Rates of in-stent restenosis after a drug-eluting stent (DES) implantation in patients with unprotected left main coronary artery (LMCA) disease reach almost 20 percent; however, incidence of cardiac events does not differ between treatment modalities, according to research published in the March 22 issue of the Journal of the American College of Cardiology.
“Current practice guidelines recommend coronary artery bypass grafting (CABG) as the standard revascularization procedure for patients with unprotected LMCA disease,” the authors wrote. Recently, PCI is being more frequently used to treat an unprotected LMCA and has been associated with improvements in interventional techniques and adjunctive drug therapy.
Jong-Young Lee, MD, of the Asan Medical Center, University of Ulsan College of Medicine in Seoul, Korea, and colleagues evaluated the incidence, predictors and long-term outcomes of patients who undergo in-stent restenosis after PCI with drug-eluting stents (DES) for left main coronary artery disease in 509 patients with unprotected LMCA disease who underwent DES implantation.
Stent implantations took place between February 2003 and November 2007 and 80.1 percent of the patients underwent angiographic follow-up.
The researchers found that incidence of angiographic in-stent restenosis in LMCA lesions was 17.6 percent (71 patients)—57 with focal-type and 14 with diffuse-type restenosis. Of the 509 patients, 40 underwent repeated PCI, 10 underwent bypass surgery and 21 percent were treated medically.
After a mean 31.7-month follow-up, one MI and six repeated target lesion revascularizations occurred. There were no deaths. The overall incidence of major adverse cardiovascular events (MACE) was 14.4 percent in the medical group, 13.6 percent in the repeated PCI group and 10 percent in the bypass surgery group.
The authors reported that the occurrence of DES in-stent restenosis did not affect the risk of death or MI.
Additionally, the researchers found that patients who underwent angiographic follow-up had a higher incidence of all-cause mortality but no differences in cardiac mortality, 3.6 versus 8 percent and 2 percent versus 2.8 percent, respectively.
The researchers also reported that patients with in-stent restenosis were more likely to be female and have higher rates of diabetes and procedural complexities compared to those without in-stent restenosis.
The authors reported that angiographic restenosis after LMCA stenting with DES varied and the numbers were between 8 percent and 42 percent.
And while the three-year outcomes after treatment of the LMCA in-stent restenosis did not differ between medical therapy, PCI or CABG, the authors said it is still unclear as to whether or not surveillance angiography should be mandatory after LMCA stenting.
Recent PCI guidelines do not recommend routine angiographic follow-up after LMCA stenting; however, the authors noted that angiography could help detect a silent LMCA in-stent restenosis but is unable to predict when a patient is more prone to sudden stent thrombosis.
"The clinical consequences of LMCA in-stent restenosis after DES treatment seemed to be benign, with the incidence of major adverse cardiac event not differing significantly among treatment modalities, given that these patients were optimally treated with the clinical judgment of the treating physician," the authors concluded.