In Reply: Dr Lin and colleagues make an important point about the influence of sample size on the power to distinguish differences in outcome in clinical trials. Our study was designed to compare differences in occurrence of a composite outcome; as such, we are unable to draw definitive conclusions on the effect of elective IABP insertion on mortality alone. A larger sample size and more protracted follow-up would reduce the potential for a type II error, although we note that this is the largest randomized controlled trial of elective IABP therapy in this high-risk population to date. We are currently reviewing medium-term mortality data.
Perera D, Stables R, Redwood S. Elective Intra-aortic Balloon Pump Placement in High-Risk Percutaneous Coronary Intervention—Reply. JAMA. 2010;304(20):2240-2242. doi:10.1001/jama.2010.1700