Clinical outcomes of state-of-the-art percutaneous coronary revascularization in patients with de novo three vessel disease: 1-year results of the SYNTAX II study
Selected in European Heart Journal by C. Cook
Escaned J, Collet C, Ryan N, De Maria GL, Walsh S, Sabate M, Davies J, Lesiak M, Moreno R, Cruz-Gonzalez I, Hoole SP, West NE, Piek JJ, Zaman A, Fath-Ordoubadi F, Stables RH, Appleby C, van Mieghem N, van Geuns R Jm., Uren N, Zueco J, Buszman P, Iñiguez A, Goicolea J, Hildick-Smith D, Ochala A, Dudek D, Hanratty C, Cavalcante R, Kappetein AP, Taggart DP, van Es GA, Morel MA, de Vries T, Onuma Y, Farooq V, Serruys PW, Banning AP
European Heart Journal, ehx512, https://doi.org/10.1093/eurheartj/ehx512
LinkRead the abstract
Why this study – the rationale/objective?
Current European guidelines for the management of patients with 3 vessel disease (3VD) are predominantly based on the results of the 2009 SYNTAX I trial. However, contemporary PCI practice has evolved significantly since then. In particular, second generation drug eluting stents, physiology guided revascularization, stent optimization with intravascular imaging and increased rates of successful CTO recanalization characterize the modern approach to PCI. The aim of the SYNTAX II trial was to investigate if these recent technical and procedural developments translated into better patient outcomes for patients with 3VD PCI.
How was it executed – the methodology?
This was a multicentre, all-comers, open label, single-arm study of patients with de novo 3VD with no left main involvement (n=454). Eligible patients had an equipoise recommendation between CABG and PCI based on 4-year mortality. The primary endpoint was a composite of major adverse cardiac and cerebrovascular events (MACCE) at 1-year follow-up. Major adverse cardiac and cerebrovascular event was defined as all-cause death, stroke, any myocardial infarction (MI) or any revascularization. The control group were matched patients with 3VD from the SYNTAX I trial. An additional exploratory endpoint was the composite MACCE compared to the SYNTAX 1 CABG group.
What is the main result?
- PCI undertaken using the SYNTAX II strategy was associated with superior outcomes compared with the PCI arm of the original SYNTAX I trial (10.6% SYNTAX II vs. 17.4% SYNTAX I PCI cohort; HR 0.59 [95% CI 0.59–0.89], P = 0.01). This lower incidence of MACCE was driven by a reduction in MI, revascularization and definite stent thrombosis at 1-year follow-up.
- No difference in MACCE was found between SYNTAX II and the SYNTAX I PCI cohort with an anatomical SYNTAX Score >22 (HR 0.66 [95% CI 0.36 to 1.21], P = 0.179).
- Physiological assessment with a hybrid iFR/FFR strategy was feasible in 75.5% of lesions, and significantly decreased the number of lesions treated per patient (2.64 SYNTAX II vs. 4.02 SYNTAX I PCI cohort, P = <0.001).
- CTO procedural success significantly improved (87% SYNTAX II vs. 53% SYNTAX I PCI cohort, P = <0.0001).
- Post-implantation IVUS led to further optimisation of the stented lesion in 30.2%.
- PCI with the SYNTAX II strategy was associated with similar clinical outcomes to the SYNTAX I CABG cohort (SYNTAX II 10.6% vs. equipoise-derived SYNTAX I CABG cohort 11.2%; HR 0.91 [95% CI 0.59 to 1.14], P = 0.684)
Critical reading and the relevance for clinical practice
SYNTAX II provides an important snapshot of contemporary PCI practice and achieves its goal of demonstrating that recent advancements in PCI translate into improved patient outcomes in 3VD. The most important message of SYNTAX II is that no single component of modern PCI practice can claim all of the credit for the demonstrated improvement in MACCE. Although most benefit is likely attributable to newer generation stent platforms, SYNTAX II reminds us that modern PCI remains a ‘team approach’ – identification of ischemia with coronary physiology, stent optimization with intracoronary imaging and improved procedural success with continued device innovation all play important roles.
Although the study was cleverly designed to maximize clinically relevant outputs, SYNTAX II remains a non-randomised study comparing current practice to a historical control group. In the era of EXCEL and NOBLE, those hoping for guideline changing data to support 3VD PCI may well be disappointed. Furthermore, only 1 year follow up data is currently available. The planned reporting of 5 year follow up data may reveal that CABG still retains superiority over PCI in the long run.