External Validation of the FREEDOM Score for Individualized Decision Making Between CABG and PCI.

Background: Although randomized trials have established that coronary artery bypass grafting (CABG) is, on average, the most effective revascularization strategy compared with percutaneous coronary intervention (PCI) in patients with diabetes and multivessel disease (MVD), individual patients differ in many characteristics that can affect the benefits and harms of treatment. The FREEDOM (Future Revascularization Evaluation in Patients with Diabetes Mellitus) score was developed to predict different outcomes with CABG vs PCI on the basis of 8 patient characteristics and the smoking-treatment interaction.
Objectives: This study aimed to assess the ability of the 5-year major adverse cardiovascular event (MACE) model to predict treatment benefit of CABG vs PCI in the SYNTAX (Synergy Between Percutaneous Coronary Intervention With Taxus and Cardiac Surgery) and BEST (Bypass Surgery and Everolimus-Eluting Stent Implantation in the Treatment of Patients with Multivessel Coronary Artery Disease) trials.
Methods: This study identified 702 patients with diabetes and MVD to mirror the FREEDOM participants. Discrimination was assessed by C-index, and calibration was assessed by calibration plots in the PCI and CABG arms, respectively. The ability of the FREEDOM score to predict treatment benefit of CABG vs PCI was assessed.
Results: Overall, CABG was associated with a lower rate of 5-year MACE compared with PCI (12.4% vs 20.3%; log-rank P = 0.021) irrespective of a history of smoking (P _interaction  = 0.975). Both discrimination and calibration were helpful in the PCI arm (C-index: 0.69; slope: 0.96, intercept: -0.24), but moderate in the CABG arm (C-index: 0.61; slope: 0.61; intercept: -0.53). The FREEDOM score showed some heterogeneity of treatment benefit.
Conclusions: The FREEDOM score could identify some heterogeneity of treatment benefit of CABG vs PCI for 5-year MACE. Until further prospective validations are performed, these results should be taken into consideration when using the FREEDOM score in patients with diabetes and MVD. (Synergy Between Percutaneous Coronary Intervention With Taxus and Cardiac Surgery [SYNTAX]; NCT00114972) (Bypass Surgery and Everolimus-Eluting Stent Implantation in the Treatment of Patients with Multivessel Coronary Artery Disease [BEST]; NCT00997828) (Future Revascularization Evaluation in Patients with Diabetes Mellitus [FREEDOM]; NCT00086450).
Competing Interests: Funding Support and Author Disclosures This work was supported by Boston Scientific Corporation (SYNTAX study, 0-5-year follow-up). The study funders had no role in trial design, data collection, data analyses, interpretation of the data, writing of the report, or making a decision to submit the manuscript for publication. Dr Serruys has received personal consulting fees from Biosensors, Medtronic, Micell, Sino Medical Sciences Technology, Philips Volcano, Xeltis, and Heartflow, outside the submitted work. Dr Farkouh has received research grants from Amgen, Novartis, and Novo Nordisk, outside the submitted work. Dr Spertus has ownership of the Seattle Angina Questionnaire; has received consulting fees from United Healthcare, Merck, Bayer, Novartis, Janssen, Myokardia, and Janssen; has received a research grant from Abbott Vascular; and has served on the Board of Directors of Blue Cross Blue Shield of Kansas City, all outside the submitted work. Dr Cohen has received institutional research grants and personal fees from Medtronic, Boston Scientific, and Abbott Vascular, outside the submitted work. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
(Copyright © 2022 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)