Cutting Antiplatelet Costs in ACS Improves Therapy, Not Outcomes

March 23, 2018

ORLANDO, Florida — Removing the copay on antiplatelet drugs given after acute coronary syndromes (ACS) resulted in different physician prescribing patterns favouring more use of higher-potency agents and led to more patients completing 1  year of therapy — both of which are recommended in the guidelines — but this did not translate into a reduction in major adverse cardiac events, in a new study.

The ARTEMIS study was presented here at the recent American College of Cardiology (ACC)  2018 Annual Scientific Session by Tracey Wang, MD, Duke University Medical School, Durham, North Carolina.

"Costs appear to be just one part of a broader-scale intervention needed to help patients improve adherence," she concluded.

Wang reported that current guidelines recommend 1 year's therapy with a P2Y12 inhibitor antiplatelet agent (preferably prasugrel or ticagrelor rather than the lower-potency clopidogrel) after ACS.  

"But we are not very good at achieving either the 1-year's treatment or use of the higher-potency agents, with most patients on clopidogrel and 30% to 60% of patients stopping treatment before a year," she said.  

Noting that one of the reasons often cited for this suboptimal treatment is affordability, Wang hypothesized that by removing copays on the cost of the drugs, treatment decisions would be more likely to be made on the scientific evidence rather than what a patient could afford. This, in turn, should lead to more use of the higher-potency drugs (which are still branded and therefore more expensive) and patients staying on treatment for the whole year, translating into better outcomes.

So she and her colleagues conducted the ARTEMIS trial, in which 11,000 patients with ST-segment elevation myocardial infarction and non–ST-segment myocardial infarction patients from 301 hospitals in the United States were randomly assigned (at the individual hospital level) to be given a copayment voucher offsetting out-of-pocket patient costs for P2Y12 inhibitor therapy or usual practice (ie, no voucher and no cost offset). 

All the patients were insured: 64% had private insurance, 42% were on Medicare, and 9% were on Medicaid. In addition, 17% of patients reported previously not filling a prescription because of the medication's cost. 

Results showed that the percentage of patients prescribed clopidogrel at discharge fell from 55% in the usual care group to 36% in the voucher group, and those prescribed ticagrelor rose from 32% in the usual care group to 60% in those given a voucher.

Among patients who received vouchers, 87% reported taking their medication as prescribed for the full year, compared with 84% of patients who received usual care. By contrast, the analysis of pharmacy records showed an adherence rate of 55% for the patients receiving vouchers compared with 46% for those receiving usual care.

In the subset of patients who had their blood tested, 925 in the voucher group were adherent to treatment compared with 88% in the usual-care group. All of these differences were statistically significant.

"While we know that patients often overestimate their own adherence, I was surprised by the size of the discrepancy between patient reports and pharmacy records," Wang said. "I suspect the true answer is somewhere in between, but both indicate that treatment adherence is still a huge problem."

The rate of major adverse cardiovascular events (death, recurrent myocardial infarction, or stroke) did not differ between the two groups; these events occurred in 10.63% of the usual care group vs 10.17% in those given the voucher. 

Patients Did Not Use Voucher

Wang noted that "amazingly," 28% of patients in the voucher group did not actually use the voucher, and when the analysis was restricted to just patients who did use the voucher, the nonpersistence rate fell to 10% and the rate of major adverse cardiac events was reduced to 7.5%. However, this was still not significantly different from the usual care group (P = .90).

She also noted that patients who did not use the provided voucher had the highest rates of nonpersistence and adverse clinical outcomes. "So the highest-risk patients didn't take advantage of the costs assistance offered. It is possible that the voucher system was too complicated for some patients."  

"Our findings raise further questions about how best to deploy copayment reduction to effectively improve clinical outcomes, as well as how to consider copayment reduction strategies alongside other measures to improve patient adherence," she said.

Discussing the study at the ACC press conference, Craig Beavers, PharmD, University of Kentucky Healthcare and College of Pharmacy, Lexington, said the finding that so many patients did not use the voucher was very puzzling. 

"You can take a horse to water, but you can't make them drink," Beavers said. "There is obviously more education needed here."

Commenting on the study for | Medscape Cardiology, Kim Eagle, MD, University of Michigan Medical School, Ann Arbor, said, "This is a terrific study which is important for the notion of implementation science. We are so focused on finding drugs that work in clinical trials but when we look in the real world patients aren't getting them."

"While they did see some improvement in usage when costs were removed, this was not as much as had been hoped for," Eagle added. "The fact that 28% of patients do not cash their vouchers in is quite stunning. It shows that we need a lot more education on the benefits of guideline-recommended therapy."

The study was funded by AstraZeneca. Wang reports consultant fees/honoraria from Gilead, Merck, and Sanofi and research grants from AstraZeneca, Boston Scientific, Bristol-Myers Squibb, Eli Lilly/Daiichi Sankyo Alliance, Gilead, Novartis, Pfizer, and Regeneron.

American College of Cardiology (ACC) 2018 Annual Scientific Session. Presentation 404-10. Presented March 11, 2018.

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