The mandate to weigh risks and benefits for use of cardiac rhythm devices (specifically implantable cardioverter/defibrillators [ICDs]) for the primary prevention of sudden cardiac death is substantial, given the cost of the devices and their potential impact on patient outcomes including health-related quality of life. Recent studies have demonstrated that comorbidities such as renal failure,1,2 underuse of β-blockers,3 and inappropriate timing of implants4 are all in play. In their analysis, Miller and colleagues5 use data from the National Cardiovascular Data Registry (NCDR) to assess whether patients undergoing device implantation with reduced ejection fraction are receiving optimal medical therapy (OMT) for congestive heart failure.5 This is a descriptive analysis for the period January 2007 to June 2009 that relies on NCDR reports by the participating institution of medication use at discharge. Given the limitations of the NCDR (for example, the lack of linkage to patient and pharmacy records), the investigators do not have information about antecedent and subsequent medication adherence or medication dosing. Furthermore, the authors acknowledge that, as for many NCDR data elements, on-site auditing was not performed on the medication variable.