Predictor of wasted implantable cardioverter defibrillator for secondary prevention

ICD is the first line treatment to prevent sudden cardiac death from recurrence of VT/VF. However, patients with organic heart disease have many comorbidities, and some patients die without history of appropriate ICD therapy in lifetime.

The aim of this study is to examine the predictors of death without appropriate ICD therapy in lifetime, among ICD patients for secondary prevention with organic heart disease.

We enrolled consecutive patients implanted with ICD/CRT-D for secondary prevention between 2000 and 2022. We excluded patients without organic heart disease, and alive patients without history of appropriate ICD therapy. Inappropriate candidate (Wasted-group) for defibrillator was defined as the patient who died without history of appropriate ICD therapy or died within one year from appropriate ICD therapy. Appropriate candidate (Appropriate-group) was defined as the patient who had been alive over one year from appropriate ICD therapy (Wasted-group:36, Appropriate-group:131).

During a follow-up of 8.3 ± 5.3 years, a total of 93 (56%) patients died, including 6 (4%) patients died within one year from ICD/CRT-D implantation. Among the 36 patients of Wasted-group, 28 patients died without history of appropriate ICD therapy. Higher age, ischemic cardiomyopathy, non-ARVC, a past history of VF, diabetes mellitus, and higher serum creatinine was the predictor of Wasted-group (P<0.05). Wasted ICD risk score was constructed with the summation of these predictors for predicting candidates of Wasted-group. When the Wasted ICD risk score was ≥3, positive predictive value and negative predictive value were 39.7% and 89.4%, respectively (AUC=0.77, P<0.001).

Patients with a Wasted ICD risk score <3 is likely to receive appropriate ICD therapy in lifetime. Therefore, Wasted ICD risk score might be useful to decide to need for ICD therapy, regarding elderly patients who would be hesitant to have ICD implanted.

Wasted ICD risk score