Response to Letter Regarding Article, “Risk Index for Perioperative Renal Dysfunction/Failure: Critical Dependence on Pulse Pressure Hypertension”

We thank Dr Augoustides for his interest regarding our study1 and are pleased to respond to his questions regarding the independent effects of use of perioperative aprotinin and preoperative ACE inhibitors (ACEI). To assess the effect of aprotinin on our findings, we must realize certain limitations: (1) the analysis is post hoc, for our formal design for this question (2001) did not include aprotinin; and (2) such analysis would include only one half of our cohort (the derivation cohort), reducing the sample size by 2420 patients, and further reduction for multiple drugs/incomplete information …