ECLIPSE Trial: Evaluating the Efficacy of Orbital Atherectomy Prior to DES Implantation in Calcified Coronary Lesions

 

Study Description:
The trial aimed to assess the efficacy of orbital atherectomy before DES implantation compared to conventional PCI in patients with calcified coronary lesions. Patients were randomly assigned to either orbital atherectomy prior to DES implantation (1,008 patients) or conventional PCI without atherectomy (997 patients), totaling 2,005 enrollees. The mean age was 70 years, with a follow-up duration of 12 months. Among participants, 26% were female, and 43% had diabetes.

Study Design:
The study followed a randomized, parallel design. Patients with calcified coronary lesions were included based on specific criteria, such as evidence of calcification via angiogram or intravascular imaging. The majority of patients (97%) had severe coronary calcification, with chronic kidney disease present in 23%. The orbital atherectomy group received an average of 3.8 passes, with variations in speed settings applied based on clinical assessment.

Principal Findings:
The primary imaging outcome, post-PCI minimal stent area at the site of maximum calcification, was slightly larger in the orbital atherectomy group (7.67 mm²) compared to the conventional PCI group (7.42 mm²), though this difference was not statistically significant (p = 0.08). The primary clinical outcome, target vessel failure at one year, was also similar between groups, occurring in 11.5% of the orbital atherectomy group and 10.0% of the conventional PCI group (p = 0.28).

Secondary Outcomes:
Additional findings included slightly higher rates of dissection (6.9% vs. 6.3%) and coronary perforation (1.8% vs. 1.0%) in the orbital atherectomy group, neither of which was statistically significant. However, slow flow was more frequent in the atherectomy group (1.4% vs. 0.4%, p = 0.03). Notably, all-cause mortality at 30 days was 1.0% in the orbital atherectomy group compared to 0.3% in the conventional PCI group (p = 0.05), with cardiac deaths also higher at 0.8% in the atherectomy group versus 0.0% in the PCI group (p = 0.005).

Interpretation:
The ECLIPSE trial did not establish a clear advantage for orbital atherectomy over conventional PCI in reducing target vessel failure in patients with calcified coronary lesions. While the stent area at maximum calcium was similar across groups, a slight, nonsignificant trend favored atherectomy. Importantly, an observed increase in 30-day all-cause and cardiac mortality in the atherectomy group raised concerns, though the underlying mechanism remains unclear.

Limitations:
This study was conducted primarily before intravascular lithotripsy became widely available, which may have influenced outcomes. Moreover, patients in whom atherectomy was clearly deemed necessary were excluded from randomization, potentially impacting generalizability. Calcified coronary arteries remain high-risk regardless of treatment approach, and while orbital atherectomy remains a useful adjunct, best practices in PCI should be prioritized.

Contribution to Literature:

Presented on October 29, 2024, and presented at the Transcatheter Cardiovascular Therapeutics meeting, the ECLIPSE trial investigated whether orbital atherectomy before drug-eluting stent (DES) implantation is superior to conventional percutaneous coronary intervention (PCI) without atherectomy in treating calcified coronary lesions. The trial ultimately found no significant benefit of orbital atherectomy over conventional PCI in these patients.

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