Assuntos
Teste de Esforço , Adolescente , Criança , Humanos , Brasil , Teste de Esforço/normas , Teste de Esforço/métodosRESUMO
Classes de Recomendação Classe I: Condições para as quais há evidências conclusivas e, na sua falta, consenso geral de que o procedimento é seguro e útil/eficaz. Classe II: Condições para as quais há evidências conflitantes e/ou divergência de opinião sobre a segurança e utilidade/eficácia do procedimento. Classe IIa: Peso ou evidência/opinião a favor do procedimento. A maioria aprova. Classe IIb: Segurança e utilidade/eficácia menos estabelecidas, havendo opiniões divergentes. Classe III: Condições para as quais há evidências e/ou consenso de que o procedimento não é útil/eficaz e, em alguns casos, pode ser prejudicial. Níveis de Evidência Nível A: Dados obtidos a partir de múltiplos estudos randomizados de bom porte, concordantes e/ou de metanálise robusta de estudos randomizados. Nível B: Dados obtidos a partir de metanálise menos robusta, a partir de um único estudo randomizado e/ou de estudos observacionais. Nível C: Dados obtidos de opiniões consensuais de especialistas.
Classes of Recommendation Class I: Conditions for which there is conclusive evidence and, failing that, general agreement that a given procedure is safe and useful/effective. Class II: Conditions for which there is conflicting evidence and/or a divergence of opinion about the safety and usefulness/efficacy of a procedure. Class IIa: Weight or evidence/opinion in favor of the procedure. Most approve. Class IIb: Safety and usefulness/efficacy less well established, with divergence of opinions. Class III: Conditions for which there is evidence and/or general agreement that a procedure is not useful/effective and, in some cases, may be harmful. Levels of Evidence Level A: Data derived from multiple large, concordant randomized trials and/or robust meta-analyses of randomized trials. Level B: Data derived from less robust meta-analyses, from a single randomized trial and/or from observational studies. Level C: Data derived from consensus opinion of experts.
Assuntos
Teste de Esforço , Humanos , Brasil , Teste de Esforço/normas , Teste de Esforço/métodos , Adulto , Feminino , Masculino , Doenças CardiovascularesRESUMO
PURPOSE: Peak oxygen uptake (VO2peak) is a crucial health marker, extensively studied in adults for its prognostic value. However, its significance in the older persons, especially octogenarians, remains underexplored due to limited representation in research. This study aims to assess the predictive power of VO2peak for survival in individuals aged 80 and above. METHODS: We included individuals aged 80 or older who underwent cardiopulmonary exercise tests at a single center. Mortality rates were compared based on VO2peak relative to 80% of predicted values (%VO2peak). We employed three multivariate Cox regression models: Model 1 (unadjusted), Model 2 (adjusted for age) and Model 3 (adjusted for age and stroke). RESULTS: Among 188 participants (mean age 83.3 ± 3 years, 68.9% male), 22 (11.7%) passed away during a median follow-up of 494 days. Non-survivors tended to be older with lower VO2peak and %VO2peak. All models demonstrated associations between %VO2peak ≤ 80% and mortality: HR = 3.19 (95% CI: 1.30-7.86, p = 0.011) for M1; HR = 3.12 (95% CI: 1.26-7.74, p = 0.013) for M2 and HR = 2.80 (95% CI: 1.11-7.06, p = 0.028) for M3. CONCLUSION: In the context of an aging population, this study underscores the enduring significance of VO2peak as a survival predictor among the older person, including octogenarians. These findings carry profound implications for tailoring healthcare strategies to address the evolving demographic landscape.
