7.1.3.1 Implantable cardioverter-defibrillator therapy

The evidence for the recommendations for implantable cardioverter-defibrillator (ICD) therapy in HF management has been discussed extensively in previous CCS HF guidelines. Since the publication of these updates, no new indications for ICD therapy have arisen for the general HF population; however, it is worth highlighting some of the most salient points.

7.1.3.1.1 ICD therapy in patients with HF and previous occurrence of sustained ventricular arrhythmia (secondary prevention)

Recommendation 50: We recommend an implantable cardioverter-defibrillator be implanted in patients with HFrEF and a history of hemodynamically significant or sustained ventricular arrhythmia (secondary prevention) (Strong Recommendation, High Quality Evidence).

7.1.3.1.2 ICD therapy in patients with HF without a history of sustained ventricular arrhythmia (primary prevention)

Recommendation 51: We recommend consideration of primary implantable cardioverter-defibrillator therapy in patients with:

• Ischemic cardiomyopathy, NYHA class II-III, EF ≤ 35%, measured at least 1 month post MI, and at least 3 months post coronary revascularization procedure (Strong Recommendation, High Quality Evidence);
• Ischemic cardiomyopathy, NYHA class I, and an EF ≤ 30% at least 1 month post MI, and at least 3 months post coronary revascularization procedure (Strong Recommendation, High Quality Evidence);
• Nonischemic cardiomyopathy, NYHA class II-III, EF ≤ 35%, measured at least 3 months after titration and optimization of GDMT (Strong Recommendation, High Quality Evidence).

Recommendation 52: We recommend against implantable cardioverter-defibrillator implantation in patients with NYHA class IV symptoms who are not expected to improve with any further therapy and who are not candidates for cardiac transplant or mechanical circulatory support (Strong Recommendation, Moderate Quality Evidence).