乌鸦传媒

ORLANDO -- Using the SYNTAX score to guide the choice of revascularization in patients with three-vessel coronary artery disease improves clinical outcomes, a single-center study suggested.

Compared with patients who underwent percutaneous coronary intervention (PCI) with a SYNTAX score greater than 22 (considered inappropriate), those who underwent appropriate revascularization with coronary artery bypass graft (CABG) or PCI had a significantly reduced risk of all-cause death, acute myocardial infarction (MI), or stroke (11.3% versus 25.8%, hazard ratio 0.27, 95% CI 0.15 to 0.52), according to Tonga Nfor, MD, of Aurora St. Luke's Medical Center in Milwaukee.

The finding, which was consistent across various subgroups, supports current practice guidelines and appropriate use criteria that recommend using the SYNTAX score to guide decision-making for patients with three-vessel disease, Nfor reported at the Society for Cardiovascular Angiography and Interventions meeting.

Because of the observational and single-center design of the study, Farouc Jaffer, MD, MPH, of Massachusetts General Hospital in Boston, said the findings give food for thought for clinicians, adding that "it is a very important study to demonstrate in a real-world environment that the SYNTAX score is very helpful for understanding the method of revascularization." Jaffer moderated the SCAI session.

The SYNTAX trial showed that in the subset of patients with three-vessel disease, the rate of major adverse cardiovascular and cerebrovascular events through 5 years was comparable in the PCI and CABG groups when the SYNTAX score was 22 or lower (33.3% versus 26.8%, P=0.21) but significantly higher with PCI when the SYNTAX score was higher.

That information was then incorporated into practice guidelines, although the SYNTAX score is measured in a minority of patients because of a perception that it is a burdensome tool to use, Nfor said.

He and his colleagues initiated a study to assess whether incorporating the SYNTAX score into clinical decision-making might improve clinical outcomes for patients with symptomatic three-vessel disease.

Using information from the National Cardiovascular Data Registry CathPCI and Society of Thoracic Surgeons databases, the researchers identified 1,530 adult patients with three-vessel disease -- with or without left main vessel disease -- who underwent revascularization at their center in 2009 and 2010.

Revascularization was considered appropriate, defined as CABG for any SYNTAX score and PCI for SYNTAX scores of 22 or less, in 94% of patients. It was considered inappropriate, defined as PCI for SYNTAX scores of 23 or higher, in the rest.

The researchers matched every inappropriate case to four appropriate cases using propensity matching to account for the likelihood of undergoing PCI, the presence of left main disease, and SYNTAX score in order to compare outcomes between the appropriate and inappropriate groups.

After matching, there were 93 inappropriate cases (mean age 63) and 372 appropriate cases (mean age 65). The average SYNTAX score was 31 in each group, the average EuroSCORE was 7.1 and 7.6 in the inappropriate and appropriate groups, respectively, and the average STS risk score was 4.7 and 4.3, respectively.

The significantly lower risk of all-cause death, acute MI, or stroke with appropriate revascularization was seen after multivariate adjustment for age, sex, ejection fraction, cardiac presentation, left main disease, SYNTAX score, and STS risk score.

It was driven by significantly lower rates of death (9.7% versus 17.2%, HR 0.29, 95% CI 0.08 to 0.44) and acute MI (1.6% versus 9.7%, HR 0.11, 95% CI 0.08 to 0.21). The stroke rate was not significantly different (1.3% versus 3.2%, HR 0.41, 95% CI 0.08 to 5.32).

In addition, appropriate revascularization was associated with lower rates of repeat revascularization (3.5% versus 32.3%, HR 0.06, 95% CI 0.02 to 0.19) and major adverse cardiovascular and cerebrovascular events (14.5% versus 48.4%, HR 0.15, 95% CI 0.09 to 0.25).

Jaffer noted that according to the appropriate use criteria, PCI in patients with SYNTAX scores higher than 22 has "uncertain" benefit rather than being inappropriate.

The findings showed, however, that most cardiologists in the study appropriately picked revascularization despite not routinely measuring the SYNTAX score, he said.

"I think we can refine that certainly by calculating the SYNTAX score formally," Jaffer said. "I think that was one of the messages, that we could go from 94% to higher."

Nfor noted some limitations of the analysis, including the single-center and nonrandomized design and the lack of information on why inappropriate revascularization was performed. Nfor speculated that it may be related to patient preference.

Also, he said, the categorization of revascularization as appropriate or inappropriate may be an oversimplification of decisions made in practice.

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