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TCT: Near-Infrared Spectroscopy IDs Plaques Likely to Cause Problems

<ѻý class="mpt-content-deck">— Non-culprit lesions with large lipid core associated with events
Last Updated September 27, 2018
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SAN DIEGO -- Multivessel near-infrared spectroscopy (NIRS) can help evaluate vulnerable patients and vulnerable plaques for possible percutaneous coronary intervention (PCI), a study found.

On a patient level, the lipid core burden index measure was a significant predictor of events as a continuous variable, with adjusted risk of a major adverse cardiovascular event in a non-culprit lesion within 24 months rising 18% for every 100-unit increase in maxLCBI4mm.

Action Points

  • Note that this study was published as an abstract and presented at a conference. These data and conclusions should be considered to be preliminary until published in a peer-reviewed journal.

The same was true when looked at on a plaque level too, with event risk rising 45% per 100-unit increase in maxLCBI4mm, Ron Waksman, MD, of MedStar Washington Hospital Center in Washington, D.C., reported here at the Transcatheter Cardiovascular Therapeutics meeting.

A lipid core burden above the threshold identified (maxLCBI4mm over 400) was associated with an 87% higher risk of those events on a patient-level analysis and more than four-fold risk on the individual lesion level.

"Intravascular NIRS imaging in mildly or non-obstructive coronary arteries can be used as a tool to identify both patients and non-culprit arteries at high risk for future events and should be considered for use in patients undergoing cardiac catheterization with possible PCI," the researchers wrote.

However, Morton Kern, MD, of the University of California in Irvine, called it "confusing" to see that "incidence of lipid core plaque in stable patients and the acute unstable patients were similar" in the study.

Thus "some of the hypotheses about the acute unstable plaques being more lipid rich than those with plaques in stable patients are sort of at odds with one another," he said as a panelist at the press conference for the late-breaking clinical trial session.

The researchers evaluated 1,552 patients (average age 64 years, 69.5% men) with evaluable lipid core burden index. The patients presented with stabilized STEMI (2.5%), non-STEMI (14.3%), unstable angina (36.8%), and stable angina (46.3%).

Among them, nearly 9% experienced subsequent non-culprit events within 24 months, Waksman said.

Moreover, at 2-year follow-up, the researchers reported that adjudicated patient level events were as follows:

  • Cardiac death: 2.2%
  • Cardiac arrest: 0.4%
  • Acute coronary syndromes: 2.9%
  • Non-fatal MI: 1.3%
  • Rehospitalization, progressive angina, greater than 20% diameter stenosis progression: 0.7%
  • PCI: 5.3%
  • Coronary artery bypass grafting: 1.2%

"The events rates were low, relatively speaking, for finding the plaque but a lot of plaque seemed to be associated with more events," Kern noted.

"It's just not solely the amount of plaque detected by the lipid core near-infrared spectroscopy, but also the other clinical features, which weren't dissected, which was a limitation and, of course, the outcomes related to the addition of those," Kern added.

Looking ahead, the researchers concluded, "studies for the use of NIRS-guided therapy should be conducted to address and mitigate the high risk of these patients and arteries."

Ultimately, Kern said, we want to know which patients are going to have these events. "I want to know, I can't know yet, but we are getting closer," he concluded.

Disclosures

Waksman disclosed relationships with Abbott Vascular, AstraZeneca, Amgen, Boston Scientific, Medtronic, Philips Volcano, Pi-CardiaLTD, Chiesi, Cardioset, Biosensors, Biotronik, MedAlliance, and DOMed.

Primary Source

Transcatheter Cardiovascular Therapeutics meeting

Waksman R, et al "Assessment of coronary near-infrared spectroscopy imaging to detect vulnerable plaques and vulnerable patients: the lipid-rich plaque study" TCT 2018.