Table 1.

CERTAINTY inclusion/exclusion criteria.

Inclusion criteria	Exclusion criteria
18 to 80 years of age	ICD implantation for secondary prevention
Cardiac magnetic resonance (CMR) with intravenous gadolinium contrast within 30 days prior to ICD/CRT implantation	Patients with a permanent pacemaker or a preexisting class 1 indication for pacemaker implantation
History of acute myocardial infarction ≥ 40 days old (confirmed by persistent pathologic Q waves on ECG, clinical reports of CPK-MB > 3 times the upper limit of normal, or a fixed perfusion defect on nuclear imaging) with an ejection fraction (EF) ≤ 30% and no history of revascularization within the last 3 months	Patients with New York Heart Association Class IV heart failure (unless undergoing CRT implantation)
History of ischemic or nonischemic left ventricular systolic dysfunction with stable NYHA Class II to III heart failure symptoms for ≥ 3 months on optimal pharmacotherapy and an EF ≤ 35%. For CRT patients, EF ≤ 35%, QRS > 120 ms, NYHA Class III to IV heart failure symptoms on optimal pharmacotherapy	Patients with history of a confirmed myocardial within 40 days of implant or revascularization within the last 3 months
	Patients fulfilling class III indications for primary prevention ICD implantation