Blood Urea Nitrogen

Loop diuretics are used in patients with heart failure (HF) to relieve symptoms of systemic and pulmonary venous congestion. Despite their nearly universal use for this indication, loop diuretics have not been shown to improve survival—indeed, a number of recent studies suggest an adverse relationship between the use of loop diuretics and survival (1–3). This is plausible because loop diuretics block sodium chloride absorption at the macula densa in the thick ascending limb of the loop of Henle, activating the reninangiotensin-aldosterone system (RAAS) and potentially exacerbating HF (4). Few data exist to inform providers how to use loop diuretics to provide the greatest symptomatic benefit with the least adverse effect. In this issue of the Journal, Testani et al. (5) have provided insight into this