To the Editor: In their trial of treatment to prevent atrial fibrillation, Dr Ahmed and colleagues1 reported more atrial fibrillation recurrences, all-cause mortality, and bleeding complications in patients with atrial fibrillation undergoing electrical cardioversion who were randomized to receive episodic amiodarone treatment compared with those who received continuous treatment. However, there are several issues that may have affected the validity of the conclusions.
The authors reported unadjusted survival curves for all of the prespecified end points. However, the episodic amiodarone group had significantly larger left atria (P = .01 for the long axis measurements), and atrial size has been shown to predict atrial fibrillation recurrences.2 Therefore, the higher atrial fibrillation recurrence rate in that group cannot be attributed solely to the different treatment strategy.
Moreover, the choice of a high intensity of anticoagulation (targeted international normalized ratio [INR] between 2.5 and 3.5),3 and the lack of data on the INR values achieved in both treatment groups, may have affected both the bleeding complications and the all-cause mortality rates. There is no increase in anticoagulant efficacy at INR levels greater than 3, while bleeding complications (including fatal bleedings) increase significantly.3
Since the chronic use of amiodarone carries significant adverse effects, the issue of the efficacy of episodic amiodarone in patients undergoing atrial fibrillation electrical cardioversion cannot be considered settled at this time and needs further study.
Financial Disclosures: None reported.
Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature
Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal
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