Central venous-to-arterial CO2 difference as a biomarker of outcome in children who underwent surgery for congenital heart disease.

BACKGROUND: In congenital heart surgery, low cardiac output syndrome (LCOS) is a major cause of morbidity in the immediate post-operative period. A decrease in cardiac output leads to an increase in tissue oxygen consumption. Several biomarkers such as venous oxygen saturation (SvO2), arteriovenous oxygen difference (DavO2), and lactate can assess tissue perfusion in the presence of LCOS. Recently, central venous to arterial CO2 difference (ΔCO2) has been proposed as a biomarker of tissue ischemia that could be used as a predictor of death in neonatal patients. This study aimed to analyze the relationship between ΔCO2 and immediate post-operative outcomes in pediatric patients undergoing congenital heart surgery and its correlation with DavO2, SvO2, and lactate. METHODS: We conducted a longitudinal study of patients aged 0-18 years who underwent congenital heart surgery with or without cardiopulmonary bypass at the Instituto Nacional de Pediatría, from March 2019 to March 2021. RESULTS: Eighty-two patients were included; the median age was 17 months. About 59% had a ΔCO2 ≥ 6 mmHg. Patients with ΔCO2 ≥ 6 mmHg had a vasoactive-inotropic score > 5 (p < 0.001), DavO2 > 5 mL/dL (p = 0.048), and lactate > 2 mmol/L (p = 0.027), as well as a longer hospital stay (p = 0.043). Patients with ΔCO2 > 6 mmHg and vasoactive-inotropic score ≥ 10 were 12.6 times more likely to die. CONCLUSION: ΔCO2 is a good marker of tissue hypoperfusion and outcome in the post-operative period of congenital heart surgery.

INTRODUCCIÓN: En la cirugía cardiaca de malformaciones congénitas, el síndrome de bajo gasto cardiaco (SBGC) es una de las principales causas de morbilidad en el postoperatorio inmediato. La caída del gasto cardiaco aumenta el consumo de oxígeno en los tejidos. Varios biomarcadores, como la saturación venosa de oxígeno (SvO2), la diferencia arteriovenosa de oxígeno (DavO2) y el lactato han sido utilizados como indicadores hipoperfusión tisular en presencia de SBGC. Recientemente, la diferencia arteriovenosa de CO2 (ΔCO2) se ha propuesto como otro biomarcador de isquemia tisular que podría utilizarse como predictor de muerte en pacientes en edad neonatal. El objetivo de este estudio fue analizar la relación entre la ΔCO2 y la evolución postoperatoria de pacientes pediátricos operados de cardiopatías congénitas y correlacionarlo con la DavO2, SvO2 y lactato. MÉTODOS: Se realizó un estudio longitudinal en pacientes de 0 a 18 años operados de corazón con empleo de bomba de circulación extracorpórea en el Instituto Nacional de Pediatría. RESULTADOS: Se incluyeron 82 pacientes; la mediana de edad fue de 17 meses. El 59% presentó un ΔCO2 > 6 mmHg. Los pacientes con un ΔCO2 > 6 mmHg mostraron un puntaje de inotrópicos > 5 (p < 0.001), DavO2 > 5 mL/dL (p = 0.048) y lactato > 2 mmol/L (p = 0.027), así como mayor estancia hospitalaria (p = 0.043). Los pacientes con ΔCO2 > 6 mmHg y un puntaje de inotrópicos ≥ 10 presentaron una probabilidad de muerte 12.6 veces mayor. CONCLUSIONES: El ΔCO2 en el periodo postoperatorio de una cirugía cardiaca congénita es un buen marcador de hipoperfusión tisular y de desenlace.

Central venous-to-arterial CO2 difference as a biomarker of outcome in children who underwent surgery for congenital heart disease / Diferencia arteriovenosa de CO2 como biomarcador de desenlace en niños operados de cardiopatías congénitas

