Predictors of in-ICU length of stay among congenital heart defect patients using artificial intelligence model: A pilot study.

Objective: This study aims to develop a predictive model using artificial intelligence to estimate the ICU length of stay (LOS) for Congenital Heart Defects (CHD) patients after surgery, improving care planning and resource management. Design: We analyze clinical data from 2240 CHD surgery patients to create and validate the predictive model. Twenty AI models are developed and evaluated for accuracy and reliability. Setting: The study is conducted in a Brazilian hospital's Cardiovascular Surgery Department, focusing on transplants and cardiopulmonary surgeries. Participants: Retrospective analysis is conducted on data from 2240 consecutive CHD patients undergoing surgery. Interventions: Ninety-three pre and intraoperative variables are used as ICU LOS predictors. Measurements and main results: Utilizing regression and clustering methodologies for ICU LOS (ICU Length of Stay) estimation, the Light Gradient Boosting Machine, using regression, achieved a Mean Squared Error (MSE) of 15.4, 11.8, and 15.2 days for training, testing, and unseen data. Key predictors included metrics such as "Mechanical Ventilation Duration", "Weight on Surgery Date", and "Vasoactive-Inotropic Score". Meanwhile, the clustering model, Cat Boost Classifier, attained an accuracy of 0.6917 and AUC of 0.8559 with similar key predictors. Conclusions: Patients with higher ventilation times, vasoactive-inotropic scores, anoxia time, cardiopulmonary bypass time, and lower weight, height, BMI, age, hematocrit, and presurgical oxygen saturation have longer ICU stays, aligning with existing literature.

Functional lymphatic reserve capacity is depressed in patients with a Fontan circulation.

BACKGROUND: Lymphatic abnormalities play a role in effusions in individuals with a Fontan circulation. Recent results using near-infrared fluorescence imaging disclosed an increased contraction frequency of lymphatic vessels in Fontan patients compared to healthy controls. It is proposed that the elevated lymphatic pumping seen in the Fontan patients is necessary to maintain habitual interstitial fluid balance. Hyperthermia has previously been used as a tool for lymphatic stress test. By increasing fluid filtration in the capillary bed, the lymphatic workload and contraction frequency are increased accordingly. Using near-infrared fluorescence imaging, the lymphatic functional reserve capacity in Fontan patients were explored with a lymphatic stress test. METHODS: Fontan patients (n = 33) were compared to a group of 15 healthy individuals of equal age, weight, and gender. The function of the superficial lymphatic vessels in the lower leg during rest and after inducing hyperthermia was investigated, using near-infrared fluorescence imaging. RESULTS: Baseline values in the Fontan patients showed a 57% higher contraction frequency compared to the healthy controls (0.4 ± 0.3 min-1 vs. 0.3 ± 0.2 min-1 , p = 0.0445). After inducing stress on the lymphatic vessels with hyperthermia the ability to increase contraction frequency was decreased in the Fontan patients compared to the controls (0.6 ± 0.5 min-1 vs. 1.2 ± 0.8 min-1 , p = 0.0102). CONCLUSIONS: Fontan patients had a higher lymphatic contraction frequency during normal circumstances. In the Fontan patients, the hyperthermia response is dampened indicating that the functional lymphatic reserve capacity is depressed. This diminished reserve capacity could be part of the explanation as to why some Fontan patients develop late-onset lymphatic complications.

Aerobic exercise and inspiratory muscle training increase functional capacity in patients with univentricular physiology after Fontan operation: A randomized controlled trial.

BACKGROUND: The effect of exercise training and its mechanisms on the functional capacity improvement in Fontan patients (FP) are virtually unknown. This trial evaluated four-month aerobic exercise training and inspiratory muscle training on functional capacity, pulmonary function, and autonomic control in patients after Fontan operation. METHODS: A randomized controlled clinical trial with 42 FP aged 12 to 30 years and, at least, five years of Fontan completion. Twenty-seven were referred to a four-months supervised and personalized aerobic exercise training (AET) or an inspiratory muscle training (IMT). A group of non-exercise (NET) was used as control. The effects of the exercise training in peak VO2; pulmonary volumes and capacities, maximal inspiratory pressure (MIP); muscle sympathetic nerve activity (MSNA); forearm blood flow (FBF); handgrip strength and cross-sectional area of the thigh were analyzed. RESULTS: The AET decreased MSNA (p = 0.042), increased FBF (p = 0.012) and handgrip strength (p = 0.017). No significant changes in autonomic control were found in IMT and NET groups. Both AET and IMT increased peak VO2, but the increase was higher in the AET group compared to IMT (23% vs. 9%). No difference was found in the NET group. IMT group showed a 58% increase in MIP (p = 0.008) in forced vital capacity (p = 0.011) and forced expiratory volume in the first second (p = 0.011). No difference in pulmonary function was found in the AET group. CONCLUSIONS: Both aerobic exercise and inspiratory muscle training improved functional capacity. The AET group developed autonomic control, and handgrip strength, and the IMT increased inspiratory muscle strength and spirometry. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02283255.

