The CALIPSO Trial: OCT vs Angiography for Guidance of Calcified Lesions PCI

Published in congress: EuroPCR 2024

Dr. Mahmut Buğrahan Çiçek

Introduction:
Calcified coronary lesions pose significant challenges in the treatment of atherosclerotic stenosis and are frequently encountered in interventional cardiology. The CALIPSO study was initiated with the hypothesis that Optical Coherence Tomography (OCT) guided percutaneous coronary intervention (PCI) might be superior to angiography-guided PCI in the treatment of calcified coronary lesions. OCT provides high-resolution imaging, offering detailed information for stent placement and lesion assessment. This study aims to evaluate the superiority and safety of OCT-guided PCI compared to angiography-guided PCI in the treatment of calcified lesions.

Objective:
The objective of the CALIPSO study is to evaluate the superiority and safety of OCT-guided PCI compared to angiography-guided PCI in patients with calcified coronary lesions. The study aims to determine whether OCT-guided PCI provides better outcomes in terms of stent placement success, hemodynamic performance, and clinical results compared to angiography-guided PCI.

Methods:
The CALIPSO study is a prospective, multicenter, randomized superiority trial conducted from November 2021 to June 2023. The study included patients with stable coronary lesions, with moderate to severe calcified lesions according to the Mintz classification and with lesions expected to be crossable with an OCT catheter. Patients were randomized into two groups: the OCT-guided PCI group and the angiography-guided PCI group. Treatment protocols included lesion preparation, stent placement, and post-PCI evaluations. The primary endpoint was the minimal stent area (MSA) as assessed by final OCT evaluation after PCI. Secondary endpoints included geometric stent expansion (%), post-PCI stenosis (%), residual major malapposition (%), major cardiovascular events (MACE) at 30 days and 1 year, and safety-related factors (peri-procedural MI, radiation dose, contrast volume, procedure duration).

Results:
In the OCT-guided PCI group, the post-PCI minimal stent area (MSA) was significantly higher compared to the angiography-guided group (8.4 mm² vs. 7.4 mm², p=0.01), with a higher rate of successful geometric stent expansion (75% vs. 29%, p<0.001). The proportion of patients with MSA <4.5 mm² was 8% in the OCT-guided group and 36% in the angiography-guided group (p<0.001). No additional MACE were observed in either group within the first month. There were no significant differences between the groups in terms of procedure duration, contrast volume used, and radiation dose.

Conclusion:
The CALIPSO study demonstrated that OCT-guided PCI is superior to angiography-guided PCI in patients with calcified coronary lesions. The superiority in stent expansion and malapposition rates suggests that OCT-guided PCI may be preferred in clinical practice. Future research will investigate whether these imaging advantages translate into long-term clinical outcomes.