean age of (32±10) years were finished cardiopulmonary exercise test (CPET) and received regular follow-up study including 159 female. There were 31 patients died and 1 received lung transplantation over 41 months follow-up period. OUES was positively related to peak oxygen uptake (VO2)/body weight (r=0.71, P0.52 L/(min?m2) (41.9% vs 89.8%), P<0.0001.Conclusion: OUES as a submaximal CPET parameter may well predict the prognosis in IPAH patients.
ABSTRACT
Objective To study correlation between oxygen uptaking efficiency and exercise endurance of patients with stable chronic obstructive pulmonary disease (COPD).Methods From January 2013 to December 2014,50 patients with COPD plateau were selected as the research subjects,and according to the severity,28 cases of gradeⅠ -Ⅱ,22 cases of grade Ⅲ -Ⅳ.50 COPD patients with acute phase of disease were selected as disease control group.50 healthy people were selected as healthy control group.The forced vital capacity (FVC),forced expiratory volume in first second (FEV1 ),FEV1 /FVC,peak oxygen uptake (peak VO2 ),peak oxygen uptake of expected value (peak VO2% Mr Pred),oxygen uptake efficiency slope (OUES),oxygen uptake efficiency platform (OUEP),when the anaerobic threshold (OUE @ AT)such as index,and the oxygen uptake efficiency and movement endurance were detected and analyzed.Results FVC,FEV1 ,FEV1 /FVC index values of COPD group were less than those of the control group,the differences were statistically significant (all P <0.05),and COPD patients with acute phase of FVC(2.86 ±0.36)L,FEV1 (1.25 ±0.36)L,FEV1 /FVC(50.16 ±5.37)% index values were less than COPD stabilization [(3.12 ±0.46)L,(1.51 ±0.38)L,(60.16 ±6.16)%)],the differences were statistically significant (all P <0.05).The peak VO2 ,peak VO2% Mr Pred,OUES,OUEP,OUE @ AT index values of COPD group were less than those of the control group,the differences were statistically significant (all P <0.05),and COPD patients with acute phase of peak VO2 (1 072.35 ±271.21)mL/min,peak VO2%pred(62.79 ±6.31),OUES(1.59 ±0.29),OUEP (25.72 ±3.42),OUE@AT(26.75 ±3.12)index values were less than patients with COPD stabilization[(1190.67 ± 286.21)mL/min,(70.76 ±6.27),(1.89 ±0.31 ),(31.46 ±4.05 ),(31.62 ±3.16)],the differences were statistically significant (all P <0.05).As the stabilization of disease severity in patients with COPD was aggravated, peak,VO2 peak VO2% Mr Pred,OUES,OUEP,OUE @ AT declined (1 089.62 ±221.68)mL/min vs.(1236.75 ± 235.37)mL/min,(67.28 ±5.03)vs.(75.81 ±5.39),(1.62 ±0.18)vs.(2.04 ±0.25),(30.67 ±6.47)vs. (34.17 ±4.40),(30.31 ±3.42)vs.(36.59 ±3.63)(F =16.92,12.71,4.27,8.75,7.59,P <0.05).Patients with COPD stabilization OUES,OUEP,OUE @ AT peak oxygen uptake efficiency indexes and movement endurance targets were positively correlated with VO2% Mr Pred (r =0.451,0.462,0.451,P =0.019,0.012,0.26),there was a positive correlation with peak VO2 (r =0.446,0.452,0.446,P =0.023,0.011,0.29).Conclusion COPD patients oxygen uptake efficiency and movement endurance than healthy people,patients with COPD oxygen uptake efficiency and movement endurance is associated with illness and severity of COPD,and COPD patients exercise endurance on the oxygen uptake efficiency also has a certain degree of influence.
ABSTRACT
@#Objective To investigate the efficacy of oxygen uptake efficiency slope (OUES) on evaluation the cardiopulmonary function of patients with chronic obstructive pulmonary disease (COPD). Methods The cardiopulmonary function of 54 stable COPD patients with the cardiopulmonary function of Ⅱ~Ⅳ were evaluated, following a symptom-limited Steep protocol with simultaneous respiratory gas measurement,they were performed exercise tests on a treadmill, simultaneously the oxygen uptake (VO2), carbon dioxide production (VCO2),peak oxygen uptake (VO2peak), minute ventilation (VE), and respiratory gas exchange rate (RER) were measured. OUES was derived from the relation between VO2 and VE during incremental exercise and was determined by VO2=algVE+b, where a=OUES, to measure anaerobic threshold (VAT) meanwhile. Results OUES correlated with the VO2peak (P<0.001). 75% OUES, 90% OUES and 100% OUES were not significantly different (F=0.239, P=0.830). Conclusion OUES can respond the cardiopulmonary function in patients with COPD, 75% OUES from sub-maximal exercise can be an index for cardiopulmonary function.
