Deepak Voora

Aims CYP2C19-guided P2Y12 inhibitor selection can reduce cardiovascular (CV) events and bleeding in patients with acute coronary syndromes (ACSs) post-percutaneous coronary intervention (PCI). The 12-month cost-effectiveness of CYP2C19-guided P2Y12 inhibitor selection for Veterans post-ACS/PCI was evaluated from the Veterans Health Administration's (VHA) perspective. Methods and results Using average annualized PCI volumes and P2Y12 inhibitor use from VA data, a decision-analytic model simulated CYP2C19 testing vs. no testing outcomes in 2800 hypothetical Veterans receiving PY212 inhibitor for 12 months post-ACS/PCI (74% clopidogrel, 5% prasugrel, and 21% ticagrelor use at baseline without testing). CYP2C19 loss-of-function (LOF) carrier prevalence was 28%. Model inputs were from studies (bleeding/ischaemic events, CYP2C19-guided therapy effect, health state utilities, CYP2C19 LOF carrier prevalence) and VHA administrative data (costs of events, drugs, CYP2C19 testing; PCI volumes, and P2Y12 inhibitor prescriptions). The primary outcome was cost (2020 US${\$}$) per quality-adjusted life year (QALY) gained. Base-case scenarios, probabilistic sensitivity analyses, and scenario analyses were completed. CYP2C19-guided therapy resulted in 496 (24%) escalations (clopidogrel to prasugrel/ticagrelor) and 465 (65%) de-escalations (prasugrel/ticagrelor to clopidogrel). CYP2C19 testing averted 1 stroke, 27 myocardial infarctions, 8 CV-related deaths, and caused 3 bleeds. CYP2C19 testing (vs. no testing) was dominant in the base-case scenario (0.0027 QALYs gained, ${\$}$527 saved/person) and in 97.1% of simulations, making it cost-effective and high-value. In scenario analyses, de-escalation in conjunction with escalation is required for CYP2C19 testing to be cost-effective and high-value. Conclusion In Veterans post-ACS/PCI, CYP2C19-guided P2Y12 inhibitor selection can improve CV outcomes and lower costs for the VHA within 12 months of implementation.