Contemporary approach to management of unstable angina

Abstract

Unstable angina pectoris is one of the commonest diseases requiring hospital admission in Western countries, the estimated incidence being 2 per 1000 admissions annually. 1 Chierchia S Current therapeutic strategies in unstable angina. Eur Heart J. 1999; 1: 2-6 Google Scholar The course of the disease is highly variable; in some patients an anginal attack progresses rapidly to myocardial infarction or death, whereas in others there is uneventful recovery in 24 h. How best to manage patients is of crucial importance because of the high risk of myocardial infarction (15–20%) and death (15%) in the ensuing 3 months. 2 Théroux P Lidon RM Unstable angina:pathogenesis, diagnosis and treatment. Curr Probl Cardiol. 1993; 18: 159-214 Summary Full Text PDF Scopus (31) Google Scholar Endothelial dysfunction, plaque erosion and rupture, platelet adhesion and aggregation, and thrombus formation contribute to the pathogenesis of unstable angina. The goal of medical therapy is to relieve symptoms (primarily with classic antianginal agents such as nitrates, β-blockers, or calcium antagonists alone or in combination) and to stabilise plaque. Anticoagulation with intravenous heparin or low-molecular-weight heparin given together with aspirin and, more recently, glycoprotein IIb/IIIa inhibitors reduces the likelihood of myocardial infarction, with a trend towards reduced mortality. 3 PRISM PLUS Study Investigators.Inhibition of the platelet glycoprotein IIb/IIIa receptor with tirofiban in unstable angina and non-Q-wave infarction. N Engl J Med. 1998; 338: 1488-1497 Crossref PubMed Scopus (1647) Google Scholar The rationale for the use of heparin (fractionated or unfractionated) is based on many trials and meta-analyses. 4 Oler S Whooley MA Oler J Grady D Adding heparin to aspirin reduces the incidence of myocardial infarction and death in patients with unstable angina. JAMA. 1996; 276: 811-815 Crossref PubMed Google Scholar In the Fragmin during Instability in Coronary Artery Disease (FRISC) study, dalteparin was superior to placebo in reducing the incidence of death and myocardial infarction in patients presenting with unstable angina. 5 Fragmin during Instability in Coronary Artery Disease (FRISC) study group.Low-molecular-weight heparin during instability in coronary artery disease. Lancet. 1996; 347: 561-568 Summary PubMed Google Scholar How long to give heparin remained uncertain until the FRISC II medical-management study, reported in this issue of The Lancet, showed that 3 months of dalteparin lowered the risk of death and myocardial infarction and need for revascularisation by about 13% at the end of that period (this benefit being due largely to the reduced need for revascularisation). Invasive compared with non-invasive treatment in unstable coronary-artery disease: FRISC II prospective randomised multicentre studyThe early invasive approach should be the preferred strategy in most patients with unstable coronary-artery disease who have signs of ischaemia on electrocardiography or raised biochemical markers of myocardial damage. Full-Text PDF Long-term low-molecular-mass heparin in unstable coronary-artery disease: FRISC II prospective randomised multicentre studyLong-term dalteparin lowers the risk of death, myocardial infarction, and revascularisation in unstable coronary-artery disease at least during the first month of therapy. These early protective effects could be used to lower the risk of events in patients waiting for invasive procedures. Full-Text PDF