Secondary prevention after acute coronary syndrome: antiplatelet therapy and risk factor control

Background: One of the leading causes of death and disability worldwide is cardiovascular disease (CVD), including acute myocardial infarction (AMI). Despite improvements in medical treatment, management, and care over the years and the halving of mortality in recent decades, there is considerable room for improvement. Following myocardial infarction (MI), a patient is at great risk for subsequent infarctions or other related complications. In addition, the risk of ischemic stroke is increased following MI. Secondary prevention after MI is paramount for reducing further complications and consists of lifestyle changes, optimised medical treatment, and risk factor control of blood pressure (BP) and blood lipid levels. Although secondary preventive measures are effective, the proportion of patients reaching set treatment target levels is disappointingly low. Most patients are prescribed dual antiplatelet therapy (DAPT) following MI as part of their secondary preventive treatment. Several articles have been published on treatment efficacy based on comparisons with different kinds of antiplatelet drugs and in different combinations. However, little data specifically address the incidence of ischemic stroke after MI in real-world populations. In addition to antiplatelet treatment, secondary prevention comprises risk factor control of hypertension and hyperlipidaemia. Given the low proportion of patients reaching set target levels for BP and blood lipids, new strategies are needed. Aims: The aim of this dissertation is partly to elucidate if the rapid change in preferred DAPT in Sweden, from clopidogrel to ticagrelor in addition to aspirin, affected the incidence of ischemic stroke in patients suffering AMI (paper I) and in patients suffering AMI who have a history of ischemic stroke (paper II). The second part of the dissertation aims to investigate the feasibility and implementation of a randomised controlled trial of a nurse-led telephone-based secondary preventive program, and to assess the proportion of patients who can be included in an unselected acute coronary syndrome (ACS) population (paper III). Furthermore, the aim of the trial was to assess the long term results regarding systolic BP (SBP), diastolic BP (DBP), and low-density lipoprotein cholesterol (LDL-C) after 36 months of intervention and follow-up compared to a control group receiving usual care (paper IV). Methods: Papers I and II examined the impact of a change in the antiplatelet regimen f