Epidemiology of Myocardial Infarction

The Clinical Practice Research Datalink (CPRD) is an ongoing primary care database of anonymised medical records from general practitioners, with coverage of over 11.3 million patients from 674 practices in the UK. With 4.4 million active (alive, currently registered) patients meeting quality criteria, approximately 6.9% of the UK population are included and patients are broadly representative of the UK general population in terms of age, sex and ethnicity. General practitioners are the gatekeepers of primary care and specialist referrals in the UK. The CPRD primary care database is therefore a rich source of health data for research, including data on demographics, symptoms, tests, diagnoses, therapies, health-related behaviours and referrals to secondary care. For over half of patients, linkage with datasets from secondary care, disease-specific cohorts and mortality records enhance the range of data available for research. The CPRD is very widely used internationally for epidemiological research and has been used to produce over 1000 research studies, published in peer-reviewed journals across a broad range of health outcomes. However, researchers must be aware of the complexity of routinely collected electronic health records, including ways to manage variable completeness, misclassification and development of disease definitions for research.

despite the widespread use of electrocardiographic changes to characterize patients presenting with acute myocardial infarction, little is known about recent trends in the incidence rates, treatment, and outcomes of patients admitted for acute myocardial infarction further classified according to the presence of ST-segment elevation. The objectives of this population-based study were to examine recent trends in the incidence and death rates associated with the 2 major types of acute myocardial infarction in residents of a large central Massachusetts metropolitan area. We reviewed the medical records of 5383 residents of the Worcester (MA) metropolitan area hospitalized for either ST-segment elevation acute myocardial infarction (STEMI) or non-ST-segment acute myocardial infarction (NSTEMI) between 1997 and 2005 at 11 greater Worcester medical centers. the incidence rates (per 100,000) of STEMI decreased appreciably (121 to 77), whereas the incidence rates of NSTEMI increased slightly (126 to 132) between 1997 and 2005. Although in-hospital and 30-day case-fatality rates remained stable in both groups, 1-year postdischarge death rates decreased between 1997 and 2005 for patients with STEMI and NSTEMI. the results of this study demonstrate recent decreases in the magnitude of STEMI, slight increases in the incidence rates of NSTEMI, and decreases in long-term mortality in patients with STEMI and NSTEMI. Our findings suggest that acute myocardial infarction prevention and treatment efforts have resulted in favorable decreases in the frequency of STEMI and death rates from the major types of acute myocardial infarction. 2011 Elsevier Inc. All rights reserved.