Therefore, although this measure is expected to have limited impact because it requires only documentation, it is an intermediate step to a more meaningful performance measure. Radiation Dose Documentedz 2,3,4 1 There are few potential unintended consequences given that there are no thresholds speci ed in this measure. However, evidence indicates that doses are inconsistently documented. Therefore, although this measure is expected to have limited impact because it requires only documentation, it is an intermediate step to a more meaningful performance measure. Postprocedural Optimal Medical Therapy Compositey 1,2,3,4 Registry data are currently limited, making it unfeasible to capture speci c medical, patient, or system exceptions. Cardiac Rehabilitation Patient Referraly 1,2,3,4 Regional or National PCI Registry Participationy 2,3,4 1 The guideline Class of Recommendation is 1, but Level of Evidence is only C. Annual Operator PCI Volumez 2,3b 1,3a,4  There are potential unintended consequences because opera- tors might be more inclined to intervene when the procedure is not indicated.  This measure could pose a feasibility challenge if a person works at multiple sites. Annual Hospital PCI Volumey 2,3 1,4 Smaller hospitals might be more inclined to intervene when the procedure is not indicated, to achieve higher volumes. Measures considered but not included in the performance measure set Assessment of patient knowledge of bene ts and risks of PCI 1,4b 2,3,4a  Limited availability of validated surveys.  Limited existing literature on patient education or actionable methods to improve it. Postprocedural dialysis 1 2,3,4  Dialysis might not be related to PCI.  Long measurement period is needed to capture data, given it is a rare event. Postprocedural blood transfusion 1 3,4 Bleeding might occur outside interventionalists locus of control. Measurement of cardiac biomarkers N/A 1,2,3,4 Evidence is still controversial. 