Impact of the SYNTAX scores I and II in patients with diabetes and multivessel coronary disease: a pooled analysis of patient level data from the SYNTAX, PRECOMBAT, and BEST trials

Aims To assess the impact of the SYNTAX scores I and II in outcomes after percutaneous coronary intervention (PCI) and coronary artery bypass graft (CABG) for patients with diabetes and multivessel disease (MVD). Methods and results We performed a patient-level pooled analysis of three large randomized trials of patients with MVD. The impact of coronary anatomic complexity as measured by the SYNTAX score in the differences in outcomes following PCI and CABG was assessed at a median follow-up of 5 years. We also assessed the performance of the SYNTAX II score model in patients with and without diabetes. From the 3280 patients enrolled in the three trials, a total of 1068 (32.6%) had diabetes. The rate of the composite of death, myocardial infarction (MI), or stroke was similar in the PCI and CABG arms in patients with low-intermediate (≤32) SYNTAX scores (15.1% vs. 14.9%, respectively; P = 0.93) while it was significantly higher in the PCI arm in patients with high (≥33) SYNTAX scores (24.5% vs. 13.2%, respectively; P = 0.018). The SYNTAX score II showed good calibration and moderate discrimination ability in patients with diabetes (c-index = 0.68) as well as in those without (c-index = 0.67). Conclusions Differences in 5 years outcomes following PCI and CABG for patients with MVD and diabetes were influenced by anatomic complexity as measured by the SYNTAX score. The SYNTAX score II mortality prediction model showed similar performance regardless of the diabetes status.