SYNTAX Score II Added to Modern PCI Translates Into Gains for Patients With Three-Vessel Disease

PARIS, France—Using a contemporary strategy to guide and optimize PCI in patients with three-vessel disease appears to improve outcomes at 30 days, potentially putting PCI on par with surgery in this complex group of patients, experts say.

Compared with historical controls from the SYNTAX I trial, the approach “results in lower MI and stent thrombosis rates at 30 days,” said Patrick W. Serruys, MD, PhD (Erasmus Medical Center, Rotterdam, the Netherlands), who presented early findings from SYNTAX II at EuroPCR 2016.

The single-arm study, he said, employed the SYNTAX score II for patient selection, instantaneous wave-free ratio (iFR) for functional assessment of stenosis severity, use of the newer-generation Synergy everolimus-eluting stent (Boston Scientific), procedural guidance by intravascular ultrasound, and modern treatment of chronic total occlusion.

Stressing that the primary endpoint of the study is meant to be assessed at 1 year, Serruys urged caution in interpreting the 30-day findings.

‘Moving Towards a PCI Option’

However, speaking with TCTMD, panelist Justin E. Davies, MD, PhD, of (Imperial College, London, England), was decidedly enthusiastic. “The results are pretty profound,” he said, citing data reported by Serruys showing an absolute reduction in MI of nearly 4% and in definite/probable stent thrombosis of 2.1%.

“At 30 days? That’s huge,” he commented, noting that these results are a reflection of how far multivessel PCI has come. According to Davies, the “future promise” is that multivessel disease now handled by surgery eventually might, with best practices, “well be something which could be moving towards a PCI option.”

Serruys reported that current European guidelines “have a Ib recommendation for patients with three-vessel disease [and] SYNTAX scores < 23, with the remainder being recommended for CABG.”

Colin Berry, MB ChB, PhD (University of Glasgow, Scotland), a panelist during the EuroPCR hotline session, told TCTMD that he’s “pretty cautious about making comparisons between two groups of patients enrolled at different times under different conditions. So I think it’s hypothesis-generating, but [fairly safe to say] the combination of new diagnostic and therapeutic approaches in percutaneous intervention is going to lead to improved outcomes.”

However, it is hard to know which aspects of the strategy made the most difference, he said. “It makes the case for a future prospective study” like SYNTAX III REVOLUTION.

PCI has evolved since the time of the original SYNTAX trial, Berry agreed, “but bear in mind that the methods being used in . . . SYNTAX II to a great extent were readily available at the time of the SYNTAX I trial.” What stands out about the current trial is that these approaches “were virtually mandated by protocol,” he explained.

Completeness of revascularization could be another reason for the good results, Berry suggested. Total stent length was 18.0 mm longer in SYNTAX II than in the original study. While this may simply reflect longer stents being available, he said, “it may also reflect a more corrective approach of interventionalists, to stent from ‘normal to normal’ and to try and cover all disease with drug-coated stents. . . .That’s an interesting difference between the two trials.”

Decreases in MI, Stent Thrombosis

SYNTAX II involved 454 patients with three-vessel disease who were selected for PCI by a heart team based on having a SYNTAX score II that indicated either PCI or equipoise between stenting and surgery. In data presented by Serruys, their results were compared against those of 315 comparable patients in the PCI arm of the original SYNTAX trial.

At 30 days, the rate of MACCE (all-cause death, stroke, MI, or repeat revascularization was similar between the SYNTAX II and SYNTAX I—PCI arm patients (2.9% vs 4.4%; log-rank P = 0.35). But when only the repeat revascularizations that were clinically indicated or due to failed index PCI were included—and those referred to as “retouching” were excluded—the difference more clearly favored the updated strategy (2.0% vs 4.4%; log-rank P = 0.055).

Among the individual components of MACCE, the SYNTAX II cohort only held an advantage for MI (0.2% vs 4.1%; P < 0.001) and definite/probable stent thrombosis (0.4% vs 2.5%; P = 0.019).

Staged procedures were more common in SYNTAX II versus SYNTAX I, Serruys said, at 30% versus 17%. These cases had to be adjudicated to avoid artificially inflating the rate of repeat revascularizations. “That, for the trialists, will be a major issue in the future,” he predicted. “We know that we put the patient on the table a second and a third time—for financial reasons, societal reasons, reimbursement—and that’s not good medicine. Ideally as a patient, you would like to go on the table one time and be finished, and that’s what a surgeon can do.”

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• PCI vs. CABG a Close Call in Some Complex Patients
• FFR Plus Syntax Score Equals Better Risk Stratification in Multivessel Patients