The Ventilatory Anaerobic Threshold in Heart Failure: A Multicenter Evaluation of Reliability

Myers, Jonathan; Goldsmith, Rochelle L.; Keteyian, Steven J.; Brawner, Clinton A.; Brazil, Deirdre A.; Aldred, Heather; Ehrman, Jonathan K.; Burkhoff, Daniel

doi:10.1016/j.cardfail.2009.08.009

Cited by 56 publications

(55 citation statements)

References 31 publications

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Section: Clinical Perspective On P 987mentioning

confidence: 99%

“…19 However, even in the presence of anaerobic metabolism, AT is not identified in a large number of patients with HF. 8,[20][21][22] It is unknown whether the finding of a reached but indeterminable AT has a clinical meaning.The present study was therefore undertaken to assess the clinical and prognostic significance of AT detection in patients with systolic HF. To find it out, we used a multicenter HF database, generated and continuously updated by the metabolic exercise and cardiac and kidney index (MECKI) score research group.…”

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confidence: 99%

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Prognostic Value of Indeterminable Anaerobic Threshold in Heart Failure

Agostoni

Corrà

Cattadori

et al. 2013

Circ: Heart Failure

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Background-In patients with heart failure (HF), during maximal cardiopulmonary exercise test, anaerobic threshold (AT)is not always identified. We evaluated whether this finding has a prognostic meaning. Methods and Results-We recruited and prospectively followed up, in 14 dedicated HF units, 3058 patients with systolic (left ventricular ejection fraction <40%) HF in stable clinical conditions, New York Heart Association class I to III, who underwent clinical, laboratory, echocardiographic, and cardiopulmonary exercise test investigations at study enrollment. We excluded 921 patients who did not perform a maximal exercise, based on lack of achievement of anaerobic metabolism (peak respiratory quotient ≤1.05). Primary study end point was a composite of cardiovascular death and urgent cardiac transplant, and secondary end point was all-cause death. Median follow-up was 3.01 (1.39-4.98) years. AT was identified in 1935 out of 2137 patients (90.54%). At multivariable logistic analysis, failure in detecting AT resulted significantly in reduced peak oxygen uptake and higher metabolic exercise and cardiac and kidney index score value, a powerful prognostic composite HF index (P<0.001). At multivariable analysis, the following variables were significantly associated with primary study end point: peak oxygen uptake (% pred; P<0.001 T he anaerobic threshold (AT) concept is based on the principle that energy production shifts from an aerobic metabolism to a metabolism that combines both anaerobic and aerobic patterns during a progressively increasing workload exercise.1,2 According to the concept of threshold, the shift of metabolic pathway during incremental exercise must be more or less simultaneous among active muscular fibers. Therefore, the distribution of blood flow during exercise to and into muscles, the resistance to O 2 flow between capillaries and mitochondria, the type of muscular fibers, and their metabolic capability must be relatively homogeneous.3 This is not always the case in patients with heart failure (HF) who have an uneven distribution of blood flow to muscles and an uneven use of O 2 , so that, for example, an important percentage of subjects with HF increase their capillary PO 2 toward the end of exercise.4-7 Inhomogeneity of blood flow distribution, of O 2 flow resistance, and of O 2 use should widen the time frame where anaerobiosis starts to develop among the muscular fibers, in few cases making the threshold indefinable. If this hypothesis is correct, then AT should be more frequently undetectable in patients with a more severe disease. Clinical Perspective on p 987From a clinical point of view, the value of oxygen uptake (VO 2 ) at AT is used for grading the severity of HF or the effects of therapy, or to assess cardiovascular risk in case of surgery, 9-18 and it has been proposed as an alternative to peak VO 2 , being it independent of patients' motivation, exercise protocol, and exercise duration. 19 However, even in the presence of anaerobic metabolism, AT is not identified in a large num...

