Prevalence and Predictors of Early Discontinuation of Dual-Antiplatelet Therapy After Drug-Eluting Stent Implantation in Korean Population

The administration of antiplatelet drugs for months after a drug-eluting stent implantation is critical in decreasing the risk of complications, and premature discontinuation of antiplatelet therapy before the recommended period is the most important predictor for late complications. Therefore, we investigated the prevalence and associated factors of premature discontinuation of antiplatelet therapy in patients in Korea. This retrospective cohort study was conducted using the Korean National Health Insurance Service National Sample Cohort data. Patients who were treated with dual-antiplatelet therapy (DAPT) were identified with medication prescription data. The Kaplan-Meier failure time plot was used to illustrate the cumulative probability of treatment discontinuation. Cox regression analysis was conducted to compare predictors of early discontinuation of DAPT. The characteristics of the early discontinuation group were not significantly different from the guideline concordance group, except for a higher prevalence of disability and a lower rate of chronic kidney disease. In a Cox regression model, the presence of hypertension was identified as a negative predictor of early discontinuation, and disability was not a statistically significant predictor. The prevalence of early discontinuation was 31.0% and seems to be significantly higher than those reported from prospective studies, which may more accurately reflect the real-world situation. In conclusion, physicians should make more effort to educate patients on the risk associated with premature discontinuation of antiplatelet therapy after percutaneous coronary intervention with drug-eluting stent, and further studies investigating the reasons for nonadherence of DAPT are needed to improve DAPT compliance. (C) 2016 Elsevier Inc. All rights reserved.