Trifurcating Coronary Artery Disease: Expanding the Frontier of Interventional Cardiology

We read with interest the manuscript published by Furuichi et al¹ in the April 2007 issue of the Journal of Invasive Cardiology. The authors presented their experience with drug-eluting stents (DES) in trifurcation lesions in the coronary arteries, predominantly left main trifurcation (13 out of 15 patients). The mean follow-up period was 19.0 ± 8.3 months. The authors reported a target lesion revascularization (TLR) rate of 20%, and a target vessel revascularization (TVR) rate of 40%. There were no deaths, acute stent thrombosis or Q-wave myocardial infarctions reported. The results overall appear favorable for this complex group of patients.
The authors described a nearly identical classification of trifurcation disease to the Shammas classification^2,3 presented at New Cardiovascular Horizons, held in New Orleans in November of 2006,⁴ and published earlier this year in the January and February issues of the Journal of Invasive Cardiology. Also, Shammas et al published the first long-term follow-up report on DES in treating left main (LM) trifurcation disease in the February 2007 issue of the Journal.³ In both the Shammas and Furuichi manuscripts, no definite relationship appears between the method of stenting and TLR or the type of disease distribution and complications. In the Shammas manuscript, a forced logistic regression analysis in 20 consecutive patients with LM trifurcation disease showed that the method of treatment or the distribution of disease did not predict the combined endpoint of death, acute stent thrombosis and TLR. In the manuscript by Furuichi et al, restenosis also occurred almost equally with trifurcation stenting using the “double-crush” and the “modified-V” techniques. It is possible that the small number of patients in both studies prevent a valid statistical conclusion about the relationship between disease distribution as described earlier by Shammas, and similarly in Furuichi et al, and the occurrence of adverse events. We propose the development of a large multicenter registry for trifurcation coronary artery disease to determine how the published classification and treatment methodology of trifurcation disease² predict overall outcomes and major adverse events during and following treatment.
Finally, we believe that current data do not allow us to conclude that trifurcation stenting is a safe procedure, as is proposed by Furuichi et al.¹ Trifurcation stenting is a complex procedure that should only be performed by highly experienced operators. In our busy interventional catheterization laboratory of several thousand interventions yearly, we previously reported in 20 consecutive patients of LM trifurcation disease an overall adverse event rate of 29.4%. These included sudden death (5.3%), acute stent thrombosis (10%) and TLR (11.8%). In the Shammas manuscript, stent thrombosis could be attributed to delayed clopidogrel administration until shortly after the end of the procedure in the only 2 patients who developed thrombosis. Stent thrombosis with DES has been reported, however, in approximately 4% of bifurcation stenting cases, and it is more likely to occur at a higher rate with trifurcation stenting. Again, larger registries are needed to determine the true rate of stent thrombosis with trifurcation DES stenting and the overall safety of the procedure. As we have previously proposed,³ LM trifurcation stenting needs to be reserved for patients who are at high risk of bypass surgery or refuse surgery as a first treatment option.
Trifurcating coronary disease involves unique coronary anatomy that is challenging even to the most experienced operators. Our previously published classification and treatment methodology² needs to be validated in larger registries before we can recommend the routine use of trifurcation stenting to the interventional community.

References

1. Furuichi S, Sangiorgi GM, Palloshi A et al. Drug-eluting stent implantation in coronary trifurcation lesions. J Invasive Cardiol 2007;19:157–162.
2. Shammas NW. Trifurcating coronary artery disease: A proposed classification and treatment methodology. J Invasive Cardiol 2007;19:32–35.
3. Shammas NW, Dippel EJ, Avial A. et al. Long-term outcomes in treating left main trifurcation coronary artery disease with the paclitaxel-eluting stent. J Invasive Cardiol 2007;19:77–82.
4. Shammas NW, et al. Long term outcome in treating trifurcation coronary artery disease with the Taxus drug eluting stent. Presented at New Cardiovascular Horizons, New Orleans, Louisiana, November 2006.