Impact of aerobic exercise capacity and procedure-related factors in lung cancer surgery

Over the past decades, major progress in patient selection, surgical techniques and anaesthetic management have largely contributed to improved outcome in lung cancer surgery. The purpose of this study was to identify predictors of post-operative cardiopulmonary morbidity in patients with a forced expiratory volume in 1 s <80% predicted, who underwent cardiopulmonary exercise testing (CPET). In this observational study, 210 consecutive patients with lung cancer underwent CPET with completed data over a 9-yr period (2001-2009). Cardiopulmonary complications occurred in 46 (22%) patients, including four (1.9%) deaths. On logistic regression analysis, peak oxygen uptake (peak V'(O₂) and anaesthesia duration were independent risk factors of both cardiovascular and pulmonary complications; age and the extent of lung resection were additional predictors of cardiovascular complications, whereas tidal volume during one-lung ventilation was a predictor of pulmonary complications. Compared with patients with peak V'(O₂) >17 mL·kg⁻¹·min⁻¹, those with a peak V'(O₂) <10 mL·kg⁻¹·min⁻¹ had a four-fold higher incidence of cardiac and pulmonary morbidity. Our data support the use of pre-operative CPET and the application of an intra-operative protective ventilation strategy. Further studies should evaluate whether pre-operative physical training can improve post-operative outcome.

Exercise capacity in subjects with type 1 diabetes mellitus in eu- and hyperglycaemia

Circumstantial evidence suggests that an increase in plasma glucose availability improves exercise capacity in subjects with type 1 diabetes mellitus. The aim of this study was to assess exercise capacity in eu- and hyperglycaemic conditions in subjects with type 1 diabetes.

Exercise capacity in athletes with mouthguards

The objective of this study was to determine the effect of wearing a mouthguard on maximal exercise capacity and cardiopulmonary parameters at peak workload, and to assess the athletes' attitudes toward wearing a mouthguard. Thirteen volunteer male athletes (18 to 27 years old) were interviewed before and after delivery of a custom-made laminated mouthguard. A visual analogue scale (VAS, 0 - 100 mm) was used for judgment of interference with breathing, speaking, concentration and athletic performance. In addition, the athletes were subjected to a cardiorespiratory examination on a cycle ergometer with and without mouthguards. Subjectively, the athletes rated the mean interference with performance to be 37 mm VAS at the beginning of the study. Mean scores of impairment decreased to 23 mm VAS (p = 0.081) after wearing the mouthguard for four weeks, and further improved to 12 mm VAS (p < 0.001) after the test on the cycle ergometer. Objectively, the maximum workload during spiroergometry was even slightly elevated during exercise with the mouthguard (330.2 W) compared to exercise without the mouthguard (314.5 W). Peak minute ventilation and oxygen uptake were not different during exercise with and without the mouthguard. The present study demonstrated that a custom-made mouthguard does not significantly affect or reduce maximum exercise performance of athletes.

Depression and anxiety symptoms affect change in exercise capacity during cardiac rehabilitation

BACKGROUND: To study whether symptoms of depression and anxiety would affect changes in exercise capacity and body mass index (BMI) during rehabilitation. DESIGN: Comprehensive cardiac outpatient rehabilitation intervention program. METHODS: We investigated exercise capacity, BMI, and symptoms of depression and anxiety before and after cardiac rehabilitation in 114 patients with coronary artery disease. The Hospital Anxiety and Depression Scale (HADS) was applied to assess symptoms of depression (HADS-D) and anxiety (HADS-A). RESULTS: Exercise capacity increased (127+/-47 vs. 144+/-51 watts, P<0.001) and symptoms of depression (4.0+/-3.6 vs. 2.7+/-2.7, P<0.001) and anxiety (5.4+/-4.4 vs. 4.1+/-3.6, P<0.001) decreased with the program, whereas BMI did not change. After controlling for covariates, HADS-D (r=-0.19, P=0.47) and HADS-A (r=0.17, P<0.09) correlated with change in exercise capacity. Change in HADS-A also correlated with that in exercise capacity (r=0.18, P<0.06). Changes in depression and anxiety were not significantly related to those in BMI. CONCLUSION: Symptoms of depression and anxiety affected change in exercise capacity during cardiac rehabilitation. Depressive symptoms may impair improvement in exercise capacity, thereby mitigating the cardiovascular benefit achieved by cardiac rehabilitation programs.

