According to the “Third universal definition of myocardial infarction” of the European Society of Cardiology we define an AMI if there is evidence of myocardial necrosis in a clinical setting consistent with acute myocardial ischaemia. “Under these conditions is an acute myocardial infarction defined as: Detection of a rise and/or fall of cardiac biomarker values (preferably cardiac troponin [cTn]) with at least one value above the 99th percentile upper reference limit and with at least one of the following: symptoms of ischaemia, new or presumed new significant ST-segment–T wave changes or new left bundle branch block, development of pathological Q waves in the ECG, imaging evidence of new loss of viable myocardium or new regional wall motion abnormality, identification of an intracoronary thrombus by angiography or autopsy” [10].

All patients with a clinically confirmed AMI are asked to give written consent to participate in the registry of RHESA by the medical staff (physicians or study nurses) of the collaborating hospitals. Trained physicians or study nurses collect data with a hospital questionnaire during patients’ hospitalization by medical record review. Data include 1) personal data, 2) preexisting risk factors and comorbidities, 3) medical treatments and interventions during hospitalization, 5) clinical complications, 6) medication before and during hospitalization and at hospital discharge [see Additional file 1]. The questionnaire was derived from the BMIR [7]. From potentially eligible patients who refuse to participate, a hospital questionnaire with anonymised data is filled in.

From each patient who consented to participate in RHESA, an emergency protocol completed by an emergency physician (mostly in the ambulance) is also collected. Information from the emergency protocols allows investigations into emergency management in the prehospital phase. Items of interest are: 1) duration from symptom onset until emergency call, 2) duration until the arrival at the patient’s home, 3) duration of the medical treatment of the emergency physician on site, 4) duration until arrival at the hospital, 5) treatments and interventions, and 6) medication.

Fatal events are defined according to the registry of the WHO-MONICA (Multinational MONItoring of trends and determinants in CArdiovascular disease)/KORA study [11].

The three health departments send anonymised death certificates to RHESA monthly that contains at least one of the following diagnoses: hypertension (ICD-10 I10), ischaemic heart disease (ICD-10 I20-25), other CVD, including sudden cardiac death (ICD-10 I30-I52), atherosclerosis (ICD-10 I70), diabetes mellitus (ICD-10 E10-E11), dyslipidemia (ICD-10 I78), obesity (ICD-10 E66). Furthermore the health departments send a physician’s questionnaire [see Additional file 2] to the most recent treating physician or coroner. These physicians send the filled physician’s questionnaire back to RHESA. We use the information from the death certificate and the physician’s questionnaire for classifying events according to the MONICA diagnostic category of coronary death. We classify four categories: “definite acute myocardial infarction” (autopsy), “possible coronary death” (acute symptoms, and a positive history of ischaemic heart disease [angina pectoris or previous myocardial infarction or diagnosed ischaemic heart disease]), “no acute myocardial infarction” (where another diagnosis has been made (clinically or at autopsy), or “fatal cases with insufficient data” (cases with no autopsy, no history of typical or atypical or inadequately described symptoms, no previous history of ischaemic heart disease and no other diagnosis) [12]. Details of definitions of the variables are given in the respective design papers [12, 11].

For the study of the survival status among AMI patients who gave consent for follow-up and re-contact, the registration offices are contacted at different points in time. For patients who have died, the responsible health department sends the corresponding death certificate to RHESA.