Decongestive therapy and renal function in acute heart failure: time for a new approach?

O utcomes after admission for acute heart failure (AHF) remain extremely poor, especially for patients with decreased renal function or those in whom worsening renal function (WRF) develops during treatment. The Table shows the baseline estimated glomerular filtration rate (GFR) with 30-and 60-day mortality from the Dose Optimization Strategies Evaluation trial in acute Heart Failure (DOSE HF), the CArdioRenal REScue Study in acute Heart Failure (CARRESS HF), and the Renal Optimization Strategies Evaluation trial in acute Heart Failure (ROSE HF). GFR at randomization in each of these trials was significantly decreased, and the 60-day mortality of 14.7% in CARRESS HF (the only study to date requiring documentation of WRF before randomization) is one of the highest yet reported. WRF may have many causes in the setting of AHF. 4 These include underdiuresis (which may lead to persistent increases in central venous pressure, thereby adversely affecting GFR), direct renal damage from the effects of drugs or procedures, progression of underlying disease, and overdiuresis leading to volume depletion with the subsequent engagement of barore-flex mechanisms and, as a result, a reduction in renal blood flow, GFR, and a fall in cardiac output. WRF may also be caused by a transient reduction in intravascular volume such that the rate at which intravascular volume is replenished from the extravascular space (the so-called plasma refill rate) is exceeded. This can occur despite persistent systemic congestion , as suggested by the results from CARRESS HF in which serum creatinine increased further during treatment with ultra-filtration, despite clinical evidence of ongoing congestion. Regardless of cause, outcomes in AHF are worse as a function of baseline GFR. Although the threshold for the degree of WRF and outcomes remains poorly defined, an increase in serum creatinine of ≥0.3 mg/dL has also clearly been associated with worse outcomes. 7 Recently, several retrospective analyses from completed trials have suggested that it may be important to consider the time course of WRF and the relationship of WRF to the degree of decongestion achieved, but even in those analyses, the best outcomes are clearly in those patients who achieve clinical decongestion while preserving renal function. 8–10 Until a prospective trial clearly establishes that any form of WRF is safe during treatment of AHF, it is reasonable to assume that the goal of treatment should be adequate clinical decongestion without causing renal dysfunc-tion (or worsening it if already present). Because reliance on changes in …