Perioperative central venous oxygen saturation and its correlation with mortality during cardiac surgery: an observational prospective study / Correlação entre saturação venosa central de oxigênio perioperatória e mortalidade em cirurgia cardíaca: estudo prospectivo observacional

Abstract Background: Cardiac surgery can produce persistent deficit in the ratio of Oxygen Delivery (DO2) to Oxygen Consumption (VO2). Central venous oxygen Saturation (ScvO2) is an accessible and indirect measure of DO2/VO2 ratio. Objective: To monitor perioperative ScvO2 and assess its correlation with mortality during cardiac surgery. Methods: This prospective observational study evaluated 273 patients undergoing cardiac surgery. Blood gas samples were collected to measure ScvO2 at three time points: T0 (after anesthetic induction), T1 (end of surgery), and T2 (24 hours after surgery). The patients were divided into two groups (survivors and nonsurvivors). The following outcomes were analyzed: intrahospital mortality, length of Intensive Care Unit (ICU) and hospital stay (LOS), and variation in ScvO2. Results: Of the 273 patients, 251 (92%) survived and 22 (8%) did not. There was a significant perioperative reduction of ScvO2 in both survivors (T0 = 78% ± 8.1%, T1 = 75.4% ± 7.5%, and T2 = 68.5% ± 9%; p< 0.001) and nonsurvivors (T0 = 74.4% ± 8.7%, T1 = 75.4% ± 7.7%, and T2 = 66.7% ± 13.1%; p < 0.001). At T0, the percentage of patients with ScvO2< 70% was greater in the nonsurvivor group (31.8% vs. 13.1%; p= 0.046) and the multiple logistic regression showed that ScvO2 is an independent risk factor associated with death, OR = 2.94 (95% CI 1.10−7.89) (p= 0.032). The length of ICU and LOS were 3.6 ± 3.1 and 7.4 ± 6.0 days respectively and was not significantly associated with ScvO2. Conclusions: Early intraoperative ScvO2 < 70% indicated a higher risk of death. A perioperative reduction of ScvO2 was observed in patients undergoing cardiac surgery, with high intraoperative and lower postoperative levels.

Resumo Justificativa: A cirurgia cardíaca pode produzir déficit persistente na razão entre oferta de oxigênio (DO2) e consumo de oxigênio (VO2). A Saturação venosa central de Oxigênio (SvcO2) é uma medida acessível e indireta da razão DO2/VO2. Objetivo: Monitorar a SvcO2 perioperatória e avaliar sua correlação com a mortalidade em cirurgia cardíaca. Método: Este estudo observacional prospectivo avaliou 273 pacientes submetidos a cirurgia cardíaca. Coletamos amostras de sangue para medir a SvcO2 em três momentos: T0 (após indução anestésica), T1 (final da cirurgia) e T2 (24 horas após a cirurgia). Os pacientes foram divididos em dois grupos (sobreviventes e não sobreviventes). Os seguintes desfechos foram analisados: mortalidade intra-hospitalar, tempo de permanência na Unidade de Terapia Intensiva (UTI) e de internação hospitalar, e variação na SvcO2. Resultados: Dos 273 pacientes, 251 (92%) sobreviveram e 22 (8%) não. Houve queda significante da SvcO2 perioperatória nos sobreviventes (T0 = 78% ± 8,1%, T1 = 75,4% ± 7,5% e T2 = 68,5% ± 9%; p< 0,001) e nos não sobreviventes (T0 = 74,4% ± 8,7%, T1 = 75,4% ± 7,7% e T2 = 66,7% ± 13,1%; p< 0,001). No T0, a porcentagem de pacientes com SvcO2< 70% foi maior no grupo não sobrevivente (31,8% vs. 13,1%; p = 0,046) e a regressão logística múltipla mostrou que a SvcO2 é um fator de risco independente associado ao óbito, OR = 2,94 (95% IC 1,10 − 7,89) (p = 0,032). O tempo de permanência na UTI e de hospitalização foi de 3,6 ± 3,1 e 7,4 ± 6,0 dias, respectivamente, e não foi significantemente associado à SvcO2. Conclusões: Valores precoces de SvcO2 intraoperatória < 70% indicaram maior risco de óbito em pacientes submetidos à cirurgia cardíaca. Observamos redução perioperatória da SvcO2, com altos níveis no intraoperatório e mais baixos no pós-operatório.

Prognostic Prediction of Cardiopulmonary Exercise Test Parameters in Heart Failure Patients with Atrial Fibrillation / Previsão Prognóstica dos Parâmetros do Teste de Esforço Cardiopulmonar em Pacientes com Insuficiência Cardíaca e Fibrilação Atrial

Abstract Background: Atrial fibrillation (AF) is associated with increased mortality in heart failure (HF) patients. Objective: To evaluate whether the risk of AF patients can be precisely stratified by relation with cardiopulmonary exercise test (CPET) cut-offs for heart transplantation (HT) selection. Methods: Prospective evaluation of 274 consecutive HF patients with left ventricular ejection fraction ≤ 40%. The primary endpoint was a composite of cardiac death or urgent HT in 1-year follow-up. The primary endpoint was analysed by several CPET parameters for the highest area under the curve and for positive (PPV) and negative predictive value (NPV) in AF and sinus rhythm (SR) patients to detect if the current cut-offs for HT selection can precisely stratify the AF group. Statistical differences with a p-value <0.05 were considered significant. Results: There were 51 patients in the AF group and 223 in the SR group. The primary outcome was higher in the AF group (17.6% vs 8.1%, p = 0.038). The cut-off value of pVO2 for HT selection showed a PPV of 100% and an NPV of 95.5% for the primary outcome in the AF group, with a PPV of 38.5% and an NPV of 94.3% in the SR group. The cut-off value of VE/VCO2 slope showed lower values of PPV (33.3%) and similar NPV (92.3%) to pVO2 results in the AF group. Conclusion: Despite the fact that AF carries a worse prognosis for HF patients, the current cut-off of pVO2 for HT selection can precisely stratify this high-risk group.

