Complete Coronary Revascularization: One Definition to Unite Them All?

A new standard definition of complete coronary artery revascularization was proposed by researchers associated with the ISCHEMIA trial.

Anatomic completeness of revascularization, according to this group, should be primarily based on the presence of residual coronary lesions with diameter stenosis ≥50% on quantitative coronary angiography (QCA) or visual estimation, as calculated by the residual SYNTAX score.

The algorithm has ischemic revascularization defined primarily by invasive physiology, without which alternative assessment is needed, such as noninvasive stress testing.

Left main disease can also be assessed with the criteria, published online in the Journal of the American Heart Association.

However, there is a modified algorithm for ischemia in the left main artery, according to the team led by Ziad Ali, MD, DPhil, of St. Francis Hospital & Heart Center in Roslyn, New York.

The proposed definition has a “comprehensive, yet pragmatic algorithm with both anatomical and ischemic parameters that aims to provide a systematic method to assess complete revascularization after percutaneous coronary intervention [PCI] or coronary artery bypass grafting [CABG] in both clinical practice and clinical trials,” the authors wrote.

Such an algorithm is being applied to evaluate the extent of revascularization achieved in the landmark ISCHEMIA trial, which found no clinical benefit to early stenting or surgery over medical therapy alone among patients with stable, moderate-to-severe ischemic heart disease. This analysis will be reported later this year, Ali and colleagues said.

In the report, the group also offered cutoffs to assess baseline ischemia: QCA diameter stenosis ≥70% or visual estimation stenosis ≥80%.

“While we strongly advocate for the use of invasive coronary physiologic assessment in all patients with intermediate coronary stenoses, real-world use shows drastic underutilization of this modality to assess for ischemia,” according to the authors.

Such an algorithmic approach could be used to guide optimal revascularization strategies in both clinical practice and clinical trials, Ali’s group said, adding that there is no specific guidance on when complete revascularization is preferred over incomplete revascularization.

Whether choice of PCI or CABG should be dictated by the likelihood of revascularization completeness is also not mentioned in U.S. guidelines.

“Instead, the circumstances in which CR [complete revascularization] should be pursued rely largely on observational data, especially for patients with stable coronary artery disease, and remains the decision of individual operators guided by their past experience,” according to the authors.

The group acknowledged the limitations of basing lesion assessments on both QCA and visual estimation as a compromise to boost “widespread adoption” of the standardized system.

Additionally, the proposed thresholds in the algorithm were based on expert consensus opinions derived from prior studies, relating anatomic stenosis severity and physiology findings to outcomes, that could have been subject to unmeasured confounding.