Anxiety and depression as risk factors for ICD shocks and mortality in patients with an implantable cardioverter defibrillator – A systematic review

OBJECTIVE: To examine associations between baseline anxiety and depression and occurrence of ICD shocks and risk of mortality in patients with an implantable cardioverter defibrillator (ICD). METHOD: We systematically searched EMBASE, PubMed, PsycINFO, and CINAHL for eligible studies fulfilling the predefined criteria. RESULTS: We included 37 studies based on 25 different cohorts following 35,003 participants for up to seven years. We observed no association between baseline anxiety nor depression and the occurrence of ICD shocks. More than half of the identified studies (respectively 56% and 60%) indicated a significant association between baseline anxiety or depression and increased risk of mortality (anxiety: n = 5, ranging from Hazard ratios (HR):1.02 [Confidence intervals (CI) 95% 1.00-1.03] to HR:3.45 [CI 95% 1.57-7.60]; depression: n = 6, ranging from HR:1.03 [CI 95% 1.00-1.06] to HR:2.10 [CI 95% 1.44-3.05]). We found a significant association between high methodological quality of the primary study and the detection of a significant association (p < 0.01). CONCLUSIONS: Baseline anxiety and depression are associated with increased risk of mortality in patients with an ICD, but not with occurrence of ICD shocks. Inclusion of baseline anxiety and depression in risk stratification of mortality may be warranted.