Diuretic Use in Heart Failure

Heart failure (HF) is a major contributor to morbidity and mortality in the US and worldwide. HF is a complex condition characterized by the disruption of normal physiology and the activation of neurohumoral pathways, including the renin-angiotensin-aldosterone system, the sympathetic system, and inflammatory pathways. These have adverse effects on renal handling of salt and water balance, leading to salt and water retention and a vicious cycle of worsening congestive changes with progressive volume overload. Meanwhile, diuretics are pharmacologic agents that are essential in the management of HF. Indeed, diuretics induce natriuresis to disrupt this vicious cycle of progressive volume overload, thereby reducing congestive changes and alleviating the symptoms of HF. In this review, we discuss the different classes of diuretics and their sites and mechanisms of action across the nephron. We highlight differences in the potency and usefulness of these diuretics. Moreover, we examine their application in the management of various stages of HF, focusing on their optimal and effective use in clinical practice. In this review, we also cover several aspects of the pathophysiology of HF. We address the milder forms of HF that are treated in outpatient clinics, as well as the more advanced states of HF, including acute decompensated HF (ADHF), which are usually managed in a hospital setting. We discuss management strategies in the outpatient setting, with a specific focus on maintaining sufficient decongestion of patients to prevent hospitalization. We stress the importance of closely monitoring congestive symptoms and weight trends, as well as electrolyte and renal parameters. We recommend setting a "target weight goal" for the patient between clinic visits, which helps with outpatient diuretic therapy adjustments and avoids drifts in volume status. We also examine the usefulness of diuretics in hospitalized patients with ADHF. For these more challenging conditions, we discuss the use of combination diuretics to overcome diuretic resistance and highlight current recommendations for achieving the desired goals and speed of diuresis. Patients with HF commonly have chronic kidney disease (CKD), which frequently complicates overall management strategies. CKD also leads to diuretic resistance, necessitating escalation of diuretic dosing and more frequent changes in diuretic prescription. Hence, this review also discusses management strategies for CKD patients and highlights the importance of close monitoring of kidney function in both inpatient and outpatient settings when using diuretics in patients with HF. We briefly discuss the benefits of monitoring central venous filling pressures in patients with ADHF as a tool to guide the optimization of diuresis. Finally, we allude to new advanced technologies such as remote monitoring of outpatients with HF. These can be used to detect early signs of impending HF decompensation that earlier adjustments to the diuretic dose could then address.