Category Archives: Publications

Peak Ventilation Reference Standards from Exercise Testing: From the FRIEND Registry.

Kaminsky LA; Harber MP; Imboden MT; Arena R; Myers J;

Medicine And Science In Sports And Exercise [Med Sci Sports Exerc] 2018 Aug 07. Date of Electronic Publication: 2018 Aug 07.

Purpose: Cardiopulmonary exercise testing (CPX) provides valuable clinical information, including peak ventilation (VEpeak), which has been shown to have diagnostic and prognostic value in the assessment of patients with underlying pulmonary disease. This report provides reference standards for VEpeak derived from CPX on treadmills in apparently healthy individuals.
Methods: Nine laboratories in the United States experienced in CPX administration with established quality control procedures contributed to the Fitness Registry and the Importance of Exercise National Database from 2014 to 2017. Data from 5232 maximal exercise tests from men and women without cardiovascular or pulmonary disease were used to create percentiles of VEpeak for both men and women by decade between 20-79 years. Additionally, prediction equations were developed for VEpeak using descriptive information.
Results: VEpeak was found to be significantly different between men and women and across age groups (p<0.05). The rate of decline in VEpeak was 8.0%/decade for both men and women. A stepwise regression model of 70% of the sample revealed sex, age, and height were significant predictors of VEpeak. The equation was cross-validated with data from the remaining 30% of the sample with a final equation developed from the full sample (r=0.73). Additionally, a linear regression model revealed forced expiratory volume in one second significantly predicted VEpeak (r=0.73).
Conclusions: Reference standards were developed for VEpeak for the United States population. Cardiopulmonary exercise testing laboratories will be able to provide interpretation of VEpeak from these age and sex specific percentile reference values or alternatively can use these non-exercise prediction equations incorporating sex, age, and height or with a single predictor of forced expiratory volume in one second.

Current challenges in managing comorbid heart failure and COPD.

Neder JA; Rocha A; Arbex F; Berton DC; Faria M; Sperandio PA; Nery LE; O’Donnell DE;

Expert Review Of Cardiovascular Therapy [Expert Rev Cardiovasc Ther] 2018 Aug 13. Date of Electronic Publication: 2018 Aug 13.

Introduction: Heart failure with reduced ejection fraction (HF) and chronic obstructive pulmonary disease (COPD) frequently coexist, particularly in the elderly. Given their rising prevalence and the contemporary trend to longer life expectancy, overlapping HF-COPD will become a major cause of morbidity and mortality in the next decade. Areas covered: Drawing on current clinical and physiological constructs, the consequences of negative cardiopulmonary interactions on the interpretation of pulmonary function and cardiopulmonary exercise tests in HF-COPD are discussed. Although those interactions may create challenges for the diagnosis and assessment of disease stability, they provide a valuable conceptual framework to rationalize HF-COPD treatment. The impact of COPD or HF on the pharmacological treatment of HF or COPD, respectively, is then comprehensively discussed. Authors finalize by outlining how the non-pharmacological treatment (i.e. rehabilitation and exercise reconditioning) can be tailored to the specific needs of patients with HF-COPD. Expert commentary: Randomized clinical trials testing the efficacy and safety of new medications for HF or COPD should include a sizeable fraction of patients with these coexistent pathologies. Multidisciplinary clinics involving cardiologists and respirologists trained in both diseases (with access to unified cardiorespiratory rehabilitation programs) are paramount to decrease the humanitarian and social burden of HF-COPD.

A new method for self-paced peak performance testing on a treadmill.

Hunt KJ; Anandakumaran P; Loretz JA; Saengsuwan J;

Clinical Physiology And Functional Imaging [Clin Physiol Funct Imaging] 2018 Jan; Vol. 38 (1), pp. 108-117.

