Low albumin levels and high impedance ratio as risk factors for worsening kidney function during hospitalization of decompensated heart failure patients.

BACKGROUND: Patients hospitalized for decompensated heart failure (DHF) frequently experience worsening of renal function (WRF), leading to volume overload and resistance to diuretics. OBJECTIVE: To investigate whether albumin levels and whole-body impedance ratio, as an indicator of water distribution, were associated with WRF in patients with DHF. METHODS: A total of 80 patients hospitalized for DHF were consecutively included in the present longitudinal study. WRF during hospitalization was defined as an increase of ≥0.3 mg/dL (≥26.52 µmol/L) or 25% of baseline serum creatinine. Clinical and echocardiographic characteristics were assessed at baseline. Whole-body bioelectrical impedance was measured using tetrapolar and multiple-frequency equipment to obtain the ratio of impedance at 200 kHz to that at 5 kHz. Serum albumin levels were also evaluated. Baseline characteristics were compared between patients with and without deteriorating renal function using a t test or χ(2) test. Subsequently, a logistic regression analysis was performed to obtain the independent variables associated with WRF. RESULTS: The incidence of WRF during hospitalization was 26%. Independent risk factors associated with WRF were low serum albumin (RR=0.11; P=0.04); impedance ratio >0.85 (RR=5.3; P=0.05), systolic blood pressure >160 mmHg (RR=12; P=0.02) and maximum dose of continuous intravenous furosemide required >80 mg/day during hospitalization (RR=5.7, P=0.015). CONCLUSIONS: WRF is frequent in patients with DHF. It results from the inability to effectively regulate volume status because hypoalbuminemia induces water loss from the vascular space (high impedance ratio), and high diuretic doses lower circulatory volumes and reduce renal blood flow, leading to a decline in renal filtration function.

Effect of L-arginine or L-citrulline oral supplementation on blood pressure and right ventricular function in heart failure patients with preserved ejection fraction.

BACKGROUND: The effect of L-arginine and L-citrulline on blood pressure and right ventricular function in heart failure patients with preserved ejection fraction (HFpEF) is unknown. We have therefore evaluated, in a randomized clinical trial, the effect of these aminoacids in chronic outstanding and stable patients with HFpEF. METHODS AND RESULTS: All patients underwent an echocardiogram and radioisotopic ventriculography rest/exercise, and were randomized in a consecutive manner to the L-arginine group (n = 15; 8 g/day); and the citrulline malate group (n = 15; 3 g/day). The duration of follow-up was two months. The principal echocardiographic finding was a statistically significant decrease in pulmonary artery pressure in the L-arginine (56.3 ± 10 vs 44 ± 16.5 mm Hg, p < 0.05) and the citrulline (56.67 ± 7.96 vs 47.67 ± 8.59 mm Hg, p < 0.05) groups. Duration on treadmill and right ventricular ejection fraction post exercise increased, while diastolic and systolic artery pressure decreased significantly in both groups. There were no other statistically significant differences between the groups. CONCLUSIONS: Administration of L-arginine and citrulline to patients with HFpEF improved right ventricular function by increasing right ventricular ejection fraction, and probably decreasing systolic pulmonary artery pressure.

The effect of L-arginine and citrulline on endothelial function in patients in heart failure with preserved ejection fraction.

BACKGROUND: To evaluate the effect of the amino acids L-arginine and citrulline on endothelial function in patients in stable diastolic and right heart failure using photoplethysmography. METHODS: Thirty patients from the Heart Failure Clinic of the Instituto Nacional de Ciencias Médicas y Nutrición "Salvador Zubirán" underwent photoplethysmography using the hyperemia technique. Index finger flow was assessed at baseline and after ischemia every 30 s by maximum amplitude time (MAT), total time of the curve (TT) and the index of the two (MAT/TT < 30 = normal) before and after the administration of L-arginine (8 g/day in two doses, n = 15) or citrulline (3 g/day in one dose, n = 15) for 60 days in addition to optimal pharmacological treatment. RESULTS: There were no statistically significant differences between the two groups at baseline. After the intervention, the MAT/TT index of all patients normalized in each evaluation period with statistically significant differences. Basal L-arginine group = 38.75 ± 11.52, final 23.32 ± 6.08, p = 0.007 and basal citrulline group = 41.4 ± 13.47, final 23.65 ± 6.74, p = 0.007 at 60-90 s. Post-ischemia: basal L-arginine 36.60 ± 11.51, final 18.81 ± 15.13, p = 0.004 and basal citrulline = 49.51 ± 15.17, final 27.13 ± 7.87, p = 0.003. CONCLUSIONS: The administration of L-arginine and citrulline has a beneficial effect on endothelial function as shown by the normalized MAT/TT index. It probably improves systemic and pulmonary hemodynamics, which could help in the treatment of diastolic heart failure.

Prognostic value of cardiac troponin T elevation is independent of renal function and clinical findings in heart failure patients.

BACKGROUND: The aim of this study is to determine the prevalence and prognostic value of elevated cardiac troponin (cTnT) and its association with clinical characteristics according to renal function status in patients with stable heart failure. METHODS: In a prospective observational study, 152 consecutive patients from the Heart Failure Clinic of the INCMNSZ were followed for a period of 42 months. All underwent clinical evaluation, echocardiography, and determination of body composition by electric bioimpedance to identify hypervolemia. Concentrations of cTnT were quantified by immunoassay with electrochemoluminescence and > or = 0.02 ng/mL levels were considered elevated. Also glomerular filtration rate (eGFR) was estimated using the Cockcroft-Gault equation. RESULTS: Elevated cTnT was significantly associated with increased all-cause mortality in the observational period even after adjusting for eGFR < 60 mL/min/1.73 m2 and clinical findings such as hypertension, functional class, loop diuretics, angiotensin converting enzyme inhibitors, pulmonary pressure and hypervolemia in Cox regression analysis with a hazard ratio of 4.58 (95% confidence interval: 1.84-11.45). CONCLUSIONS: Heart failure patients with elevated cardiac-specific troponin T are at increased risk of death independently of the presence of chronic kidney disease.