Resumo Fundamento: A fibrilação atrial (FA) está associada ao aumento da mortalidade em pacientes com insuficiência cardíaca (IC). Objetivo: Avaliar se o risco de pacientes com FA pode ser estratificado com precisão em relação aos pontos de corte do teste de esforço cardiopulmonar (TECP) para seleção do transplante cardíaco (TC). Métodos: Avaliação prospectiva de 274 pacientes consecutivos com IC com fração de ejeção do ventrículo esquerdo ≤ 40%. O endpoint primário foi um composto de morte cardíaca ou TC urgente no seguimento de 1 ano. O endpoint primário foi analisado através de vários parâmetros do TECP para a maior área sob a curva e para o valor preditivo positivo (VPP) e negativo (VPN) em pacientes com FA e ritmo sinusal (RS) para detectar se os atuais pontos de corte para a seleção de TC podem estratificar com precisão o grupo com FA. Diferenças estatísticas com valor de p < 0,05 foram consideradas significativas. Resultados: Havia 51 pacientes no grupo de FA e 223 no grupo RS. O endpoint primário foi maior no grupo FA (17,6% vs. 8,1%, p = 0,038). O valor de corte de pVO2 para a seleção do TC mostrou um VPP de 100% e um VPN de 95,5% para o endpoint primário no grupo FA, com um VPP de 38,5% e um VPN de 94,3% no grupo RS. O valor de corte da inclinação VE/VCO2 apresentou valores mais baixos de VPP (33,3%) e valor semelhante de VPN (92,3%) aos resultados de pVO2 no grupo FA. Conclusões: Apesar do fato de a FA apresentar um pior prognóstico para os pacientes com IC, o atual ponto de corte de pVO2 para a seleção de TC pode estratificar com precisão esse grupo de alto risco.

Effects of high- and moderate-intensity exercise on central hemodynamic and oxygen uptake recovery kinetics in CHF-COPD overlap

The oxygen uptake (V˙O2) kinetics during onset of and recovery from exercise have been shown to provide valuable parameters regarding functional capacity of both chronic obstructive pulmonary disease (COPD) and chronic heart failure (CHF) patients. To investigate the influence of comorbidity of COPD in patients with CHF with reduced ejection fraction on recovery from submaximal exercise, 9 CHF-COPD male patients and 10 age-, gender-, and left ventricle ejection fraction (LVEF)-matched CHF patients underwent constant-load exercise tests (CLET) at moderate and high loads. The V˙O2, heart rate (HR), and cardiac output (CO) recovery kinetics were determined for the monoexponential relationship between these variables and time. Within-group analysis showed that the recovery time constant of HR (P<0.05, d=1.19 for CHF and 0.85 for CHF-COPD) and CO (P<0.05, d=1.68 for CHF and 0.69 for CHF-COPD) and the mean response time (MRT) of CO (P<0.05, d=1.84 for CHF and 0.73 for CHF-COPD) were slower when moderate and high loads were compared. CHF-COPD patients showed smaller amplitude of CO recovery kinetics (P<0.05) for both moderate (d=2.15) and high (d=1.07) CLET. Although the recovery time constant and MRT means were greater in CHF-COPD, CHF and CHF-COPD groups were not differently affected by load (P>0.05 in group vs load analysis). The ventilatory efficiency was related to MRT of V˙O2 during high CLET (r=0.71). Our results suggested that the combination of CHF and COPD may further impair the recovery kinetics compared to CHF alone.

Sympatho-Vagal Imbalance is Associated with Sarcopenia in Male Patients with Heart Failure / Desequilíbrio Simpático-Vagal está Associado com Sarcopenia em Pacientes do Sexo Masculino com Insuficiência Cardíaca

Abstract Background: Resting sympathetic hyperactivity and impaired parasympathetic reactivation after exercise have been described in patients with heart failure (HF). However, the association of these autonomic changes in patients with HF and sarcopenia is unknown. Objective: The aim of this study was to evaluate the impact of autonomic modulation on sarcopenia in male patients with HF. Methods: We enrolled 116 male patients with HF and left ventricular ejection fraction < 40%. All patients underwent a maximal cardiopulmonary exercise testing. Maximal heart rate was recorded and delta heart rate recovery (∆HRR) was assessed at 1st and 2nd minutes after exercise. Muscle sympathetic nerve activity (MSNA) was recorded by microneurography. Dual-energy X-ray absorptiometry was used to measure body composition and sarcopenia was defined by the sum of appendicular lean muscle mass (ALM) divided by height in meters squared and handgrip strength. Results: Sarcopenia was identified in 33 patients (28%). Patients with sarcopenia had higher MSNA than those without (47 [41-52] vs. 40 [34-48] bursts/min, p = 0.028). Sarcopenic patients showed lower ∆HRR at 1st (15 [10-21] vs. 22 [16-30] beats/min, p < 0.001) and 2nd min (25 [19-39] vs. 35 [24-48] beats/min, p = 0.017) than non-sarcopenic. There was a positive correlation between ALM and ∆HRR at 1st (r = 0.26, p = 0.008) and 2nd min (r = 0.25, p = 0.012). We observed a negative correlation between ALM and MSNA (r = -0.29, p = 0.003). Conclusion: Sympatho-vagal imbalance seems to be associated with sarcopenia in male patients with HF. These results highlight the importance of a therapeutic approach in patients with muscle wasting and increased peripheral sympathetic outflow.

Resumo Fundamento: Hiperatividade simpática de repouso e uma reativação parassimpática diminuída pós-exercício têm sido descritas em pacientes com insuficiência cardíaca (IC). No entanto, a associação dessas alterações autonômicas em pacientes com IC sarcopênicos ainda não são conhecidas. Objetivo: O objetivo deste estudo foi avaliar o impacto da modulação autonômica sobre sarcopenia em pacientes com IC do sexo masculino. Métodos: Foram estudados 116 pacientes com IC e fração de ejeção ventricular esquerda inferior a 40%. Todos os pacientes foram submetidos ao teste de exercício cardiopulmonar máximo. A frequência cardíaca máxima foi registrada, e o delta de recuperação da frequência cardíaca (∆RFC) foi avaliado no primeiro e no segundo minuto após o exercício. A atividade nervosa simpática muscular (ANSM) foi registrada por microneurografia. A Absorciometria Radiológica de Dupla Energia foi usada para medir composição cpororal, e a sarcopenia definida como a soma da massa muscular apendicular (MMA) dividida pela altura em metros ao quadrado e força da mão. Resultados: A sarcopenia foi identificada em 33 pacientes (28%). Os pacientes com sarcopenia apresentaram maior ANSM que aqueles sem sarcopenia - 47 (41-52) vs. 40 (34-48) impulsos (bursts)/min, p = 0,028). Pacientes sarcopênicos apresentaram ∆RFC mais baixo no primeiro [15 (10-21) vs. 22 (16-30) batimentos/min, p < 0,001) e no segundo [25 (19-39) vs. 35 (24-48) batimentos/min, p = 0,017) minuto que pacientes não sarcopênicos. Observou-se uma correlação positiva entre a MMA e a ANSM (r = -0,29; p = 0,003). Conclusão: Um desequilíbrio simpático-vagal parece estar associado com sarcopenia em pacientes com IC do sexo masculino. Esses resultados destacam a importância de uma abordagem terapêutica em pacientes com perda muscular e fluxo simpático periférico aumentado.

