Blockage of the Left Main Coronary Artery
A blockage of the left main coronary artery is extremely dangerous and has the worst prognosis of all coronary blockages. If the blockage is severe, blood flow to much of the heart muscle is affected. The heart can develop life-threatening heart rhythms, develop a heart attack, or stop pumping altogether.
Treatment Options for Left Main Blockage
Coronary bypass graft surgery (CABG) is currently the preferred way to treat blockage of the left main coronary artery. CABG is however a surgical procedure with significant risk. This includes dying during the surgery, developing a stroke or heart attack after the procedure, and significant pain and length of recovery.
The balloon and stent procedure is a significantly less invasive alternative to CABG for treating blockage of the left main coronary artery. Its use, however, has been restricted to those who would not survive a CABG and those who have already had a certain type of CABG (protected vessels).
Is Stenting the Better Option?
A major concern about stents is their risk of closing. A closed stent may occur over time (restenosis) or suddenly (thrombosis). Either mechanism causes life-threatening blockage of the left main coronary artery. Many patients who have had stenting of the left main have required repeat procedures to deal with blockage inside the stent.
What’s New With Stenting the Left Main?
Developments in stent technology and new techniques of inserting the stents continue to evolve. As stents improve, the decision to use CABG becomes more complicated. For example, newer drug-coated (drug eluting) stents are less likely to close. They however require long-term (possibly lifetime) use of medications, such as Plavix, that increase bleeding risk. You can thus avoid CABG’s trauma of open heart surgery but must then take Plavix that makes you more likely to bleed for many months, if not forever.
A study published in the New England Journal of Medicine compared long-term outcomes in those with left main blockage who underwent CABG to those who underwent stenting. The rate of death, heart attack, and stroke was similar in the two groups. In contrast, earlier studies indicated that CABG was better. Although stenting is not yet recommend as treatment of left-main blockage, this may be a viable option in the future. Furthermore, a trial of stenting versus CABG is now an ethical and legitimate thing to do.
An important difference between stents and CABG appears to be the need for repeat angiography with the balloon and stent procedure. Studies show that those with stents have this invasive procedure more often than those who undergo CABG. It’s not clear if people who had repeat stenting were too sick to have CABG.
The controversy between CABG and stenting for blockage of the left main coronary artery will likely continue until a large randomized study is done. Such a trial will randomly assign patient with left main blockage to one of the two procedures and follow their outcomes.
Source:
Seung KB, Park DW, Kim YH, et al. Stent Versus Coronary-Artery Bypass grafting for Left Main Coronary Artery Disease. April 24, 2008. NEJM 358(17).