Contemporary Treatment of Coronary Bifurcations with Drug-Eluting Stent: Part II

Final proximal post-dilatation is necessary after kissing balloon in bifurcation stenting

AIMS

High rates of restenosis and stent thrombosis are still often observed after bifurcation stenting despite the recommended stent post-dilatation using the kissing balloon (KB) technique. We investigated the potential benefits of a final post-dilatation step in bifurcation stenting with a balloon that respects the natural diameter ratio of the proximal and distal vessels in bifurcations (Murray's law).

METHODS AND RESULTS

Fourteen commercially available stents (Xience V, Taxus Liberté and Presillion) were deployed in a silicone model of a coronary bifurcation using a provisional stenting approach. After side branch (SB) ostium dilatation and KB inflation, stent geometry and strut apposition was analysed using micro-CT. A final proximal inflation step was then performed to post-dilate only the proximal segment of the main vessel (MV). KB inflation produces an asymmetrical dilatation of the stent in the proximal part of the bifurcation with a number of struts left malapposed in the MV. Using the proposed final proximal inflation (FPI) step reduces the average stent eccentricity index from 0.72 to 0.90 (p<0.001) and the percentage of malapposed struts in the proximal part of the MV from 33.4% to 0.6% (p=0.02), while increasing the minimum stent area from 6.8 mm² to 8.5 mm² (p < 0.0001).

CONCLUSIONS

A final dilatation of the stent only in the MV proximal to the SB with a balloon sized according to the mother vessel is suggested to prevent stent malapposition and optimise stent deployment in bifurcation stenting.

Very long-term results comparing a simple versus a complex stenting strategy in the treatment of coronary bifurcation lesions

BACKGROUND

The optimal stenting strategy for coronary bifurcation lesions has not yet been defined, especially given the lack of very long-term data (>24 months). We compared our long-term results of a simple vs complex stenting strategy in patients with bifurcation lesions.

METHODS

We retrospectively selected subjects undergoing percutaneous coronary intervention (PCI) with stenting in a bifurcation lesion between June 2002 and December 2005, comparing those treated with a simple technique vs those treated with a complex one. The primary end-point was the rate of major adverse cardiac events (MACE) at >24 months of follow-up.

RESULTS

A total of 326 patients were included, 64.7% treated with a simple technique (Group A) and 35.3% with a complex strategy (Group B). Drug-eluting stents were used in 82.0% and 73.0%, respectively (P = 0.059), final kissing balloon in 47.9% and 53.0% (P = 0.37), and procedural success obtained in 99.5% and 99.1% (P = 0.66). After a median of 34 months, MACE occurred in 52 (26.5%) in Group A and in 32 (31.4%) in Group B (P = 0.37), cardiac death in six (3.1%) vs four (3.9%, P = 0.70), myocardial infarction in 13 (6.6%) vs 6 (5.9%, P = 0.80), target vessel revascularization in 36 (18.4%) vs 29 (28.4%, P = 0.04), and bypass in five (2.6%) vs two (2%, P = 0.74). Definite stent thrombosis was adjudicated in two (1%) vs one (0.9%, P = 0.98).

CONCLUSIONS

This study, comparing simple and complex stenting strategies for the treatment of coronary bifurcation lesions, shows that both techniques are associated with favorable clinical results and low adverse events rates at long-term follow-up.