Adherence to P2Y12 Inhibitors in Acute Coronary Syndrome: Prognosis

Non-adherence to medication in patients with acute coronary syndrome (ACS) remains to be solved; the use of polypills and a closer follow up have been tried out (follow up calls and motivation groups). Antiaggregation guidelines recommend dual antiplatelet therapy (DAPT) for at least one year after ACS. 

Pronóstico de la adherencia a inhibidores P2Y12 en el síndrome coronario agudo

Adherence to drug treatment is comprised of multiple aspects, including adequate start, correct and concise implementation and continuation for the duration of treatment. 

The aim of this study was to assess the different types of adherence to P2Y12 inhibitors among ACS patients treated with PCI. As a secondary objective, they looked at frequency and risk factors and their relationship to major cardiovascular events (MACE).

The study included ACS patients undergoing PCI from April 2012 to March 2016 from a registry in Alberta, Canada. Primary end point was adherence to P2Y12 inhibitors of ambulatory patients through the proportion of days covered by medication at 12 months. 

Patients were stratified into 5 adherence groups: group 1, early consistent non-adherence; group 2, rapid decline; group 3, delayed initiation; group 4, gradual decline; and group 5, persistent adherence.

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Data from 12844 patient were obtained, mean age 62, 24.6% women, 45.6% ST elevation SCA and 62.1% treated with drug eluting stents (DES). 11% were in group 1 (did not start or rapidly discontinued), 7.7% in group 2 (discontinued after 3 months), 6% were in group 3 (poor start with increasing adherence at follow up), 20.5% in group 4 (good adherence that later dropped) and 54.8% were in group 5 (persistent adherence).

At multivariable analysis, groups 1 vs 5 showed no significant differences as regards MACE risk (HR 1.10, CI 95% 0.86-1.40). However, when looking at the DES subgroup, the difference turned out to be significant (HR 2.44, CI 95% 1.60-3.71). Both groups 2 (HR 1.23, CI 95% 1.01-1.49) and 3 (HR 1.41, CI 95% 1.12-1.78) were associated with higher MACE risk, regardless the stent. As regards major bleeding, both groups 1 (HR 1.50, CI 95% 1.12-2.02) and 2 (HR 1.40, CI 95% 1.09-1.79) were associated to higher risk compared against group 5. 


Identifying adherence parameters in ACS populations should allow us to identify those at higher risk of MACE. In this cohort of patients, only 50% showed persistent adherence, with the highest risk of cardiovascular events among patients with poor adherence and late start. 

Dr. Omar Tupayachi

Dr. Omar Tupayachi.
Member of the Editorial Board of

Original Title: P2Y12 inhibitor adherence trajectories in patients with acute coronary syndrome undergoing percutaneous coronary intervention: prognostic implications.

Font: Ricky D Turgeon, Sheri L Koshman, Yuan Dong, Michelle M Graham, P2Y12 inhibitor adherence trajectories in patients with acute coronary syndrome undergoing percutaneous coronary intervention: prognostic implications, European Heart Journal, Volume 43, Issue 24, 21 June 2022, Pages 2303–2313,

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