How do you re-stratify patients with a primary prevention ICD in need of a generator change if their LVEF has improved to >40% and they have not previously required any device therapies?

This is an important question on which there remains a lack of consensus. We had tried to address this through an observational study which was published a few years back:

(Appropriateness of primary prevention implantable cardioverter-defibrillators at the time of generator replacement: are indications still met?)

This paper generated interest including a letter to the editor and our accompanying response as follows:

Reply: Ejection fraction may improve but the scar still exists! The risk may be lower but not zero.

There is really no ideal way to risk-stratify these patients. The observational data suggest that the overall risk for sudden cardiac death remains low in this population. I think this is an area where shared decision-making should ...