Improving preoperative risk-of-death prediction in surgery congenital heart defects using artificial intelligence model: A pilot study.

BACKGROUND: Congenital heart disease accounts for almost a third of all major congenital anomalies. Congenital heart defects have a significant impact on morbidity, mortality and health costs for children and adults. Research regarding the risk of pre-surgical mortality is scarce. OBJECTIVES: Our goal is to generate a predictive model calculator adapted to the regional reality focused on individual mortality prediction among patients with congenital heart disease undergoing cardiac surgery. METHODS: Two thousand two hundred forty CHD consecutive patients' data from InCor's heart surgery program was used to develop and validate the preoperative risk-of-death prediction model of congenital patients undergoing heart surgery. There were six artificial intelligence models most cited in medical references used in this study: Multilayer Perceptron (MLP), Random Forest (RF), Extra Trees (ET), Stochastic Gradient Boosting (SGB), Ada Boost Classification (ABC) and Bag Decision Trees (BDT). RESULTS: The top performing areas under the curve were achieved using Random Forest (0.902). Most influential predictors included previous admission to ICU, diagnostic group, patient's height, hypoplastic left heart syndrome, body mass, arterial oxygen saturation, and pulmonary atresia. These combined predictor variables represent 67.8% of importance for the risk of mortality in the Random Forest algorithm. CONCLUSIONS: The representativeness of "hospital death" is greater in patients up to 66 cm in height and body mass index below 13.0 for InCor's patients. The proportion of "hospital death" declines with the increased arterial oxygen saturation index. Patients with prior hospitalization before surgery had higher "hospital death" rates than who did not required such intervention. The diagnoses groups having the higher fatal outcomes probability are aligned with the international literature. A web application is presented where researchers and providers can calculate predicted mortality based on the CgntSCORE on any web browser or smartphone.

Early and long-term outcomes of surgical treatment of ebstein's anomaly

Abstract Objective: This study aimed to evaluate Ebstein's anomaly surgical correction and its early and long-term outcomes. Methods: A retrospective analysis of 62 consecutive patients who underwent surgical repair of Ebstein's anomaly in our institution from January 2000 to July 2016. The following long-term outcomes were evaluated: survival, reoperations, tricuspid regurgitation, and postoperative right ventricular dysfunction. Results: Valve repair was performed in 46 (74.2%) patients - 12 of them using the Da Silva cone reconstruction; tricuspid valve replacement was performed in 11 (17.7%) patients; univentricular palliation in one (1.6%) patient; and the one and a half ventricle repair in four (6.5%) patients. The patients' mean age at the time of surgery was 20.5±14.9 years, and 46.8% of them were male. The mean follow-up time was 8.8±6 years. The 30-day mortality rate was 8.06% and the one and 10-year survival rates were 91.9% both. Eleven (17.7%) of the 62 patients required late reoperation due to tricuspid regurgitation, in an average time of 7.1±4.9 years after the first procedure. Conclusion: In our experience, the long-term results of the surgical treatment of Ebstein's anomaly demonstrate an acceptable survival rate and a low incidence of reinterventions.

Early and Long-Term Outcomes of Surgical Treatment of Ebstein's Anomaly.

OBJECTIVE: This study aimed to evaluate Ebstein's anomaly surgical correction and its early and long-term outcomes. METHODS: A retrospective analysis of 62 consecutive patients who underwent surgical repair of Ebstein's anomaly in our institution from January 2000 to July 2016. The following long-term outcomes were evaluated: survival, reoperations, tricuspid regurgitation, and postoperative right ventricular dysfunction. RESULTS: Valve repair was performed in 46 (74.2%) patients - 12 of them using the Da Silva cone reconstruction; tricuspid valve replacement was performed in 11 (17.7%) patients; univentricular palliation in one (1.6%) patient; and the one and a half ventricle repair in four (6.5%) patients. The patients' mean age at the time of surgery was 20.5±14.9 years, and 46.8% of them were male. The mean follow-up time was 8.8±6 years. The 30-day mortality rate was 8.06% and the one and 10-year survival rates were 91.9% both. Eleven (17.7%) of the 62 patients required late reoperation due to tricuspid regurgitation, in an average time of 7.1±4.9 years after the first procedure. CONCLUSION: In our experience, the long-term results of the surgical treatment of Ebstein's anomaly demonstrate an acceptable survival rate and a low incidence of reinterventions.

