A 64-year-old man is brought to the emergency room for complaints of chest pressure, difficulty breathing, and palpitations. He has a past medical history of hypertension and type 2 diabetes and ischemic stroke and his home medications include metformin, glyburide, lisinopril, and aspirin. ECG on arrival reveals ST-segment elevation in leads I, avL and V5 to V6 . Catheterization laboratory is activated and the patient is given 325 mg of aspirin and started on nitroglycerin drip.
Which of the following additional therapies is currently indicated?
Clopidogrel 600 mg, bivalirudin drip, and atorvastatin 80 mg. This patient has acute MI. Current ACC/AHA guidelines mandate adjunctive medical therapy in addition to aspirin, including loading dose of P2Y12 receptor inhibitor (clopidogrel 600 mg, prasugrel 60 mg, or ticagrelor 180 mg) and anticoagulant therapy (unfractionated heparin or bivalirudin). Fondaparinux (a) should not be used as a sole anticoagulant to support primary PCI as it has been shown to increase catheter thrombosis. Prasugrel is contraindicated in patients with history of stroke.
Which of the following is true regarding adjunctive medical therapy in patients with acute MI receiving primary PCI?
Mortality benefit with routine intravenous nitroglycerin is not established. Although widely used, no randomized trial has established a mortality benefit with intravenous nitroglycerin. Intravenous ACE-I formulations have no proven benefit and were associated with increased mortality in Cooperative North Scandinavian Enalapril Survival Study (CONSENSUS 2). Routine intravenous β-blocker use within 24 hours also did not have any impact on mortality and led to higher rates of cardiogenic shock in the Clopidogrel and Metoprolol in Myocardial Infarction Trial/Second Chinese Cardiac Study (COMMIT/CCS-2) megatrial. No benefit with intravenous magnesium was noted in the National Heart, Lung and Blood Institute (NHLBI)-supported Myoblast Autologous Grafting in Ischemic Cardiomyopathy (MAGIC) trial.
Which of the following statements is incorrect with regard to acute MI?
Fibrinolysis should be considered 12 hours after symptom onset in hemodynamically stable patients with signs of ongoing ischemia. Fibrinolysis has not been shown to be useful and may even lead to harm after 12 hours of symptom onset in patients with STEMI. Two large, randomized trials (Late Assessment of Thrombolytic Efficacy (LATE) and Enhanced Myocardial Efficacy and Removal by Aspiration of Liberated Debris (EMERAS)) investigated the utility of late fibrinolysis in patients with STEMI and found no mortality benefit beyond 12 hours of symptom onset. Primary PCI is associated with reduced rate of intracerebral hemorrhage when compared with fibrinolysis. If rapidly available, primary PCI has been convincingly shown to reduce mortality when compared with fibrinolysis. Primary PCI may be considered 12 hours after symptom onset in patients with signs of ongoing ischemia. While primary PCI should be considered in patients with signs of ongoing ischemia 12 to 24 hours after symptom onset, routine PCI of the totally occluded infarct-related artery >24 hours after presentation in hemodynamically stable patients without signs of ischemia provides no additional benefit and may even be harmful. Delayed PCI (3 to 28 days after MI) of the occluded asymptomatic Infarct Related Artery (IRA) was evaluated in the randomized Occluded Artery Trial (OAT). While PCI did not reduce the occurrence of death, reinfarction, or heart failure, there was a trend toward excess reinfarction during long-term follow-up in stable patients.
Which of the following is an absolute contraindication for use of fibrinolytics for acute MI?
Suspected aortic dissection. Suspected aortic dissection is an absolute contraindication for use of fibrinolysis. History of stroke, pregnancy, use of warfarin, and history of seizure disorders are all relative contraindications for fibrinolysis.
Which of the statements is true regarding ventricular septal rupture (VSR) after acute MI?
Presence of collateral circulation in the infarct zone reduces risk of VSR. VSR is more likely in women and after first MI. Fibrinolytic therapy is not associated with increased risk of VSR but may accelerate rupture in vulnerable subjects. VSR is equally likely after anterior or nonanterior wall MI.
Click to expand