Cerebral embolic protection devices did not significantly reduce the risk of central nervous system (CNS) infarction at seven days after surgical aortic valve replacement (SAVR) compared with a standard aortic cannula, according to results of a study by Michael J. Mack, MD, FACC, et al., published August 8 in the Journal of the American Medical Association.

The incidence of radiographic brain infarcts associated with SAVR is up to 60 percent and clinical stroke is 17 percent. To address this complication, two cerebral embolic protection devices, an intra-aortic filtration device and a suction-based extraction device, have been approved in the U.S. This study assessed the efficacy and adverse effects of these devices among patients undergoing SAVR.

A total of 383 patients were randomized immediately after sternotomy to suction-based extraction (n = 118), intra-aortic filtration (n = 133) or in the control group to standard aortic perfusion cannula (n = 132). Within the control group, the first 12 patients served as controls for the intra-aortic filtration group only and the other 120 were controls for both device groups.

The patients were assessed at baseline and postoperative days one, three, seven, 30 and 90. The primary endpoint was freedom from clinical or radiographic CNS infarction at seven days after SAVR. The NIH stroke scale (NIHSS) at days one, three and seven was used for serial neurological assessment and reporting of ischemic stroke during hospitalization.

Three patients randomized to intra-aortic filtration and two to suction-based extraction did not receive the designated device. Embolic debris was captured in 99 percent of patients in the intra-aortic filtration group and in 75 percent in the suction-based extraction group.

No significant difference was observed in freedom from CNS infarction at postoperative day seven between the suction-based extraction and control groups (32.0 vs. 33.3 percent; 95 percent confidence interval [CI], –13.8-11.2) or the intra-aortic filtration and control groups (25.6 vs. 32.4 percent; 95 percent CI, –17.9-4.2). The rate of clinically apparent stroke in the suction-based extraction group vs. controls was 5.1 vs. 5.8 percent (95 percent CI, –6.5-5.1) and in the intra-aortic filtration group vs. controls was 8.3 percent vs. 6.1 percent (95 percent CI, –4.1-8.4).

The composite endpoint was reached by 21.4 percent in the suction-based extraction group and 24.2 percent of controls (95 percent CI, –13.5-7.9) and by 33.3 percent in the intra-aortic filtration group vs. 23.7 percent of controls (95 percent CI, –1.2-20.5). The incidence of delirium over time was significantly greater in the treatment than in control groups. Decline in overall cognitive scores was greater in patients with clinically apparent stroke.

In this study, cerebral embolic protection devices did not significantly reduce the risk of CNS infarction compared with a standard aortic cannula at seven days after SAVR. "Potential benefits for reduction in delirium, cognition, and symptomatic stroke merit larger trials with longer follow-up," write the investigators.

Keywords: Aortic Valve, Incidence, Control Groups, Sternotomy, Confidence Intervals, Infarction, Suction, American Medical Association, Research Personnel, Follow-Up Studies, Intracranial Embolism, Embolic Protection Devices, Embolism, Heart Valve Prosthesis, Stroke, Delirium, Brain, Cognition, Freedom, Hospitalization

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