Evidence-based medical therapy of patients with acute coronary syndromes.
Acute coronary syndromes (ACS) present a major health challenge in modern medicine. With new clinical trials being conducted, our knowledge of latest therapies for ACS continually evolves. In this article, we review currently available medical therapies and provide evidence-based rationale for current pharmacologic therapies. Among the antiplatelet therapies, aspirin, clopidogrel, and glycoprotein IIb/IIIa inhibitors demonstrate significant efficacy in reducing morbidity and mortality. Among the anticoagulants, unfractionated heparin and low molecular weight heparin, particularly enoxaparin sodium, remain the hallmarks of therapy against which newer anticoagulants are often compared. Bivalirudin has recently showed significant efficacy in decreasing cardiovascular events and mortality, but with potentially less risk of bleeding than heparin. Results of trials evaluating warfarin remain inconsistent regarding potential benefits. Finally, fondaparinux sodium, recently tested, shows promise as a powerful yet safe anticoagulant. Fibrinolysis is an acceptable modality for reperfusion if facilities equipped for primary percutaneous revascularization are not available. Regarding anti-ischemic therapy, beta-adrenoceptor antagonists and nitrates remain critical in the early management of ACS. Inhibitors of the renin-angiotensin-aldosterone system have also shown significant reductions in the morbidity and mortality of patients presenting with ACS, particularly in patients with left ventricular dysfunction and clinical heart failure, with ACE inhibitors being first-line agents and angiotensin receptor antagonists being a reasonable substitute if ACE inhibitors are not tolerated. Among the lipid-lowering therapies, statins (HMG-CoA reductase inhibitors) have been documented as being the most well tolerated and most efficacious therapies for ACS patients and data exist that they should be administered early in ACS management. Studies evaluating combination therapy (antiplatelet drugs, beta-adrenoceptor antagonists, ACE inhibitors, and lipid-lowering agents) show a clear benefit in mortality in patients with known coronary artery disease. Efforts to improve these key evidence-based medical therapies are numerous and include such programs as the American College of Cardiology's Guidelines Applied in Practice, international patient registries such as the Global Registry of Acute Coronary Events, and studies such as CRUSADE. Finally, patients with diabetes mellitus pose a challenge to clinicians both in terms of their glycemic control and in their apparent relative resistance to antiplatelet therapy. Studies involving ACS patients suggest that stringent glycemic control may result in benefits in both morbidity and mortality.
Ramanath
Vijay S
VS
University of Michigan Medical Center, 300 N. Ingalls, Ann Arbor, MI 48109, USA. vijayr@med.umich.edu
Eagle
Kim A
KA
D000208:Acute Disease; D000789:Angina, Unstable / Q000175:diagnosis / Q000188:drug therapy*; D000925:Anticoagulants / Q000494:pharmacology / Q000627:therapeutic use; D002317:Cardiovascular Agents / Q000494:pharmacology / Q000627:therapeutic use; D003924:Diabetes Mellitus, Type 2 / Q000150:complications; D004359:Drug Therapy, Combination; D019317:Evidence-Based Medicine; D005343:Fibrinolytic Agents / Q000494:pharmacology / Q000627:therapeutic use; D006801:Humans; D000960:Hypolipidemic Agents / Q000494:pharmacology / Q000627:therapeutic use; D009203:Myocardial Infarction / Q000175:diagnosis / Q000188:drug therapy*; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology / Q000627:therapeutic use*; D017410:Practice Guidelines as Topic
D000925:Anticoagulants; D002317:Cardiovascular Agents; D005343:Fibrinolytic Agents; D000960:Hypolipidemic Agents; D010975:Platelet Aggregation Inhibitors