SYNTAX: Repeat revascularization rates higher at 5 years after initial PCI vs. CABG
In patients with complex coronary disease, repeat revascularization rates are significantly higher after index PCI vs. index CABG, according to new data from the SYNTAX trial.
In the randomized, prospective, multicenter trial, researchers evaluated 1,800 patients with complex coronary disease, defined as the existence of unprotected left main or three-vessel disease. Patients were randomly assigned 1:1 to undergo CABG or PCI with paclitaxel-eluting stents (Taxus Express, Boston Scientific). The SYNTAX trial’s primary endpoint was a composite of MACCE, including all-cause death, MI, stroke and repeat revascularization.
The current study was focused primarily on repeat revascularization and clinical outcomes at 5 years, and researchers assessed the individual endpoints of repeat revascularization (all, repeat PCI, and repeat CABG) and all-cause mortality, as well as the composite safety endpoint of all-cause death, MI and stroke.
They found that, during 5-year follow-up, there were 459 repeat revascularization events; 86.2% of these were repeat PCI and 14.8% were repeat CABG revascularization. The rate of repeat revascularization at 5 years after initial CABG was 13.7%, and the rate of repeat revascularization at 5 years after initial PCI was 25.9% (P < .001). Repeat PCIs more frequently consisted of multiple repeat revascularizations compared with repeat CABG (9% vs. 2.8%; P = .022). More repeat PCIs were performed on de novo lesions in patients after index PCI vs. index CABG (33.3% vs. 13.4%; P < .001).
The rates of repeat revascularization were significantly higher after initial PCI than after initial CABG at all time points assessed. Nearly all repeat CABG procedures were performed within 30 days of initial CABG; other repeat revascularizations performed subsequently were repeat PCIs.
Revascularization and safety
The composite safety endpoint of all-cause death, stroke and MI was higher among patients who underwent repeat revascularization after initial PCI vs. those who did not undergo repeat revascularization (27.9% vs. 16.6%; P < .001). There was no difference in the composite safety endpoint after initial CABG (14.9% vs. 15.8%; P = .62), according to the findings.
Among the patients who underwent repeat revascularization, the rates of the composite of death, MI or subsequent revascularization were higher in patients who underwent initial PCI vs. initial CABG (57.4% vs. 38.4%; P = .03). This was largely attributable to higher rates of subsequent revascularization (43.4% vs. 25.3%; P = .012) and MI (19.2% vs. 4.8%; P = .012), the researchers wrote. No significant difference in mortality was seen in patients who underwent repeat revascularization after index PCI vs. index CABG (20.2% vs. 13.9%; P = .09).
Multivariate adjustment revealed repeat revascularization as an independent predictor of the composite safety endpoint after both initial PCI (HR = 2.2; 95% CI, 1.6-3) and initial CABG (HR = 1.8; 95% CI, 1.2-2.9).
Limitations of findings
In a related editorial, Roxana Mehran, MD, of the Icahn School of Medicine at Mount Sinai, and Michela Faggioni, MD, of the cardiothoracic department, division of cardiology, University Hospital of Pisa, Italy, discussed the association of repeat revascularization with a higher risk for subsequent MACE after initial PCI, but not CABG.
“Although certainly intriguing, these findings must be considered within certain limitations of such a post-hoc analysis. First, excess risk after repeat revascularization was confined to MI; whereas, rates of stroke and death did not differ between groups,” Mehran, who is associate medical editor of Cardiology Today’s Intervention, and Faggioni wrote. “Second, as with any subgroup analysis, the possibility of a false positive and spurious result cannot be excluded.
Third, the authors did not present a formal test of interaction, which would strengthen the claim that repeat revascularization is a modifier of risk after initial PCI but not CABG.” – by Jennifer Byrne
Disclosure: One researcher reports being employed by and holding equity in Boston Scientific. Another researcher reports consulting for Abbott Vascular, Boston Scientific and Edwards Lifesciences. Mehran reports financial ties with multiple pharmaceutical and device companies. Faggioni reports no relevant financial disclosures.