Percutaneous coronary intervention (PCI) in calcified lesions remains one of the most challenging scenarios in daily practice, as these lesions are often accompanied by stent underexpansion, malapposition, perforation, and high rates of reintervention.
In this context, optical coherence tomography (OCT) has emerged as a key tool, capable of quantifying calcium burden and thickness, guiding proper plaque preparation, optimizing stent sizing, and improving implantation strategy. However, randomized evidence on OCT-guided PCI in calcified disease remains limited.
The CALIPSO study, published by Amabile N. et al., aimed to assess whether an OCT-guided PCI strategy, combined with standardized algorithms for plaque preparation, stent selection, and post-implantation optimization, could achieve greater luminal expansion (measured as minimum stent area, MSA) compared with standard angiography-guided PCI in calcified lesions.
This was an open-label, multicenter, 1:1 randomized study conducted in 12 centers across France that included patients with chronic coronary syndrome (CCS) and a target lesion with angiographically moderate or severe calcification. In both groups, a post-PCI OCT acquisition was performed to assess the MSA.
A total of 134 patients were analyzed for the primary endpoint (65 OCT; 69 angiography). The primary outcome showed a significant advantage in favor of OCT: the mean MSA was 6.5 mm² vs. 5.0 mm² with angiography (p <0.001). The proportion of patients with MSA ≤4.5 mm² was significantly lower with OCT (8% vs. 36%; p <0.001). Similarly, the mean stent area was larger with OCT (8.4 vs. 7.4 mm²; p <0.001). These differences that remained consistent across subanalyses according to calcium severity and extent.
The OCT-guided strategy also promoted earlier and more targeted use of plaque modification devices: intravascular lithotripsy (IVL) was used as a first-line tool in 46% of cases (vs. 12% in the angiography group; p <0.001), with a lower need for bailout interventions (6% vs. 20%; p = 0.02). The incidence of periprocedural complications was similar between groups, although there was a trend toward greater malapposition in the angiography group.
In 43% of cases in the OCT arm, the first post-PCI assessment prompted additional optimization maneuvers, increasing the mean MSA from 5.9 to 7.2 mm² (p <0.001). Even before these additional steps, MSA values were already higher compared with angiography guidance.
Conclusion
In patients with CCS and moderate-to-severe calcified lesions, an OCT-guided PCI strategy using standardized algorithms achieves greater luminal expansion (MSA) compared with angiography. The CALIPSO study supports the systematic adoption of intracoronary imaging as a key tool for optimal plaque preparation and stent implantation in this complex clinical setting.
Original Title: OCT vs Angiography for Guidance of Percutaneous Coronary Intervention of Calcified Lesions The CALIPSO Randomized Clinical Trial.
Reference: Amabile N, Rangé G, Landolff Q, Bressollette E, Meneveau N, Lattuca B, Levesque S, Boueri Z, Adjedj J, Casassus F, Belfekih A, Veugeois A, Souteyrand G, Honton B. OCT vs Angiography for Guidance of Percutaneous Coronary Intervention of Calcified Lesions: The CALIPSO Randomized Clinical Trial. JAMA Cardiol. 2025 Jul 1;10(7):666-675. doi: 10.1001/jamacardio.2025.0741. PMID: 40305015; PMCID: PMC12044539.
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