Courtesy of Dr. Agustín Vecchia.
In treating bifurcations, the provisional stenting strategy continues to be preferred. However, a percentage of these lesions must be treated with two stents, which involves different techniques. In provisional stenting, when two stents are required, a recent consensus document of the European Bifurcation Club has recently recommended the TAP technique (T and protrusion). Even so, TAP has not yet been compared to Culotte stenting (CS) by any prospective randomized study.
The (BBK) II trial compared the 9-month angiographic results of TAP with those of Culotte in side branch stenting, to assess whether CS reduces restenosis rates, compared to TAP. The end point was angiographic, since the study does not have statistical power for clinical events.
It included 300 patients with bifurcations lesions requiring two stents, who were randomized 1:1 to TAP vs. CS. The implanted stents included sirolimus, everolimus, biolimus and zotarolimus DES.
Primary end point was the maximal in-stent per cent diameter stenosis at bifurcation level at 9 month angiographic follow up. Clinical end points included target lesion revascularization (TLR) and target lesion failure (TLF), a composite of cardiac death, infarction of the culprit vessel and TLR.
Angiographic follow-up was available in 91% of patients and maximal percent diameter stenosis were:
CS: 21 ± 20%
TAP: 27 ± 25%
[p=0.038].
Binary restenosis rates were:
CS: 6.5%
TAP: 17%
[p=0.006].
TLR 1 year incidence was:
CS: 6%
TAP: 12%
[p=0.069]
TLF rates were:
CS: 6.7%
TAP: 12%
From the whole series, only one patient in the CS group presented definite stent thrombosis at one year follow up.
Conclusion
The authors concluded that, compared to TAP, CS is associated to significantly lower restenosis at follow up.
Editorial Comment
The BBK II was the first randomized trial to compare TAP against Culotte.
Worth Noting:
The center were this study was conducted has highly experienced operators who treat a large number of bifurcations each year, which is why these outcomes may not reflect the reality of other centers, of different standards and populations, especially considering CS is technically more challenging than TAP.
The admission criteria established a reference diameter of the side branch that was at least 2.25 and ≤ 1.0 mm smaller that of the main branch.
Stable patients were treated with a 600 mg. load of clopidogrel. Those with ACS were treated with prasugrel or ticagrelor (clopidogrel was not used in this group.
The study only included 300 patients and, therefore, has no power to assess clinical outcomes.
There are differences in baseline characteristics, namely longer side branch lesions in the TAP group (15.5 mm vs 13.8 mm; p=0.03).
In the main branch, the difference in restenosis renders non-significant, though there is a tendency: 1.4 vs. 4.4%; p=0.434.
POT (proximal optimization technique) was conducted in both groups in general.
Stent thrombosis was low in both groups (only one in the CS group).
These limitations require a randomized study with a larger number of patients. Nevertheless, the BBK II contributes with valuable information to the growing field of bifurcations.
Original Title: Culotte stenting vs. TAP stenting for treatment of de-novo coronary bifurcation lesions with the need for side-branch stenting: the Bifurcations Bad Krozingen (BBK) II angiographic trial.
Reference: Miroslaw Ferenc et al , EurHeart J 2016; Epub ahead of print.
Courtesy of Dr. Agustín Vecchia. German Hospital, Buenos Aires, Argentina.
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