Exercise capacity and biventricular function in adult patients with repaired tetralogy of Fallot

BACKGROUND: Adult patients with repaired tetralogy of Fallot (rTOF) often have diminished exercise capacity. The primary objective of this study was to examine whether abnormalities of biventricular function play a role in exercise limitation in patients with rTOF. METHODS: This was a retrospective review of 99 adult patients with rTOF. Right ventricular (RV) and left ventricular (LV) function were assessed echocardiographically using the myocardial performance index (MPI). Maximal oxygen consumption (VO(2) Max) was measured during a level 1 cardiopulmonary exercise test. RESULTS: The mean age of the cohort was 34 +/- 11 years (50% females). Although most of the patients reported good functional capacity, the peak Vo(2)max was decreased at 22 +/- 6 mL/kg per minute (66% +/- 13% predicted Vo(2)max for age and sex). The mean RV and LV MPI were 0.30 +/- 0.07 and 0.42 +/- 0.09, respectively. In the multivariate model, higher RV MPI (P = .04) and LV MPI (P = .005) values, representing impaired ventricular function, were associated with diminished Vo(2)max. There was a significant correlation between the RV and LV MPI (r = 0.54, P = .001). CONCLUSIONS: Impairment of RV and LV function, as measured by MPI, is associated with diminished exercise capacity in patients with repaired tetralogy of Fallot. Furthermore, there is a linear relationship between the RV and LV function suggesting that ventricular interactions are contributing to the limited exercise capacity in this group of patients. Strategies aimed at preserving biventricular function or improving adverse ventricular interactions could help to improve functional capacity in these patients.

Heart rate response determines long term exercise capacity after heart transplantation

BACKGROUND: Exercise capacity after heart transplantation (HTx) remains limited despite normal left ventricular systolic function of the allograft. Various clinical and haemodynamic parameters are predictive of exercise capacity following HTx. However, the predictive significance of chronotropic competence has not been demonstrated unequivocally despite its immediate relevance for cardiac output. AIMS: This study assesses the predictive value of various clinical and haemodynamic parameters for exercise capacity in HTx recipients with complete chronotropic competence evolving within the first 6 postoperative months. METHODS: 51 patients were enrolled in this exercise study. Patients were included when at least >6 months after HTx and without negative chronotropic medication or factors limiting exercise capacity such as significant transplant vasculopathy or allograft rejection. Clinical parameters were obtained by chart review, haemodynamic parameters from current cardiac catheterisation, and exercise capacity was assessed by treadmill stress testing. A stepwise multiple regression model analysed the proportion of the variance explained by the predictive parameters. RESULTS: The mean age of these 51 HTx recipients was 55.4 +/- 13.2 yrs on inclusion, 42 pts were male and the mean time interval after cardiac transplantation was 5.1 +/- 2.8 yrs. Five independent predictors explained 47.5% of the variance observed for peak exercise capacity (adjusted R2 = 0.475). In detail, heart rate response explained 31.6%, male gender 5.2%, age 4.1%, pulmonary vascular resistance 3.7%, and body-mass index 2.9%. CONCLUSION: Heart rate response is one of the most important predictors of exercise capacity in HTx recipients with complete chronotropic competence and without relevant transplant vasculopathy or acute allograft rejection.

Diastolic dysfunction of the cardiac allograft and maximal exercise capacity

BACKGROUND: Peak oxygen uptake (peak Vo(2)) is an established integrative measurement of maximal exercise capacity in cardiovascular disease. After heart transplantation (HTx) peak Vo(2) remains reduced despite normal systolic left ventricular function, which highlights the relevance of diastolic function. In this study we aim to characterize the predictive significance of cardiac allograft diastolic function for peak Vo(2). METHODS: Peak Vo(2) was measured using a ramp protocol on a bicycle ergometer. Left ventricular (LV) diastolic function was assessed with tissue Doppler imaging sizing the velocity of the early (Ea) and late (Aa) apical movement of the mitral annulus, and conventional Doppler measuring early (E) and late (A) diastolic transmitral flow propagation. Correlation coefficients were calculated and linear regression models fitted. RESULTS: The post-transplant time interval of the 39 HTxs ranged from 0.4 to 20.1 years. The mean age of the recipients was 55 +/- 14 years and body mass index (BMI) was 25.4 +/- 3.9 kg/m(2). Mean LV ejection fraction was 62 +/- 4%, mean LV mass index 108 +/- 22 g/m(2) and mean peak Vo(2) 20.1 +/- 6.3 ml/kg/min. Peak Vo(2) was reduced in patients with more severe diastolic dysfunction (pseudonormal or restrictive transmitral inflow pattern), or when E/Ea was > or =10. Peak Vo(2) correlated with recipient age (r = -0.643, p < 0.001), peak heart rate (r = 0.616, p < 0.001) and BMI (r = -0.417, p = 0.008). Of all echocardiographic measurements, Ea (r = 0.561, p < 0.001) and Ea/Aa (r = 0.495, p = 0.002) correlated best. Multivariate analysis identified age, heart rate, BMI and Ea/Aa as independent predictors of peak Vo(2). CONCLUSIONS: Diastolic dysfunction is relevant for the limitation of maximal exercise capacity after HTx.

