The SYNTAX Trial

CABG vs. Stenting for Severe Coronary Disease
Specific benefits and harms differ somewhat for the two interventions.

Although coronary-artery bypass grafting (CABG) has been the standard of care for patients with left-main or three-vessel coronary disease who require revascularization, percutaneous coronary intervention (PCI) with stenting is also an option in such cases. These two interventions were compared in the SYNTAX trial, which was sponsored by the manufacturer of the Taxus drug-eluting stent.

Eighteen hundred patients with previously untreated left-main or three-vessel disease were randomized to CABG or PCI; in each case, either intervention was deemed feasible by a cardiologist and a surgeon. At 1 year, incidence of the primary composite endpoint (death, stroke, myocardial infarction, or repeat revascularization) was significantly lower with CABG than with PCI (12.4% vs. 17.8%). The Table shows differences in outcomes for individual components of the composite endpoint.

Comment:
In this study, CABG was superior to PCI for a predefined composite endpoint; the difference was driven largely by less need for repeat revascularization in the CABG group. However, CABG patients had a small but significantly higher rate of stroke, which was defined as a neurologic deficit lasting more than 72 hours and resulting in "irreversible brain damage or body impairment." The short follow-up (1 year) is an important limitation.

These results should inform discussions with patients who require revascularization for severe coronary disease. Choosing CABG (over PCI) implies a roughly 8-per-100 lower probability of needing another procedure during the ensuing year, at the expense of a roughly 2-per-100 higher risk for stroke. Other issues include longer recuperation time after CABG than after stenting and need for prolonged dual antiplatelet therapy with drug-eluting stents. Patients are likely to differ in how they weigh these tradeoffs.

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Allan S. Brett, MD
Published in Journal Watch General Medicine March 5, 2009