Study Patients, Design, and Data Collection

The present study retrospectively included all consecutive patients presenting with ventricular tachyarrhythmias or SCA on hospital admission from 2002 until 2016 at the First Department of Medicine, University Medical Centre Mannheim, Germany. Using the hospital information system, all relevant clinical data related to the index event was documented. The data, analytic methods, and study materials will be made available to other researchers for purposes of reproducing the results or replicating the procedure on reasonable personal request to the corresponding author.

Ventricular tachyarrhythmias comprised VT and VF, as defined by current international guidelines.8, 9 Sustained VT was defined by duration of >30 seconds or causing hemodynamic collapse within 30 seconds, and non‐sustained VT by duration of <30 seconds both characterized by wide QRS complexes (≥120 ms) at a rate greater than 100 beats per minute. Ventricular tachyarrhythmias were documented by 12‐lead electrocardiogram (ECG), ECG tele‐ monitoring, implantable cardioverter defibrillator (ICD) or in case of unstable course or during cardiopulmonary resuscitation (CPR) by external defibrillator monitoring. Documented VF was treated by external defibrillation and in case of prolonged instability with additional intravenous anti‐arrhythmic drugs during CPR. Onset of VT was stratified into VT occurring <48 hours and ≥48 hours of AMI onset. High‐risk criteria in the setting of AMI comprised the presence of life‐threatening ventricular tachyarrhythmias, aborted cardiac arrest, hemodynamic instability, or cardiogenic shock.10

Further data being documented contained baseline characteristics, prior medical history, prior medical treatment, length of index stay, detailed findings of laboratory values at baseline, data derived from all non‐invasive or invasive cardiac diagnostics and device therapies, such as coronary angiography, electrophysiological examination, ICD, pacemaker or cardiac contractility modulation, as well as imaging modalities, such as echocardiography or cardiac magnetic resonance imaging. The overall presence of ICDs comprised the total sum of all patients with either a prior implanted ICD before admission, those undergoing new ICD implantation at index stay, as well as those with ICD implantation at the complete follow‐up period after index hospitalization, referring to conventional ICD, subcutaneous‐ICD (s‐ICD) and cardiac resynchronization therapy with defibrillator function (CRT‐D). Pharmacological treatment was documented according to the discharge medication of patients surviving index hospitalization. Rates of overall ICDs and of pharmacological therapies are referred to the number of surviving patients being discharged from index hospitalization.

Every re‐visit at the outpatient clinic or rehospitalization was documented when related to recurrent ventricular tachyarrhythmias and adverse cardiac events. Adverse cardiac events comprised acute heart failure, CPR, cardiac surgery, recurrent percutaneous coronary intervention (re‐PCI), new implants or upgrades of cardiac devices, worsening or improvement of left ventricular function.

Documentation period lasted from index event until 2016. Documentation of all medical data was performed by independent cardiologists at the time of the patients′ clinical presentation at our institution, being masked to final data analyses.

The present study is derived from an analysis of the “Registry of Malignant Arrhythmias and Sudden Cardiac Death—Influence of Diagnostics and Interventions (RACE‐IT)” and represents a single‐center registry including consecutive patients presenting with ventricular tachyarrhythmias and SCA being acutely admitted to the University Medical Center Mannheim (UMM), Germany (ClinicalTrials.gov identifier: {"type":"clinical-trial","attrs":{"text":"NCT02982473","term_id":"NCT02982473"}}NCT02982473) from 2002 until 2016. The registry was performed according to the principles of the declaration of Helsinki and was approved by the medical ethics committee II of the Faculty of Medicine Mannheim, University of Heidelberg, Germany, which waived the requirement for informed consent.

The medical center covers a general emergency department for emergency admission of traumatic, surgical, neurological, and cardiovascular conditions. Interdisciplinary consultation is an in‐built feature of this 24/7 service, and connects to a stroke unit, 4 intensive care units with extracorporeal life support and a chest pain unit to alleviate rapid triage of patients. The cardiologic department itself includes cardiac catheterization and electrophysiologic laboratories, a hybrid operating room, and telemetry units.