Impact of diuretic dosing on mortality in acute heart failure using a propensity-matched analysis.
AIMS
Loop diuretics are recommended to treat congestion in heart failure (HF), despite limited quality evidence. High-dose (HD) loop diuretics seem to worsen outcomes in chronic HF, though; data for acute HF are scarce, with equivocal results.


METHODS AND RESULTS
The ALARM-HF study recorded in-hospital HF therapy in 4953 patients from nine countries. A post-hoc analysis was performed to determine if there was an interaction between intravenous (iv) bolus diuretic dosing and outcomes. Patients were classified as receiving high- or low-dose iv furosemide if their total initial 24 h dose was above (HD) or below [low dose (LD)] 1 mg/kg. Propensity scoring, matching an extensive list of variables, was performed. High-dose and LD patients were matched by propensity scores and outcomes determined. We identified 2460 LD and 848 HD patients, with overall in-hospital mortality of 9 and 13% (P= 0.002), respectively. After propensity matching, there were 506 patients in each subgroup, with the matched LD and HD cohorts having similar mortality (13 vs. 15%; P= 0.4). We further investigated in which subgroups of patients HD diuretics influenced mortality. Before matching, HD diuretics were associated with a greater risk of in-hospital death in some subgroups, including patients aged >80 years, those with an acute coronary syndrome, or with a left ventricular ejection fraction <40%. However, after propensity score matching, no association was found between diuretic dosing and death in any of the studied subgroups.


CONCLUSIONS
In the initial management of acute HF, HD iv diuretics, per se, do not influence short-term mortality.