A multitude of randomized clinical trials have demonstrated the benefits of several classes of medications in the treatment of patients with one of the acute coronary syndromes (ACS). Therapeutics that have proven efficacy include aspirin,1,2 fibrinolytic therapy,3 beta-blockers,4–6 and the platelet glycoprotein IIb/IIIa inhibitors.7,8 However, despite this extensive and compelling body of evidence, registries have consistently documented underuse of these medications.9–13 To improve care and outcomes, the American College of Cardiology, the American Heart Association, and the European Society of Cardiology have developed guidelines for the management of acute myocardial infarction (MI) and for unstable angina and non-ST elevation MI.14–16 These guidelines, based on “evidence-based medicine,” promise to improve outcomes and reduce variability in the delivery of clinical care. We sought to evaluate compliance to these guidelines at a major tertiary care center.
From September 1, to October 31, 2001, all patients admitted to coronary care unit at a tertiary medical center were screened. Patients were evaluated on daily morning rounds by the attending physician. All patients with a primary diagnosis at the time of coronary care unit admission of acute MI or unstable angina/non-ST elevation MI ACS were evaluated. Patients who were transferred from another hospital >24 hours after the onset of ACS were excluded.
Information collected about each patient included baseline demographics, electrocardiogram and cardiac marker data, reperfusion therapy, fibrinolytic treatment or primary percutaneous coronary intervention for acute MI, and medication prescriptions as ordered in the first 24 hours. Data were recorded by a physician (M.L.S.) in a Microsoft Excel 97 spreadsheet (Microsoft, Redmond, WA) and the results tabulated.
Over the 2-month period of observation, a total of 80 patients meeting the eligibility criteria were identified. All were followed for the first 24 hours.
There were 51 (63%) men and 29 (37%) women. The age distribution is shown in Figure 1 and varied from 30 to 90 years, with a mean age of 62.5 years. ST elevation MI accounted for 31 patients (40%), left bundle branch block in 2 patients (2.5%), non-ST elevation MI ACS in 26 patients (32.5%), and unstable angina ACS in 21 patients (25%) (Figure 2). Figure 3 shows the implementation of guideline-recommended therapy during the first 24 hours of admission. Aspirin and heparin (either unfractionated or low molecular weight heparin) were administered to 100% of patients. A total of 74 (92.5%) patients received oral and/or intravenous beta-blockers in the first 24 hours. Of the five patients who did not receive beta-blockers, all had had contraindications (complete atrioventricular block in two patients, cocaine use and presumed spasm in two patients, and one patient with severe pulmonary disease). Angiotensin-converting enzyme inhibitors and lipid-lowering therapy were prescribed in 53.8% and 51.3% of patients, respectively.
Of the total group, there were 31 patients with ST elevation MI and two patients with acute MI with left bundle branch block. For acute ST elevation MI 14 (45.2%) patients received fibrinolytic therapy alone and six (19.4%) patients underwent primary percutaneous coronary intervention. In addition, nine (27.2%) patients were treated with fibrinolytic and underwent early coronary angiography. Neither of the two patients with left bundle branch block received fibrinolysis or underwent primary percutaneous coronary intervention. Thus, a total of 29 of 33 (87.9%) with acute ST elevation MI or left bundle branch block received reperfusion therapy.
Of the total group of ACS, 42 patients underwent percutaneous coronary intervention. Of these, 40 (95.2%) underwent percutaneous coronary intervention with adjunctive glycoprotein IIb/IIIa inhibition, which was usually eptifibatide.
Figure 4 shows the variability (labeled 1-5) in the adherence of the prescribed medications by the coronary care unit attending physician. Angiotensin-converting enzyme inhibitor use ranged from 33% to 67%, whereas lipid-lowering therapy ranged from 20% to 52% in the first 24 hours.
We observed a very high rate of compliance to “evidence-based medicine” in this survey of ACS patients admitted to a tertiary care hospital coronary care unit. Aspirin, heparin, and beta-blocker use was 100% of patients without contraindications. Angiotensin-converting enzyme and lipid-lowering therapy was received in approximately half of the observed patients, which matches the strength of the clinical data on the use of these agents in the first 24 hours.17–19 We did observe some variability in the use of these medications, suggesting that further clarification of which patients should be treated with these agents is needed.
Our findings suggest that a tertiary care center that participates in clinical trials is an ideal environment for implementation of guidelines and evidence-based medicine. A predominant facilitating feature is the conduct of daily multidisciplinary group rounds with an attending physician, cardiology fellows, house staff, a clinical pharmacist, and nursing staff. Our findings suggest that this approach to open communication is a system that embraces the highest levels of appropriate, data-driven medical treatment.
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