Is Digoxin Safe Post-MI?
Abstract & Commentary
Synopsis: Digoxin is not safe in AMI patients. Beta blockers are a better alternative for the long-term treatment of supraventricular tachycardias and heart failure after AMI.
Source: Spargias KS, et al. Lancet 1999;354:391-392.
Although digoxin has been proven safe in chronic heart failure patients, its safety in the acute myocardial infarction (AMI) setting is controversial. Thus, Spargias and colleagues evaluated the outcomes associated with nonrandomized digoxin treatment in the Acute Infarction Ramipril Efficacy (AIRE) study, which entered patients 3-10 days post-AMI. At entry, 12% of the 1986 AIRE patients were on digoxin. These patients were older, more likely to be female (32% vs 26%; P = 0.05), and less likely to be on beta blockers (7% vs 24%; P < 0.001). Also, they had lower ejection fractions (32% vs 40%; P < 0.001), were more likely to have anterior AMIs, and be in overt heart failure. Not surprisingly, digoxin use was associated with increased total mortality. Using a Cox’s proportional hazard model to keep confounding variables to a minimum, digoxin remained a significant independent predictor of increased total mortality (hazard ratio 1.4, CI 1.07-1.86, P < 0.02). Also, digoxin was associated with an increased risk of sudden death (1.67, 1.09-2.56, P = 0.02). Spargias et al conclude that digoxin is not safe in AMI patients and suggest that beta blockers are a better alternative for the long-term treatment of supraventricular tachycardias and heart failure after AMI.
Comment by Michael H. Crawford, MD
The profound differences in the characteristics of the patients on digoxin vs. those not is a challenge to any statistical device to eliminate confounding variables. Also, we do not know how many of these patients were on digoxin before their AMI or were started on it after their AMI but before entry into AIRE. The latter group may be at particularly high risk of mortality. Despite these difficulties with a nonrandomized retrospective analysis, there seems to be little evidence that digoxin is first-line therapy for any indication in AMI. Whether it is actually harmful would require a prospective trial, which will never be done. Thus, digoxin is a second- or thirdline alternative to rate lowering calcium blockers or beta blockers for rate control in atrial fibrillation and to angiotensin converting enzyme inhibitors or beta blockers for heart failure complicating AMI. (Dr. Crawford is Robert S. Flinn Professor, Chief of Cardiology, University of New Mexico, Albuquerque.)
You have reached your article limit for the month. Subscribe now to access this article plus other member-only content.
- Award-winning Medical Content
- Latest Advances & Development in Medicine
- Unbiased Content