Some Types of Incomplete Revascularization During PCI Carry More Risk Than Others

In patients with or without STEMI undergoing PCI, failing to treat all significant lesions of those with multivessel CAD is associated with a heightened mortality risk, but certain characteristics may make that relationship even more concerning, according to New York State data.

Patients with incomplete revascularization affecting at least two vessels overall, at least one vessel with 90% stenosis, or the proximal LAD had higher rates of risk-adjusted mortality when compared with patients who lacked these characteristics, researchers led by Edward Hannan, PhD (University at Albany, NY), report in a study published online last week ahead of print in JAMA Cardiology. Such patients also were at higher risk compared with those who underwent complete revascularization.

Clinicians always need to consider all options available to them, including complete revascularization and CABG, but this study indicates that there needs to be more thoughtful deliberation for patients with these characteristics, in whom there is a trade-off between concerns about greater risks when performing more complete revascularization and a desire to do everything possible to help, Hannan told TCTMD.

“If people are aware of this trade-off and aware of the fact that these patients have an even higher risk, that just cranks up the onus on trying to think about other options,” he said. “It doesn’t mean the other options are always the best thing, it just means that it’s even more important to really give a careful consideration of other options.”

High-Risk Characteristics Relatively Common

Though numerous studies have made the connection between incomplete revascularization and poorer outcomes in patients with multivessel CAD undergoing PCI, there is little information about whether certain characteristics modify that relationship.

To find out, Hannan et al examined data from New York’s Percutaneous Coronary Interventions Reporting System on 41,639 state residents with multivessel CAD who underwent PCI between 2010 and 2012.

Incomplete revascularization was used in 78% of patients with STEMI and 71% of patients with non-STEMI, and—through a median follow-up of 3.4 years—both groups had higher rates of risk-adjusted mortality versus patients who had more complete interventions.

However, compared with other patients who underwent incomplete revascularization, those whose incomplete treatment affected at least two vessels overall, at least one vessel with greater than 90% stenosis, or the proximal LAD carried even higher risks of mortality, findings that were generally consistent in patients with and without STEMI.

Risk-Adjusted Mortality Based on Type of Incomplete Revascularization

Of note, more than 20% of patients who underwent incomplete revascularization had at least two vessels affected and more than 30% had at least one vessel with greater than 90% stenosis. Those high rates were “somewhat surprising,” Hannan said, noting that a prior study showed that the vast majority of incomplete revascularizations (96%) were planned and not due to an unsuccessful attempt at complete revascularization.

“You really need to do some hard thinking before you make this decision, because this is a group that’s going to do even worse [with incomplete revascularization],” he said.

Questions About Completeness Remain

In an accompanying editorial, William Weintraub, MD (MedStar Heart and Vascular Institute, Washington, DC), says, “A somewhat superficial reading of this article would seem to support the assertion that more complete revascularization will decrease mortality. Indeed, it may be the case that if operators perform complete revascularization that outcomes will be better. However, we should be cautious about this interpretation.”

One reason for caution is the possibility that the findings are related to confounders—such as diffuseness of disease or patient frailty—that could not be adequately controlled for in the analysis, a caveat also noted by the researchers.

Moreover, even if there is a causal link between incomplete revascularization and poorer outcomes, it’s not clear that a more complete procedure will address the issue, Weintraub says, noting that there are many valid reasons that may justify forgoing complete revascularization. “There are certainly reasons that incomplete revascularization is performed, and the least likely would seem to be because the operators are ill-informed, incapable, or in some way negligent in the performance of PCI,” he explains.

The issue of revascularization’s completeness is more complicated in STEMI, he says, because there continues to be debate about whether only the culprit artery should be opened during primary PCI and also about whether multivessel PCI should be performed during the initial procedure or in a staged fashion.

“The study by Hannan et al cannot answer all questions concerning completeness of revascularization, but it does reinforce the seriousness of the issue,” Weintraub writes. “Randomized trials of completeness of revascularization may prove impossible to carry out in the future because of issues related both to anatomy limiting complete revascularization and lack of equipoise where complete revascularization can readily be carried out. Thus, we will continue to learn more from observational studies. In this regard, the article by Hannan et al is a seminal contribution.”