Risk of out-of-hospital cardiac arrest in patients with bipolar disorder or schizophrenia.

OBJECTIVE: Patients with bipolar disorder and schizophrenia are at high cardiovascular risk; yet, the risk of out-of-hospital cardiac arrest (OHCA) compared with the general population remains scarcely investigated. METHODS: We conducted a nested case-control study using Cox regression to assess the association of bipolar disorder and schizophrenia with the HRs of OHCA of presumed cardiac cause (2001-2015). Reported are the HRs with 95% CIs overall and in subgroups defined by established cardiac disease, cardiovascular risk factors and psychotropic drugs. RESULTS: We included 35 017 OHCA cases and 175 085 age-matched and sex-matched controls (median age 72 years and 66.9% male). Patients with bipolar disorder or schizophrenia had overall higher rates of OHCA compared with the general population: HR 2.74 (95% CI 2.41 to 3.13) and 4.49 (95% CI 4.00 to 5.10), respectively. The association persisted in patients with both cardiac disease and cardiovascular risk factors at baseline (bipolar disorder HR 2.14 (95% CI 1.72 to 2.66), schizophrenia 2.84 (95% CI 2.20 to 3.67)) and among patients without known risk factors (bipolar disorder HR 2.14 (95% CI 1.09 to 4.21), schizophrenia HR 5.16 (95% CI 3.17 to 8.39)). The results were confirmed in subanalyses only including OHCAs presenting with shockable rhythm or receiving an autopsy. Antipsychotics-but not antidepressants, lithium or antiepileptics (the last two only tested in bipolar disorder)-increased OHCA hazard compared with no use in both disorders. CONCLUSIONS: Patients with bipolar disorder or schizophrenia have a higher rate of OHCA compared with the general population. Cardiac disease, cardiovascular risk factors and antipsychotics represent important underlying mechanisms.

Automated external defibrillator accessibility is crucial for bystander defibrillation and survival: A registry-based study.

AIMS: Optimization of automated external defibrillator (AED) placement and accessibility are warranted. We examined the associations between AED accessibility, at the time of an out-of-hospital cardiac arrest (OHCA), bystander defibrillation, and 30-day survival, as well as AED coverage according to AED locations. METHODS: In this registry-based study we identified all OHCAs registered by mobile emergency care units in Copenhagen, Denmark (2008-2016). Information regarding registered AEDs (2007-2016) was retrieved from the nationwide Danish AED Network. We calculated AED coverage (AEDs located ≤200 m route distance from an OHCA) and, according to AED accessibility, the likelihoods of bystander defibrillation and 30-day survival. RESULTS: Of 2500 OHCAs, 22.6% (n = 566) were covered by a registered AED. At the time of OHCA, <50% of these AEDs were accessible (n = 276). OHCAs covered by an accessible AED were nearly three times more likely to receive bystander defibrillation (accessible: 13.8% vs. inaccessible: 4.8%, p < 0.001) and twice as likely to achieve 30-day survival (accessible: 28.8% vs. inaccessible: 16.4%, p < 0.001). Among bystander-witnessed OHCAs with shockable heart rhythms (accessible vs. inaccessible AEDs), bystander defibrillation rates were 39.8% vs. 20.3% (p = 0.01) and 30-day survival rates were 72.7% vs. 44.1% (p < 0.001). Most OHCAs were covered by AEDs at offices (18.6%), schools (13.3%), and sports facilities (12.9%), each with a coverage loss >50%, due to limited AED accessibility. CONCLUSIONS: The chance of a bystander defibrillation was tripled, and 30-day survival nearly doubled, when the nearest AED was accessible, compared to inaccessible, at the time of OHCA, underscoring the importance of unhindered AED accessibility.