Effects of a high-intensity pulmonary rehabilitation program on the minute ventilation/carbon dioxide output slope during exercise in a cohort of patients with COPD undergoing lung resection for non-small cell lung cancer / Efeitos de um programa de reabilitação de alta intensidade no comando VE/VCO2 durante exercício em um grupo de pacientes submetidos à ressecção para câncer de pulmão de células não pequenas

ABSTRACT Objective: Preoperative functional evaluation is central to optimizing the identification of patients with non-small cell lung cancer (NSCLC) who are candidates for surgery. The minute ventilation/carbon dioxide output (VE/VCO2) slope has proven to be a predictor of surgical complications and mortality. Pulmonary rehabilitation programs (PRPs) could influence short-term outcomes in patients with COPD undergoing lung resection. Our objective was to evaluate the effects of a PRP on the VE/VCO2 slope in a cohort of patients with COPD undergoing lung resection for NSCLC. Methods: We retrospectively evaluated 25 consecutive patients with COPD participating in a three-week high-intensity PRP prior to undergoing lung surgery for NSCLC, between December of 2015 and January of 2017. Patients underwent complete functional assessment, including spirometry, DLCO measurement, and cardiopulmonary exercise testing. Results: There were no significant differences between the mean pre- and post-PRP values (% of predicted) for FEV1 (61.5 ± 22.0% vs. 62.0 ± 21.1%) and DLCO (67.2 ± 18.1% vs. 67.5 ± 13.2%). Conversely, there were significant improvements in the mean peak oxygen uptake (from 14.7 ± 2.5 to 18.2 ± 2.7 mL/kg per min; p < 0.001) and VE/VCO2 slope (from 32.0 ± 2.8 to 30.1 ± 4.0; p < 0.01). Conclusions: Our results indicate that a high-intensity PRP can improve ventilatory efficiency in patients with COPD undergoing lung resection for NSCLC. Further comprehensive prospective studies are required to corroborate these preliminary results.

RESUMO Objetivos: A avaliação funcional pré-operatória é fundamental para otimizar a seleção dos pacientes para cirurgia torácica para tratamento do CPCNP. Uma alta inclinação VE/VCO2 se mostrou um preditor de complicações cirúrgicas e de aumento da mortalidade. Programas de reabilitação pulmonar (PRP) demonstraram aumentar os parâmetros funcionais e os desfechos de curto prazo em pacientes com DPOC submetidos à ressecção pulmonar. O impacto dos PRP na inclinação VE/VCO2 não foi totalmente investigado. Métodos: Avaliamos retrospectivamente 25 pacientes com DPOC consecutivos submetidos aos efeitos de um programa de reabilitação pulmonar de alta intensidade (PRP) na inclinação VE/VCO2. Resultados: Não foram observadas variações significativas nos principais parâmetros espirométricos após o programa de reabilitação de três semanas (pré-reabilitação VEF1 versus pós-reabilitação VEF1 %prev: 61,5 ± 22,0% para 62,0 ± 21,1%, ns; pré-reabilitação DLCO para pós-reabilitação DLCO %prev: 67,2 ± 18,1% para 67,5 ± 13,2%, ns). Por outro lado, o pico de VO2 e a inclinação VE/VCO2 melhoraram significativamente após PRP (pico de VO2 pré-reabilitação para pico de VO2 pós-reabilitação: 14,7 ± 2,5 para 18,2 ± 2,7 mL/kg/min, p < 0,0000001; inclinação pré-reabilitação VE/VCO2 para pós-reabilitação inclinação VE/VCO2: 32,0 ± 2,8 para 30,1 ± 4,0, p<0,01). Conclusão: Documentamos o benefício no desempenho físico de um treinamento de três semanas em um grupo de pacientes com DPOC com um comprometimento funcional notável em parâmetros de esforço. Dados adicionais e mais abrangentes são necessários para esclarecer os mecanismos fisiológicos.

Intensity of physical exercise and its effect on functional capacity in COPD: systematic review and meta-analysis / Diferentes intensidades de exercício físico e capacidade funcional na DPOC: revisão sistemática e meta-análise

ABSTRACT Objective: To evaluate the effects of high-intensity interval training (HIIT), in comparison with those of continuous exercise, on functional capacity and cardiovascular variables in patients with COPD, through a systematic review and meta-analysis of randomized controlled trials. Methods: We searched PubMed, the Physiotherapy Evidence Database, the Cochrane Central Register of Controlled Trials, and EMBASE, as well as performing hand searches, for articles published up through January of 2017. We included studies comparing exercise regimens of different intensities, in terms of their effects on functional capacity and cardiovascular variables in patients with COPD. Results: Of the 78 articles identified, 6 were included in the systematic review and meta-analysis. Maximal oxygen consumption (VO2max) did not differ significantly between HIIT and control interventions. That was true for relative VO2max (0.03 mL/kg/min; 95% CI: −3.05 to 3.10) and absolute VO2max (0.03 L/min, 95% CI: −0.02 to 0.08). Conclusions: The effects of HIIT appear to be comparable to those of continuous exercise in relation to functional and cardiovascular responses. However, our findings should be interpreted with caution because the studies evaluated present a high risk of bias, which could have a direct influence on the results.

RESUMO Objetivo: Avaliar e comparar os efeitos do high-intensity interval training (HIIT, treinamento intervalado de alta intensidade) aos do exercício contínuo sobre a capacidade funcional e variáveis cardiovasculares em pacientes com DPOC por meio de revisão sistemática e meta-análise de estudos controlados randomizados. Métodos: A busca incluiu as bases PubMed, Physiotherapy Evidence Database, Cochrane Central Register of Controlled Trials e EMBASE, além de busca manual, até janeiro de 2017. Foram incluídos estudos que compararam os efeitos de diferentes intensidades de exercício em pacientes com DPOC sobre a capacidade funcional e variáveis cardiovasculares. Resultados: Dos 78 artigos identificados, 6 foram incluídos na revisão sistemática e meta-análise. Em relação ao consumo máximo de oxigênio (VO2máx), foi observado que não houve diferenças entre o HIIT e outra intervenção no VO2máx relativo (0,03 ml/kg/min; IC95%: −3,05 a 3,10) e VO2máx absoluto (0,03 l/min; IC95%: −0,02 a 0,08). Conclusões: O HIIT e o exercício contínuo atuam de maneira semelhante em relação a respostas funcionais e cardiovasculares. Entretanto, os resultados apresentados devem ser analisados com cautela, pois os estudos incluídos apresentaram alto risco de viés, podendo influenciar diretamente seus resultados.

