The SYNTAX study, which randomised patients with complex severe coronary disease to either CABG or PCI, found that CABG remains a superior treatment option for the majority of these patients.  However, in a substudy of patients who had left main stem (LMS) disease, SYNTAX suggested equipoise between the two treatments.  Since then, the debate about the role of PCI in treating LMS disease has intensified.

In the PRECOMBAT study, performed at 13 sites in S.Korea, 600 patients with left main disease were randomly assigned in a 1:1 fashion to either CABG or PCI with sirolimus-eluting stents.  Follow-up was for a mean of 2 years and the primary composite end point was major adverse cardiac or cerebrovascular events (death from any cause, myocardial infarction, stroke, or ischemia-driven target-vessel revascularization).  Superficially, the results confirm those of the SYNTAX substudy with the primary end point occurring in 26 PCI patients as compared with 20 CABG patients (cumulative event rate, 8.7% vs. 6.7%;  95% CI, -1.6 to 5.6; P=0.01 for noninferiority) with  this holding out to 2 years.  However, the overall event rate was much lower than had been anticipated leaving the non-inferiority margin extremely wide and equating to an almost 100% increase in the overall rate of the primary end-point between groups.  With such a wide margin the results become difficult to interpret and the authors concede that the study cannot be regarded as clinically directive.

Conclusions:

In this randomized trial of patients with unprotected left main disease, PCI was noninferior to CABG. However, due to a wide noninferiority margin the results are not clinically directive and the outcomes of other large trials with similar patients, such as the current EXCEL study, will be needed to guide practice.

• Park SJ, Kim YH, Park DW et al.  Randomized trial of stents versus bypass surgery for left main coronary artery disease.  N Engl J Med 2001;364(18):1718-1727.