RESUMO
AIMS: Accurate interpretation of cardiopulmonary exercise testing (CPET) relies on age, gender, and exercise modality-specific reference values. To date, clinically applicable CPET reference values derived from a source population of endurance athletes (EAs) have been lacking. The purpose of this study was to generate CPET reference values for use in the clinical assessment of EA. METHODS AND RESULTS: Prospective data accrued during the clinical care of healthy EA were used to derive CPET reference values and to develop novel equations for VËO2peak. The performance of these equations was compared to the contemporary standard of care equations and assessed in a discrete EA validation cohort. A total of 272 EA (age = 42 ± 15 years, female = 31%, VËO2peak = 3.6 ± 0.83 L/min) met inclusion criteria and comprised the derivation cohort. VËO2peak prediction equations derived from general population cohorts described a modest amount of VËO2peak variability [R2 = 0.58-0.70, root mean square error (RMSE) = 0.46-0.54 L/min] but were mis-calibrated (calibration-in-the-large = 0.45-1.18 L/min) among EA leading to significant VËO2peak underestimation. Newly derived, externally validated VËO2peak prediction equations for EA that included age, sex, and height for both treadmill (R2 = 0.74, RMSE = 0.42 L/min) and cycle ergometer CPET (Cycle: R2 = 0.69, RMSE = 0.42 L/min) demonstrated improved accuracy. CONCLUSION: Commonly used VËO2peak prediction equations derived from general population cohorts perform poorly among competitive EA. Newly derived CPET reference values including novel VËO2peak prediction equations may improve the clinical utility of CPET in this rapidly growing patient population.
Assuntos
Teste de Esforço , Consumo de Oxigênio , Adulto , Atletas , Teste de Esforço/métodos , Feminino , Humanos , Pessoa de Meia-Idade , Estudos Prospectivos , Sistema de RegistrosRESUMO
PURPOSE: Although exercise testing guidelines define cutoffs for an exaggerated exercise systolic blood pressure (SBP) response, SBPs above these cutoffs are not uncommon in athletes given their high exercise capacity. Alternately, guidelines also specify a normal SBP response that accounts for metabolic equivalents (METs; mean [SD] of 10 [2] mm Hg per MET or 3.5 mL/kg/min oxygen consumption [VËo2]). SBP and VËo2 increase less during exercise in females than males. It is not clear if sex-based differences in exercise SBP are related to differences in VËo2 or if current recommendations for normal increase in SBP per MET produce reasonable estimates using measured METs (ie, VËo2) in athletes. We therefore examined sex-based differences in exercise SBP indexed to VËo2 in athletes with the goal of defining normative values for exercise SBP that account for fitness and sex. METHODS: Using prospectively collected data from a single sports cardiology program, normotensive athlete patients were identified who had no relevant cardiopulmonary disease and had undergone cardiopulmonary exercise testing with cycle ergometry or treadmill. The relationship between ΔSBP (peak - rest) and ΔVËo2 (peak - rest) was examined in the total cohort and compared between sexes. FINDINGS: A total of 413 athletes (mean [SD] age, 35.5 [14] years; 38% female; mean [SD] peak VËo2, 46.0 [10.2] mL/kg/min, 127% [27%] predicted) met the inclusion criteria. The ΔSBP correlated with unadjusted ΔVËo2 (cycle: R2 = 0.18, treadmill: R2 = 0.12; P < 0.0001). Female athletes had lower mean (SD) peak SBP (cycle: 161 [15] vs 186 [24] mm Hg; treadmill: 165 [17] vs 180 [20] mm Hg; P < 0.05) than male athletes. Despite lower peak SBP, mean (SD) ΔSBP relative to unadjusted ΔVËo2 was higher in female than male athletes (cycle: 25.6 [7.2] vs 21.1 [7.3] mm Hg/L/min; treadmill: 21.6 [7.2] vs 17.0 [6.2] mm Hg/L/min; P < 0.05). When VËo2 was adjusted for body size and converted to METs, female and male athletes had similar mean (SD) ΔSBP /ΔMET (cycle: 6.0 [2.1] vs 5.8 [2.0] mm Hg/mL/kg/min; treadmill: 4.7 [1.8] vs 4.8 [1.7] mm Hg/mL/kg/min). IMPLICATIONS: In this cohort of athletes without known cardiopulmonary disease, observed sex-based differences in peak exercise SBP were in part related to the differences in ΔVËo2 between male and female athletes. Despite lower peak SBP, ΔSBP/unadjusted ΔVËo2 was paradoxically higher in female athletes. Future work should define whether this finding reflects sex-based differences in the peripheral vascular response to exercise. In this athletic cohort, ΔSBP/ΔMET was similar between sexes and much lower than the ratio that has been proposed by guidelines to define a normal SBP response. Our observed ΔSBP/ΔMET, based on measured rather than estimated METs, provides a clinically useful estimate for normal peak SBP range in athletes.