Vasodilation and Reduction of Systolic Blood Pressure after One Session of High-Intensity Interval Training in Patients With Heart Failure with Preserved Ejection Fraction / Vasodilatação e Redução da Pressão Arterial Sistólica após uma Sessão de Treinamento Intervalado de Alta Intensidade em Pacientes com Insuficiência Cardíaca com Fração de Ejeção Preservada

Abstract Background: Heart failure with preserved ejection fraction (HFpEF) is a multifactorial syndrome characterized by a limited exercising capacity. High-intensity interval training (HIIT) is an emerging strategy for exercise rehabilitation in different settings. In patients with HFpEF, HIIT subacute effects on endothelial function and blood pressure are still unknown. Objective: To evaluate the subacute effect of one HIIT session on endothelial function and blood pressure in patients with HFpEF. Methods: Sixteen patients with HFpEF underwent a 36-minute session of HIIT on a treadmill, alternating four minutes of high-intensity intervals with three minutes of active recovery. Brachial artery diameter, flow-mediated dilation, and blood pressure were assessed immediately before and 30 minutes after the HIIT session. In all analyses, p <0.05 was considered statistically significant. Results: There was an increase in brachial artery diameter (pre-exercise: 3.96 ± 0.57 mm; post-exercise: 4.33 ± 0.69 mm; p < 0.01) and a decrease in systolic blood pressure (pre-exercise: 138 ± 21 mmHg; post-exercise: 125 ± 20 mmHg; p < 0.01). Flow-mediated dilation (pre-exercise: 5.91 ± 5.20%; post-exercise: 3.55 ± 6.59%; p = 0.162) and diastolic blood pressure (pre-exercise: 81 ± 11 mmHg; post-exercise: 77 ± 8 mmHg; p = 1.000) did not change significantly. There were no adverse events throughout the experiment. Conclusions: One single HIIT session promoted an increase in brachial artery diameter and reduction in systolic blood pressure, but it did not change flow-mediated dilation and diastolic blood pressure.

Resumo Fundamento: Insuficiência cardíaca com fração de ejeção preservada (ICFEP) é uma síndrome multifatorial caracterizada por limitação ao exercício. O treinamento intervalado de alta intensidade (HIIT) é uma estratégia emergente para a reabilitação do exercício em diferentes contextos. Em pacientes com ICFEP, os efeitos subagudos do HIIT sobre a função endotelial e a pressão arterial ainda são desconhecidos. Objetivo: Avaliar o efeito subagudo de uma única sessão do HIIT sobre a função endotelial e a pressão arterial em pacientes com ICFEP. Métodos: Dezesseis pacientes com ICFEP foram submetidos a uma sessão de 36 minutos de HIIT em esteira rolante, alternando quatro minutos de intervalos de alta intensidade com três minutos de recuperação ativa. O diâmetro da artéria braquial, a dilatação mediada pelo fluxo e a pressão arterial foram avaliados imediatamente antes e 30 minutos após a sessão de HIIT. Em todas as análises, p <0,05 foi considerado estatisticamente significativo. Resultados: Houve aumento do diâmetro da artéria braquial (pré-exercício: 3,96 ± 0,57 mm; pós-exercício: 4,33 ± 0,69 mm; p < 0,01), e diminuição da pressão arterial sistólica (pré-exercício: 138 ± 21 mmHg; pós-exercício: 125 ± 20 mmHg; p < 0,01). A dilatação mediada por fluxo (pré-exercício: 5,91 ± 5,20%; pós-exercício: 3,55 ± 6,59%; p = 0,162) e pressão arterial diastólica (pré-exercício: 81 ± 11 mmHg; pós-exercício: 77 ± 8 mmHg; p = 1,000) não se alteraram significativamente. Não houve eventos adversos durante o experimento. Conclusões: Uma única sessão do HIIT promoveu aumento do diâmetro da artéria braquial e redução da pressão arterial sistólica, mas não alterou a dilatação mediada pelo fluxo e a pressão arterial diastólica.

Effects of high-intensity inspiratory muscle training associated with aerobic exercise in patients undergoing cabg: randomized clinical trial

Abstract Objective: Evaluate the interaction between high-intensity inspiratory muscle training (IMT) and aerobic exercise on physical capacity, respiratory muscle strength, peripheral muscle strength, and quality of life of patients who underwent coronary artery bypass grafting (CABG). Methods: Twenty-four patients underwent CABG were randomized into two groups. During 36 sessions, one group received IMT associated with aerobic exercise and the other group received only aerobic exercise. Primary outcome was the distance in the six-minute walk distance (6MWD) test. Secondary outcomes included respiratory muscle strength, peripheral muscle strength, and quality of life. Measures were taken at the baseline, at the 12th session, the 24th session, and 36th session. Results: Baseline characteristics were similar between the groups. There was no statistically significant difference between the two groups in any outcome [6MWD - P=0.935; peak oxygen consumption (PeakVO2) - P=0.853; maximal inspiratory pressure (MIP) - P=0.243; maximal expiratory pressure (MEP) - P=0.268; sitting-rising test (SRT) - P=0.212], but there was interaction in MIP (P=0.000) and all outcomes improved in the two groups (6MWD - P=0.000; PeakVO2 - P=0.000; MIP - P=0.000; MEP - P=0.000; SRT - P=0.000). Conclusion: There was an improvement of all outcomes in both groups, but IMT was not able to provide additional benefits. The use of this combination should be used with caution to not generate higher costs in the rehabilitation process of these patients.

Association of oscillatory ventilation during cardiopulmonary test to clinical and functional variables of chronic heart failure patients

Abstract Objective: The aim of this study is to characterize the presence of exercise oscillatory ventilation (EOV) and to relate it with other cardiopulmonary exercise test (CET) responses and clinical variables. Methods: Forty-six male patients (age: 53.1±13.6 years old; left ventricular ejection fraction [LVEF]: 30±8%) with heart failure were recruited to perform a maximal CET and to correlate the CET responses with clinical variables. The EOV was obtained according to Leite et al. criteria and VE/VCO2 > 34 and peak VO2 < 14 ml/kg/min were used to assess patients' severity. Results: The EOV was observed in 16 of 24 patients who performed the CET, as well as VE/VCO2 > 34 and peak VO2 < 14 ml/kg/min in 14 and 10 patients, respectively. There was no difference in clinical and CET variables of the patients who presented EOV in CET when compared to non-EOV patients. Also, there was no difference in CET and clinical variables when comparing patients who presented EOV and had a VE/VCO2 slope > 34 to patients who just had one of these responses either. Conclusion: The present study showed that there was an incidence of patients with EOV and lower peak VO2 and higher VE/VCO2 slope values, but they showed no difference on other prognostic variables. As well, there was no influence of the presence of EOV on other parameters of CET in this population, suggesting that this variable may be an independent marker of worst prognosis in HF patients.

