Three-year duration of benefit from abciximab in patient receiving stents for acute myocardial infarction in the randomized double-blind ADMIRAL study.
We have read carefully Dr Kanna’s comments trying to perform a critical appraisal of our manuscript, but it appears that most of these critics are inaccurate. Potential confounders such as coronary risk factors are important to consider, but by definition randomization is used to balance the different groups and the ADMIRAL study was randomized and the two study groups were well balanced for all baseline characteristics. Treatment compliance, another concern in Dr Kanna’s letter, is unlikely to be an issue because abciximab is administered intravenously for 12 h during and immediately after PCI and of course there was no further study drug administration during the 3-year follow-up of the ADMIRAL study. Blinded evaluation is another criterion of quality for studies and an issue in the letter; however, this critic does not apply to our study: of all randomized studies testing abciximab in primary stenting of STEMI, ADMIRAL remains, so far, the only double blind study. Moreover, the 3-year follow-up was performed blindly as indicated in Methods. The following concern in the letter is about the validity of self-reporting data in patient questionnaires but as we indicated this was not the only mode of data collection, and physicians were surveyed, medical records consulted . . . and for hard endpoints, especially mortality which was the main objective, self-reporting is clearly not an issue. Finally, the author does not concur with the conclusions of a favourable effect of abciximab in primary stenting of ST-elevation MI. However, ADMIRAL is a positive study for its primary hypothesis showing the superiority of the study drug over placebo to reduce death, re-infarction, and urgent revascularization at 30 days, confirmed also at 6 months. Because we believe that it is important to provide information on the longterm, a three-year follow-up was conducted to determine whether the benefit observed initially was preserved; we acknowledged that the study was not powered to detect a difference in hard clinical endpoints at 3 years. However, the expression of the results with Kaplan–Meier curves demonstrated the preservation of the initial absolute benefit, with two parallel curves for death or MI, over 3 years. Our data along with other studies confirm the benefit of GPIIbIIIa inhibition with abciximab in primary PCI. Meta-analyses have also shown a significant impact on mortality and a greater benefit when the drug is administered early. All guidelines recommend its use in primary PCI.