Assuntos
Teste de Esforço , Consumo de Oxigênio , Humanos , Masculino , Feminino , Consumo de Oxigênio/fisiologia , Idoso de 80 Anos ou mais , Prognóstico , Modelos de Riscos Proporcionais , Valor Preditivo dos Testes , Avaliação Geriátrica/métodosRESUMO
COVID-19 may have residual consequences in multiple organs, including the cardiovascular system. The purpose of the present investigation is to quantify myocardial function in symptomatic individuals with long COVID and investigate the association between illness severity and myocardial function. A retrospective cross-sectional study was conducted in which symptomatic individuals with previous COVID-19 underwent echocardiographic analysis of left ventricle global longitudinal strain (LVGLS) and myocardial work (MW). Individuals also performed cardiopulmonary testing (CPX) to assess peak oxygen uptake (VO2peak). Differences between illness severity subgroups were analyzed by the Mann-Whitney test. Correlations were calculated using the Spearman correlation test. Multilinear regressions were performed to evaluate the influences of COVID-19 severity, body mass index, age, and sex on MW. Fifty-six individuals were included (critical subgroup: 17; moderate/severe subgroup: 39), 59% females; median age: 56 years (IQR: 43-63). CPX revealed a substantial reduction in VO2peak (median of 53% of predicted values). LVGLS were not statistically different between subgroups. Global wasted work (GWW) was higher in the critical subgroup [146 (104-212) versus 121 (74-163) mmHg%, p = 0.01], and global work efficiency (GWE) was lower in this subgroup [93 (91-95) versus 94 (93-96), p = 0.03]. Illness severity was the only independent predictor of GWW and GWE (GWW: r2 = 0.167; p = 0.009; GWE: r2 = 0.172; p = 0.005) in multilinear regressions. In our study with long COVID-19 individuals, despite having a similar LVGLS, patients had subclinical LV dysfunction, demonstrated only by an increase in GWW and a decrease in GWE.
Assuntos
COVID-19 , Índice de Gravidade de Doença , Humanos , COVID-19/complicações , COVID-19/diagnóstico , COVID-19/fisiopatologia , Feminino , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Estudos Transversais , Adulto , Ecocardiografia , Função Ventricular Esquerda , SARS-CoV-2 , Consumo de Oxigênio , Disfunção Ventricular Esquerda/fisiopatologia , Disfunção Ventricular Esquerda/diagnóstico por imagem , Teste de EsforçoRESUMO
Objectives: To compare the elicited exercise responses at ventilatory thresholds (VTs: VT1 and VT2) identified by cardiopulmonary exercise testing (CPET) in patients with cardiovascular disease (CVD) with the guideline-directed exercise intensity domains; to propose equations to predict heart rate (HR) at VTs; and to compare the accuracy of prescription methods. Methods: A cross-sectional study was performed with 972 maximal treadmill CPET on patients with CVD. First, VTs were identified and compared with guideline-directed exercise intensity domains. Second, multivariate linear regression analyses were performed to generate prediction equations for HR at VTs. Finally, the accuracy of prescription methods was assessed by the mean absolute percentage error (MAPE). Results: Significant dispersions of individual responses were found for VTs, with the same relative intensity of exercise corresponding to different guideline-directed exercise intensity domains. A mathematical error inherent to methods based on percentages of peak effort was identified, which may help to explain the dispersions. Tailored multivariable equations yielded r2 of 0.726 for VT1 and 0.901 for VT2. MAPE for the novel VT1 equation was 6.0%, lower than that for guideline-based prescription methods (9.5 to 23.8%). MAPE for the novel VT2 equation was 4.3%, lower than guideline-based methods (5.8%-19.3%). Conclusion: The guideline-based exercise intensity domains for cardiovascular rehabilitation revealed inconsistencies and heterogeneity, which limits the currently used methods. New multivariable equations for patients with CVD were developed and demonstrated better accuracy, indicating that this methodology may be a valid alternative when CPET is unavailable.
