Emboli capture using the Embol-X intraaortic filter in cardiac surgery: a multicentered randomized trial of 1,289 patients

Background Particulate emboli are thought to play a significant role in the development of cardiac surgical complications. Intraaortic filtration of particulate emboli may reduce the burden of this morbidity in cardiac patients. Methods A multiinstitutional randomized trial was designed and enrolled 1,289 patients at 22 centers. Six hundred forty-five patients were assigned to the treatment arm and received the Embol-X intraaortic filter, whereas 644 patients were assigned to the control arm. The endpoints examined were mortality, stroke, transient ischemic attack, renal insufficiency/failure, myocardial infarction, gastrointestinal complications, and limb-threatening ischemia. All filters were examined for histologic evidence of particulate emboli. Results Particulate emboli were identified in 598 (96.8%) of 618 filters successfully deployed. Composite event rates for the clinical endpoints were similar in both the filtered and nonfiltered arm (110/645 = 17% vs 122/644 = 19%, respectively). Individual event rates were also similar in both arms. A post hoc comparison of patients with moderate or greater preoperative risk scores demonstrated event reduction favoring the filtered group for renal complications (17/124 = 14% vs 28/117 = 24%, p = 0.04) and for the composite endpoint (30/124 = 24% vs 42/117 = 36%, p = 0.047). No clinically evident complications attributed to the use of the filter were identified. Conclusions The use of the Embol-X intraaortic filter is both safe and effective, as demonstrated by the emboli capture rate of 97%. In addition, post hoc analysis indicates a reduction in postoperative renal complications for patients with moderate or greater preoperative risk. Further study of high-risk patients is warranted.