Renal dysfunction in acute and chronic heart failure: prevalence, incidence and prognosis

Abstract

Most patients with heart failure have mild or moderate renal dysfunction. This reflects the combined impact of chronic renal parenchymal disease, renal artery disease, renal congestion and hypoperfusion, neuroendocrine and cytokine activation and the effects of treatments for heart failure. Remarkably, with good treatment, the average annual rate of decline in renal function is similar in patients with chronic heart failure and healthy people of a similar age. Urea appears to be a stronger marker of an adverse prognosis than creatinine-based measures of renal function. Recent evidence suggests that minor, transient increases in creatinine in the setting of acute heart failure are not prognostically important but persistent deterioration does indicate a higher mortality. The poor prognosis of patients with worsening renal function ensures that few require renal dialysis but this may change as methods to prevent sudden death improve and new ways are found to control fluid congestion. Reversing renal dysfunction and stopping its progression remain important targets for treatment of heart failure.

Prognostic value of worsening renal function in outpatients with chronic heart failure

“…It may also limit the use of prognosis-modifying therapy, like angiotensin-converting enzyme inhibitors, angiotensin receptor blockers and beta-blockers. In previous studies, urea performed better than creatinine in predicting prognosis in patients with HF [9,12,13]. Similarly, in our study, having an increase in serum urea by more than 20 mg/dl conveyed the worst prognosis of all.…”

“…Similarly, in our study, having an increase in serum urea by more than 20 mg/dl conveyed the worst prognosis of all. Urea reflects more than just GFR, being also a marker of renal tubular reabsorption (50% is reabsorbed in renal tubules), a better measure of intravascular dehydration and diuretic resistance than creatinine [9]. Serum urea also rises with increased protein catabolism due to worsening HF, infection or reduced dietary protein [22].…”

“…Most previous studies have focused on serum creatinine and glomerular filtration rate estimating equations as markers of renal dysfunction [9,10]. These equations, like the Modification of Diet in Renal Disease equation, improve upon serum creatinine by incorporating known demographic and clinical variables as observed surrogates for the unmeasured physiological factors other than glomerular filtration rate that affects the serum creatinine concentration, such as generation and tubular secretion [11].…”

“…However, there is growing evidence that other blood markers of renal dysfunction, such as serum urea, may be superior to creatinine when it comes to predicting prognosis in patients with HF [12][13][14]. Blood urea concentration reflects a constellation of renal dysfunction, diuretic resistance and cachexia rather than just the glomerular filtration rate [9].…”

Cardiac Dysfunction, Congestion and Loop Diuretics: their Relationship to Prognosis in Heart Failure

“…The effects of diuretics on renal function are complex (20). In patients with severe oedema, diuretics may reduce renal parenchymal oedema and renal venous pressure without reducing renal arterial perfusion pressure, leading to improved renal function.…”