Adherence and persistence analysis in patients treated with double antiplatelet therapy (DAPT) at two years in real...

Double antiplatelet therapy (DAPT) is indicated for the treatment of coronary artery diseases (CAD). The optimal duration of therapy with DAPT continues to be a subject of debate in the scientific community. To improve adherence to DAPT, the FDC (fixed dose combination) of Acetylsalicylic acid (ASA) and clopidogrel was developed into a single pill instead of two separate pills thus facilitating the dosage and administration of the therapy and increasing compliance. The aim of this study was to assess adherence and persistence over a period of two years in patients treated with DAPT composed of: ASA/clopidogrel, ASA/prasugrel, ASA/ticagrelor and FDC with ASA and clopidogrel in real life and to assess whether the use of ASA and clopidogrel FDC is associated with improved adherence.

In the following retrospective pharmacological-observational non-interventional study, all patients treated with DAPT in the Hospital of Pescara from January 2010 to October 2019 were considered. Persistence to treatment is defined as the duration of time from initiation to discontinuation of treatment. Adherence was calculated as the ratio between Received Daily Dose (RDD) and Prescribed Daily Dose (PDD).

277 patients treated with ASA/clopidogrel, 77 patients treated with ASA/prasugrel, 57 patients treated with ASA/ticagrelor and 108 patients treated with FDC of ASA/clopidogrel were analysed. Persistence curves at two years showed a statistically significant difference (p < 0.001). Adherence to therapy was optimal with an absolute value at two years of 0.96. Adherence was better in patients treated with ASA/prasugrel with a value of 0.98 and with 97 % of patients with an adherence value greater than or equal to 0.8, while, it was worse in patients treated with FDC ASA/clopidogrel with an absolute value of 0.94 and with 88 % of patients with an optimal adherence value. No statistically significant difference was found between the ASA/clopidogrel FDC in comparison to each component taken as a separate pill (p = 0.0752).

DAPT along with ASA/clopidogrel showed a statistically significant better persistence than ASA/ticagrelor and ASA/prasugrel. Whereas, to our knowledge and as per the current literature no statistically significant differences were found, in terms of adherence in real life, between the use of ASA/Clopidogrel FDC and the use of two different pills.