Abstract
Purpose:
Premature discontinuation of antiplatelet therapy in ACS patients receiving a drug-eluting stent (DES) can be associated with increased morbidity and mortality. The purpose of this study was to determine if refill notification reminders for clopidgrel by a pharmacist would improve long term adherence and outcomes for patients receiving a DES.
Methods:
A prospective, randomized, controlled study was conducted to evaluate adherence to clopidogrel for up to one year in ACS patients receiving a DES. Patients randomized to the Pharmacist Reminder group were contacted by a pharmacist on a monthly basis with a refill reminder for their clopidogrel prescription and the ability to discuss any medication issues. Patients randomized to the No Reminder group did not receive any refill reminder notification from a pharmacist. Both groups were contacted at 6 and 12 months to complete a follow-up survey. Pharmacy refill records were evaluated to determine monthly adherence and actual out-of-pocket expenses for clopidogrel up to one year after enrollment. Adherence was assessed by both the proportion of months covered (PMC) and complete continuous adherence over 1 year. A PMC of >80% was considered adherent. Patients were enrolled from September 2007 to August 2009. Assuming premature discontinuation rates of 5% and 14% for Pharmacist Reminder and No Reminder groups respectively, 120 patients were required to detect significance with an alpha level of 0.05 and a power of 0.80.
Results:
A total of 114 patients were enrolled in the study with 53% (N=60) patients in the No Reminder group and 47% (N=54) in the Pharmacist Reminder group. The majority of patients were male (75%) with an average age of 62 years. Approximately 18% had a previous stent and had taken clopidogrel previously. Of the total population, 89% were adherent (102/114) with a PMC >80%, 2.6% (3/114) had a PMC 60-79%, and 7.9% (9/114) had a PMC <60%. Similarly, 88% (100/114) had complete continuous adherence to clopidogrel over 1 year. More patients in the Pharmacist Reminder group had continuous adherence to clopidogrel over 1 year (91% vs. 85%, p=NS) and a PMC >80% (93% vs. 87%, p=NS) compared to the No Reminder group. More patients who were not adherent to clopidogrel reported recent hospitalizations through follow-up (33% vs. 10%, p=NS). No significant improvement in long term adherence to clopidogrel was found through pharmacist reminder on a monthly basis, however the enrollment goal was not met and other factors could have influenced adherence.
Conclusions:
For patients receiving a DES for ACS, 1 in 9 patients was nonadherent to clopidogrel at 1 year. Pharmacist refill reminder can positively impact long term adherence to clopidogrel. Nonadherence to clopidgrel was associated with a higher rate of hospitalization. Further research is necessary to determine which factors impact long term adherence to clopidogrel in patients receiving a DES.