TY - JOUR T1 - LImitations of subgroup analyses in meta-analysis of cardiac resynchronization therapy by qrs duration AU - Magee CD, Byars L, DeZee KJ Y1 - 2012/02/27 N1 - 10.1001/archinternmed.2011.1499 JO - Archives of Internal Medicine SP - 375 EP - 376 VL - 172 IS - 4 N2 - Sipahi et al1 report a meta-analysis to evaluate the impact of QRS duration in patients with heart failure receiving cardiac resynchronization therapy (CRT) as measured by composite clinical events. This analysis including 5 randomized controlled trials attempts to address a discordance between Heart Failure Society of America (HFSA) and European Society of Cardiology (ESC) guidelines recommending CRT in patients with New York Heart Association (NYHA) III/IV heart failure and a QRS interval greater than 120 milliseconds, and published data suggesting greater benefit at higher QRS cutoffs. The conducted meta-analysis represents a post hoc subgroup analysis, according to QRS cutoff values used in each study. There are 2 major concerns that threaten the validity of the authors' conclusions in this study, namely multiplicity of analysis and loss of randomization. SN - 0003-9926 M3 - doi: 10.1001/archinternmed.2011.1499 UR - http://dx.doi.org/10.1001/archinternmed.2011.1499 ER -