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BACKGROUND: Post-COVID-19 exercise intolerance is poorly understood. Cardiopulmonary exercise testing (CPET) can identify the underlying exercise limitations. OBJECTIVES: To evaluate the source and magnitude of exercise intolerance in post-COVID-19 subjects. METHODS: Cohort study assessing subjects with different COVID-19 illness severities and a control group selected by propensity score matching. In a selected sample with CPET prior to viral infection, before and after comparisons were performed. Level of significance was 5% in the entire analysis. RESULTS: One hundred forty-four subjects with COVID-19 were assessed (median age: 43.0 years, 57% male), with different illness severities (60% mild, 21% moderate, 19% severe). CPET was performed 11.5 (7.0, 21.2) weeks after disease onset, with exercise limitations being attributed to the peripheral muscle (92%), and the pulmonary (6%), and cardiovascular (2%) systems. Lower median percent-predicted peak oxygen uptake was observed in the severe subgroup (72.2%) as compared to the controls (91.6%). Oxygen uptake differed among illness severities and controls at peak and ventilatory thresholds. Conversely, ventilatory equivalents, oxygen uptake efficiency slope, and peak oxygen pulse were similar. Subgroup analysis of 42 subjects with prior CPET revealed significant reduction in only peak treadmill speed in the mild subgroup and in oxygen uptake at peak and ventilatory thresholds in the moderate/severe subgroup. By contrast, ventilatory equivalents, oxygen uptake efficiency slope, and peak oxygen pulse did not change significantly. CONCLUSIONS: Peripheral muscle fatigue was the most common exercise limitation etiology in post-COVID-19 patients regardless of the illness severity. Data suggest that treatment should emphasize comprehensive rehabilitation programs, including aerobic and muscle strengthening components.
FUNDAMENTO: A intolerância ao exercício pós-COVID-19 não é bem entendida. O teste de esforço cardiopulmonar (TECP) pode identificar as limitações ao exercício subjacentes. OBJETIVOS: Avaliar a etiologia e a magnitude da intolerância ao exercício em sujeitos pós-COVID-19. MÉTODOS: Estudo de coorte que avaliou sujeitos com níveis de gravidades diferentes da doença COVID-19 e um grupo de controle selecionado por pareamento por escores de propensão. Em uma amostra seleta com TECP anterior à infecção viral disponível, foram realizadas comparações antes e depois. O nível de significância foi de 5% em toda a análise. RESULTADOS: Foram avaliados cento e quarenta e dois sujeitos com COVID-19 (idade mediana: 43 anos, 57% do sexo masculino), com níveis de gravidade de doença diferentes (60% leve, 21% moderada, 19% grave). O TECP foi realizado 11,5 (7,0, 21,2) semanas após o aparecimento da doença, com as limitações ao exercício sendo atribuídas aos sistemas muscular periférico (92%), pulmonar (6%), e cardiovascular (2%). Menor valor mediano do consumo de oxigênio pico percentual foi observado no subgrupo com níveis graves de doença (72,2%) em comparação com os controles (91,6%). O consumo de oxigênio foi diferente entre os grupos com diferentes níveis de gravidade de doença e o controle no pico e nos limiares ventilatórios. Inversamente, os equivalentes ventilatórios, a inclinação da eficiência do consumo de oxigênio, e o pico do pulso de oxigênio foram semelhantes. A análise do subgrupo de 42 sujeitos com TECP prévio revelou uma redução significativa no pico de velocidade da esteira no subgrupo com nível leve de doença, e no consumo de oxigênio no pico e nos limiares ventilatórios nos subgrupos com níveis moderado/grave. Por outro lado, os equivalentes ventilatórios, a inclinação da eficiência do consumo de oxigênio e o pico do pulso de oxigênio não apresentaram alterações significativas. CONCLUSÕES: A fadiga do músculo periférico foi a etiologia de limitação de exercício mais comum em pacientes pós-COVID-19 independentemente da gravidade da doença. Os dados sugerem que o tratamento deve enfatizar programas de reabilitação abrangentes, incluindo componentes aeróbicos e de fortalecimento muscular.