Asociación entre capacidad aeróbica y calidad de vida en adultos mayores de una ciudad colombiana / Association between aerobic capacity and quality of life in older adults in Colombia

RESUMEN Con el objetivo de determinar la asociación entre la capacidad aeróbica y la calidad de vida relacionada con la salud en adultos mayores, se encuestaron 121 personas en quienes se realizó el protocolo de Bruce modificado, como predictor del consumo máximo de oxígeno (VO2 máximo) y el cuestionario de calidad de vida SF-36. El promedio de VO2 máximo para hombres fue de 26,56±12,67 mL/kg/min, y para mujeres de 25,36±10,72 mL/kg/min, obteniéndose asociación significativa entre el sexo y el nivel de VO2 máximo (p=0,018), las dimensiones de función física y función social fueron las de mayor promedio en el total de la muestra y la capacidad aeróbica explica en un 15,3% la función física. Se concluye que el nivel pobre de VO2 máximo predomino en ambos sexos y existe asociación entre el nivel de VO2 máximo con las dimensiones de función física, desempeño físico, salud general, vitalidad y función social.

ABSTRACT The objective of this study was to determine the association of aerobic capacity with health-related quality of life in 121 subjects using the modified Bruce protocol as a predictor of maximum oxygen consumption (VO2 maximum) and the SF-36 quality of life questionnaire. The average maximum VO2 was 26.56 ± 12.67 mL/kg/min for men and 25.36 ± 10.72 mL/kg/min for women. There was a significant association between sex and maximum VO2 (p = 0.018). Physical function and social function were the variables with the highest average values in the total sample, and aerobic capacity explained 15.3% of the physical function. In conclusion, low maximum VO2 was found in both sexes, and there was a significant association of maximum VO2 with physical function, physical performance, general health, vitality, and social function.

Bradykinin, insulin, and glycemia responses to exercise performed above and below lactate threshold in individuals with type 2 diabetes

The aim of this study was to analyze the acute responses of bradykinin, insulin, and glycemia to exercise performed above and below lactate threshold (LT) in individuals with type 2 diabetes mellitus (T2D). Eleven participants with a diagnosis of T2D randomly underwent three experimental sessions 72 h apart: 1) 20 min of exercise performed at 120% of LT (120%LT), 2) 20 min of exercise performed at 80% of LT (80%LT), and 3) 20 min of control session. Blood glucose was analyzed before, during, and at 45 min post-exercise. Bradykinin and insulin were analyzed before and at 45 min post-exercise. Both exercise sessions elicited a parallel decrease in glucose level during exercise (P≤0.002), with a greater decrease being observed for 120%LT (P=0.005). Glucose decreased 22.7 mg/dL (95%CI=10.3 to 35, P=0.001) at the 45 min post-exercise recovery period for 80%LT and decreased 31.2 mg/dL (95%CI=18.1 to 44.4, P<0.001) for 120%LT (P=0.004). Insulin decreased at post-exercise for 80%LT (P=0.001) and control (P≤0.035). Bradykinin increased at 45 min post-exercise only for 80%LT (P=0.013), but was unrelated to the decrease in glucose (r=-0.16, P=0.642). In conclusion, exercise performed above and below LT reduced glycemia independently of insulin, but exercise above LT was more effective in individuals with T2D. However, these changes were unrelated to the increase in circulating bradykinin.

Influence of central obesity in estimating maximal oxygen uptake

OBJECTIVE: To assess the influence of central obesity on the magnitude of the error of estimate of maximal oxygen uptake in maximal cycling exercise testing. METHOD: A total of 1,715 adults (68% men) between 18-91 years of age underwent cardiopulmonary exercise testing using a progressive protocol to volitional fatigue. Subjects were stratified by central obesity into three quartile ranges: Q1, Q2-3 and Q4. Maximal oxygen uptake [mL.(kg.min)-1] was estimated by the attained maximal workload and body weight using gender- and population-specific equations. The error of estimate [mL.(kg.min)-1] and percent error between measured and estimated maximal oxygen uptake values were compared among obesity quartile ranges. RESULTS: The error of estimate and percent error differed (mean ± SD) for men (Q1=1.3±3.7 and 2.0±10.4; Q2-3=0.5±3.1 and -0.5±13.0; and Q4=-0.3±2.8 and -4.5±15.8 (p<0.05)) and for women (Q1=1.6±3.3 and 3.6±10.2; Q2-3=0.4±2.7 and -0.4±11.8; and Q4=-0.9±2.3 and -10.0±22.7 (p<0.05)). CONCLUSION: Central obesity directly influences the magnitude of the error of estimate of maximal oxygen uptake and should be considered when direct expired gas analysis is unavailable.

Cardiopulmonary Exercise Test: Background, Applicability and Interpretation / Teste Cardiopulmonar de Exercício: Fundamentos, Aplicabilidade e Interpretação

ABSTRACT Cardiopulmonary exercise test (CPET) has been gaining importance as a method of functional assessment in Brazil and worldwide. In its most frequent applications, CPET consists in applying a gradually increasing intensity exercise until exhaustion or until the appearance of limiting symptoms and/or signs. The following parameters are measured: ventilation; oxygen consumption (VO2); carbon dioxide production (VCO2); and the other variables of conventional exercise testing. In addition, in specific situations, pulse oximetry and flow-volume loops during and after exertion are measured. The CPET provides joint data analysis that allows complete assessment of the cardiovascular, respiratory, muscular and metabolic systems during exertion, being considered gold standard for cardiorespiratory functional assessment.1-6 The CPET allows defining mechanisms related to low functional capacity that can cause symptoms, such as dyspnea, and correlate them with changes in the cardiovascular, pulmonary and skeletal muscle systems. Furthermore, it can be used to provide the prognostic assessment of patients with heart or lung diseases, and in the preoperative period, in addition to aiding in a more careful exercise prescription to healthy subjects, athletes and patients with heart or lung diseases. Similarly to CPET clinical use, its research also increases, with the publication of several scientific contributions from Brazilian researchers in high-impact journals. Therefore, this study aimed at providing a comprehensive review on the applicability of CPET to different clinical situations, in addition to serving as a practical guide for the interpretation of that test.

