ABSTRACT
OBJECTIVES - We assessed the safety and efficacy of orbital atherectomy to modify severely calcified coronary plaque prior to stent implantation in patients with small vessel (2.5mm) disease.
BACKGROUND - Severe coronary artery calcification increases the risk of adverse clinical events during percutaneous coronary intervention (PCI). Patients who undergo PCI of small vessels have worse clinical outcomes including higher rates of perforation and dissection. The outcomes of orbital atherectomy of small diameter vessels (2.5mm) are unknown.
METHODS - ORBIT II was a single-arm, multicenter trial which prospectively enrolled patients with severely calcified coronary lesions treated with orbital atherectomy prior to stenting in 49U.S. sites. The primary endpoint was the 3year rate of major adverse cardiac events, which was the composite of cardiac death, myocardial infarction, and target vessel revascularization.
RESULTS - Of the 443 patients, 55 (12.4%) had reference vessel diameters (RVD) of 2.5mm and 388 (87.6%) had RVD >2.5. The rates of severe angiographic complications were similar in both groups. The primary endpoint was similar in both groups (30.6% vs. 22.5%, p=0.22), as were the rates of cardiac death (9.8% vs. 6.3%, p=0.33) and myocardial infarction (12.8% vs. 10.9%, p=0.67). Target vessel revascularization was numerically higher in the small vessel group (16.8% vs. 9.3%, p=0.13).
CONCLUSIONS - Patients with small coronary vessel disease had comparable clinical outcomes compared to the larger diameter group following orbital atherectomy. Subsequent studies are required to establish the optimal revascularization approach for such patients with small coronary vessel disease burdened by heavily calcified lesions.
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