Assuntos
COVID-19 , Teste de Esforço , Humanos , Masculino , Adulto , Feminino , Estudos de Coortes , Consumo de Oxigênio/fisiologia , Oxigênio , Tolerância ao Exercício/fisiologiaRESUMO
PURPOSE: The purpose of this study is to provide comprehensive reference values for oxygen uptake efficiency slope (OUES) in healthy adults. International heterogeneity was also explored through published databases. METHODS: A cross-sectional study was conducted with treadmill cardiopulmonary exercise testing (CPX) from a Brazilian healthy adult sample, in which absolute OUES and values normalized by weight and body surface area (BSA) were calculated. Data were stratified by sex and age group. Prediction equations were calculated using age and anthropometric variables. International data were pooled and differences were explored using factorial analysis of variance or the t test, as appropriate. The OUES age-related patterns were calculated using regression analysis. RESULTS: A total of 3544 CPX were included (1970 males and 1574 females) and the age ranged from 20-80 yr. Males had higher values than females for OUES, OUES/kg, and OUES/BSA. Lower values were found with aging and the data followed a quadratic regression curve. Reference value tables and predictive equations were provided for absolute and normalized OUES in both sexes. International comparisons of absolute OUES values among Brazilian, European, and Japanese data revealed substantial heterogeneity. The OUES/BSA measure minimized the discrepancies between Brazilian and European data. CONCLUSIONS: Our study provided comprehensive OUES reference values in a large healthy adult sample from South America with a wide age range and included absolute and normalized values. Differences observed between Brazilian and European data were reduced in the BSA-normalized OUES.
Assuntos
Teste de Esforço , Consumo de Oxigênio , Masculino , Feminino , Humanos , Adulto , Valores de Referência , Estudos Transversais , Oxigênio , BrasilRESUMO
BACKGROUND: The COVID-19 pandemic had an impact on cardiovascular rehabilitation (CR) programs in Brazil. OBJECTIVES: To describe the characteristics of CR programs in Brazil, the impacts of the first epidemiological wave of COVID-19 (first 60 days) on the programs and present the initiatives used to overcome the impacts. METHOD: This cross-sectional and retrospective study utilized a specific online survey. Participants were coordinators of CR programs. Variables were presented by Brazilian geographic region and as the following categories: demographic, clinical and operational characteristics. The significance level for statistical analysis was set at 5%. RESULTS: Fifty-nine CR programs were responsible for 5,349 patients, of which only 1,817 were post-acute cardiovascular events, which corresponded to 1.99% of hospitalized patients in the month prior to the survey (n=91,231). The greatest impact was the suspension of on-site activities, which occurred similarly in areas with the highest and the lowest rates of COVID-19 in the period. Forty-five programs (75%) were shortly interrupted, while three (5%) were ended. All 42 programs that already used remote rehabilitation strategies noticed a substantial increase in activities, based primarily on the use of media and video calling. Only three (5%) considered safe to see patients during the first 60 days. CONCLUSIONS: There was a reduction in the number of CR programs with the COVID-19 pandemic. Telerehabilitation activities increased during the first two months of the COVID-19 pandemic, but this was not enough to overcome the reduction in CR program activities across Brazil.
