# Changes in numbers needed to treat and hospital care expenditures of optimized indications for primary prevention implantable cardioverter defibrillators: a scenario analysis

## TL;DR

This study shows that stricter criteria for implantable cardioverter defibrillators (ICDs) can reduce unnecessary treatments and save hospital costs.

## Contribution

The paper introduces stricter ICD indication scenarios that improve clinical and economic outcomes for primary prevention.

## Key findings

- Stricter ICD criteria reduced the number needed to treat from 42 to 33 in eligible patients.
- Avoiding ICD implantation in low-risk patients could save €11 million annually in hospital expenditures.
- The NNT-no for non-indicated patients reached 246 under the proposed cutoff.

## Abstract

A strong need exists to better select patients with reduced left ventricular ejection fraction for primary prevention of sudden cardiac death by ICD implantation. This paper reports on the expected clinical and economic benefits of stricter indication scenarios based on minimum probabilities for patients of experiencing appropriate ICD-therapy and/or maximum risks of dying during the first 2 years following ICD implantation.

Data on clinical events and hospital care expenditures were gathered for patients in the Dutch DO-IT registry. Registry-based prediction models were used to derive individual prior probabilities. Realistic assumptions were made concerning short-term disease courses and related hospital care in absence of ICD implantation. The potential impact of stricter indication scenarios was assessed with changes in numbers needed to treat (NNT) in subpopulations with (NNT-yes) or without (NNT-no) indication for ICD implantation and with changes in the yearly incidence-based national hospital care budget for ICD-based primary prevention.

The NNT-yes under the existing guidelines equalled 42. Not indicating ICD implantation if prior probabilities of receiving appropriate therapy within 2-year post-implant are < 5% seems a promising cutoff with an NNT-yes of 33, an NNT-no of 246 and a national annual reduction in hospital expenditures for ICD-based primary prevention of €11 million (16.7%).

Stricter indication criteria for primary prevention ICD implantation enable the selection of patient subpopulations with high numbers needed to treat, in which unnecessary harm can be forgone and substantial savings can be accomplished. The scenario analysis facilitates rationing of indication policies for ICD implantations.

The online version contains supplementary material available at 10.1007/s00392-025-02687-4.