WASHINGTON – Orbital atherectomy (OA) was associated with a lower risk of in-hospital mortality than rotational atherectomy (RA) in female, obese, and elderly study groups, according to data from a prospective observational study.

Each procedure was employed to treat coronary artery calcifications (CAC) in the elderly and the obese prior to percutaneous interventions (PCI).

The data comparing OA with RA in these populations were drawn from the Clinical Outcomes of Atherectomy Prior to PCI (COAP) study, for which Perwaiz M. Meraj, MD, director of structural heart and peripheral vascular disease at the North Shore-LIJ Hospital, Manhasset, N.Y., served as the senior author.

Each set of data, as well as a third set of data comparing OA to RA in female patients, was presented separately at CRT 2017, sponsored by the Cardiovascular Research Institute at Washington Hospital Center.

In the comparison of OA to RA in the elderly, a substudy known as COAP-75, the focus was on patients 75 years of age or older who underwent either OA or RA to remove calcified coronary lesions within the context of PCI. As with the obese and female subgroups, the elderly patients in this study were drawn from 35,590 patients who underwent PCI at one of five tertiary care hospitals in a recent 5-year period.

Of the 310 elderly patients undergoing atherectomy, 117 were treated with OA and 193 with RA. The median lesion lengths and diameters were not significantly different between the two groups. Although OA was less likely to be performed through femoral access (53% vs. 68.9%; P = .005), no other measured differences in procedure were significant, with one exception: Fluoroscopy exposure was of shorter duration in the OA, versus the RA, arm (24.0 minutes vs. 29.4 minutes; P = .005).

On univariate analysis, the lower rate of in-hospital deaths for OA did not reach statistical significance (0% vs. 1.55%; P = .176), but the difference was significant on multivariate-adjusted analysis (P = .034).

There were also higher numerical rates of perforation, tamponade, heart failure, and red blood cell transfusion in the RA group, versus the OA group, but only the latter was significant (P = .002) on multivariate-adjusted analysis.

In contrast, there was a higher rate of MI among those treated with OA, rather than RA (17.1% vs. 13.5%), which was not significant on univariate analysis (P = .573) but did reach significance on adjusted-multivariate analysis (P = .008).

Overall, the authors suggested that both OA and RA are safe procedures, but the mortality reduction suggests a potential relative advantage for OA.

Similar conclusions were reached in the substudy of patients with obesity, called COAP-BMI. In that study, 222 patients were evaluated, of which 91 were treated with OA and 131 were treated with RA.

In-hospital mortality was 0% in the group treated with OA, compared with 3.05% in the group treated with RA (P = .004). The rate of in-hospital major adverse cardiovascular events was also significantly lower in the OA group (15.4% vs. 16.3%; P = .007).

“The rate of secondary outcomes for myocardial infarction and stroke were similar between groups, as were individual procedural safety endpoints, including dissection, perforation, tamponade, or heart failure,” reported Evan Shlofmitz, MD, a cardiology fellow at Northwell Health, Manhasset, N.Y., who collaborated with Dr. Meraj and presented the data at the meeting.

As with the study in the elderly, for which Dr. Shlofmitz was also a coauthor, the study in the obese is the first to compare OA and RA, he noted.

In a third substudy, called COAP-Female, OA and RA were compared in 247 women with CAC who were undergoing PCI.

Again, in-hospital mortality rates were higher in those treated with RA, compared with OA, but the difference was not significant (0.79% vs. 0%; P = .254). There were also no significant differences in any secondary outcomes, including MI, or in any procedural complications, such as rates of dissection, perforation, or major bleeding.

The only significant difference identified in the study was a lower fluoroscopy time in those treated with OA relative to RA (21.3 minutes vs. 27.6 minutes; P = .001).

Although fluoroscopy time was not a primary endpoint, “a reduction in radiation exposure has important ramifications for both patients and operators,” Dr. Shlofmitz noted. He suggested that objective data on outcomes in females is needed, because this group has been “severely underrepresented in atherectomy trials.”

Overall, the substudies reinforce a large body of evidence that atherectomy is safe and effective for achieving revascularization in patients undergoing PCI who have CAC, Dr. Shlofmitz concluded. However, the significant mortality advantage for OA relative to RA in the elderly and the obese suggests that the approaches may not be interchangeable.

Dr. Shlofmitz reported no financial relationships to disclose.

Orbital, over rotational, atherectomy holds survival edge in elderly, obese