FUNDAMENTO: A pandemia da COVID-19 teve um impacto sobre os programas de reabilitação cardiovasculares (RC) no Brasil. OBJETIVOS: Descrever características dos programas de RC no Brasil, os impactos da primeira onda epidemiológica da COVID-19 (primeiros 60 dias) sobre os programas, e apresentar as iniciativas usadas para superar esses impactos. MÉTODOS: Este estudo transversal e retrospectivo usou um questionário online específico. Os participantes eram coordenadores de programas de RC. As variáveis foram apresentadas por região geográfica do Brasil, como as seguintes categorias: característica demográficas, clínicas e operacionais. O nível de significância estatística foi definido em 5%. RESULTADOS: Cinquenta e nove programas de RC atendiam 5349 pacientes, dos quais somente 1817 eram pacientes após eventos cardiovasculares agudos, o que correspondia a 1,99% dos pacientes internados no mês anterior à pesquisa (n=91.231). O maior impacto foi a suspensão das atividades presenciais, o que ocorreu de maneira similar em áreas com as taxas mais altas e áreas com as taxas mais baixas de COVID-19 no período. Quarenta e quatro (75%) programas foram interrompidos de forma breve, e três (5%) foram encerrados. Todos os 42 programas que já utilizavam estratégias de reabilitação remota notaram aumento substancial nas atividades, baseadas principalmente no uso da mídia e chamadas por vídeo. Somente três (5%) consideraram seguro atender pacientes durante os primeiros 60 dias. CONCLUSÕES: Houve redução no número de programas de RC devido a pandemia da COVID-19. Atividades de telerreabilitação aumentaram durante os primeiros dois meses da pandemia da COVID-19, mas que não foi suficiente para superar a redução nas atividades dos programas de RC no Brasil.
Assuntos
COVID-19 , Reabilitação Cardíaca , Humanos , Estudos Transversais , Brasil/epidemiologia , Pandemias , Estudos RetrospectivosRESUMO
Resumo Fundamento A intolerância ao exercício pós-COVID-19 não é bem entendida. O teste de esforço cardiopulmonar (TECP) pode identificar as limitações ao exercício subjacentes. Objetivos Avaliar a etiologia e a magnitude da intolerância ao exercício em sujeitos pós-COVID-19. Métodos Estudo de coorte que avaliou sujeitos com níveis de gravidades diferentes da doença COVID-19 e um grupo de controle selecionado por pareamento por escores de propensão. Em uma amostra seleta com TECP anterior à infecção viral disponível, foram realizadas comparações antes e depois. O nível de significância foi de 5% em toda a análise. Resultados Foram avaliados cento e quarenta e dois sujeitos com COVID-19 (idade mediana: 43 anos, 57% do sexo masculino), com níveis de gravidade de doença diferentes (60% leve, 21% moderada, 19% grave). O TECP foi realizado 11,5 (7,0, 21,2) semanas após o aparecimento da doença, com as limitações ao exercício sendo atribuídas aos sistemas muscular periférico (92%), pulmonar (6%), e cardiovascular (2%). Menor valor mediano do consumo de oxigênio pico percentual foi observado no subgrupo com níveis graves de doença (72,2%) em comparação com os controles (91,6%). O consumo de oxigênio foi diferente entre os grupos com diferentes níveis de gravidade de doença e o controle no pico e nos limiares ventilatórios. Inversamente, os equivalentes ventilatórios, a inclinação da eficiência do consumo de oxigênio, e o pico do pulso de oxigênio foram semelhantes. A análise do subgrupo de 42 sujeitos com TECP prévio revelou uma redução significativa no pico de velocidade da esteira no subgrupo com nível leve de doença, e no consumo de oxigênio no pico e nos limiares ventilatórios nos subgrupos com níveis moderado/grave. Por outro lado, os equivalentes ventilatórios, a inclinação da eficiência do consumo de oxigênio e o pico do pulso de oxigênio não apresentaram alterações significativas. Conclusões A fadiga do músculo periférico foi a etiologia de limitação de exercício mais comum em pacientes pós-COVID-19 independentemente da gravidade da doença. Os dados sugerem que o tratamento deve enfatizar programas de reabilitação abrangentes, incluindo componentes aeróbicos e de fortalecimento muscular.