Abstract Background: In congenital heart surgery, low cardiac output syndrome (LCOS) is a major cause of morbidity in the immediate post-operative period. A decrease in cardiac output leads to an increase in tissue oxygen consumption. Several biomarkers such as venous oxygen saturation (SvO2), arteriovenous oxygen difference (DavO2), and lactate can assess tissue perfusion in the presence of LCOS. Recently, central venous to arterial CO2 difference (ΔCO2) has been proposed as a biomarker of tissue ischemia that could be used as a predictor of death in neonatal patients. This study aimed to analyze the relationship between ΔCO2 and immediate post-operative outcomes in pediatric patients undergoing congenital heart surgery and its correlation with DavO2, SvO2, and lactate. Methods: We conducted a longitudinal study of patients aged 0-18 years who underwent congenital heart surgery with or without cardiopulmonary bypass at the Instituto Nacional de Pediatría, from March 2019 to March 2021. Results: Eighty-two patients were included; the median age was 17 months. About 59% had a ΔCO2 ≥ 6 mmHg. Patients with ΔCO2 ≥ 6 mmHg had a vasoactive-inotropic score > 5 (p < 0.001), DavO2 > 5 mL/dL (p = 0.048), and lactate > 2 mmol/L (p = 0.027), as well as a longer hospital stay (p = 0.043). Patients with ΔCO2 > 6 mmHg and vasoactive-inotropic score ≥ 10 were 12.6 times more likely to die. Conclusion: ΔCO2 is a good marker of tissue hypoperfusion and outcome in the post-operative period of congenital heart surgery.

Resumen Introducción: En la cirugía cardiaca de malformaciones congénitas, el síndrome de bajo gasto cardiaco (SBGC) es una de las principales causas de morbilidad en el postoperatorio inmediato. La caída del gasto cardiaco aumenta el consumo de oxígeno en los tejidos. Varios biomarcadores, como la saturación venosa de oxígeno (SvO2), la diferencia arteriovenosa de oxígeno (DavO2) y el lactato han sido utilizados como indicadores hipoperfusión tisular en presencia de SBGC. Recientemente, la diferencia arteriovenosa de CO2 (ΔCO2) se ha propuesto como otro biomarcador de isquemia tisular que podría utilizarse como predictor de muerte en pacientes en edad neonatal. El objetivo de este estudio fue analizar la relación entre la ΔCO2 y la evolución postoperatoria de pacientes pediátricos operados de cardiopatías congénitas y correlacionarlo con la DavO2, SvO2 y lactato. Métodos: Se realizó un estudio longitudinal en pacientes de 0 a 18 años operados de corazón con empleo de bomba de circulación extracorpórea en el Instituto Nacional de Pediatría. Resultados: Se incluyeron 82 pacientes; la mediana de edad fue de 17 meses. El 59% presentó un ΔCO2 > 6 mmHg. Los pacientes con un ΔCO2 > 6 mmHg mostraron un puntaje de inotrópicos > 5 (p < 0.001), DavO2 > 5 mL/dL (p = 0.048) y lactato > 2 mmol/L (p = 0.027), así como mayor estancia hospitalaria (p = 0.043). Los pacientes con ΔCO2 > 6 mmHg y un puntaje de inotrópicos ≥ 10 presentaron una probabilidad de muerte 12.6 veces mayor. Conclusiones: El ΔCO2 en el periodo postoperatorio de una cirugía cardiaca congénita es un buen marcador de hipoperfusión tisular y de desenlace.

Body mass index is associated with low postoperative cardiac output in patients undergoing aortic valve replacement.

Background: Overweight and obesity (O/O) generate lipotoxicity of the cardiac fiber and increase the incidence and progression of aortic valve stenosis. The low cardiac output syndrome (LCOS) is a timing complication after to aortic valve replacement (AVR) surgery. Objective: The objective of the study was to investigate if body mass index (BMI) kg/m2 is a risk factor associated with LCOS and mortality in the post-operative period of AVR. Methods: A historic cohort study was designed, including patients with severe aortic stenosis (SAS), who were subjected to AVR. Results: 152 patients were included, 45 (29.6%), with normal weight (NW), 60 were overweight (39.5%), and 47 obese (30.9%). The prevalence of systemic hypertension (HT) was higher in O/O (p < 0.0001). Incidence of LCOS was 44.7%, being more frequent in the O/O groups compared to the NW group, 43.3%, 68.1%, and 22.2%, respectively, (p < 0.05 in overweight and p < 0.0001 in the obese). Assessing the presence or absence of LCOS associated with BMI as a numerical variable, we found that women, HT, BMI, left ventricular mass, and valve size, were associated with LCOS (p < 0.02, p < 0.02, p < 0.001, p < 0.032, and p < 0.045, respectively). Mortality was higher in patients who had LCOS (p < 0.02). Multivariate model showed that BMI was an independent risk factor for LCOS (odds ratio [OR] 1.21 [95% CI 1.08-1.35], p < 0.001). Conclusion: BMI is a risk factor associated to LCOS in the post-operative period of AVR in patients with SAS.

