Stenting left main coronary artery disease (CAD) produced similar outcomes to CABG, as well as a low stent thrombosis rate. However, PCI, with bare-metal or drug-eluting stents, resulted in more revascularization, according to a Korean study published in the Oct. 19 issue of the Journal of the American College of Cardiology.
Currently, guidelines and appropriate criteria recommend CABG as the standard approach to treating left main CAD, but recent improvements in PCI techniques and antiplatelet therapy have led to the re-evaluation of treatment approaches.
Because long-term data, beyond five years, comparing CABG or stenting of unprotected left main CAD are sparse, Duk-Woo Park, MD, of the University of Ulsan College of Medicine, Asan Medical Center in Seoul, Korea, and colleagues evaluated two follow-up time points in these patient populations.
One was a 10-year follow-up of 350 patients—100 of which had PCI with bare-metal stents (BMS) and 250 who had CABG. The second was a five-year clinical follow-up of 395 patients from the ASAN-MAIN (ASAN medical center-left MAIN revascularization) registry—176 patients had PCI with drug-eluting stents (DES) and 219 underwent CABG.
The researchers used all-cause mortality and a composite of death, Q-wave MI or stroke as the primary safety endpoints and target vessel revascularization (TVR) as the primary efficacy endpoint.
Complete revascularization was achieved in 67 percent of the BMS patients and 83.6 percent of the CABG patients during the 10-year follow-up. For the five-year follow-up, total revascularization was completed in 71.6 percent of the DES patients and 80.4 percent of the CABG patients.
The adjusted risks of the primary safety endpoints were similar in the 10-year BMS group and the five-year DES group compared with CABG. In both the 10-year and five-year studies, the adjusted risk of TVR was significantly higher in the PCI group than the CABG group.
Similarly, the unadjusted risks for the primary safety endpoints were not statistically significant in either study. Again, the TVR was significantly higher for PCI than CABG in both time points.
Cumulative definite and probably stent thrombosis rate was 1.8 percent, within the 1 to 2 percent reported in studies with one to three years follow-up.
“Recently, long-term safety concerns about DES use have been raised, due to increased risks of late stent thrombosis and late mortality,” the authors wrote. “Considering the catastrophic consequences of stent thrombosis in left main coronary artery stenting, a lack of long-term clinical data have hampered the widespread use of PCI with DES as an alternative to CABG for such patients.”
Park and colleagues noted that the results of this trial show that left main coronary artery stenting with DES may produce rates of stent thrombosis and mortality that are “lower, or at worst, similar” to those seen in patients with other coronary lesions.
“For the treatment of left main CAD, PCI with stent implantation showed similar long-term mortality and rates of death, Q-wave MI or stroke,” the authors wrote. “However, stenting, even with DES, was associated with higher rates of repeat revascularization than was CABG.”