Purpose: Self-paced maximal testing methods may be able to exploit central mediation of function-limiting fatigue and therefore have potential to generate more valid estimates of peak oxygen uptake. The aim of this study was to investigate the feasibility of a new method for self-paced peak performance testing on treadmills and to compare peak and submaximal performance outcomes with those obtained using a non-self-paced (‘computer-paced’) method employing predetermined speed and slope profiles.
Methods: The proposed self-paced method is based upon automatic subject positioning using feedback control together with an exercise intensity which is driven by a predetermined, individualized work-rate ramp.
Results: Peak oxygen uptake was not significantly different for the computer-paced (CP) versus self-paced (SP) protocols: 4·38 ± 0·48 versus 4·34 ± 0·46 ml min-1 , P = 0·42. Likewise, there were no significant differences in the other peak and submaximal cardiopulmonary parameters, viz. peak heart rate, peak respiratory exchange ratio and the first and second ventilatory thresholds. Ramp duration for CP was longer than for SP: 494·5 ± 71·1 versus 371·3 ± 86·0 s, P = 0·00072. Concomitantly, the peak rate of work done against gravity was higher for CP: 264·8 ± 40·8 versus 203·8 ± 53·4 W, P = 0·0021.
Conclusions: The self-paced approach was found to be feasible for estimation of the principal performance outcomes: the method was technically implementable, it was acceptable to the subjects and it showed good responsiveness. Further investigation of the self-paced method, with adjustment of the target ramp-phase duration or modification of the work-rate calculation equations, is warranted.

Validity of the Low-Impact Dance for exercise-based cardiac rehabilitation program.

Kokubo T; Tajima A; Miyazawa A; Maruyama Y;

Physical Therapy Research [Phys Ther Res] 2018 Apr 20; Vol. 21 (1), pp. 9-15. Date of Electronic Publication: 20180420 (Print Publication: 2018).

Purpose: The aim of this study was to evaluate the oxygen uptake in patients with cardiovascular disease during the low-impact dance program and to compare the findings with the values at peak oxygen uptake (VO2) and aerobic threshold (AT).
Methods: The study included 19 patients with cardiovascular disease [age, 68.3±8.7 years; left-ventricular ejection fraction, 60.3%±8.7%; peak VO2, 6.6±1.1 metabolic equivalents (METs)] who were receiving optimal medical treatment. Their heart rate and VO2 were monitored during cardiopulmonary exercise testing (CPET) and during the low impact dance. The dance involved low-impact dynamic sequences. The patients completed two patterns of low-impact dance, and metabolic gas exchange measurements were obtained using a portable ergospirometry carried in a backpack during the dance sessions.
Results: The mean values of VO2 (4.0±0.2 METs and 3.9±0.3 METs) and those of heart rate (105.2±2.9 bpm and 96.8±2.6 bpm) during the dance program were not significantly differ from the AT value (4.5±0.2 METs) obtained in CPET. The median (and interquartile range) RPE reported after the dance exercise trials was 11 (9-13). No signs of overexertion were observed in any of the patients during either dance exercise trial.
Conclusions: The results suggest that it is reasonable to consider the low-impact dance program as an aerobic exercise program in cardiac rehabilitation. Our findings have important implications for exercise training programs in the cardiac rehabilitation setting and for future studies.

Prognostic power of cardiopulmonary exercise testing in Fontan patients: a systematic review.

Udholm S; Aldweib N; Hjortdal VE; Veldtman GR;

Open Heart [Open Heart] 2018 Jul 03; Vol. 5 (1), pp. e000812. Date of Electronic Publication: 20180703 (Print Publication: 2018)

Objective: Exercise impairment is common in Fontan patients. Our aim is to systematically review previous literature to determine the prognostic value of exercise capacity in older adolescent and adult Fontan patients with respect to late outcome. Additionally, we reviewed the determinants of exercise capacity in Fontan patients and changes in exercise capacity over time.
Methods: PubMed, CINAHL, Embase, The Cochrane Library and Scopus were searched systematically for studies reporting exercise capacity and late outcome such as mortality, cardiac transplantation and hospitalisation. Studies were eligible for inclusion if more than 30 patients were included and mean age was ≥16 years.
Results: Four thousand and seven hundred and twenty-two studies were identified by the systematic search. Seven studies fulfilled the inclusion and exclusion criteria. The total number of patients was 1664 adult Fontan patients. There were 149 deaths and 35 heart transplantations. All eligible studies were retrospective cohort studies. The correlation between exercise capacity and late outcome was identified, and HRs were reported.
Conclusion: In Fontan patients, the best predictors of death and transplantation were a decline in peak VO2, heart rate variables and exercise oscillatory ventilation. Peak VO2 was not strongly predictive of mortality or hospitalisation in Fontan patients. Several variables were strong and independent predictors of hospitalisation and morbidity.