ABSTRACT
@#ObjectiveTo investigate the relationship between high-sensitivity C reactive protein （hs-CRP） and oxygen uptake efficiency slope (OUES) in patents with cardiovascular disease. MethodsExercise tests, following a symptom-limited standard Bruce protocol with simultaneous respiratory gas-exchange measurements, were performed on a treadmill in 17 post-PCI patients, 21 stable angina pectoris and 24 patients with essential hypertension (EH). The oxygen uptake (VO2), minute ventilation (VE) were determined. The OUES was derived from the relation between VO2 (ml/min) and VE (L/min) during incremental exercise and was determined by VO2=a×lgVE+b, where a = OUES. The OUES was calculated from data of the first 75% (OUES75) and 100% (OUES100) of exercise duration. The serum hs-CRP was measured by immunoassays, and the left ventricular ejection fraction (LVEF) was measured with echocardiography. ResultsOUES75 （r=-0.506,P＜0.001）, OUES100 （r=-0.567,P＜0.001） and LVEF （r=-0.286,P＜0.01） were correlated with lg(hs-CRP). In stepwise multivariable linear regression models, lg(hs-CRP) （β=-0.374，P=0.006）, body height （β=-1.854，P=0.036）, body weight （β=-5.033，P=0.034）were independent risk factors of lower OUES75. lg(hs-CRP) （β=-0.396，P=0.003）, body height （β=-2.157，P=0.013）, body weight （β=-5.912，P=0.011） were independent risk factors of lower OUES100. ConclusionThe serum leveles of hs-CRP may be the useful marker that reflecting cardiopulmonary functional reserve and left ventricular function.
ABSTRACT
@#Objective To investigate the efficacy of the oxygen uptake efficiency slope (OUES), obtained from submaximal exercise, as an index of cardiopulmonary functional reserve in adults. Methods Exercise tests, following a symptom-limited standard Bruce protocol with simultaneous respiratory gas measurement, were performed on a treadmill in 33 healthy adults free of clinically recognized cardiovascular disease and 31 patients with heart disease. The OUES was derived from the relation between oxygen uptake (VO2) and minute ventilation (VE) during incremental exercise and was determined by VO2=alog10VE+b, where a=OUES. The OUES was calculated from data of the first 75%, 90% and 100% of exercise duration (as 75%OUES，90%OUES and 100%OUES). Results The 100%OUES，90%OUES and 75%OUES were not significantly different from each other（F=0.212，P=0.809）. The 75%OUES was slightly lower (1.9%) than the 100%OUES. The 100%OUES, the 90%OUES and the 75%OUES correlated with the peak VO2 （r=0.836,r=0.824 and r=0.777, P<0.001, respectively）. The VAT correlated with the peak VO2 （r=0.878，P<0.001），and the VE/VCO2 at VAT correlated with the peak VO2 （r=-0.584，P<0.001）. The 100%OUES correlated with the 90%OUES and the 75%OUES （r=0.991 and r =0.945, P<0.001, respectively）. Conclusion The OUES is an index of exercise performance and cardiopulmonary functional reserve on healthy adults and patients with cardiac disease. The 75%OUES from submaximal exercise can be an index of cardiopulmonary functional reserve for patients with cardiac disease.
ABSTRACT
OBJECTIVE: To investigate the usefulness of the oxygen uptake efficiency slope (OUES) in the evaluation of cardiorespiratory fitness of the stroke patients. METHOD: 25 stroke patients who could walk independently were included in this syudy. The symptom-limited graded treadmill test was performed to assess cardiovascular fitness. During the test, minute ventilation (VE), oxygen consumption (VO2), carbon dioxide production (VCO2), respiratory exchange ratio (RER) and anaerobic threshold (AT) were measured through respiratory gas analysis. A linear relationship was established between the oxygen consumption and the logarithmic transformation of minute ventilation. From this linear relationship, we obtained a slope that represented the OUES. OUES values were obtained from data corresponding to 75% (OUES75), 90% (OUES90) and 100% (OUES100) of the exercise duration. RESULTS: The differences among OUES75, OUES90 and OUES100 groups were not statistically significant and these three groups were highly correlated to each other. Maximal oxygen consumption (VO2max) was positively correlated with OUES75 (r=0.723), OUES90 (r=0.762), OUES100 (r=0.809) and AT (r=0.696), respectively (p<0.01). CONCLUSION: OUES is considered to be the valuable submaximal index to evaluate the cardiorespiratory fitness of stroke patients who can not reach maximal exercise.