CREDO-Kyoto Compares CABG and PCI in Triple-Vessel Disease

August 29, 2011—The European Society of Cardiology (ESC) announced that 24-month data from the CREDO-Kyoto (Coronary Revascularization Demonstrating Outcome Study in Kyoto) PCI/CABG registry cohort-2 study were presented at the society's annual meeting in Paris, France.

According to the ESC, the CREDO-Kyoto results showed that in patients with triple-vessel disease, percutaneous coronary intervention (PCI) was associated with significantly higher risk for serious adverse events than coronary artery bypass grafting (CABG). The protective effect of CABG for myocardial infarction (MI) was described as "especially remarkable." Investigator Hiroki Shiomi, MD, stated that in view of these results, “CABG would still remain the standard treatment option in patients with triple-vessel disease, particularly when their SYNTAX scores are high.”

The ESC noted that these registry findings are derived from the largest-ever study population of triple-vessel disease patients with SYNTAX score assessment, and that they are consistent with those found in the SYNTAX randomized trial. However, Dr. Shiomi advised that although the observations were striking in patients with triple-vessel disease, the selection of revascularization strategies in patients with less-complex coronary anatomy “deserves further consideration.” The 3-year results from the SYNTAX trial suggested that for PCI relative to CABG, the excess risk for death, MI, or stroke was significant in the triple-vessel disease subset, but there were limitations in the apparent lack of statistical power to evaluate this composite endpoint.

The CREDO-Kyoto PCI/CABG registry cohort-2 is a physician-initiated, noncompany-sponsored, 26-center registry enrolling consecutive patients having a first coronary revascularization between January 2005 and December 2007. The study population for the current analysis consisted of 2,981 patients with triple-vessel disease (PCI, n = 1,825 patients; CABG, n = 1,156 patients). To ensure comparability between the PCI and CABG groups (in an observational study), anatomic complexities of coronary artery disease were assessed using the SYNTAX score. The primary endpoint of the study was a composite of all-cause death, MI, and stroke.

The investigators found that PCI as compared with CABG was associated with a higher 3-year risk for this primary endpoint (adjusted hazard ratio [HR], 1.47; 95% confidence interval [CI], 1.13–1.92; P = .004]) and for MI (HR, 2.39; 95% CI, 1.31–4.36; P = .004). However, the risk for cardiac death was not significantly different (HR, 1.30; 95% CI, 0.81–2.07; P = .28), although the risk for all-cause death was significantly higher after PCI (HR, 1.62; 95% CI, 1.16–2.27; P = .005).

The results also showed that the cumulative incidence of the primary endpoint was comparable between the PCI and CABG groups in patients with low (< 23) and intermediate (23–32) SYNTAX scores, but in patients with high SYNTAX scores (≥ 33) was markedly higher after PCI than after CABG (15.8% and 12.5% [P = .25]; 18.8% and 16.7% [P = .24]; and 27% and 16.4% [P = .004], respectively). However, the adjusted risk of PCI relative to CABG for the primary endpoint was HR 1.66 (95% CI, 1.04–2.65; P = .03) in the low-score category, HR 1.24 (95% CI, 0.83–1.85; P = .29) in the intermediate-score category, and HR 1.59 (95% CI, 0.998–2.54; P = .051) in the high-score category. “Further studies are therefore warranted to investigate whether PCI is a viable option in patients with less complex coronary anatomy,” stated Dr. Shiomi.