# Indications, prognosis, and complications of de Novo implantable cardioverter defibrillators in patients with and without type 2 diabetes: a nationwide registry-based cohort study

## TL;DR

This study finds that patients with type 2 diabetes are more likely to receive implantable cardioverter defibrillators for primary prevention and have worse outcomes than those without diabetes.

## Contribution

The study provides new insights into how diabetes affects ICD implantation indications and outcomes, highlighting the need for tailored risk management.

## Key findings

- Patients with type 2 diabetes had a higher adjusted risk of all-cause mortality and MACE compared to those without diabetes.
- Primary prevention ICD implantations were more common in type 2 diabetes patients than in non-diabetic patients.
- Despite similar infection rates, diabetes patients had worse prognosis, likely due to greater comorbidity and diabetes-specific factors.

## Abstract

Patients with type 2 diabetes have an increased risk of tachyarrhythmias and more frequently require implantable cardioverter defibrillators (ICD) than those without diabetes (No-DM). This study aims to investigate whether there is a difference in the indication, prognosis and complication rates for ICD-implantation between patients with and without type 2 diabetes in different ICD prevention groups.

This Swedish retrospective cohort study included patients with de novo ICDs implanted between 2010 and 2021. Data from six national registries were analyzed to compare type 2 diabetes and No-DM patients regarding indications, complications, and outcomes (major adverse cardiovascular events [MACE], all-cause mortality). Subgroup analyses compared type 2 diabetes and No-DM by primary (PP) or secondary prevention (SP) ICD indication, and within the type 2 diabetes and No-DM groups (PP vs. SP).

The study cohort consisted of 12,885 patients, including 2,843 with type 2 diabetes. Patients with diabetes had a mean age of 67.9 years and 85.4% were male, compared with 62.1 years and 78.1% among No-DM patients (both p < 0.0001). PP was more frequent in patients with type 2 diabetes (62.7%) than No-DM (54.4%, p < 0.0001). Ischemic heart disease was the most common etiology in both patients with/without type 2 diabetes (47.7% vs. 32.6%, p < 0.0001). Non-ischemic etiologies were more common in No-DM patients, e.g. dilated cardiomyopathy (15.3% vs. 17.5%, p = 0.007). Type 2 diabetes patients had a higher adjusted risk of all-cause mortality (Hazard ratio 1.95 [95% CI: 1.81–2.11]) and MACE (1.87 [1.71–2.05]), with a more pronounced risk in SP than PP. Infection rates were comparable between patients with type 2 diabetes and No-DM (1.1% vs. 1.3%).

Patients with type 2 diabetes more often received ICDs for PP and ischemic indications than No-DM patients and had a worse prognosis despite similar one-year infection risk. This likely reflects greater comorbidity burden and diabetes-specific factors, indicating the need for tailored risk management strategies beyond device implantation in patients with type 2 diabetes.

The online version contains supplementary material available at 10.1186/s12933-025-03044-5.