Using polygenic risk scores for prioritising individuals at greatest need of a CVD risk assessment

ABSTRACT Background To provide quantitative evidence of the use of polygenic risk scores (PRS) for systematically identifying individuals for invitation for full formal cardiovascular disease (CVD) risk assessment. Methods 108,685 participants aged 40-69, with measured biomarkers, linked primary care records and genetic data in UK Biobank were used for model derivation and population health modelling. Prioritisation tools using age, PRS for coronary artery disease and stroke, and conventional risk factors for CVD available within longitudinal primary care records were derived using sex-specific Cox models. Rescaling to account for the healthy cohort effect, we modelled the implications of initiating guideline-recommended statin therapy after prioritising individuals for invitation to a formal CVD risk assessment. Results 1,838 CVD events were observed over median follow up of 8.2 years. If primary care records were used to prioritise individuals for formal risk assessment using age- and sex-specific thresholds corresponding to 5% false negative rates then we would capture 65% and 43% events amongst men and women respectively. The numbers of men and women needed to be screened to prevent one CVD event (NNS) are 74 and 140 respectively. In contrast, adding PRS to both prioritisation and formal assessments, and selecting thresholds to capture the same number of events resulted in a NNS of 60 for men and 90 for women. Conclusion The use of PRS together with primary care records to prioritise individuals at highest risk of a CVD event for a formal CVD risk assessment can more efficiently prioritise those who need interventions the most than using primary care records alone. This could lead to better allocation of resources by reducing the number of formal risk assessments in primary care while still preventing the same number CVD events.