Diuretics in chronic heart failure - Benefits and hazards

Diuretics are indispensable in the management of oedema of chronic heart failure (CHF). When given to patients with congestion, diuretics relieve symptoms and improve cardiac performance. However, the use of diuretics in patients without fluid retention may have deleterious effects because they may decrease stroke volume and blood pressure, resulting in neurohormonal activation. Moreover, the effects of diuretics on electrolyte and metabolic imbalance may trigger ventricular arrhythmias with adverse consequences on survival. Whereas treatment of hypertension with diuretics prevents the development of CHF, no randomized trial has assessed the effects of diuretics on mortality in patients with CHF. Reduced mortality using spironolactone in patients with CHF in the RALES trial may not be related to its diuretic effects. Baseline use of a non-potassium-sparing diuretic in the SOLVD prevention and treatment trials was associated with an increased risk of arrhythmic death. As only limited data are available on improved prognosis with diuretics, long-term randomized mortality trials should be conducted. The recent TORIC study may be the first step in this direction.