RESUMO O teste cardiopulmonar de exercício (TCPE) vem ganhando importância crescente como método de avaliação funcional tanto no Brasil quanto no Mundo. Nas suas aplicações mais frequentes, o teste consiste em submeter o indivíduo a um exercício de intensidade gradativamente crescente até a exaustão ou o surgimento de sintomas e/ou sinais limitantes. Neste exame se mensura a ventilação (VE), o consumo de oxigênio (VO2), a produção de gás carbônico (VCO2) e as demais variáveis de um teste de exercício convencional. Adicionalmente, podem ser verificadas, em situações específicas, a oximetria de pulso e as alças fluxo-volume antes, durante e após o esforço. A análise integrada dos dados permite a completa avaliação dos sistemas cardiovascular, respiratório, muscular e metabólico no esforço, sendo considerado padrão-ouro na avaliação funcional cardiorrespiratória.1-6 O TCPE permite definir mecanismos relacionados à baixa capacidade funcional, os quais podem ser causadores de sintomas como a dispneia, correlacionando-os com alterações dos sistemas cardiovascular, pulmonar e musculoesquelético. Também pode ser de grande aplicabilidade na avaliação prognóstica em cardiopatas, pneumopatas e em pré-operatório, além de auxiliar na prescrição mais criteriosa do exercício em sujeitos normais, em atletas, em cardiopatas e em pneumopatas. Assim como ocorre com o uso clínico, a pesquisa nesse campo também cresce e várias contribuições científicas de pesquisadores nacionais são publicadas em periódicos de alto fator de impacto. Sendo assim, o objetivo deste documento é fornecer uma revisão ampla da aplicabilidade do TCPE nas diferentes situações clínicas, bem como servir como guia prático na interpretação desse teste propedêutico.

Exercise and non-exercise aerobic power prediction models using six-minute walk test / Equações de predição da potência aeróbica usando o teste de caminhada de seis minutos

BACKGROUND AND OBJECTIVE: A simple, low-cost approach commonly used to objectively analyze the cardiorespiratory fitness of individuals with different health conditions is the six-minute walk test (6-MWT). Our objective was to develop peak aerobic power prediction using the six-minute walk test in healthy older men. METHODS: We measured body composition (body mass [BM], body mass index [BMI], fat percentage [FAT]) and peak aerobic power breath-by-breath during cardiopulmonary exercise testing (CPET [velocity, heart rate [HR] and VO2 at the anaerobic threshold and peak]) and a 6-MWT (distance [D], weight by distance [WxD], HR and oxygen consumption [VO2] at peak) in 76 healthy older men aged 65 to 80 years (69.1 ± 0.3 yrs-old). RESULTS: We observed significant correlations for VO2peak during the 6-MWT as a function of WxD (R = 0.75, P < 0.0005), BM (R = 0.56, P < 0.0005), D (R = 0.43, P = 0.0004) and maximum HR (R = 0.37, P = 0.001). Distance correlated significantly with FAT (R = -0.43, P = 0.005), BMI (R = -0.36, P = 0.021) and age (R = -0.31, P < 0.045), whereas WxD correlated with BM (R = 0.86, P<0.005).The inclusion of WxD increased the R2 from 0.65 to 0.74 and decreased the estimative error while yielding the following equation (R = 0.86, standard error of the estimate (SEE) = 182.1 mL•min-1, P < 0.0005) to predict VO2peak: VO2peak = 962.2 + (0.037 x WxD) + (8.565 x maximum HR). A non-exercise model was obtained by univariate regressions but not multiple regressions. The FAT (R = 0.43, SEE = 702.2 m, P < 0.005) yielded the best model for predicting distance, i.e., distance = 702.2 - (3.067 x FAT). CONCLUSION: Our prediction model seems to accurately estimate VO2peak in healthy older men primarily when WxD is considered.

OBJETIVO: O teste de caminhada de seis minutos (TC6M) é uma estrategia simples e de baixo custo operacional que objetivamente mede a aptidão cardiorrespiratória de indivíduos com diferentes condições de saúde. Nosso objetivo foi desenvolver equações de predição da potência aeróbica em homens idosos saudáveis usando o TC6M. MÉTODOS: Foram medidos a composição corporal (massa corporal [MC], índice de massa corporal [BMI], porcentagem de gordura [%G]) e potência aeróbica de pico através de teste cardiopulmonar de exercício máximo (velocidade, frequência cardíaca [FC] e consumo de oxigênio [VO2] no limiar anaeróbico e no pico]) e através do TC6M (distancia [D], produto massa corporal x distância, FC e VO2de pico) em 76 idosos saudáveis com idade entre 65 e 80 anos (69.1 ± 0.3 anos). RESULTADOS: Foram observadas correlações significativas para VO2pico no TC6M em função do produto MCxD (R = 0,75, P < 0,0005), MC (R = 0,56, P < 0,0005), D (R = 0,43, P = 0,0004) e FC máxima (R = 0,37, P = 0,001). A correlacionou-se significativamente com %G (R = -0,43, P = 0,005), IMC (R = -0,36, P = 0,021) e idade (R = -0,31, P < 0,045), enquanto que a MCxD correlacionou-se com MC (R = 0,86, P < 0,005). A inclusão da MCxD aumentou o R 2 de 0,65 para 0,74 e diminuiu o erro padrão da estimativa (EPE) gerando a equação (R = 0,86, EPE = 182,1 mL·min-1, P < 0,0005) para a predição do VO2peak: VO2peak = 962,2 + (0,037 x MCxD) + (8,565 x FC máxima). Foi também gerado um modelo preditivo não dependente de exercício através de regressão univariada, mas não múltipla. A %G (R=0,43, EPE = 702,2 m, P < 0,005) gerou o melhor modelo para a predição da distancia, i.e., distancia = 702,2 - (3,067 x %G). CONCLUSÃO: Nossas modelos de predição parecem estimar precisamente o VO2pico de idosos saudáveis, especialmente quando a MCxD é considerada.

Does low serum TSH within the normal range have negative impact on physical exercise capacity and quality of life of healthy elderly people?

