The U.S. FDA’s final guidance for clinical decision support (CDS) systems may be the subject of two citizen’s petitions requesting the agency scrap the guidance and start over, but that doesn’t mean the agency is not enforcing the terms of the guidance. Danvers, Mass.-based Abiomed Inc., took in a Sept. 19 warning letter stating that the company’s Impella Connect system qualifies as a CDS product because it provides “patient-specific medical information to detect a life-threatening condition,” an interpretation that is sure to intensify the larger debate about whether the CDS final guidance is an extra-statutory exercise in regulatory engineering.