Letters Section Editor: Robert M. Golub, MD, Senior Editor.
In Reply: In response to Dr Rosenberger and colleagues, in our original analyses peripheral vascular disease did not meet pre-specified criteria for retention in the final clinical prediction rule. When peripheral vascular disease was forced into the final model, the interaction term between peripheral vascular disease and preoperative IABP was not statistically significant (P = .79). Nonetheless, this finding does not disprove a deleterious interaction between aortic calcification and IABP. Our data set did not capture the presence or location of aortic atheroma; hence, it was not ideally suited to evaluate this physiologically plausible hypothesis. Studies that use methods such as echocardiography to capture this information should be performed, and thereby better determine if optimal IABP positioning attenuates kidney injury.
Wijeysundera DN, Karkouti K, Beattie WS. Predictive Index for Renal Replacement Therapy—Reply. JAMA. 2007;298(7):737-738. doi:10.1001/jama.298.7.737-b