Associations of Albuminuria in Patients With Chronic HF
Associations of Albuminuria in Patients With Chronic HF
Aims To examine the relationships between baseline characteristics and urinary albumin excretion in the extensively phenotyped patients in the ALiskiren Observation of heart Failure Treatment (ALOFT) study.
Methods and results Urinary albumin creatinine ratio (UACR) was available in 190 of 302 (63%) patients randomized in ALOFT. Of these, 107 (56%) had normal albumin excretion, 63 (33%) microalbuminuria, and 20 (11%) macroalbuminuria. Compared with patients with normoalbuminuria, those with microalbuminuria had a greater prevalence of diabetes (48 vs. 26%, P = 0.005) and a lower estimated glomerular filtration rate (eGFR) (60.7 vs. 68.3 mL/min/1.73 m, P = 0.01). Patients with macroalbuminuria had additional differences from those with a normal UACR, including younger age (63 vs. 69 years, P = 0.02), higher glycated haemoglobin (HbA1c; 7.9 vs. 6.2%, P < 0.001), and different echocardiographic findings. Of the non-diabetic patients, 28% had microalbuminuria and 7% had macroalbuminuria. Independent predictors of UACR in these patients included N-terminal pro B-type natriuretic peptide (NT-proBNP), HbA1c, and left ventricular diastolic dimension. Increased UACR was not associated with markers of inflammation or of renin angiotensin aldosterone system activation and was not reduced by aliskiren.
Conclusions Increased UACR is common in patients with heart failure, including non-diabetics. Urinary albumin creatinine ratio is independently associated with HbA1c and NT-proBNP, even in non-diabetic patients.
The prevalence and prognostic significance of increased urinary albumin excretion in patients with chronic heart failure was recently reported in two large studies. Microalbuminuria was present in between 20 and 30% of patients (and macroalbuminuria in 5 and 11%) and was common even in the absence of diabetes, hypertension, and renal dysfunction. An elevated urinary albumin creatinine ratio (UACR) was associated with a significantly increased risk of adverse clinical outcomes, including death, even after adjustment for other prognostic variables.
The pathophysiological mechanisms underlying albuminuria in heart failure are unknown. However, several systemic disease processes that occur in patients with heart failure have been linked to elevated urinary albumin excretion, including diffuse vascular dysfunction, systemic inflammation, and neurohumoral activation. In heart failure, cardio-renal interactions lead to several abnormalities of renal function, including reduction in renal arterial flow, increased renal venous pressure, and tubular dysfunction. The former two abnormalities may alter glomerular haemodynamics and permeability.
We studied urinary albumin excretion in patients with heart failure enrolled in the ALiskiren Observation of heart Failure Treatment (ALOFT) study. These participants were extensively phenotyped, permitting detailed comparison of the characteristics of those with and without an elevated UACR and identification of potential pathophysiological correlates of increased urinary albumin excretion in heart failure.
Abstract and Introduction
Abstract
Aims To examine the relationships between baseline characteristics and urinary albumin excretion in the extensively phenotyped patients in the ALiskiren Observation of heart Failure Treatment (ALOFT) study.
Methods and results Urinary albumin creatinine ratio (UACR) was available in 190 of 302 (63%) patients randomized in ALOFT. Of these, 107 (56%) had normal albumin excretion, 63 (33%) microalbuminuria, and 20 (11%) macroalbuminuria. Compared with patients with normoalbuminuria, those with microalbuminuria had a greater prevalence of diabetes (48 vs. 26%, P = 0.005) and a lower estimated glomerular filtration rate (eGFR) (60.7 vs. 68.3 mL/min/1.73 m, P = 0.01). Patients with macroalbuminuria had additional differences from those with a normal UACR, including younger age (63 vs. 69 years, P = 0.02), higher glycated haemoglobin (HbA1c; 7.9 vs. 6.2%, P < 0.001), and different echocardiographic findings. Of the non-diabetic patients, 28% had microalbuminuria and 7% had macroalbuminuria. Independent predictors of UACR in these patients included N-terminal pro B-type natriuretic peptide (NT-proBNP), HbA1c, and left ventricular diastolic dimension. Increased UACR was not associated with markers of inflammation or of renin angiotensin aldosterone system activation and was not reduced by aliskiren.
Conclusions Increased UACR is common in patients with heart failure, including non-diabetics. Urinary albumin creatinine ratio is independently associated with HbA1c and NT-proBNP, even in non-diabetic patients.
Statistical Analyses
The prevalence and prognostic significance of increased urinary albumin excretion in patients with chronic heart failure was recently reported in two large studies. Microalbuminuria was present in between 20 and 30% of patients (and macroalbuminuria in 5 and 11%) and was common even in the absence of diabetes, hypertension, and renal dysfunction. An elevated urinary albumin creatinine ratio (UACR) was associated with a significantly increased risk of adverse clinical outcomes, including death, even after adjustment for other prognostic variables.
The pathophysiological mechanisms underlying albuminuria in heart failure are unknown. However, several systemic disease processes that occur in patients with heart failure have been linked to elevated urinary albumin excretion, including diffuse vascular dysfunction, systemic inflammation, and neurohumoral activation. In heart failure, cardio-renal interactions lead to several abnormalities of renal function, including reduction in renal arterial flow, increased renal venous pressure, and tubular dysfunction. The former two abnormalities may alter glomerular haemodynamics and permeability.
We studied urinary albumin excretion in patients with heart failure enrolled in the ALiskiren Observation of heart Failure Treatment (ALOFT) study. These participants were extensively phenotyped, permitting detailed comparison of the characteristics of those with and without an elevated UACR and identification of potential pathophysiological correlates of increased urinary albumin excretion in heart failure.
Source...