Objective Investigate the differences in cardiopulmonary (CP) capacity and Quality of Life (QOL) between healthy elderly (≥ 65 years) with different TSH levels (< 1.0 and ≥ 1.0 μIU/mL) both within the normal range. Also, evaluate the effects of TSH elevation on CP test and QOL, by administering methimazole to subjects with initial lower-normal TSH, in order to elevate it to superior-normal limit. Materials and methods Initially, a cross-sectional study was performed to compare CP capacity at peak exercise and QOL (using WHOQOL-OLD questionnaire) between healthy seniors (age ≥ 65 years) with TSH < 1.0 μIU/mL vs. TSH ≥1.0 μIU/mL. In the second phase, participants with TSH < 1.0 μIU/mL were included in a non-controlled-prospective-interventional study to investigate the effect of TSH elevation, using methimazole, on QOL and CP capacity at peak exercise. Results From 89 elderly evaluated, 75 had TSH ≥ 1 μIU/mL and 14 TSH < 1 μIU/mL. The two groups had similar basal clinical characteristics. No difference in WHOQOL-OLD scores was observed between groups and they did not differ in terms of CP function at peak exercise. QOL and CP variables were not correlated with TSH levels. Twelve of 14 participants with TSH < 1.0 μIU/mL entered in the prospective study. After one year, no significant differences in clinical caracteristics, QOL, and CP variables were detected in paired analysis before and after methimazole intervention. Conclusions We found no differences in CP capacity and QOL between health elderly with different TSH levels within normal range and no impact after one year of methimazole treatment. More prospective-controlled-randomized studies are necessary to confirm or not the possible harm effect in normal low TSH.

Brazilian Cardiorespiratory Fitness Classification Based on Maximum Oxygen Consumption / Classificação Nacional da Aptidão Cardiorrespiratória pelo Consumo Máximo de Oxigênio

Abstract Background: Cardiopulmonary exercise test (CPET) is the most complete tool available to assess functional aerobic capacity (FAC). Maximum oxygen consumption (VO2 max), an important biomarker, reflects the real FAC. Objective: To develop a cardiorespiratory fitness (CRF) classification based on VO2 max in a Brazilian sample of healthy and physically active individuals of both sexes. Methods: We selected 2837 CEPT from 2837 individuals aged 15 to 74 years, distributed as follows: G1 (15 to 24); G2 (25 to 34); G3 (35 to 44); G4 (45 to 54); G5 (55 to 64) and G6 (65 to 74). Good CRF was the mean VO2 max obtained for each group, generating the following subclassification: Very Low (VL): VO2 < 50% of the mean; Low (L): 50% - 80%; Fair (F): 80% - 95%; Good (G): 95% -105%; Excellent (E) > 105%. Results: Men VL < 50% L 50-80% F 80-95% G 95-105% E > 105% G1 < 25.30 25.30-40.48 40.49-48.07 48.08-53.13 > 53.13 G2 < 23.70 23.70-37.92 37.93-45.03 45.04-49.77 > 49.77 G3 < 22.70 22.70-36.32 36.33-43.13 43.14-47.67 > 47.67 G4 < 20.25 20.25-32.40 32.41-38.47 38.48-42.52 > 42.52 G5 < 17.54 17.65-28.24 28.25-33.53 33.54-37.06 > 37.06 G6 < 15 15.00-24.00 24.01-28.50 28.51-31.50 > 31.50 Women G1 < 19.45 19.45-31.12 31.13-36.95 36.96-40.84 > 40.85 G2 < 19.05 19.05-30.48 30.49-36.19 36.20-40.00 > 40.01 G3 < 17.45 17.45-27.92 27.93-33.15 33.16-34.08 > 34.09 G4 < 15.55 15.55-24.88 24.89-29.54 29.55-32.65 > 32.66 G5 < 14.30 14.30-22.88 22.89-27.17 27.18-30.03 > 30.04 G6 < 12.55 12.55-20.08 20.09-23.84 23.85-26.35 > 26.36 Conclusions: This chart stratifies VO2 max measured on a treadmill in a robust Brazilian sample and can be used as an alternative for the real functional evaluation of physically and healthy individuals stratified by age and sex.

Resumo Fundamento: O teste cardiopulmonar de exercício (TCPE) é a ferramenta disponível mais completa na avaliação da capacidade aeróbica funcional (CF) do indivíduo. O consumo máximo de oxigênio (VO2 max), importante marcador biológico, reflete a real CF. Objetivo: Elaborar uma classificação de aptidão cardiorrespiratória (ACR) baseada no VO2 max em uma amostra nacional de sujeitos saudáveis e ativos de ambos os sexos. Métodos: Selecionamos 2837 TCPE de indivíduos entre 15 e 74 anos, assim distribuídos: G1 (15 a 24); G2 (25 a 34); G3 (35 a 44); G4 (45 a 54); G5 (55 a 64) e G6 (65 a 74). A ACR boa foi a média do VO2 max obtido em cada grupo, gerando as seguintes subclassificações: Muito Fraca (MF) VO2 < 50% da média; Fraca (F): 50%-80%; Regular (R): 80%-95%; Boa (B): 95%-105%; e Excelente (E) > 105%. Resultados: Homens MF < 50% F 50-80% R 80-95% B 95-105% E > 105% G1 < 25,30 25,30-40,48 40,49-48,07 48,08-53,13 > 53,13 G2 < 23,70 23,70-37,92 37,93-45,03 45,04-49,77 > 49,77 G3 < 22,70 22,70-36,32 36,33-43,13 43,14-47,67 > 47,67 G4 < 20,25 20,25-32,40 32,41-38,47 38,48-42,52 > 42,52 G5 < 17,54 17,65-28,24 28,25-33,53 33,54-37,06 > 37,06 G6 < 15 15,00-24,00 24,01-28,50 28,51-31,50 > 31,50 Mulheres G1 < 19,45 19,45-31,12 31,13-36,95 36,96-40,84 > 40,85 G2 < 19,05 19,05-30,48 30,49-36,19 36,20-40,00 > 40,01 G3 < 17,45 17,45-27,92 27,93-33,15 33,16-34,08 > 34,09 G4 < 15,55 15,55-24,88 24,89-29,54 29,55-32,65 > 32,66 G5 < 14,30 14,30-22,88 22,89-27,17 27,18-30,03 > 30,04 G6 < 12,55 12,55-20,08 20,09-23,84 23,85-26,35 > 26,36 Conclusão: A presente tabela estratifica o VO2 max aferido em esteira em uma robusta amostra nacional e pode ser utilizada como opção para a real avaliação funcional de indivíduos ativos e saudáveis de acordo com sexo e faixa etária.

