SYNTAX: Stenting vs. Surgery in Left Main and Triple Vessel Disease

New subgroup analyses from the SYNTAX trial show equivalent safety and efficacy endpoints between PCI with Taxus paclitaxel-eluting stents and CABG for patients with unprotected left main disease, while CABG still shows improved efficacy outcomes in triple-vessel disease.

Initial results from SYNTAX, announced at the European Society of Cardiology Congress 2008, showed that PCI was not noninferior to CABG for the treatment of complex disease, based on the primary endpoint of 2-month major adverse cardiac and cerebrovascular events (MACCE).

Investigators Tuesday released expanded results stratifying patients by the SYNTAX score (see Figure 1), an amalgamation of angiographic and lesion characteristics that allows adjustment for the complexity of potential PCI procedures, incuding such factors as presence or absence of CTO lesions and lesion location in the arterial tree.
Patrick W. Serruys, MD, PhD, of Thoraxcenter, Rotterdam, Netherlands, presented details on the subset of patients with left main disease, either isolated or with single , double , or triple-vessel disease, in the randomized segment of SYNTAX. These patients accounted for 33.7% of the 897 patients assigned to CABG and 34.6% of the 903 assigned to PCI.
At 12 months, overall MACCE rates (composite of death, stroke, MI, and repeat revascularization) were similar for CABG and PCI (15.8% and 13.7%, P=.44). Equivalent MACCE rates also were shown with CABG and PCI in patients with isolated left main disease (8.5% vs. 7.1%; P=1.0) as well as patients with left main disease plus single-vessel disease (13.2% vs. 7.5%; P=.27), double-vessel disease (14.4% vs. 19.8%; P=.29), and triple-vessel disease (15.4% vs. 19.3%; P=.42).
Stroke rates were significantly higher in CABG patients (2.7% vs. 0.3%; P=.009) and, conversely, repeat revascularization was more prevalent in PCI patients (12.0% vs. 6.7%; P=.02).
Using the newly-developed SYNTAX score, patients in the lowest and intermediate tertiles of coronary lesion complexity had equivalent rates of MACCE at 12 months between PCI and CABG (see Figure 2; see Figure 3). Patients in the highest tertile had significantly higher 12-month MACCE rates with PCI.
"For patients with left main disease, revascularization with PCI has comparable safety and efficacy outcomes to CABG," Serruys concluded. "[PCI] is therefore a reasonable treatment alternative in this patient population, in particular when the SYNTAX score is low or intermediate."
CABG better for complex triple vessel disease
Friedrich W. Mohr, MD, of Herzzentrum Leipzig, Germany, presented data on the subgroup of randomized patients with triple-vessel disease, which accounted for the remaining 66.3% of patients assigned to CABG and 65.4% of those assigned to PCI.
For triple-vessel disease, 12-month MACCE rates were significantly higher in the PCI group than in the CABG group (19.1% vs. 11.2%; P,.001). The PCI group also had higher rates of MI (5.2%