Outcomes of the Conversion of the Fontan-Kreutzer Operation to a Total Cavopulmonary Connection for the Failing Univentricular Circulation.

BACKGROUND: The Fontan-Kreutzer procedure (FK) was widely performed in the past, but in the long-term generated many complications resulting in univentricular circulation failure. The conversion to total cavopulmonary connection (TCPC) is one of the options for treatment. OBJECTIVE: To evaluate the results of conversion from FK to TCPC. METHODS: A retrospective review of medical records for patients who underwent the conversion of FK to TCPC in the period of 1985 to 2016. Significance p < 0,05. RESULTS: Fontan-type operations were performed in 420 patients during this period: TCPC was performed in 320, lateral tunnel technique in 82, and FK in 18. Ten cases from the FK group were elected to conversion to TCPC. All patients submitted to Fontan Conversion were included in this study. In nine patients the indication was due to uncontrolled arrhythmia and in one, due to protein-losing enteropathy. Death was observed in the first two cases. The average intensive care unit (ICU) length of stay (LOS) was 13 days, and the average hospital LOS was 37 days. A functional class by New York Heart Association (NYHA) improvement was observed in 80% of the patients in NYHA I or II. Fifty-seven percent of conversions due to arrhythmias had improvement of arrhythmias; four cases are cured. CONCLUSIONS: The conversion is a complex procedure and requires an experienced tertiary hospital to be performed. The conversion has improved the NYHA functional class despite an unsatisfactory resolution of the arrhythmia.

Outcomes of the Conversion of the Fontan-Kreutzer Operation to a Total Cavopulmonary Connection for the Failing Univentricular Circulation / Resultados da Conversão da Cirurgia de Fontan-Kreutzer para Cavo-Pulmonar Total Devido Falência da Circulação Univentricular

Abstract Background: The Fontan-Kreutzer procedure (FK) was widely performed in the past, but in the long-term generated many complications resulting in univentricular circulation failure. The conversion to total cavopulmonary connection (TCPC) is one of the options for treatment. Objective: To evaluate the results of conversion from FK to TCPC. Methods: A retrospective review of medical records for patients who underwent the conversion of FK to TCPC in the period of 1985 to 2016. Significance p < 0,05. Results: Fontan-type operations were performed in 420 patients during this period: TCPC was performed in 320, lateral tunnel technique in 82, and FK in 18. Ten cases from the FK group were elected to conversion to TCPC. All patients submitted to Fontan Conversion were included in this study. In nine patients the indication was due to uncontrolled arrhythmia and in one, due to protein-losing enteropathy. Death was observed in the first two cases. The average intensive care unit (ICU) length of stay (LOS) was 13 days, and the average hospital LOS was 37 days. A functional class by New York Heart Association (NYHA) improvement was observed in 80% of the patients in NYHA I or II. Fifty-seven percent of conversions due to arrhythmias had improvement of arrhythmias; four cases are cured. Conclusions: The conversion is a complex procedure and requires an experienced tertiary hospital to be performed. The conversion has improved the NYHA functional class despite an unsatisfactory resolution of the arrhythmia.

