Increasing Prevalence and Incidence of Atherosclerotic Cardiovascular Disease in Adult Patients in Ontario, Canada From 2002 to 2018

BACKGROUND: Cardiovascular disease is the second-leading cause of death in Canada. However, limited data are available on the prevalence of atherosclerotic cardiovascular disease (ASCVD) in Canada. The study objective was to describe the incidence and prevalence of ASCVD in adult patients in Ontario, Canada, and to evaluate temporal trends for subsequent ASCVD events among those with new-onset ASCVD. METHODS: This retrospective, observational study identified ASCVD incidence and prevalence data from the Institute for Clinical Evaluative Sciences Data Repository for adults from Ontario. Overall prevalence was established for the period from 2002 to 2018. Incident cases from April 1, 2005 to March 2016 were then identified, and followed up to 2018. Primary outcomes were date and type of index event/procedure, patient characteristics/baseline demographics, and comorbidities. Secondary outcomes assessed were time from first to second ASCVD event, subsequent event(s) and/or mortality, and type of subsequent event(s) relative to the type of index/primary event. RESULTS: A total of 1,042,621 eligible prevalent ASCVD cases were identified; of these, 743,309 patients (69%) were newly diagnosed with incident ASCVD. The 10-year prevalence rates for all ASCVD subtypes increased over the study period. Overall event incidence rates per 1000 person-years were mostly stable or increased. Among incident cases, 50% experienced subsequent events over the study period. CONCLUSIONS: This observational study demonstrated increasing prevalence and high incidence of new ASCVD diagnoses in adults from Ontario, over the study period. These data, together with the substantial number of subsequent events in ASCVD patients, demonstrate significant clinical burden of this disease in Ontario.