Author + information
- Hideaki Kaneda, MD, PhD∗ ()
- ↵∗Okinaka Memorial Institute for Medical Research, 2-2-2 Toranomon, Tokyo 105-8470, Japan
With great interest, I read the article by Colombo et al. (1) that examined the noninferiority of 6 versus 12 months of dual antiplatelet therapy (DAPT) in patients undergoing percutaneous coronary intervention with second-generation drug-eluting stents. The investigators described in the Results section (p. 2091) that “There was at least 1 occurrence of the primary composite endpoint by 12 months in 31 patients in the 6-month DAPT group (4.5%; 95% CI: 2.9 to 6.1) and 27 patients in the 12-month DAPT group (3.7%; 95% CI: 2.3 to 5.1; p = 0.469) (Table 5). There was a 0.8% (95% CI: -2.4 to 1.7) difference in occurrence of the primary endpoint between the 6-month and 12-month groups. The upper limit of the 95% CI was lower than the pre-set margin of 2%, confirming the noninferiority hypothesis (p < 0.05).” However, on the basis of the result (31 of 682 vs. 27 of 717) in Table 5, the 95% confidence interval (CI) for the difference between 2 sample proportions is -1.3% to 2.9% (90% CI: -1.0 to 2.5). Therefore, the upper limit of the 95% CI appears more than the pre-set margin of 2%, rejecting the noninferiority hypothesis of 6 months versus 12 months of DAPT. It would be of great help if the investigators could provide the method they used to calculate 95% CI.
Please note: Dr. Kaneda has reported that he has no relationships relevant to the contents of this paper to disclose.
- American College of Cardiology Foundation