Resumo Fundamento: O procedimento de Fontan-Kreutzer (FK) foi amplamente realizado no passado, mas a longo prazo gerou muitas complicações, resultando em falha na circulação univentricular. A conversão para conexão cavopulmonar total (CCPT) é uma das opções de tratamento. Objetivo: Avaliar os resultados da conversão de FK para CCPT. Métodos: Revisão retrospectiva de prontuários de pacientes submetidos à conversão de FK para CCPT no período de 1985 a 2016. Significância p < 0,05. Resultados: Operações do tipo Fontan foram realizadas em 420 pacientes durante este período: CCPT foi realizada em 320, técnica de túnel lateral em 82 e FK em 18. Dez casos do grupo FK foram eleitos para conversão em CCPT. Todos os pacientes submetidos à conversão de Fontan foram incluídos neste estudo. Em nove pacientes, a indicação deveu-se a arritmia não controlada e em um devido à enteropatia perdedora de proteínas. A morte foi observada nos dois primeiros casos. O tempo médio de internação na unidade de terapia intensiva (UTI) foi de 13 dias e o tempo médio de internação hospitalar foi de 37 dias. Uma classe funcional pela melhora da New York Heart Association (NYHA) foi observada em 80% dos pacientes em NYHA I ou II. Cinquenta e sete por cento das conversões devido a arritmias tiveram melhora das arritmias; quatro casos foram curados. Conclusões: A conversão é um procedimento complexo e requer que um hospital terciário experiente seja realizado. A conversão melhorou a classe funcional da NYHA, apesar de uma resolução insatisfatória da arritmia.

Blunted peripheral blood supply and underdeveloped skeletal muscle in Fontan patients: The impact on functional capacity.

BACKGROUND: Changes in circulatory physiology are common in Fontan patients due to suboptimal cardiac output, which may reduce the peripheral blood flow and impair the skeletal muscle. The objective of this study was to investigate the forearm blood flow (FBF), cross-sectional area (CSA) of the thigh and functional capacity in asymptomatic clinically stable patients undergoing Fontan surgery. METHODS: Thirty Fontan patients and 27 healthy subjects underwent venous occlusion plethysmography, magnetic resonance imaging of the thigh musculature and maximal cardiopulmonary exercise testing. Muscle sympathetic nerve activity (MSNA), norepinephrine measures, cardiovascular magnetic resonance, handgrip strength and 6-minute walk test were also performed. RESULTS: Fontan patients have blunted FBF (1.59 ±â€¯0.33 vs 2.17 ±â€¯0.52 mL/min/100 mL p < 0.001) and forearm vascular conductance (FVC) (1.69 ±â€¯0.04 vs 2.34 ±â€¯0.62 units p < 0.001), reduced CSA of the thigh (81.2 ±â€¯18.6 vs 116.3 ±â€¯26.4 cm2p < 0.001), lower peak VO2 (29.3 ±â€¯6 vs 41.5 ±â€¯9 mL/kg/min p < 0.001), walked distance (607 ±â€¯60 vs 701 ±â€¯58 m p < 0.001) and handgrip strength (21 ±â€¯9 vs 30 ±â€¯8 kgf p < 0.001). The MSNA (30 ±â€¯4 vs 22 ±â€¯3 bursts/min p < 0.001) and norepinephrine concentration [265 (236-344) vs 222 (147-262) pg/mL p = 0.006] were also higher in Fontan patients. Multivariate linear regression showed FVC (ß = 0.653; CI = 0.102-1.205; p = 0.022) and stroke volume (ß = 0.018; CI = 0.007-0.029; p = 0.002) to be independently associated with reduced CSA of the thigh adjusted for body mass index. The CSA of the thigh adjusted for body mass index (ß = 5.283; CI = 2.254-8.312; p = 0.001) was independently associated with reduced peak VO2. CONCLUSION: Patients with Fontan operation have underdeveloped skeletal muscle with reduced strength that is associated with suboptimal peripheral blood supply and diminished exercise capacity.

Risk factors for prolonged hospital stay after isolated coronary artery bypass grafting.

INTRODUCTION: Characteristics of the patient and the coronary artery bypass grafting may predispose individuals to prolonged hospitalization, increasing costs and morbidity and mortality. OBJECTIVE: The objective of this study was to evaluate individual and perioperative risk factors of prolonged hospitalization in intensive care units and wards. METHODS: We conducted a case-control study of 104 patients undergoing isolated coronary artery bypass grafting with cardiopulmonary bypass. Patients hospitalized >3 days in the intensive care unit or >7 days in the ward were considered for the study. The association between variables was estimated by the chi-square test, odds ratio and logistic regression; P <0.05 was considered statistically significant. RESULTS: Hospital stay >3 days in the intensive care unit occurred for 22.1% of patients and >7 days in the ward for 27.9%. Among preoperative factors, diabetes (OR=3.17) and smoking (OR=4.07) were predictors of prolonged intensive care unit stay. Combining the pre-, intra-and postoperative variables, only mechanical ventilation for more than 24 hours (OR=6.10) was predictive of intensive care unit outcome. For the ward outcome, the preoperative predictor was left ventricular ejection fraction <50% (OR=3.04). Combining pre- and intraoperative factors, diabetes (OR=2.81), and including postoperative factors, presence of infection (OR=4.54) were predictors of prolonged hospitalization in the ward. CONCLUSION: Diabetes and smoking were predictors of intensive care unit outcome, and ejection fraction <50% of ward outcome. For the set of perioperative factors, prolonged hospitalization after isolated coronary artery bypass grafting was associated with mechanical ventilation >24 hours for the intensive care unit and presence of infection for the ward.

