PROSPECT ABSORB: Is PCI of Angiographically Mild Lesions With Large Plaque Burden Safe Compared With GDMT Alone?

PCI of angiographically mild lesions with large plaque burden was safe, substantially enlarged the follow-up minimum lumen area (MLA), and was associated with favorable long-term clinical outcomes, said researchers presenting findings from the PROSPECT ABSORB Trial Oct. 14 during TCT 2020.

The study, which was simultaneously published in the Journal of the American College of Cardiology, used three-vessel imaging and a combination intravascular ultrasound (IVUS) and near-infrared spectroscopy (NIRS) catheter in 898 patients presenting with myocardial infarction following successful PCI of all flow-limiting coronary lesions. Those patients with an angiographically non-obstructive stenosis not intended for PCI but with IVUS plaque burden ≥65%  (N=192) were randomized to treatment of the lesion with either a bioresorbable vascular scaffold (BVS) plus guideline-directed medical therapy (GDMT) or GDMT alone.

The primary powered effectiveness endpoint was the IVUS-derived MLA at protocol-driven 25-month follow-up. Additionally, the primary safety endpoint was randomized target lesion failure at 24 months and the secondary clinical effectiveness endpoint was randomized lesion-related major adverse cardiac events (MACE) at latest follow-up.

Results showed the median angiographic diameter stenosis of the randomized lesions was 41.6%, while the NIRS-IVUS median plaque burden was 73.7%. The median MLA was 2.9 mm2, and median maximum lipid plaque content was 33.4%. Angiographic follow-up at 25 months was completed in 167 patients. The follow-up MLA in BVS-treated lesions was 6.9±2.6 mm2 compared with 3.0±1.0 mm2 in those treated with GDMT alone. Researchers also noted that the rates of target lesion failure at 24 months were similar across both groups. Randomized lesion-related MACE occurred in 4.3% of patients in the BVS-treated group compared with 10.7% in the GDMT-alone group (P=0.12).

Among the limitations to the study: it was not powered for clinical outcomes, and the present PCI results only apply to the first generation everolimus-eluting Absorb BVS. “Whether the results would be superior with a thinner-strut BVS or a contemporary metallic DES is unknown,” said Gregg W. Stone, MD, FACC. However, Stone and colleagues note that the “the favorable randomized lesion-related MACE rates observed after BVS treatment compared with GDMT alone warrants the performance of an adequately powered randomized trial to determine whether PCI treatment of focal vulnerable plaques improves patient outcomes.” But they also add, that “until such a study, PCI of non-ischemic lesions, even those with high-risk morphologic features, cannot be routinely recommended.”

The PROSPECT ABSORB study was embedded in the PROSPECT II study, also presented at TCT 2020.

Clinical Topics: Invasive Cardiovascular Angiography and Intervention, Interventions and Imaging, Angiography, Nuclear Imaging

Keywords: TCT20, Transcatheter Cardiovascular Therapeutics, Plaque, Amyloid, Plaque, Atherosclerotic, Angiography, Percutaneous Coronary Intervention


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