Abstract Background Post-COVID-19 exercise intolerance is poorly understood. Cardiopulmonary exercise testing (CPET) can identify the underlying exercise limitations. Objectives To evaluate the source and magnitude of exercise intolerance in post-COVID-19 subjects. Methods Cohort study assessing subjects with different COVID-19 illness severities and a control group selected by propensity score matching. In a selected sample with CPET prior to viral infection, before and after comparisons were performed. Level of significance was 5% in the entire analysis. Results One hundred forty-four subjects with COVID-19 were assessed (median age: 43.0 years, 57% male), with different illness severities (60% mild, 21% moderate, 19% severe). CPET was performed 11.5 (7.0, 21.2) weeks after disease onset, with exercise limitations being attributed to the peripheral muscle (92%), and the pulmonary (6%), and cardiovascular (2%) systems. Lower median percent-predicted peak oxygen uptake was observed in the severe subgroup (72.2%) as compared to the controls (91.6%). Oxygen uptake differed among illness severities and controls at peak and ventilatory thresholds. Conversely, ventilatory equivalents, oxygen uptake efficiency slope, and peak oxygen pulse were similar. Subgroup analysis of 42 subjects with prior CPET revealed significant reduction in only peak treadmill speed in the mild subgroup and in oxygen uptake at peak and ventilatory thresholds in the moderate/severe subgroup. By contrast, ventilatory equivalents, oxygen uptake efficiency slope, and peak oxygen pulse did not change significantly. Conclusions Peripheral muscle fatigue was the most common exercise limitation etiology in post-COVID-19 patients regardless of the illness severity. Data suggest that treatment should emphasize comprehensive rehabilitation programs, including aerobic and muscle strengthening components.
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Resumo Fundamento A pandemia da COVID-19 teve um impacto sobre os programas de reabilitação cardiovasculares (RC) no Brasil. Objetivos Descrever características dos programas de RC no Brasil, os impactos da primeira onda epidemiológica da COVID-19 (primeiros 60 dias) sobre os programas, e apresentar as iniciativas usadas para superar esses impactos. Métodos Este estudo transversal e retrospectivo usou um questionário online específico. Os participantes eram coordenadores de programas de RC. As variáveis foram apresentadas por região geográfica do Brasil, como as seguintes categorias: característica demográficas, clínicas e operacionais. O nível de significância estatística foi definido em 5%. Resultados Cinquenta e nove programas de RC atendiam 5349 pacientes, dos quais somente 1817 eram pacientes após eventos cardiovasculares agudos, o que correspondia a 1,99% dos pacientes internados no mês anterior à pesquisa (n=91.231). O maior impacto foi a suspensão das atividades presenciais, o que ocorreu de maneira similar em áreas com as taxas mais altas e áreas com as taxas mais baixas de COVID-19 no período. Quarenta e quatro (75%) programas foram interrompidos de forma breve, e três (5%) foram encerrados. Todos os 42 programas que já utilizavam estratégias de reabilitação remota notaram aumento substancial nas atividades, baseadas principalmente no uso da mídia e chamadas por vídeo. Somente três (5%) consideraram seguro atender pacientes durante os primeiros 60 dias. Conclusões Houve redução no número de programas de RC devido a pandemia da COVID-19. Atividades de telerreabilitação aumentaram durante os primeiros dois meses da pandemia da COVID-19, mas que não foi suficiente para superar a redução nas atividades dos programas de RC no Brasil.
Abstract Background The COVID-19 pandemic had an impact on cardiovascular rehabilitation (CR) programs in Brazil. Objectives To describe the characteristics of CR programs in Brazil, the impacts of the first epidemiological wave of COVID-19 (first 60 days) on the programs and present the initiatives used to overcome the impacts. Method This cross-sectional and retrospective study utilized a specific online survey. Participants were coordinators of CR programs. Variables were presented by Brazilian geographic region and as the following categories: demographic, clinical and operational characteristics. The significance level for statistical analysis was set at 5%. Results Fifty-nine CR programs were responsible for 5,349 patients, of which only 1,817 were post-acute cardiovascular events, which corresponded to 1.99% of hospitalized patients in the month prior to the survey (n=91,231). The greatest impact was the suspension of on-site activities, which occurred similarly in areas with the highest and the lowest rates of COVID-19 in the period. Forty-five programs (75%) were shortly interrupted, while three (5%) were ended. All 42 programs that already used remote rehabilitation strategies noticed a substantial increase in activities, based primarily on the use of media and video calling. Only three (5%) considered safe to see patients during the first 60 days. Conclusions There was a reduction in the number of CR programs with the COVID-19 pandemic. Telerehabilitation activities increased during the first two months of the COVID-19 pandemic, but this was not enough to overcome the reduction in CR program activities across Brazil.
