Study Compares Embolic Protection Devices Used in CAS

April 20, 2015—The American College of Cardiology (ACC) announced that a study showing that in-hospital and 30-day stroke or death rates were equally low when using either a distal filter embolic protection device (F-EPD) or a proximal device (P-EPD) to protect patients from blood clots during carotid artery stenting (CAS) was published by Jay Giri, MD, et al in Journal of the American College of Cardiology: Cardiovascular Interventions (2015;8:609–615). The ACC cautioned, however, that a small sample size for one device raises questions about the study’s ability to detect potentially meaningful differences in outcomes.

As noted by the ACC, the US Centers for Medicare & Medicaid Services mandates that cardiologists use one of these two devices in order to be reimbursed for CAS. The F-EPD uses small baskets to catch any debris produced during angioplasty and stent placement, whereas the P-EPD uses balloons to arrest or reverse flow to the internal carotid artery. Although some argue that the latter method is superior because the carotid artery is protected throughout the entire procedure, it is less popular among cardiovascular professionals, stated the ACC.

Using data from the ACC’s CARE registry, the largest national registry of CAS patients, researchers assessed records from 10,246 patients who had elective CAS procedures with embolic protection between January 2009 and March 2013. Of these procedures, practitioners used P-EPD in approximately 6% of cases. These patients had higher rates of symptomatic lesions at the time of the procedure; higher rates of fast, irregular heartbeats; and a history of previous neurological events.

According to the ACC, the results showed little difference in either in-hospital stroke or death between the two groups: 1.6% for the P-EPD group compared to 2% for the F-EPD group. For the 76.5% of patients for whom 30-day follow-up data were available, 2.7% of the P-EPD group experienced stroke or death, and 4% of the F-EPD group had these adverse outcomes. Furthermore, no differences in outcomes were found between symptomatic and asymptomatic patients treated with either device. Because of the modest number of P-EPD devices used, the study may not have been large enough to detect potentially meaningful differences in outcomes between the two devices, advised the ACC.

Dr. Giri commented in the ACC’s press release, “According to our calculations, a randomized trial of more than 6,000 patients would be needed to determine a statistically significant difference between P-EPD and F-EPD for 30-day adverse outcomes. There are no known plans to organize such an effort, so it is likely that the current data will remain the best available evidence for the foreseeable future.” Dr. Giri, the study’s lead author, is Assistant Professor of Clinical Medicine at the Hospital of the University of Pennsylvania in Philadelphia, Pennsylvania.