Effect of Medication Co-payment Vouchers on P2Y₁₂ Inhibitor Use and Major Adverse Cardiovascular Events among Patients with Myocardial Infarction: The ARTEMIS Randomized Clinical Trial

Importance: Despite guideline recommendations, many patients discontinue P2Y₁₂ inhibitor therapy earlier than the recommended 1 year after myocardial infarction (MI), and higher-potency P2Y₁₂ inhibitors are underutilized. Cost is frequently cited as an explanation for both of these observations. Objective: To determine whether removing co-payment barriers increases P2Y₁₂ inhibitor persistence and lowers risk of major adverse cardiovascular events (MACE). Design, Setting, and Participants: Cluster randomized clinical trial among 301 hospitals enrolling adult patients with acute MI (June 5, 2015, through September 30, 2016); patients were followed up for 1 year after discharge (final date of follow-up was October 23, 2017), with blinded adjudication of MACE; choice of P2Y₁₂ inhibitor was per clinician discretion. Interventions: Hospitals randomized to the intervention (n = 131 [6436 patients]) provided patients with co-payment vouchers for clopidogrel or ticagrelor for 1 year (median voucher value for a 30-day supply, $137 [25th-75th percentile, $20-$339]). Hospitals randomized to usual care (n = 156 [4565 patients]) did not provide study vouchers. Main Outcomes and Measures: Independent coprimary outcomes were patient-reported persistence with P2Y₁₂ inhibitor (defined as continued treatment without gap in use ≥30 days) and MACE (death, recurrent MI, or stroke) at 1 year among patients discharged with a prescription for clopidogrel or ticagrelor. Results: Among 11001 enrolled patients (median age, 62 years; 3459 [31%] women), 10102 patients were discharged with prescriptions for clopidogrel or ticagrelor (clopidogrel prescribed to 2317 [36.0%] in the intervention group and 2497 [54.7%] in the usual care group), 4393 of 6135 patients (72%) in the intervention group used the voucher, and follow-up data at 1 year were available for 10802 patients (98.2%). Patient-reported persistence with P2Y₁₂ inhibitors at 1 year was higher in the intervention group than in the control group (unadjusted rates, 5340/6135 [87.0%] vs 3324/3967 [83.8%], respectively; P <.001; adjusted difference, 2.3% [95% CI, 0.4% to 4.1%]; adjusted odds ratio, 1.19 [95% CI, 1.02 to 1.40]). There was no significant difference in MACE at 1 year between intervention and usual care groups (unadjusted cumulative incidence, 10.2% vs 10.6%; P =.65; adjusted difference, 0.66% [95% CI, -0.73% to 2.06%]; adjusted hazard ratio, 1.07 [95% CI, 0.93 to 1.25]). Conclusions and Relevance: Among patients with MI, provision of vouchers to offset medication co-payments for P2Y₁₂ inhibitors, compared with no vouchers, resulted in a 3.3% absolute increase in patient-reported persistence with P2Y₁₂ inhibitors and no significant reduction in 1-year MACE outcomes. Trial Registration: ClinicalTrials.gov Identifier: NCT02406677.