Torn et al1 conclude that the target international normalized ratio (INR) for atrial fibrillation (AF) should be 3.0 to 3.4, rather than the standard INR range of 2.0 to 3.0,2 based on a Leiden Thrombosis Centre cohort observed from 1994 to 1998. We believe that their data do not support their conclusion.
Singer DE, Fang MC, Go AS. The International Normalized Ratio Range of 2.0 to 3.0 Remains Appropriate for Atrial Fibrillation. Arch Intern Med. 2009;169(21):2032. doi:10.1001/archinternmed.2009.419