Value of the oxygen pulse curve for the diagnosis of coronary artery disease.

De Lorenzo A; Da Silva CL; Castro Souza FC; De Souza Leao Lima R

Physiological Research [Physiol Res] 2018 Jul 25. Date of Electronic Publication: 2018 Jul 25.

This study investigated the value of oxygen (O(2)) pulse curves obtained during cardiopulmonary exercise testing (CPET) for the diagnosis of coronary artery disease (CAD). Forty patients with known coronary anatomy (35.0 % normal, 27.0 % single-vessel and 38.0 % multivessel CAD) underwent CPET with radiotracer injection at peak exercise, followed by myocardial scintigraphy. O(2) pulse curves were classified as: A-normal, B-probably normal (normal slope with low peak value); C-probably abnormal (flat, with low peak value); or D- definitely abnormal (descending slope). Sensitivity, specificity, positive and negative predictive values of the O(2) pulse curve pattern (A or B vs. C or D) for the diagnosis of CAD were, respectively, 38.5 %, 81.3 %, 76.9 %, and 44.8 %. The concordance rate between the abnormal O2 pulse curve pattern and ischemia in myocardial scintigraphy was 38.1 %. Age and the extent of scintigraphic perfusion defect, but not the abnormal O(2) pulse curve patterns (B or C or both combined) were independently associated with CAD. In conclusion, the O(2) pulse curve pattern has low diagnostic performance for the diagnosis of obstructive CAD, and the abnormal curve pattern was not associated with myocardial ischemia defined by scintigraphy.

Delayed parasympathetic reactivation and sympathetic withdrawal following maximal cardiopulmonary exercise testing (CPET) in hypoxia.

Fornasiero A; Savoldelli A; Skafidas S; Stella F; Bortolan L; Boccia G;
Zignoli A; Schena F; Mourot L; Pellegrini B;

European Journal Of Applied Physiology [Eur J Appl Physiol] 2018 Jul 26. Date of Electronic Publication: 2018 Jul 26.

Purpose: This study investigated the effects of acute hypoxic exposure on post-exercise cardiac autonomic modulation following maximal cardiopulmonary exercise testing (CPET).
Methods: Thirteen healthy men performed CPET and recovery in normoxia (N) and normobaric hypoxia (H) (FiO2 = 13.4%, ≈ 3500 m). Post-exercise cardiac autonomic modulation was assessed during recovery (300 s) through the analysis of fast-phase and slow-phase heart rate recovery (HRR) and heart rate variability (HRV) indices.
Results: Both short-term, T30 (mean difference (MD) 60.0 s, 95% CI 18.2-101.8, p = 0.009, ES 1.01), and long-term, HRRt (MD 21.7 s, 95% CI 4.1-39.3, p = 0.020, ES 0.64), time constants of HRR were higher in H. Fast-phase (30 and 60 s) and slow-phase (300 s) HRR indices were reduced in H either when expressed in bpm or in percentage of HRpeak (p < 0.05). Chronotropic reserve recovery was lower in H than in N at 30 s (MD - 3.77%, 95% CI - 7.06 to - 0.49, p = 0.028, ES - 0.80) and at 60 s (MD - 7.23%, 95% CI - 11.45 to - 3.01, p = 0.003, ES - 0.81), but not at 300 s (p = 0.436). Concurrently, Ln-RMSSD was reduced in H at 60 and 90 s (p < 0.01) but not at other time points during recovery (p > 0.05).
Conclusions: Affected fast-phase, slow-phase HRR and HRV indices suggested delayed parasympathetic reactivation and sympathetic withdrawal after maximal exercise in hypoxia. However, a similar cardiac autonomic recovery was re-established within 5 min after exercise cessation. These findings have several implications in cardiac autonomic recovery interpretation and in HR assessment in response to high-intensity hypoxic exercise.

Iron deficiency in patients with heart failure with preserved ejection fraction and its association with reduced exercise capacity, muscle strength and quality of life.

