Author + information
- Serban Puricel, Dr Med,
- Florim Cucul, Dr Med,
- Melissa Weissner, MTA,
- Axel Schmermund, Dr Med,
- Peiman Jamshidi, Dr Med,
- Tobias Nyffenegger, Dr Med,
- Harald Binder, PhD,
- Holger Eggebrecht, Dr Med,
- Thomas Münzel, Dr Med,
- Stephane Cook, Dr Med and
- Tommaso Gori, MD, PhD∗ ()
- ↵∗Zentrum für Kardiologie, University Medical Center Mainz, Langenbeckstrasse 1, 55131 Mainz, Germany
We thank Dr. Foin and colleagues for their letter and fully share their comments. As they state, the results of our study are in line with the evidence from the ABSORB III study that the scaffold footprint (or strut/artery ratio [SAR]) is a strong predictor of patient prognosis (1). This concept has led to a warning against the use of scaffolds in vessels <2.5 mm, which was reinforced strongly at the recent Food and Drug Administration panel, and with which we fully agree.
There are other implications of this concept. First, sizing is particularly important, especially in the 2.5 mm range. Quantitative coronary angiography might be, in the authors’ opinion, an insufficiently accurate tool. In our practice, we rather meticulously follow the “1:1:1 rule”: the nominal diameter of the predilation balloon must be the same as the target vessel size and the scaffold intended to be implanted. Sizing can be made by comparing, in 2 different planes, the diameter of the balloon with that of the vessel.
Second, full expansion of the balloon in 2 orthogonal planes is also critical, as even a 10% indentation in a 2.5-mm balloon leads to a minimum lumen diameter below the threshold of danger. Imaging in two different angiographic planes again provides important information and reassurance.
Third, as reported in our paper (Figure 4) (2), the curves describing the footprint/SAR of 3.5-mm scaffolds versus 2.5-/3.0-mm scaffolds differ substantially, with a much larger footprint/SAR for the 3.5-mm device. Accordingly, when treating vessels of a diameter intermediate between 3.0 and 3.5 mm, the operator should be aware of the fact that the underdeployment of a 3.5-mm scaffold also leads to a footprint/SAR close to the threshold of safety (Figure 1). The expression “the larger, the better” does not apply in the case of bioresorbable vascular scaffolds.
Fourth, post-dilation is an important “equalizer” of the result: rather than noncontrolled high-pressure dilation of the scaffold balloon, which is semicompliant, high-pressure post-dilation with a noncompliant balloon is in the authors’ opinion the safest method to reach the target diameter, avoiding both underexpansion and vessel damage.
Collectively, these simple recommendations do not prolong implantation times significantly, but have a profound impact on patient prognosis.
Please note: Drs. Cuculi, Schmermund, Cook, Münzel, and Gori have received speaker fees from Abbott Vascular. Dr. Eggebrecht has received unrestricted research grants from Abbott Vascular. Abbott Vascular had no role in any phase of this research. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose. Drs. Purcil, Cuculi, Cook, and Gori contributed equally to this work.
- American College of Cardiology Foundation