CYP2C19 LOF and GOF-Guided Antiplatelet Therapy in Patients with Acute Coronary Syndrome: A Cost-Effectiveness Analysis

PURPOSE

This study aimed to examine the cost-effectiveness of CYP2C19 loss-of-function and gain-of-function allele guided (LOF/GOF-guided) antiplatelet therapy in patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI).

METHODS

A life-long decision-analytic model was designed to simulate outcomes of three strategies: universal clopidogrel (75 mg daily), universal alternative P2Y₁₂ inhibitor (prasugrel 10 mg daily or ticagrelor 90 mg twice daily), and LOF/GOF-guided therapy (LOF/GOF allele carriers receiving alternative P2Y₁₂ inhibitor, wild-type patients receiving clopidogrel). Model outcomes included clinical event rates, quality-adjusted life-years (QALYs) gained and direct medical costs from perspective of US healthcare provider.

RESULTS

Base-case analysis found nonfatal myocardial infarction (5.62%) and stent thrombosis (1.2%) to be the lowest in universal alternative P2Y₁₂ inhibitor arm, whereas nonfatal stroke (0.72%), cardiovascular death (2.42%), and major bleeding (2.73%) were lowest in LOF/GOF-guided group. LOF/GOF-guided arm gained the highest QALYs (7.5301 QALYs) at lowest life-long cost (USD 76,450). One-way sensitivity analysis showed base-case results were subject to the hazard ratio of cardiovascular death in carriers versus non-carriers of LOF allele and hazard ratio of cardiovascular death in non-carriers of LOF allele versus general patients. In probabilistic sensitivity analysis of 10,000 Monte Carlo simulations, LOF/GOF-guided therapy, universal alternative P2Y₁₂ inhibitor, and universal clopidogrel were the preferred strategy (willingness-to-pay threshold = 50,000 USD/QALY) in 99.07%, 0.04%, and 0.89% of time, respectively.

CONCLUSIONS

Using both CYP2C19 GOF and LOF alleles to select antiplatelet therapy appears to be the preferred antiplatelet strategy over universal clopidogrel and universal alternative P2Y₁₂ inhibitor therapy for ACS patients with PCI.

Latin American Clinical Epidemiology Network Series - Paper 8: Ticagrelor was cost-effective vs. clopidogrel in acute coronary syndrome in Chile

OBJECTIVE

To evaluate the incremental cost-effectiveness ratio (ICER) of the use of ticagrelor as a substitute for clopidogrel for secondary prevention of acute coronary syndrome in Chile.

STUDY DESIGN AND SETTING

Cost-effectiveness analysis based on a Markov model: Safety and effectiveness data of ticagrelor were obtained from a systematic review of the literature. Costs are expressed in Chilean pesos (CLP) as of 2013. The evaluation was conducted from the payer standpoint. A probabilistic sensitivity analysis comprising discount rates and national cost variability was done. A budget impact analysis estimated for 2015 was conducted to calculate the total cost for both treatments.

RESULTS

The ICER with a discount rate of 6% for ticagrelor vs. clopidogrel was CLP 4,893,126 per quality-adjusted life-year (QALY) gained (=9,689 US$). In the budget impact analysis for the baseline scenario, considering 100% of treatment, coverage, and adherence, ticagrelor represented an additional cost of CLP 5,233,854,272, for 979 QALYs gained compared with clopidogrel.

CONCLUSIONS

Ticagrelor is cost-effective in comparison with clopidogrel for the secondary prevention of acute coronary syndrome. These findings are similar to those reported in other international cost-effectiveness studies.

Rationale and design of the Affordability and Real-world Antiplatelet Treatment Effectiveness after Myocardial Infarction Study (ARTEMIS): A multicenter, cluster-randomized trial of P2Y12 receptor inhibitor copayment reduction after myocardial infarction

BACKGROUND

The use of oral P2Y12 receptor inhibitors after acute myocardial infarction (MI) can reduce risks of subsequent major adverse cardiovascular events (composite of all-cause death, recurrent MI, and stroke), yet medication persistence is suboptimal. Although copayment cost has been implicated as a factor influencing medication persistence, it remains unclear whether reducing or eliminating these costs can improve medication persistence and/or downstream clinical outcomes.

DESIGN

ARTEMIS is a multicenter, cluster-randomized clinical trial designed to examine whether eliminating patient copayment for P2Y12 receptor inhibitor therapy affects medication persistence and clinical outcomes. We will enroll approximately 11,000 patients hospitalized for acute ST-elevation and non-ST-elevation MI at 300 hospitals. Choice and duration of treatment with a P2Y12 receptor inhibitor will be determined by the treating physician. Hospitals randomized to the copayment intervention will provide vouchers to cover patients' copayments for their P2Y12 receptor inhibitor for up to 1 year after discharge. The coprimary end points are 1-year P2Y12 receptor inhibitor persistence and major adverse cardiovascular events. Secondary end points include choice of P2Y12 receptor inhibitor, patient-reported outcomes, and postdischarge cost of care.

CONCLUSION

ARTEMIS will be the largest randomized assessment of a medication copayment reduction intervention on medication persistence, clinical outcomes, treatment selection, and cost of care after acute MI.

Prasugrel

Prasugrel is a third-generation thienopyridine which selectively inhibits the platelet P2Y(12) receptor more rapidly, more potently, and with less interindividual response variability compared with the second-generation thienopyridine clopidogrel. Large-scale phase III clinical testing showed that in high-to moderate-risk acute coronary syndrome patients undergoing percutaneous coronary intervention, prasugrel translates into a greater reduction in ischemic events, including stent thrombosis, in the short and long term compared to clopidogrel. Prasugrel, however, is associated with an increased risk of major bleeding, which is more pronounced in certain patient subgroups. The ideal patient population for prasugrel use are those patients without prior transient ischemic attack/stroke, <75 years of age and >60 kg in whom the greatest ischemic benefit is achieved without a significant increase in major bleeding risk. Dose modifications in specific populations or at given time-points may represent an avenue to minimize bleeding risk and therefore maximize the clinical benefit of prasugrel. Ongoing clinical studies with prasugrel will better define the safety and efficacy profiles of this agent and potentially set the basis for new indications for use.

Antiplatelet therapy beyond 2012: role of personalized medicine

Since its first approval in 1997, clopidogrel has revolutionized interventional cardiology and transformed therapy for non‑ST‑segment elevation myocardial infarction (NSTEMI), STEMI, and percutaneous coronary intervention‑treated patients. It enjoyed a remarkable 15‑year "homerun" in the world market without any major competition. With the introduction of more potent P2Y12 receptor blockers, the current antiplatelet strategy is undergoing a transition period. Generic clopidogrel is inexpensive and pharmacodynamically effective in at least two thirds of the patients with coronary artery disease. The unpredictable, slow onset, and overall modest pharmacodynamic effects are the major limitations of clopidogrel. The new, more potent P2Y12 receptor blockers overcome the limitations of clopidogrel therapy and are associated with better clinical efficacy, but are more costly and associated with more bleeding. In this scenario, personalization of antiplatelet therapy based on platelet function and genetic testings to strike a balance between cost, benefit, and safety is a potential option.