Risk factors for prolonged hospital stay after isolated coronary artery bypass grafting / Fatores de risco para tempo de internação prolongada após revascularização isolada do miocárdio

INTRODUCTION: Characteristics of the patient and the coronary artery bypass grafting may predispose individuals to prolonged hospitalization, increasing costs and morbidity and mortality. OBJECTIVE: The objective of this study was to evaluate individual and perioperative risk factors of prolonged hospitalization in intensive care units and wards. METHODS: We conducted a case-control study of 104 patients undergoing isolated coronary artery bypass grafting with cardiopulmonary bypass. Patients hospitalized >3 days in the intensive care unit or >7 days in the ward were considered for the study. The association between variables was estimated by the chi-square test, odds ratio and logistic regression; P <0.05 was considered statistically significant. RESULTS: Hospital stay >3 days in the intensive care unit occurred for 22.1% of patients and >7 days in the ward for 27.9%. Among preoperative factors, diabetes (OR=3.17) and smoking (OR=4.07) were predictors of prolonged intensive care unit stay. Combining the pre-, intra-and postoperative variables, only mechanical ventilation for more than 24 hours (OR=6.10) was predictive of intensive care unit outcome. For the ward outcome, the preoperative predictor was left ventricular ejection fraction <50% (OR=3.04). Combining pre- and intraoperative factors, diabetes (OR=2.81), and including postoperative factors, presence of infection (OR=4.54) were predictors of prolonged hospitalization in the ward. CONCLUSION: Diabetes and smoking were predictors of intensive care unit outcome, and ejection fraction <50% of ward outcome. For the set of perioperative factors, prolonged hospitalization after isolated coronary artery bypass grafting was associated with mechanical ventilation >24 hours for the intensive care unit and presence of infection for the ward.

INTRODUÇÃO: Características do paciente e da cirurgia de revascularização do miocárdio podem predispor à internação prolongada, aumentando custos e a morbimortalidade. OBJETIVO: Avaliar fatores de risco individuais e transoperatórios para internação prolongada na unidade de terapia intensiva e na enfermaria. MÉTODOS: Realizou-se estudo de caso-controle com 104 pacientes submetidos à revascularização do miocárdio isolada sob circulação extracorpórea. Consideraram-se casos os pacientes com internação >3 para terapia intensiva ou >7 dias para enfermaria. A associação entre variáveis foi estimada pelo teste do qui-quadrado e pela razão de chances (odds ratio-OR) empregando-se a regressão logística, ao nível de P<0,05. RESULTADOS: A permanência >3 dias na terapia intensiva ocorreu em 22,1% dos pacientes e >7 dias na enfermaria em 27,9%. Entre os fatores pré-operatórios, o diabetes (OR=3,17) e o tabagismo (OR=4,07) foram os preditores para permanência prolongada na terapia intensiva. Combinando-se as variáveis pré-, intra- e pós-operatórias, somente a ventilação mecânica por mais que 24 horas (OR=6,10) foi preditora para o desfecho na terapia intensiva. Para o desfecho na enfermaria, o preditor pré-operatório foi a fração de ejeção ventricular esquerda <50% (OR=3,04). Combinando os fatores pré- e intraoperatórios, o diabetes (OR=2,81) e, somando-se os pós-operatórios, a presença de infecção (OR=4,54), foram os preditores para internação prolongada na enfermaria. CONCLUSÃO: Diabetes e tabagismo foram os preditores para o desfecho na terapia intensiva, e a fração de ejeção <50% para a enfermaria. Para o conjunto dos fatores transoperatórios, internação prolongada após revascularização do miocárdio isolada associou-se à ventilação mecânica >24 horas para terapia intensiva e à presença de infecção para a enfermaria.

