Acute decompensated heart failure
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* Joe Nemeth MD

*   © 2007 Canadian Medical Association or its licensors

Although Larry Allen and Christopher O'Connor's review of the management of acute decompensated heart failure1 was generally well written, I have reservations about their interpretation of the evidence concerning the role of loop diuretics, specifically furosemide, and their recommendations regarding furosemide's place in the treatment of acute decompensated heart failure.

First, I disagree with their implication that congestion indicates volume overload and their suggestion that clinicians consequently “rely heavily on diuretic therapy.” Such statements help to perpetuate the misuse of furosemide in acute decompensated heart failure. Up to 50% of patients with acute cardiogenic pulmonary edema are euvolemic, and treatment should emphasize fluid redistribution rather than fluid removal. Second, although diuretics have been weakly shown to decrease mortality,2 if they are relied upon exclusively in acute care in hospitals they have the opposite effect. Third, in acute decompensated heart failure caused by high afterload (e.g., hypertensive emergencies), renal perfusion can drop by as much as 80% and furosemide will produce a delayed diuretic effect 30–120 minutes after administration. Finally, there is very little evidence for any beneficial hemodynamic effect of furosemide. In fact, many studies have shown that furosemide is responsible for adverse hemodynamic effects in patients with acute decompensated heart failure, because it causes an initial release of catecholamines and activates the renin–angiotensin system.3–5

In conclusion, I disagree with the authors' summary that “therapy with a loop diuretic currently forms the foundation” of treatment of acute decompensated heart failure despite good evidence that loop diuretics should be reserved for use as third-line agents behind therapies to reduce preload and afterload (e.g., nitroglycerin and angiotensin-converting-enzyme inhibitors) in acute decompensated heart failure in the hospital setting.

## Footnotes

*   **Competing interests:** None declared.

## REFERENCES

1.  1. Allen LA, O'Connor CM. Management of acute decompensated heart failure. CMAJ 2007;176(6):797-805.
    
    [Abstract/FREE Full Text](http://www.cmaj.ca/lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6NDoiQUJTVCI7czoxMToiam91cm5hbENvZGUiO3M6NDoiY21haiI7czo1OiJyZXNpZCI7czo5OiIxNzYvNi83OTciO3M6NDoiYXRvbSI7czoyMjoiL2NtYWovMTc3LzIvMTc1LjEuYXRvbSI7fXM6ODoiZnJhZ21lbnQiO3M6MDoiIjt9) 

2.  2. Faris R, Flather M, Purcell H, et al. Current evidence supporting the role of diuretics in heart failure: a meta analysis of randomised controlled trials. Int J Cardiol 2002;82(2):149-58.
    
    [CrossRef](http://www.cmaj.ca/lookup/external-ref?access_num=10.1016/S0167-5273(01)00600-3&link_type=DOI) 
    
    [PubMed](http://www.cmaj.ca/lookup/external-ref?access_num=11853901&link_type=MED&atom=%2Fcmaj%2F177%2F2%2F175.1.atom) 
    
    [Web of Science](http://www.cmaj.ca/lookup/external-ref?access_num=000174575900008&link_type=ISI) 

3.  3. Nelson GI, Ahuja RC, Silke B, et al. Haemodynamic effects of frusemide and its influence on repetitive rapid volume loading in acute myocardial infarction. Eur Heart J 1983;4(10):706-11.
    
    [Abstract/FREE Full Text](http://www.cmaj.ca/lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6NDoiQUJTVCI7czoxMToiam91cm5hbENvZGUiO3M6MzoiZWhqIjtzOjU6InJlc2lkIjtzOjg6IjQvMTAvNzA2IjtzOjQ6ImF0b20iO3M6MjI6Ii9jbWFqLzE3Ny8yLzE3NS4xLmF0b20iO31zOjg6ImZyYWdtZW50IjtzOjA6IiI7fQ==) 

4.  4. Francis GS, Siegel RM, Goldsmith SR, et al. Acute vasoconstrictor response to intravenous furosemide in patients with chronic congestive heart failure. Activation of the neurohumoral axis. Ann Intern Med 1985;103(1):1-6.
    
    [CrossRef](http://www.cmaj.ca/lookup/external-ref?access_num=10.7326/0003-4819-103-1-1&link_type=DOI) 
    
    [PubMed](http://www.cmaj.ca/lookup/external-ref?access_num=2860833&link_type=MED&atom=%2Fcmaj%2F177%2F2%2F175.1.atom) 
    
    [Web of Science](http://www.cmaj.ca/lookup/external-ref?access_num=A1985ALY3700001&link_type=ISI) 

5.  5. Kraus PA, Lipman J, Becker PJ. Acute preload effects of furosemide. Chest 1990;98(1):124-8.
    
    [PubMed](http://www.cmaj.ca/lookup/external-ref?access_num=2361377&link_type=MED&atom=%2Fcmaj%2F177%2F2%2F175.1.atom)