Acute coronary syndrome: unstable angina and non-ST segment elevation myocardial infarction

Abstract

The term acute coronary syndrome refers to a range of acute myocardial ischaemic states. It encompasses unstable angina, non-ST segment elevation myocardial infarction (ST segment elevation generally absent), and ST segment elevation infarction (persistent ST segment elevation usually present). This article will focus on the role of percutaneous coronary intervention in the management of unstable angina and non-ST segment elevation myocardial infarction; the next article will address the role of percutaneous intervention in ST segment elevation infarction.Although there is no universally accepted definition of unstable angina, it has been described as a clinical syndrome between stable angina and acute myocardial infarction. This broad definition encompasses many patients presenting with varying histories and reflects the complex pathophysiological mechanisms operating at different times and with different outcomes. Three main presentations have been describedangina at rest, new onset angina, and increasing angina. PathogenesisThe process central to the initiation of an acute coronary syndrome is disruption of an atheromatous plaque. Fissuring or rupture of these plaques-and consequent exposure of core constituents such as lipid, smooth muscle, and foam cells-leads to the local generation of thrombin and deposition of fibrin. This in turn promotes platelet aggregation and adhesion and the formation of intracoronary thrombus.Unstable angina and non-ST segment elevation myocardial infarction are generally associated with white, platelet-rich, and only partially occlusive thrombus. Microthrombi can detach and embolise downstream, causing myocardial ischaemia and infarction. In contrast, ST segment elevation (or Q wave) myocardial infarction has red, fibrin-rich, and more stable occlusive thrombus.

Physical health status assessed during hospitalization for acute coronary syndrome predicts mortality 12 months later

“…ACS includes unstable angina (UA), in which myocardial ischemia is not severe or prolonged enough to cause detectable necrosis of heart muscle, and myocardial infarction (MI) in which detectable necrosis can be demonstrated. Acute myocardial infarction (AMI), in turn, is categorized based on the appearance of the electrocardiogram as either non-ST-segment elevation MI or ST-segment elevation MI [21]. No studies have investigated whether patient-reported health status assessed during hospitalization for ACS predicts post-discharge mortality, and, if so, whether it continues to predict mortality after controlling for prognostic variables that have been shown to affect survival, including symptoms of depression.…”

Evaluative and Discriminative Properties of the Portuguese MacNew Heart Disease Health-related Quality of Life Questionnaire

“…As a measure of the patient's perspective, the MacNew Heart Disease Health-related Quality of Life questionnaire (MacNew) is a self-administered health-related quality of life (HRQL) questionnaire, validated and used with patients with myocardial infarction (MI) and patients with angina [3]. Acute coronary syndrome (ACS) refers to a range of acute myocardial ischemia states comprising a spectrum of conditions that includes unstable angina and acute MI and characterized by the common pathophysiologic process of a disrupted atherosclerotic plaque [4,5]. As the MacNew has not yet been validated in Portuguese, the purpose of this study was to examine the evaluative and discriminative properties of the Portuguese version of the MacNew in patients with a diagnosis of ACS.…”

Custo-efetividade de fondaparinux em pacientes com Síndrome Coronariana Aguda sem supradesnivelamento do ST

“…In Brazil, as well as in developed countries, cardiovascular disease is the leading cause of death 1,2 . According to the Ministry of Health in 2005, cardiovascular diseases accounted for about one third of deaths in Brazil 3 .…”