Relação do teste de caminhada pós-operatório e função pulmonar com o tempo de internação da cirurgia cardíaca / Relationship on walk test and pulmonary function tests with the length of hospitalization in cardiac surgery patients

Objetivo: A função pulmonar é apontada como preditora do tempo de hospitalização na cirurgia cardíaca. E o teste de caminhada de seis minutos (TC6') tem sido utilizado para caracterizar a capacidade funcional em pacientes cardiopatas, porém há poucos estudos que o correlacione com tempo de internação hospitalar. O objetivo desta pesquisa foi verificar se há correlação da função pulmonar pré e pós-operatória e da capacidade da deambulação pósoperatória com tempo de internação pós-operatória. Métodos: Foi realizada uma coorte prospectiva com 18 pacientes, sendo 8 do gênero masculino e 10 do gênero feminino, com idade acima de 40 anos (média 64,89 ± 6,95 anos), internados para a submissão de cirurgias de revascularização do miocárdio e/ou troca valvar. Para caracterizar a função pulmonar, os pacientes foram submetidos a uma espirometria no pré-operatório e ao 5º dia pós-operatório. Neste último período também foi realizado um teste de caminhada de 6 minutos (TC6') para caracterizar a capacidade de deambulação. RESULTADO: Não houve correlação significativa da função pulmonar pré e pós-operatória com o tempo de internação pós-operatória. Somente a distância percorrida no TC6' apresentou correlação negativa significativa (rho=-0,62) com o tempo de internação pós-operatória. A distância no TC6' obteve correlação positiva significativa com a capacidade vital forçada (r=0,59) e volume expiratório forçado no 1º segundo (r=0,52). Conclusão: Esses resultados sugerem que os pacientes com maior capacidade de deambulação no pós-operatório apresentam menor tempo de internação e sugere-se também que a distância no TC6' pode representar melhor a capacidade funcional desses pacientes do que a função pulmonar isoladamente.

Objective: The lung function is identified as a predictor of time of hospitalization in heart surgery. Meanwhile sixminute walk test has been used to establish functional capacity of cardiac patients, however there are few studies that correlate it with the length of hospital stay. The aim of this research was to determine whether there is correlation of preoperative and postoperative lung function and the ability of walking during the hospital stay. Methods: A prospective cohort with 18 patients was performed, being 8 males and 10 females, with age above 40 years (medium 64.89 ± 6.95 years). Patients where admitted for coronary artery bypass graft surgery and/or exchange valve. To characterize the pulmonary function, patients were submitted to spirometry in preoperative and the 5th postoperative day. In the latter period was also a test for 6 minutes walk (6MWT) to characterize the ability to walk. RESULTS: There was not significant correlation of preoperative and postoperative pulmonary function with length of hospital stay. Only the distance covered in 6MWT showed a significant negative correlation (rho= 0.62) with length of stay. The distance in 6MWT obtained a significant positive correlation with forced vital capacity (r=0.59) and first second of a maximal forced expiratory manoeuvre (r=0.52). Conclusion: These results suggest that patients with increased postoperative capacity to walk have a shorter time of hospitalization and it also suggest that the distance in the 6MWT can better represent the functional capacity of these patients than pulmonary function alone.

Relationship on walk test and pulmonary function tests with the length of hospitalization in cardiac surgery patients.

OBJECTIVE: The lung function is identified as a predictor of time of hospitalization in heart surgery. Meanwhile sixminute walk test has been used to establish functional capacity of cardiac patients, however there are few studies that correlate it with the length of hospital stay. The aim of this research was to determine whether there is correlation of preoperative and postoperative lung function and the ability of walking during the hospital stay. METHODS: A prospective cohort with 18 patients was performed, being 8 males and 10 females, with age above 40 years (medium 64.89 +/- 6.95 years). Patients where admitted for coronary artery bypass graft surgery and/or exchange valve. To characterize the pulmonary function, patients were submitted to spirometry in preoperative and the 5th postoperative day. In the latter period was also a test for 6 minutes walk (6MWT) to characterize the ability to walk. RESULTS: There was not significant correlation of preoperative and postoperative pulmonary function with length of hospital stay. Only the distance covered in 6MWT showed a significant negative correlation (rho= 0.62) with length of stay. The distance in 6MWT obtained a significant positive correlation with forced vital capacity (r=0.59) and first second of a maximal forced expiratory manoeuvre (r=0.52). CONCLUSION: These results suggest that patients with increased postoperative capacity to walk have a shorter time of hospitalization and it also suggest that the distance in the 6MWT can better represent the functional capacity of these patients than pulmonary function alone.