Assuntos
Exercício Físico , Consumo de Oxigênio , Adulto , Pressão Sanguínea/fisiologia , Estudos de Coortes , Exercício Físico/fisiologia , Teste de Esforço , Feminino , Humanos , Masculino , Consumo de Oxigênio/fisiologiaRESUMO
Cardiopulmonary exercise testing (CPET) guidelines recommend analysis of the oxygen (O2 ) pulse for a late exercise plateau in evaluation for obstructive coronary artery disease (OCAD). However, whether this O2 pulse trajectory is within the range of normal has been debated, and the diagnostic performance of the O2 pulse for OCAD in physically fit individuals, in whom VËO2 may be more likely to plateau, has not been evaluated. Using prospectively collected data from a sports cardiology program, patients were identified who were free of other cardiac disease and underwent clinically-indicated CPET within 90 days of invasive or computed tomography coronary angiography. The diagnostic performance of quantitative O2 pulse metrics (late exercise slope, proportional change in slope during late exercise) and qualitative assessment for O2 pulse plateau to predict OCAD was assessed. Among 104 patients (age:56 ± 12 years, 30% female, peak VËO2 119 ± 34% predicted), the diagnostic performance for OCAD (n = 24,23%) was poor for both quantitative and qualitative metrics reflecting an O2 pulse plateau (late exercise slope: AUC = 0.55, sensitivity = 68%, specificity = 41%; proportional change in slope: AUC = 0.55, sensitivity = 91%, specificity = 18%; visual plateau/decline: AUC = 0.51, sensitivity = 33%, specificity = 67%). When O2 pulse parameters were added to the electrocardiogram, the change in AUC was minimal (-0.01 to +0.02, p ≥ 0.05). Those patients without OCAD with a plateau or decline in O2 pulse were fitter than those with linear augmentation (peak VËO2 133 ± 31% vs. 114 ± 36% predicted, p < 0.05) and had a longer exercise ramp time (9.5 ± 3.2 vs. 8.0 ± 2.5 min, p < 0.05). Overall, a plateau in O2 pulse was not a useful predictor of OCAD in a physically fit population, indicating that the O2 pulse should be integrated with other CPET parameters and may reflect a physiologic limitation of stroke volume and/or O2 extraction during intense exercise.
Assuntos
Doença da Artéria Coronariana/diagnóstico , Oclusão Coronária/diagnóstico , Teste de Esforço/métodos , Consumo de Oxigênio , Idoso , Teste de Esforço/normas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Aptidão Física , Pulso ArterialAssuntos
Atletas , Cardiomegalia Induzida por Exercícios , Ventrículos do Coração/diagnóstico por imagem , Resistência Física , Corrida , Volume Sistólico , Função Ventricular Esquerda , Remodelação Ventricular , Adaptação Fisiológica , Adulto , Ecocardiografia , Feminino , Humanos , Estudos Longitudinais , Consumo de Oxigênio , Fatores de Tempo , Adulto JovemRESUMO
Importance: Aortic dilatation is frequently encountered in clinical practice among aging endurance athletes, but the distribution of aortic sizes in this population is unknown. It is additionally uncertain whether this may represent aortic adaptation to long-term exercise, similar to the well-established process of ventricular remodeling. Objective: To assess the prevalence of aortic dilatation among long-term masters-level male and female athletes with about 2 decades of exercise exposure. Design, Setting, and Participants: This cross-sectional study evaluated aortic size in veteran endurance athletes. Masters-level rowers and runners aged 50 to 75 years were enrolled from competitive athletic events across the United States from February to October 2018. Analysis began January 2019. Exposures: Long-term endurance exercise. Main Outcomes and Measures: The primary outcome was aortic size at the sinuses of Valsalva and the ascending aorta, measured using transthoracic echocardiography in accordance with contemporary guidelines. Aortic dimensions were compared with age, sex, and body size-adjusted predictions from published nomograms, and z scores were calculated where applicable. Results: Among 442 athletes (mean [SD] age, 61 [6] years; 267 men [60%]; 228 rowers [52%]; 214 runners [48%]), clinically relevant aortic dilatation, defined by a diameter at sinuses of Valsalva or ascending aorta of 40 mm or larger, was found in 21% (n = 94) of all participants (83 men [31%] and 11 women [6%]). When compared with published nomograms, the distribution of measured aortic size displayed a rightward shift with a rightward tail (all P < .001). Overall, 105 individuals (24%) had at least 1 z score of 2 or more, indicating an aortic measurement greater than 2 SDs above the population mean. In multivariate models adjusting for age, sex, body size, hypertension, and statin use, both elite competitor status (rowing participation in world championships or Olympics or marathon time under 2 hours and 45 minutes) and sport type (rowing) were independently associated with aortic size. Conclusions and Relevance: Clinically relevant aortic dilatation is common among aging endurance athletes, raising the possibility of vascular remodeling in response to long-term exercise. Longitudinal follow-up is warranted to establish corollary clinical outcomes in this population.