Antecedentes: El sobrepeso y la obesidad (O/O) generan lipotoxicidad de la fibra cardíaca y aumentan la incidencia y progresión de la estenosis de la válvula aórtica. El síndrome de bajo gasto cardíaco (SBGC) es una complicación postquirúrgica de la cirugía de reemplazo de válvula aórtica (RVA). Objetivo: Investigar si el índice de masa corporal kg/m2 (IMC) es un factor de riesgo asociado con SBGC y mortalidad en el postoperatorio de RVA. Métodos: Se diseñó un estudio de cohorte histórico, que incluyó pacientes con estenosis aórtica importante (EAI), que fueron sometidos a RVA. Resultados: Se incluyeron 152 pacientes, 45 (29.6%), con peso normal (N), 60 tenían sobrepeso (39.5%) y 47 obesos (30.9%). La prevalencia de hipertensión sistémica (HT) fue mayor en O/O (p < 0.0001). La incidencia de SBGC fue del 44.7%, siendo más frecuente en los grupos O/O en comparación con el grupo N, 43.3%, 68.1%, 22.2% respectivamente, (p < 0.05 en sobrepeso y p < 0.0001 en obesos). Al evaluar la presencia o ausencia de SBGC asociado con el IMC como una variable numérica, encontramos que las mujeres, HT, IMC, masa ventricular izquierda y tamaño de la válvula, se asociaron con SBGC (p < 0.02, p < 0.02, p < 0.001, p < 0.032, p < 0.045, respectivamente). La mortalidad fue mayor en pacientes con SBGC (p < 0.02). El modelo multivariado mostró que el IMC fue un factor de riesgo independiente asociado a SBGC [OR 1.21 (IC 95% 1.08-1.35), p < 0.001]. Conclusión: El IMC es un factor de riesgo asociado a SBGC en el postoperatorio de RVA en pacientes con EAI.

Body mass index is associated with low postoperative cardiac output in patients undergoing aortic valve replacement / El índice de masa corporal se asocia a bajo gasto cardiaco postoperatorio de pacientes sometidos a reemplazo valvular aórtico

Abstract Background: Overweight and obesity (O/O) generate lipotoxicity of the cardiac fiber and increase the incidence and progression of aortic valve stenosis. The low cardiac output syndrome (LCOS) is a timing complication after to aortic valve replacement (AVR) surgery. Objective: The objective of the study was to investigate if body mass index (BMI) kg/m2 is a risk factor associated with LCOS and mortality in the post-operative period of AVR. Methods: A historic cohort study was designed, including patients with severe aortic stenosis (SAS), who were subjected to AVR. Results: 152 patients were included, 45 (29.6%), with normal weight (NW), 60 were overweight (39.5%), and 47 obese (30.9%). The prevalence of systemic hypertension (HT) was higher in O/O (p < 0.0001). Incidence of LCOS was 44.7%, being more frequent in the O/O groups compared to the NW group, 43.3%, 68.1%, and 22.2%, respectively, (p < 0.05 in overweight and p < 0.0001 in the obese). Assessing the presence or absence of LCOS associated with BMI as a numerical variable, we found that women, HT, BMI, left ventricular mass, and valve size, were associated with LCOS (p < 0.02, p < 0.02, p < 0.001, p < 0.032, and p < 0.045, respectively). Mortality was higher in patients who had LCOS (p < 0.02). Multivariate model showed that BMI was an independent risk factor for LCOS (odds ratio [OR] 1.21 [95% CI 1.08-1.35], p < 0.001). Conclusion: BMI is a risk factor associated to LCOS in the post-operative period of AVR in patients with SAS.

Resumen Antecedentes: El sobrepeso y la obesidad (O/O) generan lipotoxicidad de la fibra cardíaca y aumentan la incidencia y progresión de la estenosis de la válvula aórtica. El síndrome de bajo gasto cardíaco (SBGC) es una complicación postquirúrgica de la cirugía de reemplazo de válvula aórtica (RVA). Objetivo: Investigar si el índice de masa corporal kg/m2 (IMC) es un factor de riesgo asociado con SBGC y mortalidad en el postoperatorio de RVA. Métodos: Se diseñó un estudio de cohorte histórico, que incluyó pacientes con estenosis aórtica importante (EAI), que fueron sometidos a RVA. Resultados: Se incluyeron 152 pacientes, 45 (29.6%), con peso normal (N), 60 tenían sobrepeso (39.5%) y 47 obesos (30.9%). La prevalencia de hipertensión sistémica (HT) fue mayor en O/O (p < 0.0001). La incidencia de SBGC fue del 44.7%, siendo más frecuente en los grupos O/O en comparación con el grupo N, 43.3%, 68.1%, 22.2% respectivamente, (p < 0.05 en sobrepeso y p < 0.0001 en obesos). Al evaluar la presencia o ausencia de SBGC asociado con el IMC como una variable numérica, encontramos que las mujeres, HT, IMC, masa ventricular izquierda y tamaño de la válvula, se asociaron con SBGC (p < 0.02, p < 0.02, p < 0.001, p < 0.032, p < 0.045, respectivamente). La mortalidad fue mayor en pacientes con SBGC (p < 0.02). El modelo multivariado mostró que el IMC fue un factor de riesgo independiente asociado a SBGC [OR 1.21 (IC 95% 1.08-1.35), p < 0.001]. Conclusión: El IMC es un factor de riesgo asociado a SBGC en el postoperatorio de RVA en pacientes con EAI.

