Cardiorenal Syndrome in the Decompensated Patient: Diuretic Strategy When the Creatinine Rises

Abstract

A rising creatinine during decongestion of acute decompensated heart failure is one of the most common reasons a clinician
pulls back on diuretic therapy, but the evidence on what that rise actually means, and what to do about it, points the other way.
In CARRESS-HF, 188 patients with worsening renal function were randomised to ultrafiltration or stepped pharmacologic
diuretic therapy; ultrafiltration produced a worse day-4 creatinine change (+0.23 vs -0.04 mg/dL, p=0.003) with no extra
weight loss (5.7 vs 5.5 kg, p=0.58) and more adverse events (72% vs 57%, p=0.03). In the DOSE trial, a high-dose diuretic
strategy (2.5 times a patient's baseline oral dose) produced significantly greater dyspnoea relief, greater total diuresis, and
fewer serious adverse events than low-dose therapy, without a significant difference in creatinine change -- meaning more
aggressive decongestion did not worsen renal function despite the intuitive concern that it would. A separate synthesis of this
literature makes the underlying principle explicit: worsening renal function is associated with poor outcomes specifically
when congestion persists despite treatment, but is typically a benign physiological response when decongestion is actually
achieved. This review sets out why the reflex to de-escalate diuresis when creatinine rises is often the wrong response, and
what should be checked instead.