Assuntos
Aorta/diagnóstico por imagem , Doenças da Aorta/etiologia , Atletas , Treino Aeróbico/efeitos adversos , Exercício Físico/fisiologia , Aorta/fisiopatologia , Doenças da Aorta/diagnóstico , Estudos Transversais , Dilatação Patológica , Ecocardiografia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos ProspectivosRESUMO
Clinical guidelines advocate for customization of exercise testing to address patient-specific diagnostic goals, including reproduction of presenting exertional symptoms. However, the diagnostic yield of adding customized exercise testing to graded exercise in patients presenting with exertional complaints has not been rigorously examined and is the focus of this study. Using prospectively collected data, we analyzed the diagnostic yield of customized additional exercise provocation following inconclusive graded exercise test with measurement of gas exchange. Additional testing was defined as "positive" if it revealed a clinically-actionable diagnosis related to the chief complaint or reproduced symptoms in the absence of an explanatory diagnosis or pathology. Of 1,110 patients who completed a graded test, 122 (11%) symptomatic patients underwent additional customized exercise testing (e.g., sprint intervals and race simulations). Compared with those who did not undergo additional testing, this group was younger (29 [interquartile range 19 to 45] vs 46 [25 to 58] year old) and disproportionately female (43% vs 27%). Presenting symptoms included palpitations (46%), lightheadedness/syncope (25%), chest pain (14%), dyspnea (11%), and exertional intolerance (3%). Additional testing was "positive" in 48 of 122 (39%) of patients by revealing a clinically actionable diagnosis in 26 of 48 (54%) or reproducing symptoms without an explanatory diagnosis in 22 of 48 (46%). In conclusion, while patient-centered customization of exercise testing is suggested by clinical guidelines, these data are the first to demonstrate that the selective addition of customized exercise provocation following inconclusive graded exercise testing improves the diagnostic yield of exercise assessment.
Assuntos
Doenças Cardiovasculares/diagnóstico , Teste de Esforço , Tolerância ao Exercício/fisiologia , Esforço Físico/fisiologia , Troca Gasosa Pulmonar/fisiologia , Adulto , Doenças Cardiovasculares/fisiopatologia , Feminino , Frequência Cardíaca/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Consumo de Oxigênio/fisiologia , Valor Preditivo dos Testes , Avaliação de Sintomas , Adulto JovemRESUMO
KEY POINTS: Intense physical activity, a potent stimulus for sympathetic nervous system activation, is thought to increase the risk of malignant ventricular arrhythmias among patients with hypertrophic cardiomyopathy (HCM). As a result, the majority of patients with HCM deliberately reduce their habitual physical activity after diagnosis and this lifestyle change puts them at risk for sequelae of a sedentary lifestyle: weight gain, hypertension, hyperlipidaemia, insulin resistance, coronary artery disease, and increased morbidity and mortality. We show that plasma catecholamine levels remain stably low at exercise intensities below the ventilatory threshold, a parameter that can be defined during cardiopulmonary exercise testing, but rise rapidly at higher intensities of exercise. These findings suggest that cardiopulmonary exercise testing may be a useful tool to provide an individualized moderate-intensity exercise prescription for patients with HCM. ABSTRACT: Intense physical activity, a potent stimulus for sympathetic nervous system activation, is thought to increase the risk of malignant ventricular arrhythmias among patients with hypertrophic cardiomyopathy (HCM). However, the impact of exercise intensity on plasma catecholamine levels among HCM patients has not been rigorously defined. We conducted a prospective observational case-control study of men with non-obstructive HCM and age-matched controls. Laboratory-based cardiopulmonary exercise testing coupled with serial phlebotomy was used to define the relationship between exercise intensity and plasma catecholamine levels. Compared to controls (C, n = 5), HCM participants (H, n = 9) demonstrated higher left ventricular mass index (115 ± 20 vs. 90 ± 16 g/m2 , P = 0.03) and maximal left ventricular wall thickness (16 ± 1 vs. 8 ± 1 mm, P < 0.001) but similar body mass index, resting heart rate, peak oxygen consumption (H = 40 ± 13 vs. C = 42 ± 7 ml/kg/min, P = 0.81) and heart rate at the ventilatory threshold (H = 78 ± 6 vs. C = 78 ± 4% peak heart rate, P = 0.92). During incremental effort exercise in both groups, concentrations of adrenaline and noradrenaline were unchanged through low- and moderate-exercise intensity until reaching a catecholamine threshold (H = 82 ± 4 vs. C = 85 ± 3% peak heart rate, P = 0.86) after which levels of both molecules rose rapidly. In patients with mild non-obstructive HCM, plasma catecholamine levels remain stably low at exercise intensities below the ventilatory threshold but rise rapidly at higher intensities of exercise. Routine cardiopulmonary exercise testing may be a useful tool to provide an individualized moderate-intensity exercise prescription for patients with HCM.