Infused cardioplegia index: A new tool to improve myocardial protection. A cohort study. / Índice de cardioplejía infundida: una nueva herramienta en la protección miocárdica. Un estudio de cohortes.

BACKGROUND: Strategies for cardio-protection are essential in coronary artery bypass graft surgery. The authors explored the relationship between cardioplegia volume, left ventricular mass index and ischemia time by means of the infused cardioplegia index and its relationship with post-operative low cardiac output syndrome. DESIGN: All patients undergoing coronary artery bypass graft surgery between January 2013 and December 2015 were included. Low cardiac output syndrome was defined according to criteria of the SEMICYUC's consensus document. The perioperative factors associated with low cardiac output syndrome were estimated, and using a ROC curve, the optimum cut-off point for the infused cardioplegia index to predict the absence of low cardiac output syndrome was calculated. RESULTS: Of 360 patients included, 116 (32%) developed low cardiac output syndrome. The independent risk predictors were: New York Heart Association Functional Classification (OR 1.8 [95% CI=1.18-2.55]), left ventricle ejection fraction (OR 0.95 (95% CI=0.93-0.98]), ICI (OR 0.99 [95% CI=0.991-0.996]) and retrograde cardioplegia (OR 1.2 [95% CI=1.03-1.50]). The infused cardioplegia index showed an area under the ROC curve of 0.77 (0.70-0.83; P<.001) for the absence of postoperative low cardiac output syndrome using the optimum cut-off point of 23.6ml·min-1(100g/m2 of LV)-1. CONCLUSIONS: The infused cardioplegia index presents an inverse relationship with the development of post-operative low cardiac output syndrome. This index could form part of new strategies aimed at optimising cardio-protection. The total volume of intermittent cardioplegia, especially that of maintenance, should probably be individualised, adjusting for ischemia time and left ventricle mass index.

Morbilidad posquirúrgica en pacientes pediátricos operados por cardiopatías congénitas en la UMAE de Yucatán / Post-surgical morbidity in paediatric patients undergoing surgery for congenital heart disease in the UMAE of Yucatan, Mexico

Resumen: Objetivo: Describir la evolución clínica de pacientes pediátricos operados por cardiopatías congénitas en la UMAE de Yucatán. Métodos: Encuesta descriptiva sobre expedientes de pacientes pediátricos intervenidos quirúrgicamente por cardiopatía congénita del 1 de noviembre de 2011 al 30 de noviembre de 2013. Resultados: Las cardiopatías más frecuentes fueron la persistencia del conducto arterioso (37.6%) y la transposición de grandes vasos. La estancia en cuidados intensivos fue de 3 días (mediana). El 11.76% fallecieron por choque séptico (44.4%) en la mayoría de los casos. Las complicaciones más frecuentes fueron sepsis (5.9%), síndrome de bajo gasto (4.7%), paro cardíaco, bloqueo AV y taquicardia ventricular (2.4% cada uno). Existe una correlación positiva moderada entre las complicaciones trans y posquirúrgicas y la sobrevida o muerte del paciente. Conclusiones: El volumen de pacientes quirúrgicos es menor comparado con centros de referencia de cirugía cardiovascular. Existe una marcada tendencia a la realización de cirugías correctivas y paliativas en patologías específicas en pacientes con riesgos agregados o con «mala¼ anatomía cardiaca que impiden la corrección total de primera intención. Se deben realizar estudios epidemiológicos y clínicos prospectivos para conocer el comportamiento de las cardiopatías congénitas atendidas en la región. © 2016 Instituto Nacional de Cardiología Ignacio Chávez. Publicado por Masson Doyma México S.A. Este es un artículo Open Access bajo la licencia CC BY-NC-ND (https://creativecommons.org/licenses/by-nc-nd/4.0/).

