Table 1.

Definition of Adverse Events

	Severity Level	Definition	Examples
Low	1—None (very mild)	No harm, no change in condition, may have required monitoring to assess for potential change in condition with no intervention indicated.	Imaging equipment problem, medication error, minor bleeding from access site without hematoma resolved with compression, device malfunction removed easily, short self limited arrhythmia from catheter manipulation.
	2—Minor	Transient change in condition, not life threatening, condition returns to baseline, required monitoring, required minor intervention such as holding a medication, or obtaining lab test.	Coil malposition or embolization while in the cath lab easily retrieved, device malposition requiring sheath size change or snaring, pulse loss resolved spontaneously, hematoma or large bruising, minor airway problem, transient arrhythmia, allergic reaction
High	3—Moderate	Transient change in condition may be life threatening if not treated, condition returns to baseline, required monitoring, required intervention such as reversal agent, additional medication, transfer to the intensive care unit for monitoring, or moderate transcatheter intervention to correct condition.	Blood loss, hemothorax, respiratory acidosis, atrial arrhythmia requiring intervention, anesthesia problem requiring reintubation, any device embolization in the catheterization lab or afterward
	4—Major	Change in condition, life threatening if not treated, change in condition may be permanent, may have required an intensive care unit admission or emergent readmit to hospital, may have required invasive monitoring, required interventions such as electrical cardioversion or unanticipated intubation or required major invasive procedures or transcatheter interventions to correct condition.	Ventricular arrhythmia requiring medication, vessel dissection, hypotension requiring inotrope support, atrioventricular block, coil or device malposition or embolization requiring surgery
	5—Catastrophic	Any death, and emergent surgery or heart lung bypass support (extracorporeal membrane oxygenation) to prevent death with failure to wean from bypass support.	Death

AV indicates atrioventricular; ECMO, extra‐corporeal membrane oxygenator.