Of course, individual circumstances during a case often will dictate whether the use of additional contrast is worthwhile for the safety of the pro- cedure. Nevertheless, recording the total volume of contrast used for each case, as required by the measure, should serve as the first step toward understanding and modifying patterns of contrast use in cardiac catheterization laboratories. 5.6. Radiation Dose Documentation Current guidelines recommend that procedural radiation dose should be recorded for all patients and should be limited to as low as reasonably achievable, according to clinical circum- stances. Measures of radiation dose include total air kerma at the interventional reference point, air kerma area product, fluoroscopy time, and number of cine images.4 Furthermore, it is recommended that every catheterization laboratory define thresholds, with corresponding follow-up protocols, for patients who receive a high procedural radiation dose. It is most typical to report total fluoroscopy time, but the writing committee recognized that this is a limited measure of total radiation exposure and dose. All contemporary interventional x-ray systems report the total air kerma area product (in Gray [Gy]) and air kerma area product (in Gycm2 ). When available, one or both of these measures should be documented in the procedure report in addition to fluoroscopy time. At the pres- ent time, the writing committee designated this measure for internal quality improvement only to avoid potential unin- tended consequences, such as operators feeling a need to limit additional imaging even when it would be clinically useful (see Appendix C for a summary of the analysis). 5.7. Postprocedural Optimal Medical Therapy Composite Medical therapy, including aspirin, P2Y12 inhibitors, and statins, has been proved to reduce all-cause mortality and car- diovascular morbidity in multiple studies. 