Predictors of non-invasive therapy and 28-day-case fatality in elderly compared to younger patients with acute myocardial infarction: an observational study from the MONICA/KORA Myocardial Infarction Registry

Amann et al. BMC Cardiovascular Disorders (2016) 16:151 DOI 10.1186/s12872-016-0322-3 RESEARCH ARTICLE Open Access Predictors of non-invasive therapy and 28-day-case fatality in elderly compared to younger patients with acute myocardial infarction: an observational study from the MONICA/KORA Myocardial Infarction Registry Ute Amann1,2*, Inge Kirchberger1,2, Margit Heier1,2, Christian Thilo3, Bernhard Kuch3,4, Annette Peters2 and Christa Meisinger1,2 Abstract Background: A substantial proportion of patients with acute myocardial infarction (AMI) did not receive invasive therapy, defined as percutaneous coronary intervention and/or coronary artery bypass grafting. Aims of this study were to evaluate predictors of non-invasive therapy in elderly compared to younger AMI patients and to assess the association between invasive therapy and 28-day-case fatality. Methods: From the German population-based registry, 3475 persons, consecutively hospitalized with an AMI between 2009 and 2012 were included. Data were collected by standardized interviews and chart review. All-cause mortality was assessed on a regular basis. Multivariable logistic regression analyses were conducted. Results: The sample consisted of 1329 patients aged 28–65 years (age category [AC] 1), 1083 aged 65–74 years (AC 2), and 1063 aged 75–84 years (AC 3). The proportion of patients receiving non-invasive therapy was 10.7, 17.7, and 35.8 % in AC 1, 2, and 3, respectively. Predictors of non-invasive therapy in all ACs were non-ST segment elevation MI, bundle branch block, reduced left ventricular ejection fraction, prior stroke, absence of hyperlipidemia, and low creatine kinase. Elderly women (≥65 years) were less likely to receive invasive therapy. Stratifying the models by type of AMI revealed fewer predictors in patients with ST segment elevation MI. Regarding 28-day-case fatality, strong inverse relations with invasive therapy were seen in all AC: odds ratio of 0.35 (95 % confidence interval [CI] 0.15–0.84), 0.45 (95 % CI 0.22–0.92) , and 0.39 (95 % CI 0.24–0.63) in AC 1, 2 and 3, respectively. Conclusion: In today’s real-life patient care we found that predictors of non-invasive therapy were predominantly the same in all age groups, but differed particularly by type of AMI. Further research is necessary to investigate the real reasons for non-invasive therapy, especially among elderly women. Moreover, we confirmed that receiving invasive therapy was inversely associated with 28-day-case fatality independent of age. Keywords: Myocardial infarction, Mortality, Invasive therapy, Predictors * Correspondence: 1 MONICA/KORA Myocardial Infarction Registry, Central Hospital of Augsburg, Stenglinstr. 2, 86156 Augsburg, Germany 2 Institute of Epidemiology II, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany Full list of author information is available at the end of the article © 2016 The Author(s). Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Amann et al. BMC Cardiovascular Disorders (2016) 16:151 Background Percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) are today’s standard invasive treatment options for patients with acute coronary syndrome (ACS) independent of patient’s chronological age [1–5]. Over the last years, an increasing trend in use of these invasive procedures in patients with an acute myocardial infarction (AMI) was reported in several registry studies [6–9]. Nevertheless, there is still a substantial proportion of AMI patients who neither receive PCI nor CABG, even though being eligible for invasive therapy. Earlier studies have determined reasons for the underuse of reperfusion therapy in ST-segment elevation myocardial infarction (STEMI) patients and found that several factors such as older age, female sex, delayed presentation, comorbidities, prior stroke, prior MI, contraindications to the use of fibrinolytic agents and/or mechanical reperfusion (e.g., bleeding risk) are related with no reperfusion therapy in the acute setting [7, 9– 13]. To our knowledge, previous studies have not investigated predictive factors of invasive treatment in patients with non-ST segment elevation myocardial infarction (NSTEMI) and did not distinct between younger and elderly persons beneath consideration of shortterm survival. The aim of this study was firstly to evaluate predictive factors for non-invasive treatment in elderly and younger AMI patients including the type of AMI (e.g., STEMI, NSTEMI). Secondly, to assess the association between invasive compared to non-invasive therapy and 28-day-case fatality by age group in real-life patient care. Methods Study design and data source The present study is based on data from the populationbased MI registry in Augsburg, Germany, which was established in 1984 as part of the World Health Organization MONICA Project (MONItoring Trends and Determinants in CArdiovascular disease). After the termination of MONICA in 1995, the MI registry became part of the framework of KORA (Cooperative Health Research in the Region of Augsburg). Since 1984, coronary deaths and non-fatal (at least 24 h surviving) AMI cases of the 25- to 74-year old inhabitants of the city of Augsburg and 2 adjacent counties (about 600,000 inhabitants) have been continuously registered. About 80 % of all AMI cases of the study region are treated in the region’s major hospital, Klinikum Augsburg, a tertiary care center offering 24/7 interventional cardiovascular procedures, as well as heart surgery facilities. From 2009 onwards, the registry was extended for the elderly up to 84 years. The methods of case identification, diagnostic classification of events, and data quality control have been described in detail elsewhere [14, 15]. Since Page 2 of 10 2001, diagnostic criteria according to the European Society of Cardiology and American College of Cardiology criteria were used for case identification, including assessment of troponin levels especially for identification of NSTEMI [16]. Data collection Patients were interviewed during hospital stay by trained nurses using a standardized questionnaire to collect sociodemographic characteristics, cardiovascular risk factors, medical history of previous MI, stroke and comorbidities, and information on the acute event. Further information on type of AMI, treatment procedures and complications during hospital stay, vital signs, medic (...truncated)