ROME—A short-term course of dual antiplatelet therapy (DAPT) may be non-inferior to a longer course in patients who have a certain type of drug-eluting stent (DES), according to research presented at ESC Congress 2016.
Patients in this study, known as NIPPON, had the Nobori bioabsorbable abluminal-coated stent and received 6 months or 18 months of DAPT, which consisted of aspirin plus clopidogrel or ticlopidine.
The results showed similar rates of net adverse clinical and cerebrovascular events, as well as similar rates of bleeding complications, whether patients received DAPT for 6 months or 18 months.
“Based on these findings, a combination of short[-term] DAPT and a newer DES with bioabsorbable abluminal coating should be able to minimize the incidence of thrombotic events and bleeding complications simultaneously,” said Masato Nakamura, MD, PhD, of Toho University Ohashi Medical Center in Tokyo, Japan.
However, Dr Nakamura also noted that this study had limitations, so the results should be interpreted with caution.
Dr Nakamura presented the results at the congress as abstract 2218.
The study enrolled 3775 patients with coronary artery disease or acute myocardial infarction who had undergone percutaneous coronary intervention and stent placement at 130 Japanese institutions.
All patients had received the Nobori bioabsorbable abluminal-coated stent, with DAPT consisting of aspirin (81–162 mg/day) combined with clopidogrel (75 mg/day) or ticlopidine (200 mg/day).
An interim analysis of the study data showed slow enrolment and substantially lower events than expected, so the study was terminated early.
Dr Nakamura presented results from the first 2772 patients to be followed for at least 18 months.
There was no significant difference in the occurrence of the primary endpoint—net adverse clinical and cerebrovascular events—among patients randomized to either short-term or long-term DAPT—1.92% and 1.45%, respectively—confirming the non-inferiority of short-term therapy.
The rate of bleeding events was similar between the treatment arms as well—0.73% in the long-term arm and 0.96% in the short-term arm—as was the rate of stent thrombosis—0.07% in both arms.
“The results of the present study should be interpreted with caution before trying to draw firm conclusions,” Dr Nakamura said. “The interpretation of the NIPPON trial is complicated by the fact that the event rate was lower than the expected incidence of the primary endpoint in both groups. Therefore, the statistical power may not have been adequate to fully assess the risk of [the] primary endpoint.”
Dr Nakamura also noted that the follow-up period may not have been long enough to draw conclusions about the optimum duration of DAPT for patients with DES.
Furthermore, the early termination of the study, in conjunction with the enrollment of relatively low-risk subjects, suggests the study’s results may not be generalizable to high-risk patients. Similarly, as antiplatelet therapy was mainly limited to clopidogrel, the use of more potent antiplatelet agents may have led to different conclusions.
This study was funded by Associations for Establishment of Evidence in Interventions Studies. Dr Nakamura has received research grant support and honoraria from Terumo Corporation, Sanofi, and Daiichi Sankyo.
