Basal natriuresis as a predictor of diuretic resistance and clinical evolution in acute heart failure.

BACKGROUND: Some clinical guidelines recommend serial measurement of natriuresis to detect diuretic resistance (DR) in acute heart failure (AHF) patients, but it adds complexity to the management. OBJECTIVES: To correlate a single measurement of basal natriuresis (BN) on admission with the development of DR and clinical evolution in AHF hospitalized patients. METHODS: Prospective and multicenter study included AHF hospitalized patients, without shock or creatinine >2.5mg%. Patients received 40mg of intravenous furosemide on admission, then BN was measured, and diuretic treatment was guided by protocol. BN was considered low if <70 meq/L. DR was defined as the need of furosemide >240mg/day, tubular blockade (TB), hypertonic saline solution (HSS) or renal replacement therapy (RRT). In-hospital cardiovascular (CV) mortality, CV mortality and AHF readmissions at 60-day post-discharge were evaluated. RESULTS: 157 patients were included. BN was low in 22%. DR was development in 19% (12.7% furosemide >240mg/day, 8% TB, 4% RRT). Low NB was associated with DR (44% vs 12%; p 0.0001), persistence of congestion (26.5% vs 11.4%; p 0.05), furosemide >240 mg/day (29% vs 8%; p 0.003), higher cumulative furosemide dose at 72 hours (220 vs 160mg; p 0.0001), TB (20.6 vs 4.9%; p 0.008), RRT (11.8 vs 1.6%; p 0.02), worsening of AHF (27% vs 9%; p 0.01), inotropes use (21% vs 7%; p 0.48), respiratory assistance (12% vs 2%; p 0.02) and a higher in-hospital CV mortality (12% vs 4%; p 0.1). No association was demonstrated with post-discharge endpoints. CONCLUSIONS: In AHF patients, low BN was associated with DR, persistent congestion, need for aggressive decongestion strategies, and worse in-hospital evolution.

Eficiencia diurética inicial como predictor de resistencia a diuréticos y evolución clínica en insuficiencia cardíaca aguda descompensada / Initial Diuretic Efficiency as Predictor of Diuretic Resistance and Clinical Outcome in Acute Decompensated Heart Failure

RESUMEN Introducción: En pacientes con insuficiencia cardíaca aguda descompensada (ICAD) la eficiencia diurética (ED) evaluada en forma precoz podría predecir la respuesta a diuréticos y la evolución clínica. Objetivos: Nuestro objetivo fue evaluar la asociación de la ED con la resistencia a diuréticos (RD), la mortalidad cardiovascular intrahospitalaria, y la mortalidad cardiovascular y las reinternaciones a 60 días en la ICAD. Material y métodos: Estudio prospectivo y multicéntrico que incluyó pacientes internados por ICAD. Recibieron 40 mg de furosemida dentro de las 2 horas del ingreso y 20 mg cada 8 horas en las primeras 24 horas. El escalamiento diurético posterior quedó a criterio del investigador según un protocolo preestablecido. Se definió la ED como balance hídrico/dosis de furosemida en las primeras 24 horas y la RD como el requerimiento de infusión de furosemida ≥240 mg/día en las primeras 72 horas. Se evaluaron variables clínicas y bioquímicas, y el punto final combinado (PFC) de mortalidad cardiovascular intrahospitalaria, y mortalidad cardiovascular y reinternaciones por ICAD a 60 días. Resultados: Se incluyeron 157 pacientes, mediana de edad de 74 años, 56 % hombres. La ED fue -15 mL/mg (rango intercuartílico, RIC, -20 a -11). Se evidenció la RD en el 13 % de los pacientes, el 8 % requirió bloqueo tubular y el 4 % terapia de reemplazo renal. El 22 % desarrolló empeoramiento de la función renal. La mortalidad cardiovascular intrahospitalaria fue del 5,7 % y en el seguimiento a 60 días, del 6 %. Las reinternaciones por ICAD a 60 días fueron del 12 %. Una peor ED se asoció al desarrollo de RD (p = 0,013) y los pacientes con ED superior a -11 mL/mg tuvieron mayor probabilidad de no desarrollar RD (área bajo la curva, AUC, 0,73; valor predictivo negativo, VPN, 92,5 %). Una peor ED se asoció al PFC (p = 0,025), mayor mortalidad cardiovascular intrahospitalaria (p = 0,003), persistencia de congestión a 48 horas (p = 0,007), mayor dosis de furosemida a 72 horas (p = 0,001) y empeoramiento de la ICAD en la internación (p = 0,004). Conclusión: La ED inicial baja se asoció a la RD, la dificultad en la descongestión y una mayor mortalidad cardiovascular intrahospitalaria en ICAD. Es un parámetro útil para detectar pacientes que podrían beneficiarse de un tratamiento diurético intensivo precoz.