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Section: Clinical Perspective On P 987mentioning

confidence: 99%

mentioning

confidence: 99%

Prognostic Value of Indeterminable Anaerobic Threshold in Heart Failure

Agostoni

Corrà

Cattadori

et al. 2013

Circ: Heart Failure

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“…At a point, known as the gas exchange threshold (GET), the linear relationship betweenV CO 2 andV CO 2 becomes steeper, as the subject switches from aerobic to a mixture of aerobic and anaerobic metabolism. Change-point methodology can be used to estimate the GET, which in turn can be used to monitor changes in fitness and heart functioning [27]. It is currently enjoying great popularity among athletes, with many companies offering metabolic analysis systems with professional software for determination of the GET [28].…”

Section: Physiology Datamentioning

confidence: 99%

Approximations to thep-values of tests for a change-point under non-standard conditions

Kelly

2015

Journal of Statistical Computation and Simulation

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“…5,[12][13][14][15][16][17] The VT is defined as an exercise intensity beyond which the increase in ventilation becomes disproportionate to the increase in power output or oxygen uptake during progressive exercise. 11,18 This measure provides important information regarding the major physiological systems involved in aerobic exercise and constitutes a determinant of an individual's functional capabilities and cardiorespiratory performance. 6,[8][9][10][11]18 The VT is an effort-independent variable that can be determined during submaximal exercise, and thus, it is considered safer than maximal exercise for particular patients.…”

Section: Résumémentioning

confidence: 99%

“…11,18 This measure provides important information regarding the major physiological systems involved in aerobic exercise and constitutes a determinant of an individual's functional capabilities and cardiorespiratory performance. 6,[8][9][10][11]18 The VT is an effort-independent variable that can be determined during submaximal exercise, and thus, it is considered safer than maximal exercise for particular patients. In pre-and postsurgical settings, this may be advantageous relative to peak VO 2 , which requires maximal effort.…”

Section: Résumémentioning

confidence: 99%

Comparaison des méthodes de détermination des seuils ventilatoires: implications pour la stratification du risque chirurgical

Vainshelboim

Rao

Chan

et al. 2017

Can J Anesth/J Can Anesth

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Purpose The ventilatory threshold (VT) is an objective physiological marker of the capacity of aerobic endurance that has good prognostic applications in preoperative settings. Nevertheless, determining the VT can be challenging due to physiological and methodological issues, especially in evaluating surgical risk. The purpose of the current study was to compare different methods of determining VT and to highlight the implications for assessing perioperative risk. Methods Our study entailed analysis of 445 treadmill cardiopulmonary exercise tests from 140 presurgical candidates with an aortic abdominal aneurysm (C3.0 to B5.0 cm) and a mean (standard deviation [SD]) age of 72 (8) yr. We used three methods to determine the VT in 328 comparable tests, namely, self-detected metabolic system (MS), experts' visual (V) readings, and software using a log-log transformation (LLT) of ventilation vs oxygen uptake. Differences and agreement between the three methods were assessed using analysis of variance (ANOVA), coefficient of variation (CV), typical error limits of agreement (LoA), and interclass correlation coefficients (ICC).Results Overall, ANOVA revealed significant differences between the methods [MS = 14.1 (4.3) mLO 2 Ákg -1 Ámin-1 ; V = 14.6 (4.4) mLO 2 Ákg -1 Ámin -1 ; and LLT = 12.3 (3.3) mLO 2 Ákg -1 Ámin -1 ; P \ 0.001]. The assessment of agreement between methods provided the following results: ICC = 0.85; 95% confidence interval (CI), 0.82 to 0.87; P \ 0.001; typical error, 2.1-2.8 mLO 2 Ákg -1 Ámin -1 ; and, 95% LoA and CV ranged from 43 to 55% and 15.9 to 19.6%, respectively. Conclusions The results show clinically significant variations between the methods and underscore the challenges of determining VT for perioperative risk stratification. The findings highlight the importance of meticulous evaluation of VT for predicting surgical outcomes. Future studies should address the prognostic perioperative utility of computed mathematical models combined with an expert's review. This trial was registered at ClinicalTrials.gov, identifier: NCT00349947.

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The Ventilatory Anaerobic Threshold in Heart Failure: A Multicenter Evaluation of Reliability

Cited by 56 publications

References 31 publications

Prognostic Value of Indeterminable Anaerobic Threshold in Heart Failure

Prognostic Value of Indeterminable Anaerobic Threshold in Heart Failure

Approximations to thep-values of tests for a change-point under non-standard conditions

Comparaison des méthodes de détermination des seuils ventilatoires: implications pour la stratification du risque chirurgical

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