ECLIPSE on Orbital Atherectomy: Balloon Angioplasty Still Shines in Calcified Lesions

The ECLIPSE trial, presented at TCT 2024, investigated whether orbital atherectomy (OA) provides better outcomes than conventional balloon angioplasty in patients with severely calcified coronary lesions undergoing percutaneous coronary intervention (PCI). Despite initial expectations that atherectomy could improve lesion modification and stent expansion in calcified vessels, the trial found no significant advantage of OA over balloon angioplasty for most clinical outcomes.

ECLIPSE enrolled 2,005 patients across multiple centers, randomizing them to either OA with balloon angioplasty or balloon angioplasty alone before drug-eluting stent placement. The primary endpoint was target vessel failure (TVF), defined as a composite of cardiac death, target vessel-related myocardial infarction (MI), and ischemia-driven target vessel revascularization (TVR) at one year. The study aimed to determine if OA, by facilitating better lesion preparation, could reduce adverse events and improve stent outcomes in this challenging patient population.

Results showed that TVF rates were nearly identical between the two groups at one year: 11.5% in the OA group compared to 10.0% in the balloon angioplasty group (p = 0.28). Subgroup analyses did not identify specific patient populations that particularly benefited from OA. Additionally, procedural complications, including perforation and device-related events, were slightly higher in the OA group, although these differences were not statistically significant. There was also no significant difference in the primary imaging outcome of mean post-PCI minimal stent area by optical coherence tomography (7.67 mm² vs 7.42 mm², p = 0.08).

Secondary endpoints, such as stent thrombosis and acute procedural success, were similar between groups. Notably, OA led to longer procedural times, additional costs, and the need for specialized operator skills, raising questions about its routine use in this patient population when balloon angioplasty appears comparably effective.

The ECLIPSE findings suggest that OA may not provide additional clinical benefits over balloon angioplasty in treating calcified coronary lesions, challenging assumptions about atherectomy’s role in optimizing PCI outcomes. Notably, however, randomization occurred after a coronary wire was across the lesion and surely was only considered in cases with procedural equipoise for atherectomy versus balloon angioplasty for a given coronary lesion. This may have excluded patients in whom the operator felt a priori that atherectomy may be preferred.

When deciding between different calcium modification techniques, operators should continue to use their judgment, develop comfortability with different devices, and deploy intracoronary imaging guidance whenever possible. Future research might explore whether specific subpopulations or lesion types could benefit from atherectomy or alternative lesion modification devices such as intravascular lithotripsy, high-pressure balloons, and cutting or scoring balloons.