To the Editor: The report on the Acetazolamide in Decompensated Heart Failure with Volume Overload (ADVOR) trial by Mullens et al. (Sept. 29 issue)1 suggests that acetazolamide, added to loop-diuretic therapy, may produce more efficient decongestion in patients with acute decompensated heart failure. Patients who used other diuretic agents with the exception of mineralocorticoid receptor antagonists (MRAs) were excluded. Although similar numbers of patients in the two trial groups took MRAs at discharge (64.1% in the acetazolamide group and 62.2% in the placebo group), MRAs were more often administered to patients in the acetazolamide group than to those in the . . .