ABSTRACT Background: In patients with acute decompensated heart failure (ADHF), early evaluation of diuretic efficiency (DE) could predict diuretic response and clinical outcome. Objectives: The aim of our study was to evaluate the association of DE with diuretic resistance (DR) in-hospital cardiovascular mortality, and readmission or cardiovascular mortality at 60 days in ADHF. Methods: We conducted a multicenter and prospective study of patients hospitalized for ADHF. All patients received 40 mg of furosemide within two hours of admission and 20 mg every 8 hours in the first 24 hours. Subsequent adjustment of diuretic dose was left to the discretion of the investigator as determined by a pre-established protocol. Diuretic efficiency was defined as the ratio of net fluid balance and cumulative amount of furosemide within the first 24 hours. Diuretic resistance was defined as requirement of furosemide infusion ≥240 mg/day during the first 72 hours. The clinical and biochemical variables were evaluated. The primary outcome was a composite of in-hospital cardiovascular mortality, and cardiovascular mortality or readmissions for ADHF at 60 days. Results: The cohort was made up of 157 patients; median age was 74 years and 56 % were men. Diuretic efficiency was -15 mL/ mg (interquartile range, IQR, -20 to -11). Diuretic resistance was evident in 13 % of patients, 8 % required sequential diuretic blockade, and 4 % required renal replacement therapy. Worsening renal function occurred in 22 % of patients. Cardiovascular mortality during hospitalization and at 60 days was 5.7 % and 6 %, respectively. Readmission rate for ADHF at 60 days was 12 %. Worse DE value was associated DR (p = 0.013), while patients in DE quartiles above -11 mL/mg were highly unlikely to develop DR (AUC 0.73, negative predictive value, NPV, 92.5 %). Worse DE value was associated with the CEP (p = 0.025), higher in-hospital cardiovascular mortality (p = 0.003), persistent congestion at 48 hours (p = 0.007), higher cumulative dose of furosemide at 72 hours (p = 0.001) worsening ADHF during hospitalization (p = 0.004). Conclusion: Low initial DE was associated with DR, persistent congestion, and higher in-hospital cardiovascular mortality in ADHF and constitutes a useful parameter to detect those patients who could benefit from early intensive diuretic treatment.

Fluid Status After Cardiac Surgery Assessed by Bioelectrical Impedance Vector Analysis and the Effects of Extracorporeal Circulation.