Abstract: Objective: To describe the clinical course of paediatric patients undergoing surgery for congenital heart disease in UMAE of Yucatan. Methods: Descriptive review was performed on the records of paediatric patients undergoing surgery for congenital heart disease from 1 November 2011 to 30 November 2013. Results: The most frequent heart diseases were persistent ductus arteriosus (37.6%) and trans- position of the great vessels. The median intensive care stay was 3 days. Mortality was 11.76%, with septic shock (44.4%) in most cases. The most frequent complications were sepsis (5.9%), low cardiac output syndrome (4.7%), cardiac arrest, and AV block and ventricular tachycardia (2.4% each). There was a moderate positive correlation between surgical complications and survival or death. Conclusions: The number of surgical patients is lower compared to reference centres for cardiovascular surgery. There is a marked tendency to perform corrective and palliative surgeries in specific disease in patients with added risk or 'bad' cardiac anatomy that prevent full correction at the first attempt. Prospective epidemiological and clinical studies should be conducted to understand the behaviour of congenital heart diseases treated in the region. © 2016 Instituto Nacional de Cardiología Ignacio Chávez. Published by Masson Doyma México S.A. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/).

[Post-surgical morbidity in paediatric patients undergoing surgery for congenital heart disease in the UMAE of Yucatan, Mexico]. / Morbilidad posquirúrgica en pacientes pediátricos operados por cardiopatías congénitas en la UMAE de Yucatán.

OBJECTIVE: To describe the clinical course of paediatric patients undergoing surgery for congenital heart disease in UMAE of Yucatan. METHODS: Descriptive review was performed on the records of paediatric patients undergoing surgery for congenital heart disease from 1 November 2011 to 30 November 2013. RESULTS: The most frequent heart diseases were persistent ductus arteriosus (37.6%) and transposition of the great vessels. The median intensive care stay was 3 days. Mortality was 11.76%, with septic shock (44.4%) in most cases. The most frequent complications were sepsis (5.9%), low cardiac output syndrome (4.7%), cardiac arrest, and AV block and ventricular tachycardia (2.4% each). There was a moderate positive correlation between surgical complications and survival or death. CONCLUSIONS: The number of surgical patients is lower compared to reference centres for cardiovascular surgery. There is a marked tendency to perform corrective and palliative surgeries in specific disease in patients with added risk or 'bad' cardiac anatomy that prevent full correction at the first attempt. Prospective epidemiological and clinical studies should be conducted to understand the behaviour of congenital heart diseases treated in the region.

Low cardiac output syndrome in the postoperative period of cardiac surgery. Profile, differences in clinical course and prognosis. The ESBAGA study. / Síndrome de bajo gasto cardiaco en el postoperatorio de cirugía cardiaca. Perfil, diferencias en evolución clínica y pronóstico. Estudio ESBAGA.

OBJECTIVES: An analysis is made of the clinical profile, evolution and differences in morbidity and mortality of low cardiac output syndrome (LCOS) in the postoperative period of cardiac surgery, according to the 3 diagnostic subgroups defined by the SEMICYUC Consensus 2012. DESIGN: A multicenter, prospective cohort study was carried out. SETTING: ICUs of Spanish hospitals with cardiac surgery. PATIENTS: A consecutive sample of 2,070 cardiac surgery patients was included, with the analysis of 137 patients with LCOS. INTERVENTIONS: No intervention was carried out. RESULTS: The mean patient age was 68.3±9.3 years (65.2% males), with a EuroSCORE II of 9.99±13. NYHA functional class III-IV (52.9%), left ventricular ejection fraction<35% (33.6%), AMI (31.9%), severe PHT (21.7%), critical preoperative condition (18.8%), prior cardiac surgery (18.1%), PTCA/stent placement (16.7%). According to subgroups, 46 patients fulfilled hemodynamic criteria of LCOS (group A), 50 clinical criteria (group B), and the rest (n=41) presented cardiogenic shock (group C). Significant differences were observed over the evolutive course between the subgroups in terms of time subjected to mechanical ventilation (114.4, 135.4 and 180.3min in groups A, B and C, respectively; P<.001), renal replacement requirements (11.4, 14.6 and 36.6%; P=.007), multiorgan failure (16.7, 13 and 47.5%), and mortality (13.6, 12.5 and 35.9%; P=.01). The mean maximum lactate concentration was higher in cardiogenic shock patients (P=.002). CONCLUSIONS: The clinical evolution of these patients leads to high morbidity and mortality. We found differences between the subgroups in terms of the postoperative clinical course and mortality.