The findings from the Nordic-Baltic Bifurcation IV study were presented today at the 25th annual Transcatheter Cardiovascular Therapeutics (TCT) scientific symposium. Sponsored by the Cardiovascular Research Foundation (CRF), TCT is the world's premier educational meeting specializing in interventional cardiovascular medicine.
Coronary bifurcation lesions are caused from a build-up of plaque in the heart at a location where one artery branches from another. In provisional side branch stenting, the main vessel branch is stented and the side branch only if compromised. Currently, provisional side branch stenting is the preferred strategy for treatment of bifurcation lesions.
The safety and effectiveness of provisional stenting for bifurcations that involve a large side branch of the coronary arteries is unknown. The Nordic-Baltic IV trial was a randomized, controlled, non-blinded, multicenter, superiority trial that compared provisional stenting with a two-stent strategy for the treatment of coronary bifurcation lesions involving a major side branch.
The primary endpoint was the composite of major adverse cardiac events (MACE) including cardiac death, non-procedure-related myocardial infarction, target vessel revascularization and stent thrombosis after six months. Follow up is planned until five years. A total of 450 patients with coronary bifurcation lesions were randomized 1:1 to the provisional strategy (stenting of the main vessel and provisional stenting of the side branch) or a complex two-stent strategy (planned stenting of both the main vessel and the side branch).
After six months, the MACE rate was not significantly different between provisional and two-stent techniques (4.6 percent and 1.8 percent, respectively, p=0.09). Individual endpoints were also similar between the two techniques including total death (0 and 0.4 percent, p=0.32), non-procedural myocardial infarction (1.8 percent and 0.9 percent, p=0.50) and target vessel revascularization (3.7 percent and 1.3 percent, p=0.11). There were no incidents of cardiac death in either group.
However, in contrast to prior studies, longer and more complex procedures in the two-stent group did not translate into more procedural myocardial infarctions.
"Results of this trial indicate that a two-stent technique does not significantly improve mid-term outcomes for patients with bifurcation lesions compared to provisional stenting," said lead investigator Indulis Kumsars, MD. Dr. Kumsars is Head of the Cardiac Catheterization Laboratory at the Latvian Cardiology Center in Riga, Latvia.
Given the fact that there was a weak trend towards lower MACE in the two stent strategy and follow up is continuing for five years, the Nordic-Baltic investigators concluded, "Recommendations on optimal strategies for this lesion subset should await longer term follow up."