Updated: 12/28/2021

Antianginal Drugs

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  • Snapshot
    • A 54-year-old man presents to the emergency department after experiencing pressure-like sternal chest pain that radiates down the left arm. Medical history is significant for hypertension, hypercholesterolemia, and type II diabetes. He smokes 2 packs of cigarettes per day for the past 25 years. On physical exam, the patient appears anxious and diaphoretic. An electrocardiogram demonstrates an ST-segment elevation in leads V1-V4. Cardiac troponins are sent. He is given aspirin, nitroglycerin, metoprolol, clopidogrel, and unfractionated heparin. The cardiac catheterization lab is activated .
  • Introduction
    • Appropriate treatment for acute coronary syndrome must be instituted immediately in order to
      • limit myocardial damage
      • decrease the risk of complications
      • restore the balance between myocardial oxygen supply and demand
  • NSTEMI and Unstable Angina (UA)
    • Introduction
      • NSTEMI and UA are managed in the same manner
      • the goal is to to provide
        • anti-ischemic therapy
          • restores the myocardial oxygen supply and demand
        • anti-thrombotic therapy
          • prevents further growth of the partial thrombotic occlusion
    • Medications
      • anti-ischemic therapy
        • β-blockers (e.g., metoprolol)
          • mechanism
            • decreased sympathetic drive to the heart
              • promotes myocardial electrical stability
              • decreases myocardial demand
              • ↓ cAMP
            • improves mortality in patients with an MI
          • contraindications
            • bronchospasm
            • decompensated heart failure
            • hypotension
        • nitrates (e.g., nitroglycerin, isosorbide mononitrate, and dinitrate)
          • mechanism
            • venodilation reduces preload to the heart, which reduces myocardial demand
              • recall that a reduction in preload reduces ventricular wall stress
            • afterload reduction and decreased SVR
            • coronary artery dilation improves blood flow to the myocardium
              • recall that venodilation >> arterial dilation
              • this can steal blood from already maximally dilated ischemic myocardium
            • ↑ cGMP
          • adverse events
            • nitroprusside causes cyanide toxicity
            • development of tolerance for the vasodilating action during the work week
            • a headache may result from vasodilation of cerebral arteries
            • can results in hypotension when combined with other blood pressure lowering medications
        • calcium channel blockers (e.g., verapamil and diltiazem)
          • mechanism
            • reduces heart rate and cardiac contractility
            • this medication is reserved for patients unresponsive to β-blockers and nitrates or have contraindications to β-blockers
              • this is because calcium channel blockers do not provide a mortality benefit
      • anti-thrombotic therapy
        • aspirin
          • mechanism
            • an inhibitor of thromboxane A2 synthesis
              • thromboxane A2 is a prominent promoter of platelet activation
            • improves mortality and should be continued indefinitely
        • P2Y12 ADP receptor inhibitor (e.g., clopidogrel and ticagrelor)
          • mechanism
            • prevents ADP from binding to the P2Y12 receptor, which would normally further activate platelets
      • anti-coagulation therapy
        • unfractionated heparin
          • mechanism
            • binds to antithrombin to enhance its effects
            • inhibits factor Xa
  • ST-Segment Elevation Myocardial Infarction (STEMI)
    • Introduction
      • STEMI suggest that there is a total occlusion of the vessel
        • thus the main goal is to induce rapid reperfusion via
          • percutaneous coronary intervention (PCI) OR
          • fibrinolytic therapy
        • patients are also given medications such as those used in NSTEMI and UA
          • aspirin
          • unfractionated heparin
          • β-blockers
          • nitrates
          • P2Y12 ADP receptor inhibitor
    • Reperfusion therapy
      • primary PCI
        • the preferred method for reperfusion
        • must be performed within 90 minutes of first medical contact
          • aspirin and a P2Y12 receptor inhibitor is given prior to the procedure
      • fibrinolytic therapy (e.g., alteplase)
        • performed if PCI cannot be performed within 90 minutes or is unavailable
        • fibrinolytics convert plasminogen to plasmin, which degrades newly formed clots
  • Adjunctive Therapy
    • Angiotensin-converting enzyme (ACE) inhibitors (e.g., lisinopril)
      • provides a mortality benefit
      • prevents ventricular cardiac remodeling and reduces the rate of heart failure
    • Statins (e.g., atorvastatin)
      • an HMG-CoA reductase inhibitor that lowers cholesterol levels
  • Therapy And Their Effect On Mortality
    • Effect on Mortality of Therapy Used in Acute Coronary Syndromes
      Mortality Benefit
      No Mortality Benefit
      • Aspirin
      • β-blockers
      • PCI
      • Statins
      • P2Y12 ADP receptor inhibitor
      • Thrombolytics
      • Oxygen
      • Morphine
      • Nitrates
      • Calcium channel blockers
      • Lidocaine
      • Amiodarone
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