We recommend an ICD be implanted in patients with HF-REF with a history of hemodynamically significant or sustained ventricular arrhythmia (secondary prevention) (Recommendation Strong, Quality High).

We recommend consideration of primary ICD therapy in patients with:

1. Ischemic cardiomyopathy, NYHA class II-III, EF ≤35 %, measured at least one month post MI, and at least three months post coronary revascularization procedure (Recommendation Strong, Quality High)
2. Ischemic cardiomyopathy, NYHA class I, and an EF ≤30 % at least one month post MI, and at least three months post coronary revascularization procedure (Recommendation Strong, Quality High)
3. Nonischemic cardiomyopathy, NYHA class II-III, EF ≤35 %, measured at least nine months after optimal medical therapy (Recommendation Strong, Quality High)

We recommend an ICD not be implanted in NYHA class IV HF patients who are not expected to improve with any further therapy and who are not candidates for cardiac transplantation or mechanical circulatory support (Recommendation Strong, Quality Moderate).

Values and Preferences These recommendations place a very high value on the recognition that patients and family members should be carefully counselled as to the purpose of an ICD and the associated complications. If HF progresses to terminal stage, deactivation of the ICD can be considered after careful discussion.