Barriers to accessing cascade screening for families of heritable sudden cardiac death victims

Abstract Background In younger individuals, many sudden cardiac deaths (SCDs) are caused by potentially heritable cardiac diseases (i.e. HCM, ARVC, LQTS, etc). First-degree relatives may have a 50% risk of being affected and should be referred for cascade genetic screening. Within Ontario, Canada, knowledge is lacking on how many receive cascade screening, and the reason(s) for not obtaining screening. Methods Between April 2023 to May 2024, we conducted a mixed methods study employing web-based surveys, including both closed and open-ended questions, and telephone interviews. First-degree relatives of individuals who died from heritable SCD in 2022, were invited to participate by email, and family physicians were recruited by emailing faculty members of the University of Toronto and using social media. Quantitative survey results using descriptive statistics are reported. Results Out of 91 eligible first-degree relatives, 54 (59.3%) responded and 37 completed the survey. The average age of participants was 42.7± 13.7 and 80.0% (24/30) were female. Three quarters (27/34) saw a cardiologist for screening and of those, 22.2% (6/27) were diagnosed with a heritable cardiac disease. Fewer than half (45.5%, 15/33) saw a genetic counsellor and 18.1% (6/33) had genetic testing performed. Reported reasons for not accessing cascade screening were: (1) hard to access the required specialist (16.7%, 1/6), (2) referral not sent by the family physician (16.7%, 1/6), (3) lack of time (16.7%, 1/6), (4) still waiting to be seen (16.7%, 1/6). Fifty family physicians completed the survey, with average age of 50.1 ± 12.3 and 69% (29/42) female. Fewer than 20% (9/48) reported having had a patient die from SCD due to a heritable cardiac disease. Most (91.1%; 41/45) reported limited knowledge about heritable cardiac diseases and few were familiar (7%; 3/45) with the term cascade screening. The most frequently reported barriers to referring first-degree relatives were: (1) not being notified about the SCD (82%; 36/44), (2) First-degree relatives not within their practice (70%; 31/44), (3) not knowing the cause of the SCD (68%; 30/44) and (4) lack of knowledge about heritable cardiac diseases (57%; 25/44). Conclusions The majority of first-degree relatives reported seeing a cardiologist, however less than half saw a genetic counsellor and even fewer had genetic testing. Most family physicians had limited knowledge about heritable cardiac diseases and the term cascade screening. Many family physicians reported substantial barriers to referring first-degree relatives. Systemic changes and education are needed to address these barriers.