Bekfani T; Pellicori P; Morris D; Valentova M; Sandek A; Doehner W; Cleland JG;
Lainscak M; Schulze PC; Anker SD; von Haehling S;

Clinical Research In Cardiology: Official Journal Of The German Cardiac Society [Clin Res Cardiol] 2018 Jul 26. Date of Electronic Publication: 2018 Jul 26.

Background: The prevalence of iron deficiency (ID) in outpatients with heart failure with preserved ejection fraction (HFpEF) and its relation to exercise capacity and quality of life (QoL) is unknown.
Methods: 190 symptomatic outpatients with HFpEF (LVEF 58 ± 7%; age 71 ± 9 years; NYHA 2.4 ± 0.5; BMI 31 ± 6 kg/m2) were enrolled as part of SICA-HF in Germany, England and Slovenia. ID was defined as ferritin < 100 or 100-299 µg/L with transferrin saturation (TSAT) < 20%. Anemia was defined as Hb < 13 g/dL in men, < 12 g/dL in women. Low ferritin-ID was defined as ferritin < 100 µg/L. Patients were divided into 3 groups according to E/e’ at echocardiography: E/e’ ≤ 8; E/e’ 9-14; E/e’ ≥ 15. All patients underwent echocardiography, cardiopulmonary exercise test (CPX), 6-min walk test (6-MWT), and QoL assessment using the EQ5D questionnaire.
Results: Overall, 111 patients (58.4%) showed ID with 89 having low ferritin-ID (46.84%). 78 (41.1%) patients had isolated ID without anemia and 54 patients showed anemia (28.4%). ID was more prevalent in patients with more severe diastolic dysfunction: E/e’ ≤ 8: 44.8% vs. E/e’: 9-14: 53.2% vs. E/e’ ≥ 15: 86.5% (p = 0.0004). Patients with ID performed worse during the 6MWT (420 ± 137 vs. 344 ± 124 m; p = 0.008) and had worse exercise time in CPX (645 ± 168 vs. 538 ± 178 s, p = 0.03). Patients with low ferritin-ID had lower QoL compared to those without ID (p = 0.03).
Conclusion: ID is a frequent co-morbidity in HFpEF and is associated with reduced exercise capacity and QoL. Its prevalence increases with increasing severity of diastolic dysfunction.

Is objectively assessed sedentary behavior, physical activity and cardiorespiratory fitness linked to brain plasticity outcomes in old age?

Engeroff T; Füzéki E; Vogt L; Fleckenstein J; Schwarz S; Matura S; Pilatus U; Deichmann R;
Hellweg R; Pantel J; Banzer W;

Neuroscience [Neuroscience] 2018 Aug 02. Date of Electronic Publication: 2018 Aug 02.

The aim of this cross-sectional study was to determine the associations of objectively assessed habitual physical activity and physical performance with brain plasticity outcomes and brain derived neurotrophic factor (BDNF) levels in cognitively healthy older adults. Physical performance was analyzed based on cardiopulmonary exercise testing data and accelerometer based physical activity was analyzed as total activity counts, sedentary time, light physical activity and moderate to vigorous physical activity. Brain plasticity outcomes included magnetic resonance spectroscopy (MRS) based markers, quantitative imaging based hippocampal volume and BDNF serum levels. The association between physical performance and hippocampal volume was strongly influenced by participants’ education, sex, age and BMI. Confounder controlled correlation revealed significant associations of brain plasticity outcomes with physical activity but not with performance. MRS based adenosine-triphosphate to phosphocreatine and glycerophosphocholine to phosphocreatine ratios were significantly associated with accelerometer total activity counts. BDNF was detrimentally associated with sedentary time but beneficially related to accelerometer total activity counts and moderate to vigorous physical activity. Exceeding the current moderate to vigorous physical activity recommendations led to significantly higher BDNF levels. Our results indicate that regular physical activity might be beneficial for preserving brain plasticity in higher age. In this study these associations were not mediated significantly by physical performance. Overall physical activity and exceeding current moderate to vigorous physical activity recommendations were positively associated with BDNF. Sedentary behavior, however, seems to be negatively related to neurotrophic factor bioavailability in the elderly.