Cardiac genetic testing mainstreaming increases uptake and reduces wait times but lowers informed decision making

This observational study compared two pathways for genetic testing in patients diagnosed with hypertrophic or dilated cardiomyopathy. One pathway offered testing through a mainstreaming model conducted in cardiology clinics, while the comparator involved referral to Medical Genetics where patients attended either an online webinar or a one-on-one genetic counseling appointment. The primary outcomes examined were uptake of testing, time to testing, informed choice, and patient satisfaction.

Mainstreaming demonstrated higher uptake of genetic testing (82%) compared with referral to Medical Genetics (69%). It also substantially reduced wait times, with patients referred to Genetics waiting a median of 94-185 additional days. However, informed decision making was significantly lower in the mainstreaming pathway, with only 62% of patients considered informed compared to 91% of patients who attended the Medical Genetics webinar (p < 0.01). Patient satisfaction with decision-making was reported as high across both pathways.

No safety or adverse event data were reported for this study. Key limitations include the observational design, which prevents causal inference, and the lack of reported sample size, which limits assessment of statistical power and generalizability. The timeframe was limited to September 2024 through September 2025.

For clinical practice, these findings suggest that integrating genetic testing into cardiology clinics can improve access and reduce delays, potentially addressing barriers to genetic evaluation. However, the significantly lower rate of informed decision making in the mainstreaming pathway highlights the importance of incorporating structured education components when implementing such models. Clinicians should recognize that while mainstreaming may increase testing rates, it may not adequately support patient understanding without dedicated educational interventions.