A short-term course of dual antiplatelet therapy (DAPT) is non-inferior to a longer course in patients who have undergone placement of a particular kind of drug-eluting stent (DES), researchers reported here.
Results of the NIPPON (NoborI dual antiplatelet therapy as aPPrOpriate DuratioN) study, presented at ESC Congress 2016 and published simultaneously in the European Heart Journal, showed similar rates of "net adverse clinical and cerebrovascular events" (NACCE) - the main outcome - with both 6 and 18-month DAPT durations, and no difference in bleeding complications.
"Based on these findings, a combination of short DAPT and a newer DES with bioabsorbable abluminal coating should be able to minimize the incidence of thrombotic events and bleeding complications simultaneously," concluded investigator Masato Nakamura, MD, PhD, of Toho University Ohashi Medical Center in Tokyo, Japan.
All patients in the trial 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).
The study enrolled 3,775 patients with coronary artery disease or acute myocardial infarction who had undergone percutaneous coronary intervention and stent placement at 130 Japanese institutions.
It incorporated broad inclusion criteria to reflect the real-world clinical setting.
However, an interim analysis showed slow enrolment and substantially lower events than expected, and the study was terminated early.
Results from only the first 2,772 patients to be followed for at least 18 months showed there was a 0.46% difference in occurrence of the primary endpoint among patients randomised to either short or long-term DAPT (1.92% vs 1.45% respectively), confirming the non-inferiority of short-term therapy.
The rate of bleeding events was similar (0.73 % of the long-term and 0.96% of the short-term DAPT group), as was the rate of stent thrombosis (0.07% in both).
"The results of the present study should be interpreted with caution before trying to draw firm conclusions," cautioned Professor Nakamura. "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 primary endpoint."
European Society of Cardiology (ESC)