Table 3.

Atrial fibrillation—clinical outcomes and their definitions

AF: Level 1 variables
Cardiovascular hospitalisation	Admission to hospital primarily due to cardiovascular disease. Unscheduled hospitalisation is defined as a being admitted for more than 24 h or past a calendar day due to primarily a cardiovascular condition. CV causes include conditions such as heart failure, cardiogenic shock, bioprosthetic or native valve dysfunction, myocardial infarction, stroke, thromboembolism, bleeding, tamponade, vascular complication, arrhythmia or conduction system disturbances, cardiovascular infection (e.g. mediastinitis, endocarditis), or other clear cardiovascular cause.6,53
Catheter ablation	Catheter ablation for AF or AFL is defined as a procedure in which catheters are inserted through the veins or arteries to the heart, and energy (e.g. radiofrequency, cryoablation) is delivered to prevent propagation of abnormal AF or AFL. AF is defined as a supraventricular tachyarrhythmia with uncoordinated atrial electrical activation and consequently ineffective atrial contraction. The minimum duration of an ECG tracing of AF required to establish the diagnosis of clinical AF is at least 30 s, or entire 12-lead ECG. AFL is defined as a supraventricular tachyarrhythmia with co-ordinated but overly rapid atrial electrical activation, usually with some degree of AV node conduction block. The minimum duration of an ECG tracing of AFL required to establish the diagnosis of clinical AFL is at least 30 s, or entire 12-lead ECG.17
Atrial fibrillation: Level 2 variables
All-cause hospitalisation	Unscheduled admission to hospital for any reason. Hospitalisation is defined as a being admitted for more than 24 h or past a calendar day.6,53
Burden of atrial fibrillation	Burden is defined as the amount of time spent in atrial fibrillation as a proportion of the total monitoring period. Monitoring can be in the form of invasive and non-invasive monitoring devices. Duration of the device monitoring period is the fixed monitoring period using ambulatory and between downloads of invasive monitoring devices.58
Cardioversion	Electrical cardioversion (external or internal) is defined as a procedure in which direct current is used to restore sinus rhythm. Pharmacologic cardioversion is defined as a procedure in which antiarrhythmic medications are used to restore sinus rhythm.58
Device implantation	Implantation of: Transvenous permanent pacemaker is an electronic device that is implanted in the subcutaneous tissue and gives the heart an electrical stimulation through transvenous wires. Leadless pacemaker is an electronic device that is implanted directly into the right ventricle. ICD, a device that is used to correct abnormal heartbeat with transvenous wires. Subcutaneous ICD is an ICD with a presternal lead and is positioned between the latissimus dorsi and serratus muscle within the subcutaneous tissue. Extravascular ICD is an ICD with a substernal lead and the device in the subcutaneous tissue of the lateral thorax. CRT device and pacemaker (CRT-P) is defined as a biventricular pacemaker that sends electrical stimulation to both ventricles. CRT-D is a biventricular pacemaker and defibrillator.55,56
Implantable monitoring device	An implantable device that allows remote rhythm monitoring.55
Recurrence of AF	Recurrence of atrial fibrillation/flutter. AF is defined as a supraventricular tachyarrhythmia with uncoordinated atrial electrical activation and consequently ineffective atrial contraction. The minimum duration of an ECG tracing of AF required to establish the diagnosis of clinical AF is at least 30 s, or entire 12-lead ECG. AFL is defined as a supraventricular tachyarrhythmia with co-ordinated but overly rapid atrial electrical activation, usually with some degree of AV node conduction block. The minimum duration of an ECG tracing of AFL required to establish the diagnosis of clinical AFL is at least 30 s, or entire 12-lead ECG.17

Abbreviations: AF, atrial fibrillation; AFL, atrial flutter; CRT, cardiac resynchronisation therapy; ECG, electrocardiogram; ICD, implantable cardioverter defibrillator.