A nurse in an emergency department is receiving report on a group of clients. Which of the following clients should the nurse assess first?

A. A client with a femur fracture and pain level of 7: Although painful, it is not immediately life-threatening compared to a myocardial infarction. B. A client who has left shoulder pain and S-T elevation on a 12-lead ECG: ST-segment elevation indicates acute myocardial infarction (STEMI). This is a medical emergency requiring immediate interventions to restore coronary perfusion (e.g., oxygen, nitrates, antiplatelets, possible PCI). C. A client with C. difficile and fever: This infection requires isolation and treatment but does not pose an immediate threat to life. D. A client with heart failure and 2+ edema: This is a chronic condition and can safely wait for assessment after the emergent cardiac case.