Peripheral brain-derived neurotrophic factor is related to cardiovascular risk factors in active and inactive elderly men

Regular exercise plays an important preventive and therapeutic role in heart and vascular diseases, and beneficially affects brain function. In blood, the effects of exercise appear to be very complex and could include protection of vascular endothelial cells via neurotrophic factors and decreased oxidative stress. The purpose of this study was to identify the age-related changes in peripheral brain-derived neurotrophic factor (BDNF) and its relationship to oxidative damage and conventional cardiovascular disease (CVD) biomarkers, such as atherogenic index, C-reactive protein (hsCRP) and oxidized LDL (oxLDL), in active and inactive men. Seventeen elderly males (61-80 years) and 17 young males (20-24 years) participated in this study. According to the 6-min Åstrand-Rhyming bike test, the subjects were classified into active and inactive groups. The young and elderly active men had a significantly better lipoprotein profile and antioxidant status, as well as reduced oxidative damage and inflammatory state. The active young and elderly men had significantly higher plasma BDNF levels compared to their inactive peers. BDNF was correlated with VO2max (r=0.765, P<0.001). In addition, we observed a significant inverse correlation of BDNF with atherogenic index (TC/HDL), hsCRP and oxLDL. The findings demonstrate that a high level of cardiorespiratory fitness reflected in VO2max was associated with a higher level of circulating BDNF, which in turn was related to common CVD risk factors and oxidative damage markers in young and elderly men.

Use of the Wasserman equation in optimization of the duration of the power ramp in a cardiopulmonary exercise test: a study of Brazilian men

This study aimed to analyze the agreement between measurements of unloaded oxygen uptake and peak oxygen uptake based on equations proposed by Wasserman and on real measurements directly obtained with the ergospirometry system. We performed an incremental cardiopulmonary exercise test (CPET), which was applied to two groups of sedentary male subjects: one apparently healthy group (HG, n=12) and the other had stable coronary artery disease (n=16). The mean age in the HG was 47±4 years and that in the coronary artery disease group (CG) was 57±8 years. Both groups performed CPET on a cycle ergometer with a ramp-type protocol at an intensity that was calculated according to the Wasserman equation. In the HG, there was no significant difference between measurements predicted by the formula and real measurements obtained in CPET in the unloaded condition. However, at peak effort, a significant difference was observed between oxygen uptake (V˙O2)peak(predicted)and V˙O2peak(real)(nonparametric Wilcoxon test). In the CG, there was a significant difference of 116.26 mL/min between the predicted values by the formula and the real values obtained in the unloaded condition. A significant difference in peak effort was found, where V˙O2peak(real)was 40% lower than V˙O2peak(predicted)(nonparametric Wilcoxon test). There was no agreement between the real and predicted measurements as analyzed by Lin’s coefficient or the Bland and Altman model. The Wasserman formula does not appear to be appropriate for prediction of functional capacity of volunteers. Therefore, this formula cannot precisely predict the increase in power in incremental CPET on a cycle ergometer.

Sex-Specific Equations to Estimate Maximum Oxygen Uptake in Cycle Ergometry / Equações Específicas por Sexo para Estimativa do Consumo Máximo de Oxigênio em Cicloergometria

AbstractBackground:Aerobic fitness, assessed by measuring VO2max in maximum cardiopulmonary exercise testing (CPX) or by estimating VO2max through the use of equations in exercise testing, is a predictor of mortality. However, the error resulting from this estimate in a given individual can be high, affecting clinical decisions.Objective:To determine the error of estimate of VO2max in cycle ergometry in a population attending clinical exercise testing laboratories, and to propose sex-specific equations to minimize that error.Methods:This study assessed 1715 adults (18 to 91 years, 68% men) undertaking maximum CPX in a lower limbs cycle ergometer (LLCE) with ramp protocol. The percentage error (E%) between measured VO2max and that estimated from the modified ACSM equation (Lang et al. MSSE, 1992) was calculated. Then, estimation equations were developed: 1) for all the population tested (C-GENERAL); and 2) separately by sex (C-MEN and C-WOMEN).Results:Measured VO2max was higher in men than in WOMEN: -29.4 ± 10.5 and 24.2 ± 9.2 mL.(kg.min)-1 (p < 0.01). The equations for estimating VO2max [in mL.(kg.min)-1] were: C-GENERAL = [final workload (W)/body weight (kg)] x 10.483 + 7; C-MEN = [final workload (W)/body weight (kg)] x 10.791 + 7; and C-WOMEN = [final workload (W)/body weight (kg)] x 9.820 + 7. The E% for MEN was: -3.4 ± 13.4% (modified ACSM); 1.2 ± 13.2% (C-GENERAL); and -0.9 ± 13.4% (C-MEN) (p < 0.01). For WOMEN: -14.7 ± 17.4% (modified ACSM); -6.3 ± 16.5% (C-GENERAL); and -1.7 ± 16.2% (C-WOMEN) (p < 0.01).Conclusion:The error of estimate of VO2max by use of sex-specific equations was reduced, but not eliminated, in exercise tests on LLCE.

ResumoFundamento:A condição aeróbica, avaliada pela medida do VO2máx no teste cardiopulmonar de exercício máximo (TCPE) ou estimada por equações no teste de exercício, é preditora de mortalidade. Porém, o erro obtido pela estimativa em um dado indivíduo pode ser alto, afetando decisões clínicas.Objetivo:Determinar o erro de estimativa do VO2máx em cicloergometria em população atendida nos serviços de ergometria e propor equações específicas por sexo para minimizar o erro na estimativa do VO2máx.Métodos:Foram avaliados 1715 adultos (18 a 91 anos) (68% homens) submetidos a TCPE máximo em cicloergômetro de membros inferiores (CMI) com protocolo de rampa. Calculou-se o erro percentual (E%) entre o VO2máx medido e o estimado pela equação ACSM modificada (Lang e col. MSSE, 1992). A seguir, foram desenvolvidas equações de estimativa: 1) para toda a amostra testada (C-GERAL) e 2) separadamente por sexo (C-HOMENS e C-MULHERES).Resultados:O VO2máx medido foi maior em homens do que em mulheres - 29,4 ± 10,5 e 24,2 ± 9,2 mL.(kg.min)-1 (p < 0,01) -. As equações de estimativa do VO2máx foram mL.(kg.min)-1: C-GERAL = [carga final (W)/peso (kg)] x 10,483 + 7; C‑HOMENS = [carga final (W)/peso (kg)] x 10,791 + 7; e C-MULHERES = [carga final (W)/peso (kg)] x 9,820 + 7. Os E% em homens foram -3,4 ± 13,4% (ACSM modificada), 1,2 ± 13,2% (C-GERAL) e -0,9 ± 13,4% (C-HOMENS) (p < 0,01). Em mulheres, obtivemos: -14,7 ± 17,4% (ACSM modificada), -6,3 ± 16,5% (C-GERAL) e -1,7 ± 16,2% (C-MULHERES) (p < 0,01).Conclusão:O erro de estimativa do VO2máx através de equações específicas por sexo foi reduzido, porém não eliminado, nos testes de exercício em CMI.