Which of the following is a Class I indication for primary prevention ICD?

Which of the following is a Class I indication for primary prevention ICD?

• A. LVEF ≤ 35% NYHA II-III
• B. LVEF ≤ 40% NYHA II-III
• C. LVEF ≤ 50% NYHA II-III
• D. LVEF ≤ 30% NYHA I

Answer: (A)

A Class I indication for primary prevention ICD is reserved for patients with severely reduced LV function (LVEF ≤ 35%) who have at least moderate heart failure symptoms (NYHA II–III) despite optimized medical therapy. This combination identifies those at highest risk of sudden cardiac death who are most likely to benefit from an ICD to prevent it. The scenario with LVEF ≤ 35% and NYHA II–III fits this criterion, so it is the strongest, most guideline-supported choice. Higher LVEF thresholds (such as ≤40% or ≤50%) or being NYHA class I do not meet the Class I primary prevention indication.

A Class I indication for primary prevention ICD is reserved for patients with severely reduced LV function (LVEF ≤ 35%) who have at least moderate heart failure symptoms (NYHA II–III) despite optimized medical therapy. This combination identifies those at highest risk of sudden cardiac death who are most likely to benefit from an ICD to prevent it.

The scenario with LVEF ≤ 35% and NYHA II–III fits this criterion, so it is the strongest, most guideline-supported choice. Higher LVEF thresholds (such as ≤40% or ≤50%) or being NYHA class I do not meet the Class I primary prevention indication.