Exercise capacity, physical activity patterns and outcomes six years after cardiac rehabilitation in patients with heart failure.

OBJECTIVE To determine the short- and long-term effects of an intensive, concentrated rehabilitation programme in patients with chronic heart failure. DESIGN Randomized controlled trial, with one-month and six-year evaluations. SETTING Residential rehabilitation centre in Switzerland. SUBJECTS Fifty patients with chronic heart failure, randomized to exercise or control groups. INTERVENTIONS A rehabilitation programme lasting one month, including educational sessions, a low-fat diet, and 2 hours of individually prescribed exercise daily. MAIN MEASURES Exercise test responses, health outcomes and physical activity patterns. RESULTS Peak Vo(2) increased 21.4% in the exercise group during the rehabilitation programme (P<0.05), whereas peak Vo(2) did not change among controls. After the six-year follow-up period, peak Vo(2) was only slightly higher than that at baseline in the trained group (7%, NS), while peak Vo(2) among controls was unchanged. During long-term follow-up, 9 and 12 patients died in the exercise and control groups, respectively (P = 0.63). At six years, physical activity patterns tended to be higher in the exercise group; the mean energy expenditure values over the last year were 2,704 +/- 1,970 and 2,085 +/- 1,522 kcal/week during recreational activities for the exercise and control groups, respectively. However, both groups were more active compared to energy expenditure prior to their cardiac event (P<0.001). CONCLUSIONS Six years after participation in a residential rehabilitation programme, patients with chronic heart failure had slightly better outcomes than control subjects, maintained exercise capacity and engaged in activities that exceed the minimal amount recommended by guidelines for cardiovascular health.

Chronotropic incompetence predicts impaired response to exercise training in heart failure patients in sinus rhythm

Background: In most patients with chronic heart failure (CHF), endurance training improves exercise capacity. However, some patients do not respond favourably. The purpose of this study was to explore the reasons of non-response and to determine their predictive value.Methods: We studied a cohort of 120 consecutive CHF patients with sinus rhythm (mean age 57 ± 12 years, ejection fraction 29.3 ± 9.9%, peak VO2 17.3 ± 5.1 ml/min/kg), participating in a 3-month outpatient cardiac rehabilitation programme. Responders were defined as subjects who improved peak VO2 by more than 5%, work load by more than 10%, or VE/VCO2 slope by more than 5%. Subjects who did not fulfil at least one of the above criteria were characterized as non-responders. Multivariate regression analyses were performed to identify parameters that were predictive for a response. Receiver operating characteristic (ROC) analyses were performed for predictive parameters to identify thresholds for response or non-response.Results: Multivariate regression analyses revealed heart rate (HR) reserve, HR recovery at 1 min, and peak HR as significant predictors for a positive training response. ROC curves revealed the optimal thresholds separating responders from non-responders at less than 30 bpm for HR reserve, less than 6 bpm for HR recovery and less than 101 bpm for peak HR.Conclusions: The presence of impaired chronotropic competence is a major predictor of poor training response in CHF patients with sinus rhythm.

Exercise training reverses exertional oscillatory ventilation in heart failure patients

Exertional oscillatory ventilation (EOV) is an ominous prognostic sign in chronic heart failure (CHF), but little is known about the success of specific therapeutic interventions. Our aim was to study the impact of an exercise training on exercise capacity and cardiopulmonary adaptation in stable CHF patients with left ventricular systolic dysfunction and EOV. 96 stable CHF patients with EOV were included in a retrospective analysis (52 training versus 44 controls). EOV was defined as follows: 1) three or more oscillatory fluctuations in minute ventilation (V'(E)) during exercise; 2) regular oscillations; and 3) minimal average ventilation amplitude ≥5 L. EOV disappeared in 37 (71.2%) out of 52 patients after training, but only in one (2.3%) out of 44 without training (p<0.001). The decrease of EOV amplitude correlated with changes in end-tidal carbon dioxide tension (r= -0.60, p<0.001) at the respiratory compensation point and V'(E)/carbon dioxide production (V'(CO(2))) slope (r=0.50, p<0.001). Training significantly improved resting values of respiratory frequency (f(R)), V'(E), tidal volume (V(T)) and V'(E)/V'(CO(2)) ratio. During exercise, V'(E) and V(T) reached significantly higher values at the peak, while f(R) and V'(E)/V'(CO(2)) ratio were significantly lower at submaximal exercise. No change was noted in the control group. Exercise training leads to a significant decrease of EOV and improves ventilatory efficiency in patients with stable CHF.

