Is the COMPASS pointing towards clinical equipoise for the right internal mammary artery?

The right internal mammary artery (RIMA) has been considered the second-best graft after the left internal mammary artery by many. Recent guidelines have awarded class IIa recommendation for using the RIMA. The findings of the Cardiovascular Outcomes for People Using Anticoagulation Strategies (COMPASS)-coronary artery bypass grafting (CABG) sub-study showed a high graft failure rate for the RIMA. The findings of the study should initiate further scientific scrutiny of the RIMA and studies need to be carried out for further evaluation of the RIMA as a conduit.