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Background: Persistent symptoms and exercise intolerance have been reported after COVID-19, even months after the acute disease. Although, the long-term impact on exercise capacity and health-related quality of life (HRQoL) is still unclear. Research question: To assess the long-term functional capacity and HRQoL in patients hospitalized due to COVID-19. Study design and methods: This is a prospective cohort study, conducted at two centers in Brazil, that included post-discharge COVID-19 patients and paired controls. The cohort was paired by age, sex, body mass index and comorbidities, using propensity score matching in a 1:3 ratio. Patients were eligible if signs or symptoms suggestive of COVID-19 and pulmonary involvement on chest computed tomography. All patients underwent cardiopulmonary exercise testing (CPET) and a HRQoL questionnaire (SF-36) 6 months after the COVID-19. The main outcome was the percentage of predicted peak oxygen consumption (ppVO2). Secondary outcomes included other CPET measures and HRQoL. Results: The study sample comprised 47 post-discharge COVID-19 patients and 141 healthy controls. The mean age of COVID-19 patients was 54 ± 14 years, with 19 (40%) females, and a mean body mass index of 31 kg/m2 (SD, 6). The median follow-up was 7 months (IQR, 6.5-8.0) after hospital discharge. PpVO2 in COVID-19 patients was lower than in controls (83% vs. 95%, p = 0.002) with an effect size of 0.38 ([95%CI], 0.04-0.70). Mean peak VO2 (22 vs. 25 mL/kg/min, p = 0.04) and OUES (2,122 vs. 2,380, p = 0.027) were also reduced in the COVID-19 patients in comparison to controls. Dysfunctional breathing (DB) was present in 51%. HRQoL was significantly reduced in post COVID patients and positively correlated to peak exercise capacity. Interpretation: Hospitalized COVID-19 patients presented, 7 months after discharge, with a reduction in functional capacity and HRQoL when compared to historical controls. HRQoL were reduced and correlated with the reduced peak VO2 in our population.
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PURPOSE: This study aimed to propose reference standards for cardiorespiratory fitness (CRF) for Brazil from a pooled analysis and to compare peak oxygen uptake (VË o2peak ) in Brazilian, United States (US), and Norwegian samples, exploring possible national and international differences. METHODS: Reference values for treadmill VË o2peak in three different Brazilian regions were assessed from previous publications. We analyzed available samples to assess possible differences, generate weighted average data for Brazil, and compared them with US and Norwegian data. RESULTS: Brazilian reference values had a lower VË o2peak value for the Northeast region and a higher VË o2peak value for the Southeast region for all sex and age groups. International comparisons with the Brazilian pooled data (n = 26661) revealed higher values for the Norwegian sample (n = 3810) and lower values for the US sample (n = 16278). The observed heterogeneity in CRF is possibly related to differences in anthropometric (weight, height) and socioeconomic factors, which differed among the samples. Also, Brazilian data showed a curvilinear VË o2peak age reduction trend rather than the linear characteristic commonly utilized, and the regression curves were different from those for US and Norwegian data. CONCLUSION: This study provides new CRF reference standards for Brazil. After pooling data from three Brazilian regions, a comparison revealed notable differences between regions, evidencing a negative gradient from Southern to Northern regions. Similarly, the international comparisons between Brazil, US, and Norway data revealed CRF heterogeneity, with differences in the VË o2peak values and in the age relationship patterns. These findings reinforce the importance of using national- or regional-specific VË o2peak reference values, ensuring proper CRF evaluation.