A Korean research team has once again set a milestone by changing the global standard for the lifelong medication prescribed after percutaneous coronary intervention (PCI), commonly known as “stent placement,” used to treat myocardial infarction and angina.

Having previously gained global recognition, first in the U.S. and then in Europe, this team has now proven the superiority of clopidogrel over aspirin, further supporting a shift in standard treatment.

Current U.S. treatment guidelines recommend dual antiplatelet therapy combining aspirin and clopidogrel (a P2Y12 inhibitor) for six months to one year after coronary artery intervention, followed by lifelong aspirin monotherapy.

Samsung Medical Center announced on Friday that this finding was confirmed in a meta-analysis of seven randomized clinical trials worldwide comparing the outcomes of aspirin versus clopidogrel monotherapy in patients with coronary artery disease. The meta-analysis was conducted by a multinational research team led by Professors Hahn Joo-yong, Song Young-bin, and Choi Ki-hong of the Department of Cardiology at Samsung Medical Center, in collaboration with foreign institutions, including the University Hospital Bern in Switzerland. This study was published on Monday in the prestigious medical journal, The Lancet.

The research team had previously published a study in The Lancet last March showing that clopidogrel was more effective than aspirin as a long-term antiplatelet therapy in patients at high risk of recurrent cardiovascular events. Furthermore, following the previous study's selection as the “Late-breaking Clinical Trial” at the American College of Cardiology (ACC) Scientific Session in March, this latest study was also named a “Late-breaking Clinical Trial” at the European Society of Cardiology (ESC) Congress on Sunday.

The research team conducted this meta-analysis not only to elevate the level of evidence and move closer to changing treatment standards but also because the initial shift toward using aspirin as monotherapy after stent procedures was itself based on meta-analysis research.

The research team included 28,982 patients in total in the seven global randomized clinical trials examining treatment outcomes based on whether aspirin or clopidogrel was used after dual antiplatelet therapy (DAPT) ended in patients who underwent stenting for conditions like myocardial infarction.

The study found that when comparing the risk of cardiovascular death, myocardial infarction, and stroke, the clopidogrel group (14,507 patients) showed a 14 percent lower risk than the aspirin group (14,475 patients).

Notably, clopidogrel use was found to reduce the risk of myocardial infarction by 24 percent and stroke by 21 percent. Conversely, the research team reported no significant difference in bleeding rates between the clopidogrel and aspirin groups.

The research team explained that while the effectiveness of antiplatelet agents often increases alongside the risk of bleeding, clopidogrel demonstrated an ideal outcome -- reducing ischemic events without raising bleeding risk.

“This analysis demonstrated that clopidogrel monotherapy is superior to aspirin monotherapy in nearly 30,000 patients of diverse ethnicities,” Professor Hahn said. “We anticipate that after the dual antiplatelet therapy period in patients who have undergone stent procedures, clopidogrel will become the standard treatment for lifelong maintenance therapy.”