Hi, my name is Hirotoshi Watanabe from Kyoto University in Japan. I'm the presenter of the STOPDAPT ACS trial at ESC 2021.

Importance of the study

Yes. As for the ACS patients, the standard DAPT duration is twelve months as a class 1 recommendation. However, the extended DAPT had a concern about the increasing of the bleeding event. So now recent studies to rate [Inaudible] as for the base short DAPT duration, especially the P2Y12i monotherapy after the STOPDAPT is promising because the several studies demonstrated the decrease of the bleeding event without the increase of cardiovascular event. However, the studies were driven by mainly the newer P2Y12i like Ticagrelor and Clopidogrel monotherapy after the STOPDAPT study is very limited. So, we conducted this study for the confirm the efficacy and safety of the Clopidogrel monotherapy after it showed that DAPT for the ACS patient.

Key methods and results

About this STOPDAPT ACS, we enrolled over 4,000 ACS patients and assigned them into the Clopidogrel monotherapy with one month DAPT that the experiment has showed DAPT arm and to the standard twelve month DAPT with aspirin and clopidogrel. We found at one year, the primary endpoint was a composite of the cardiovascular endpoint, the primary endpoint And the result [Inaudible] the distant rate with one year was 3.2% in one month DAPT group and 2.83% in the twelve month DAPT group. So, the hypothesis is that the non-inferiority with the one month DAPT. However, the hazard ratio was 1.14, with 95% confidence interval, 0.802 to 1.62. The upper limit of the interval was over the 1.5. So, we cannot confirm the non-inferiority of one month DAPT. So, we can say that there are a full ACS patient, the Clopidogrel monotherapy after the one month DAPT was inconclusive for the net clinical benefit, compared with the standard twelve month DAPT with aspirin and Clopidogrel. And for the major secondary cardiovascular endpoint, there is a signal to increase the cardiovascular event in the one month DAPT group, but the bleeding event was consistently reduced in the one month DAPT. That is consistent with a previous STOP DAPT2 trial. So, this study we can say that for the one month DAPT with subsequent Clopidogrel monotherapy, the conclusion for the measure, unmet clinical benefit and a higher event rate in the cardiovascular event and the reduction for the bleeding event. So that is a little confusing to interpret this regimen, so we must discuss the further investigation needed, to decide the optimal medical therapy for the ACS patient.

Impact on practice

Now, in this medical practice, it's difficult to apply the, show DAPT with Clopidogrel monotherapy for the ACS patient. So we should be cautious, but someone maybe think the reduction of the bleeding event is confirmed. So, maybe for the selected high bleeding risk patient, such that Clopidogrel monotherapy after one month DAPT was applicable, but we should be cautious. We should be cautious to the increase of the cardiovascular event.

Applicability to populations outside of Japan

Yes, there are very many differences between Japan and the Europe or US. Like, the risk difference of the ischaemic bleeding event. And in the PCI in Japan, there are almost 100 percent of patients received the imaging devices like [Inaudible] OCT, such a medical practice is also different between Japan and the US or Europe. And also, we must consider about the [Inaudible] of the [Inaudible] polymorphism. That's what I was doing actually, in the adjunct patient. So it's background difference. We must be careful to upgrade outside Japan. I think.