PCI may benefit patients with unblocked arteries but vulnerable plaque vs. medical therapy
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Key takeaways:
- For patients with vulnerable plaque but no flow-limiting stenosis, PCI provided better clinical outcomes than medical therapy at 2 years.
- The results held at 7 years and may suggest a new population for PCI.
ATLANTA — Preventive PCI plus optimal medical therapy was superior to optimal medical therapy alone for patients with nonflow-limiting vulnerable coronary plaques, according to the results of the PREVENT trial.
The patient population of 1,606 included those with coronary stenosis greater than 50% but negative fractional flow reserve ( 0.8) who had vulnerable plaque as determined by meeting at least two of the following criteria on intracoronary imaging: minimal lumen area of 4 mm2 or less, plaque burden greater than 70%, thin-capped fibroatheroma by OCT or radiofrequency IVUS or lipid-rich plaque by near-infrared spectroscopy (maximum lipid core burden index in a 4 mm segment > 315), Seung-Jung Park, MD, professor of medicine at University of Ulsan College of Medicine Asan Medical Center, Seoul, South Korea, said during a presentation at the American College of Cardiology Scientific Session.
PCI for nonflow-limiting vulnerable plaques
“Intracoronary imaging-defined vulnerable plaque has more of a tendency to increase major adverse cardiac events,” Park said during the presentation. “Optimal medical therapy is the standard approach to stabilize plaque vulnerability. However, the safety and effectiveness of focal preventive PCI for nonflow-limiting vulnerable plaques are unknown. So, [PREVENT was conducted] in order to assess whether focal preventive PCI of nonflow-limiting, imaging-defined vulnerable plaques improves clinical outcomes compared with optimal medical therapy alone.”
Patients were randomly assigned to PCI plus optimal medical therapy (mean age, 64 years; 76% men) or optimal medical therapy alone (mean age, 65 years; 71% men). The primary outcome was target vessel failure, defined as cardiac death, target vessel MI, ischemia-driven target vessel revascularization or hospitalization for unstable or progressive angina, at 2 years. The results were simultaneously published in The Lancet.
The primary outcome occurred in 0.4% of the PCI group and 3.4% of the medical therapy group at 2 years (HR = 0.11; 95% CI, 0.03-0.36; log-rank P = .0003), and the results were sustained out to 7 years (6.5% vs. 9.4%; HR = 0.54; 95% CI, 0.33-0.87; log-rank P = .0097), Park said during the presentation.
The patient-oriented composite outcome of all-cause death, any MI or any repeat revascularization also favored the PCI group at 2 years (3% vs. 5.2%) and at 7 years (14.4% vs. 19.3%; HR = 0.69; 95% CI, 0.5-0.95; log-rank P = .022), he said.
“Our key findings might provide novel insights on the role of preventive PCI on nonflow-limiting high-risk vulnerable plaques in the future,” Park said during the presentation.
‘Brave to challenge the paradigm’
In a discussion after the presentation, J. Dawn Abbott, MD, FACC, FSCAI, associate chief of faculty development and academic advancement in the division of cardiology and professor of medicine at The Warren Alpert Medical School of Brown University and director of interventional cardiology and cardiac catheterization laboratories at Lifespan Cardiovascular Institute at Rhode Island Hospital and The Miriam Hospital, said: “It is brave to challenge the paradigm that medical therapy alone is sufficient to treat vulnerable moderate nonobstructive plaque. [There were] remarkably high rates of safety and great long-term outcomes with an interventional approach.”
Reference:
Perspective
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Brett L. Wanamaker, MD, FACC, FSCAI
I think the results are intriguing and support what a lot of us have been thinking. Evidence has been accumulating that the majority of MIs and other sudden cardiac events are caused by vulnerable atherosclerotic plaques which are prone to rupture or sudden worsening as part of the ACS. The Holy Grail of coronary care in interventional cardiology has been to determine whether prophylactic treatment of these plaques with PCI can modify outcomes and reduce downstream coronary events, and this trial is certainly a major step in that direction. It’s a paradigm shift from the treatment of ischemia to the treatment of lesions that might cause ACS.
More research is needed to support these results and to delineate the key plaque characteristics interventional cardiologists should be on the lookout for. Additionally, we may also see further refinement of noninvasive techniques such as coronary CT that might enable us to do this in a safer, noninvasive and more cost-effective manner.
Potentially down the road, these results could expand the use of PCI, but more supportive data are needed before we see a change in guidelines or practice patterns. However, this study certainly does support the hypothesis of vulnerable lesions and reducing risk regardless of the hemodynamic effect of those lesions during the index procedure.
People receiving a treatment who should not is always a concern anytime the indication for a procedure expands. If we do get more supportive data in the future to support this practice pattern, a key step will be quality control and the continued education of interventional cardiologists on the use of intracoronary imaging and other adjunctive technology to assess for vulnerable plaques.
It is worth noting that overall event rates were low in this trial. Also, patients in this trial were not blinded to their treatment arm. In other words, they were aware whether they were in the PCI/stent group vs. the group who received medical therapy alone. When patients are aware that they have a coronary lesion that has not been addressed with PCI, this may influence outcomes such as the patient’s perception of coronary symptoms or the later need to perform PCI for chest discomfort or ischemia. However, in this trial, the group who underwent intervention to vulnerable plaques had lower rates of death and MI at two years, and these harder outcomes are less affected by blinding issues and placebo effect.
Collapse
Park SJ, et al. Late-breaking clinical trials V. Presented at: American College of Cardiology Scientific Session; April 6-8, 2024; Atlanta.
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