LOW CARDIOVASCULAR HEALTHCARE UTILIZATION PRIOR TO OUT OF HOSPITAL CARDIAC ARREST: A CANADA WIDE ANALYSIS

BACKGROUND Out-of-hospital cardiac arrest (OHCA) usually occurs unexpectedly and is frequently attributed to an underlying cardiac cause. Previous studies have indicated that some OHCA patients may seek medical help in the weeks to months leading up to their OHCA event. The aim of this study was to assess the prior healthcare utilization burden of OHCA patients admitted to hospitals across Canada. METHODS AND RESULTS We conducted a population-based study of all OHCA patients ages 18-85 who were successfully resuscitated and admitted to an acute-care hospital across Canada from Jan 1 2013 to December 31 2017. Patients were identified from the Discharge Abstract Database using previously validated International Classification of Disease, Tenth Revision, codes associated with cardiac arrest (I460, I461, I469, I4900, I4901, R960, R961, R98, and R99) and the Canadian Classification of Health Interventions codes for cardiopulmonary resuscitation (1HZ30JN and 1HZ30JY). Patients with ages 85, or who had an arrest attributed to life-threatening trauma or therapeutic abortion were excluded. The cohort was composed of 10,345 patients, with an average age of 63.8 ± 14.4 and 66.2% were male. In the year prior to their OHCA event, 28.4% (2966) had a diagnosis of ≥1 cardiovascular condition, including coronary artery disease (7.6%), diabetes (13%), hypertension (13.8%), heart failure (13.8%), MI (3.7%) or AF (2.0%). The percentage of cardiovascular (CV) hospitalizations within a year of the OHCA event remained constant at 0.8% /week until 17 weeks prior, rising to 1.5% up to about 2 weeks before, when it markedly increased (Figure 1). In the year prior to the OHCA event, 36.8% (3843) of the cohort were hospitalized for any reason and 24.2% (2521) were hospitalized for a CV condition. A small percentage (5.7%) had a CV procedure including angiography (4.9%), percutaneous coronary intervention (1.8%), coronary artery bypass graft surgery (0.7%), implantable cardioverter defibrillator (0.5%) or pacemaker (0.7%). Rates of hospitalization for any reason and CV hospitalizations were 11.8% (1235) and 7.3% (759) respectively, in the 30 days before the OHCA event. CONCLUSION A minority of individuals admitted to hospital for OHCA have a history of diagnosed CV disease requiring hospitalization or treatment in the 30 days prior. Identifying those most at risk for OHCA will require novel strategies.