OBJECTIVE: Hydration status after cardiac surgery can be difficult to assess, often requiring invasive measurements. Bioelectrical impedance vector analysis (BIVA) is based on patterns of resistance (R) and reactance (Xc), corrected by height, and has been used in various clinical scenarios to determine body composition and monitor its changes over time. The purpose of the present study was to apply this method in cardiac surgery patients to assess the variation in hydration status and to compare its changes according to the use of extracorporeal circulation. DESIGN: Single-center, observational, prospective study including patients older than 18 years undergoing elective or urgent cardiac surgery. SETTING: Intensive cardiac care unit of a tertiary center in a metropolitan area. PARTICIPANTS: The study comprised 76 patients with a median age of 60 years and mostly undergoing coronary artery bypass grafting (CABG) (n = 47 [61.8%]) with extracorporeal circulation (n = 54 [73%]). INTERVENTIONS: Bioimpedance was measured with a standard tetrapolar single-frequency bioimpedance meter using a standardized procedure and plotted in an R-Xc graph. MEASUREMENTS AND MAIN RESULTS: The study demonstrated an increase in total body water immediately after surgery that was sustained until producing hyperhydration 24 hours later. Off-pump CABG was associated with a normal hydration status after surgery, whereas on-pump CABG produced a significant increase in total body water. CONCLUSIONS: Fluid status assessment with BIVA in cardiac surgery showed an increase in total body water up to 24 hours after surgery. Off-pump surgery prevented overhydration, which partially could explain the reduction in some of the postoperative complications. BIVA could serve as a useful method for monitoring fluid status in the setting of goal-directed therapy to assist in maintaining euvolemia in cardiac surgical patients.

Relación entre la grasa corporal y la morbimortalidad en cirugía cardíaca / Relationship Between Body Fat and Morbidity and Mortality in Cardiac Surgery

RESUMEN Introducción: Existe un efecto potencialmente protector de la obesidad cuando coexiste con la enfermedad cardiovascular, conocido como "paradoja de la obesidad". Es posible que se deba a que las medidas antropométricas no sean un marcador fidedigno de la grasa corporal. En este estudio, proponemos estimar la grasa corporal con métodos no invasivos y estudiar su relación con la morbimortalidad en cirugía cardíaca. Métodos: Llevamos a cabo un estudio prospectivo y observacional en pacientes adultos sometidos a cirugía cardíaca. Analizamos variables demográficas, antropométricas y clínicas junto con la estimación de la composición corporal a través de la impedancia bioeléctrica, para relacionarlas con los días de internación y eventos adversos luego de la cirugía cardíaca. Resultados: En el análisis de 98 pacientes, encontramos una relación directa entre el porcentaje de grasa corporal y los días de internación, independiente de la edad, el sexo, el índice de masa corporal y el riesgo prequirúrgico (coeficiente de 0,27, p: 0,021). Además, los pacientes que presentaron mediastinitis tuvieron una grasa corporal significativamente mayor (31,55 ± 0,64% contra 27,13 ± 7,9%, p <0,001), y los pacientes que fallecieron presentaron una tendencia a presentar más masa grasa (36,05 ± 3,19% contra 27,20 ± 7,82%, p: 0,08). Conclusiones: La mayor cantidad de grasa corporal estimada por análisis de impedancia bioeléctrica se relacionó con una mayor morbilidad en la cirugía cardíaca. A pesar de que esto es biológicamente plausible, sería necesario llevar a cabo estudios de mayor tamaño para poder esclarecer definitivamente la "paradoja del índice de masa corporal".

ABSTRACT Introduction: There is a potentially protective effect of obesity when it coexists with cardiovascular disease, known as the "obesity paradox." It could be explained by the fact that anthropometric measurements are not a reliable marker of body fat. In this study we propose to estimate body fat with a non-invasive method and study its relationship with morbidity and mortality in cardiac surgery. Methods: We conducted a prospective and observational study in adult patients undergoing cardiac surgery. We analyzed demographic, anthropometric and clinical variables along with the estimation of body composition using bioelectric impedance, to study their association to hospitalization days and adverse events after cardiac surgery. Results: In the analysis of 98 patients, we found a direct relationship between the percentage of body fat and the length of hospital stay, independent of age, sex, body mass index (BMI) and surgical risk (coefficient of 0.27, p = 0.021). In addition, patients who had mediastinitis showed a significantly higher body fat (31.55 ± 0.64% versus 27.13 ± 7.9%, p <0.001), and patients who died had a tendency to have more fat mass (36.05 ± 3.19% versus 27.20 ± 7.82%, p = 0.08). Conclusion: Increased body fat as assessed with BIA was related to morbidity in cardiac surgery. Although this is biologically plausible, it would be necessary to carry out larger studies in order to definitively establish the "BMI paradox".