Therapy to improve PCI outcome.
A 56-year-old African-American male admitted to your hospital with progressive angina had percutaneous coronary intervention (PCI) with stent placement in the right coronary and circumflex arteries. The patient's medical history is significant for hypertension, Type 2 diabetes, and 35% left ventricular ejection fraction. The resident plans to discharge the patient on carvedilol 3.125 mg and glyburide 10 mg twice daily, and hydrochlorothiazide 25 mg daily. He recognizes the need for anticoagulation/antithrombotic therapy. What do you suggest and why?
Following intracoronary stent placement, combination aspirin and clopidogrel antiplatelet therapy is used to prevent death, myocardial infarction, and revascularization. The 2001 American College of Cardiology/American Heart Association guidelines for PCI recommend 300 mg clopidogrel initially prior to PCI, followed by 75 mg daily for four weeks in combination with chronic aspirin 80-325 mg daily.
The CREDO trial (November 2002) confirmed that in patients treated with aspirin plus clopidogrel for 28 days post-PCI, pretreatment with clopidogrel plus aspirin prior to PCI decreased relative risk of death, MI, or revascularization by 18.5% compared with pretreatment with aspirin alone. After four weeks of initial combination therapy, long-term use of clopidogrel plus aspirin reduced the one-year relative risk of death, MI, or stroke by 27% compared with long-term aspirin alone. Benefits were seen without increased risk of minor or major bleeding compared with aspirin alone.
Aside from the risk of bleeding, clopidogrel is generally well tolerated, with only a small risk of thrombotic thrombocytopenic purpura. A baseline platelet count, hematocrit, and serum creatinine should be obtained and repeated based on symptom development.
The ACC/AHA PCI guidelines recommend daily aspirin and clopidogrel following a PCI with stent placement. So this patient should be started on aspirin 75 mg to 325 mg daily and clopidogrel 75 mg daily. After 30 days, clopidogrel may be stopped; however, the results of the CREDO trial suggest that a longer duration of the antiplatelet combination may provide additional benefit. The patient should continue daily aspirin indefinitely.
This patient should also be started on an ACE inhibitor for secondary prevention of coronary events and treatment of systolic dysfunction. Because of his diabetes, his blood pressure goal is < 130/80 mm Hg. A cholesterol panel should be drawn to evaluate lipid levels. In patients with established coronary disease, the LDL goal is < 100 mg/dl.
The addition of an HMG-CoA reductase inhibitor (statin) should be considered. Before beginning a statin, hepatic function should be assessed. Three months after initiation of statin therapy, hepatic panel should be checked to ensure AST and ALT levels have not increased from baseline. The other medications that were started should also be continued.
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Kathy Hitchens. Clinical Twisters: Therapy to improve PCI outcome. Drug Topics 2002;23:HSE 18.