NIPPON: With Nobori Stent, 6 Months of DAPT as Safe and Effective as 18 Months

ROME, Italy—In patients treated with a biolimus A9-eluting stent with a biodegradable polymer (Nobori, Terumo), 6 months of dual antiplatelet therapy (DAPT) does not result in an increased risk of net adverse clinical and cerebrovascular events (NACCE) when compared with a longer duration of therapy.

Results of the NIPPON study presented today at the European Society of Cardiology Congress 2016 show that the NACCE rate, a composite that includes all-cause mortality, MI, cerebrovascular events, and major bleeding, was 1.92% in patients treated with 6 months of DAPT versus 1.45% in patients treated with 18 months of therapy. 

Despite the statistical noninferiority of the short treatment course, lead author Masato Nakamura, MD (Toho University Ohashi Medical Center, Tokyo, Japan), and colleagues said the results need to be interpreted with caution given that the trial was prematurely halted and is likely underpowered to detect clinical differences. 

Speaking to TCTMD, Stephan Gielen, MD (University of Leipzig Heart Center, Germany), who moderated the press conference where the results were announced, said the NIPPON study has some unique characteristics that make its results difficult to extrapolate into wider clinical practice. For example, the platelet inhibitor used in patients with acute coronary syndromes in Europe is largely ticagrelor (Brilinta, AstraZeneca) or prasugrel (Effient, Daiichi-Sankyo/Lilly) with aspirin, whereas DAPT for patients treated with the Nobori bioabsorbable abluminal-coated stent in NIPPON consisted of aspirin combined with clopidogrel or ticlopidine.

Moreover, European recommendations for DAPT are very clear as to how to treat patients with ACS. 

“The current European Society of Cardiology guidelines clearly recommend that all ACS patients be treated for 12 months,” said Gielen. “There is a very good database to support this. Only in patients with a very high risk of bleeding complications do we reduce this to 6 months, such as in patients who might need additional oral anticoagulation for atrial fibrillation.”

In the NIPPON study, which included 1,391 patients treated for 18 months with aspirin plus clopidogrel/ticlopidine and 1,381 patients treated with a 6-month course of DAPT, 30% of patients in the study presented with ACS. The NIPPON investigators had originally enrolled 3,775 patients, but 1,003 individuals were excluded from the analysis due to insufficient follow-up (less than 18 months). The trial was halted early due to slow enrollment and a lower than expected event rate. 

Among the 2,772 patients included in the analysis, the bleeding rate was 0.73% for patients treated with DAPT for 18 months and 0.96% for those treated with a 6-month course. The rate of stent thrombosis was 0.07% in both treatment arms. 

To TCTMD, Nakamura said that while the trial was ongoing, results from the DAPT Study were published. In that large-scale study evaluating 12 months versus 30 months of thienopyridine therapy in patients who received DES, investigators showed that continuing treatment beyond 1 year reduced the risk of stent thrombosis and major adverse cardiovascular and cerebrovascular events, a benefit driven by a reduction in MI. 

Nakamura noted there was frequent crossover between the two DAPT regimens and a wide noninferiority margin. Given the results from the DAPT Study, he added, the follow-up period in NIPPON might have been too short to show a difference between the 6- and 18-month antiplatelet regimens. Gielen agreed the results should be interpreted cautiously, but he told TCTMD the study does have some relevance in terms of selecting length of DAPT for patients.

“I would say it fits into my concept of the cardiology world,” said Gielen. “If you reduce dual antiplatelet therapy to 6 months, you don’t see a very high additional thrombotic risk. That’s the message I’d subscribe to, at least for patients in stable condition, those without ACS, and who receive the newest third- or fourth-generation coronary stents. The general trend for elective coronary intervention is towards reducing the duration of dual platelet inhibition.”

Source:

• Nakamura M. Six months versus 18 months dual antiplatelet treatment for patients undergoing bioabsorbable polymer and abluminal-coated DES deployment: NIPPON randomized study. Presented at: European Society of Cardiology Congress 2016. August 28, 2016. Rome, Italy.

Disclosures:

• Nakamura reports research grants and/or honoraria from Terumo, Daiichi-Sankyo, Sanofi Aventis, and AstraZeneca.

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