Coronary collateral flow in response to endurance exercise training

BACKGROUND: In humans, it is not known whether physical endurance exercise training promotes coronary collateral growth. The following hypotheses were tested: the expected collateral flow reduction after percutaneous coronary intervention of a stenotic lesion is prevented by endurance exercise training; collateral flow supplied to an angiographically normal coronary artery improves in response to exercise training; there is a direct relationship between the change of fitness after training and the coronary collateral flow change. METHODS AND RESULTS: Forty patients (age 61+/-8 years) underwent a 3-month endurance exercise training program with baseline and follow-up assessments of coronary collateral flow. Patients were divided into an exercise training group (n=24) and a sedentary group (n=16) according to the fact whether they adhered or not to the prescribed exercise program, and whether or not they showed increased endurance (VO2max in ml/min per kg) and performance (W/kg) during follow-up versus baseline bicycle spiroergometry. Collateral flow index (no unit) was obtained using pressure sensor guidewires positioned in the coronary artery undergoing percutaneous coronary intervention and in a normal vessel. In the vessel initially undergoing percutaneous coronary intervention, there was an increase in collateral flow index among exercising but not sedentary patients from 0.155+/-0.081 to 0.204+/-0.056 (P=0.03) and from 0.189+/-0.084 to 0.212+/-0.077 (NS), respectively. In the normal vessel, collateral flow index changes were from 0.176+/-0.075 to 0.227+/-0.070 in the exercise group (P=0.0002), and from 0.219+/-0.103 to 0.238+/-0.086 in the sedentary group (NS). A direct correlation existed between the change in collateral flow index from baseline to follow-up and the respective alteration of VO2max (P=0.007) and Watt (P=0.03). CONCLUSION: A 3-month endurance exercise training program augments coronary collateral supply to normal vessels, and even to previously stenotic arteries having undergone percutaneous coronary intervention before initiating the program. There appears to be a dose-response relation between coronary collateral flow augmentation and exercise capacity gained.

Influence of exertional oscillatory ventilation on exercise performance in heart failure

BACKGROUND: Exertional oscillatory ventilation (EOV) in heart failure may potentiate the negative effects of low cardiac output and high ventilation on exercise performance. We hypothesized that the presence of EOV might, per se, influence exercise capacity as evaluated by maximal cardiopulmonary exercise test. METHODS AND RESULTS: We identified 78 severe chronic heart failure patient pairs with and without EOV. Patients were matched for sex, age and peak oxygen consumption (VO2). Patients with EOV showed, for the same peak VO2, a lower workload (WL) at peak (DeltaWatts=5.8+/-23.0, P=0.027), a less efficient ventilation (higher VE/VCO2 slope: 38.0+/-8.3 vs. 32.8+/-6.3, P<0.001), lower peak exercise tidal volume (1.49+/-0.36 L vs. 1.61+/-0.46 L, P=0.015) and higher peak respiratory rate (34+/-7/min vs. 31+/-6/min, P=0.002). In 33 patients, EOV disappeared during exercise, whereas in 45 patients EOV persisted. Fifty percent of EOV disappearing patients had an increase in the VO2/WL relationship after EOV regression, consistent with a more efficient oxygen delivery to muscles. No cardiopulmonary exercise test parameter was associated with the different behaviour of VO2/WL. CONCLUSION: The presence of EOV negatively influences exercise performance of chronic heart failure patients likely because of an increased cost of breathing. EOV disappearance during exercise is associated with a more efficient oxygen delivery in several cases.

Heart rate recovery after exercise in chronic heart failure: Role of vital exhaustion and type D personality

OBJECTIVE: Vital exhaustion and type D personality previously predicted mortality and cardiac events in patients with chronic heart failure (CHF). Reduced heart rate recovery (HRR) also predicts morbidity and mortality in CHF. We hypothesized that elevated levels of vital exhaustion and type D personality are both associated with decreased HRR. METHODS: Fifty-one patients with CHF (mean age 58+/-12 years, 82% men) and left ventricular ejection fraction (LVEF) exercise testing before receiving outpatient cardiac rehabilitation. They completed the 9-item short form of the Maastricht Vital Exhaustion Questionnaire and the 14-item type D questionnaire asking about negative affectivity and social inhibition. HRR was calculated as the difference between heart rate at the end of exercise and 1min after abrupt cessation of exercise (HRR-1). Regression analyses were adjusted for gender, age, LVEF, and maximum exercise capacity. RESULTS: Vital exhaustion explained 8.4% of the variance in continuous HRR-1 (p=0.045). For each point increase on the vital exhaustion score (range 0-18) there was a mean+/-SEM decrease of 0.54+/-0.26bpm in HRR-1. Type D personality showed a trend toward statistical significance for being associated with lower levels of HRR-1 explaining 6.5% of the variance (p<0.08). The likelihood of having HRR-1