Author + information
Dr. Alfonso asks why two patients in our study (1) with occlusive dissection after percutaneous transluminal coronary angioplasty (PTCA) were excluded and when these dissections occurred. As it is clearly stated in the article these two type E dissections evolved toward complete artery occlusion during the procedure and how they caused an acute myocardial infarction immediately after the procedure. Because the study reported the results of nonocclusive unstented dissections, they were excluded from the analysis at the beginning.
As far as the second point is concerned, we have acknowledged the higher prevalence of lesions A and B in the unstented group, but this limitation derives from the later stage in which the stented patients were assessed, when the easy availability of stenting allowed higher inflation pressures. However, although unstented patients had a higher prevalence of dissections grades A and B (namely 85% vs. 56% at 24 h), the restenosis rate for stented and unstented patients was similar for each dissection grade (p = NS).
What we would like to stress in our study is that in this stenting era, where there is a growing and widespread use of these devices (2), the “minor” dissections (type A and B), most frequently occurring during PTCA, are associated with a very low risk of complications and restenosis, suggesting a more conservative approach.
Finally, Dr. Alfonso states that “the large lumen diameter of the dissected segments indicates that the dissection image was fully included into the lumen measurements.” However, as clearly shown in Table 1 of our article, the mean lumen diameter post-PTCA in dissected vessels was not 3.23 ± 0.65 mm but 3.11 ± 0.89 mm, a lower value than that of the mean reference artery diameter pre-PTCA (3.18 ± 0.7 mm) in the same vessels. We do agree that the methodology of quantitative coronary angiography is technically demanding, especially for the analysis of dissected segments. Therefore, we are promoting in our Institute new and different tools for quantitative analysis, such as intracoronary ultrasound (IVUS), coronary Doppler evaluation, and myocardial fractional flow-reserve measurement.
- American College of Cardiology