PROFI Study Supports Proximal Balloon Occlusion for Embolic Protection in CAS

January 25, 2012—Klaudija Bijuklic, MD, et al published results from the PROFI (Prevention of Cerebral Embolization by Proximal Balloon Occlusion Compared to Filter Protection During Carotid Artery Stenting [CAS]) study online ahead of print in Journal of the American College of Cardiology. The PROFI investigators concluded that proximal balloon occlusion as compared with filter protection significantly reduced the embolic load to the brain in this randomized trial of patients undergoing CAS.

The background of the study is that randomized trials of CAS using filter-based embolic protection devices (EPD) compared with carotid endarterectomy revealed a higher periprocedural stroke rate after CAS. The PROFI investigators sought to determine if proximal balloon occlusion may be more effective in preventing cerebral embolization than filters by comparing the cerebral embolic load of filter-protected versus proximal balloon-protected CAS.

As detailed by the PROFI investigators, 62 consecutive patients (mean age, 71.7 years; 76.4% men) undergoing CAS with cerebral embolic protection for internal carotid artery stenosis were randomly assigned to proximal balloon occlusion (n = 31) or filter protection (n = 31). The primary endpoint was the incidence of new cerebral ischemic lesions assessed by diffusion-weighted magnetic resonance imaging. Secondary endpoints were the number and volume of new ischemic lesions and major adverse cardiovascular and cerebral events (MACCE).

In PROFI, proximal balloon occlusion compared to filter protection resulted in a significant reduction in the incidence of new cerebral ischemic lesions (45.2% vs 87.1%; P = .001). The number (median [range]: 2 [0–13] vs 0 [0–4]; P = .0001) and the volume (0.47 [0–2.4] cm³ vs 0 [0–0.84] cm³; P = .0001) of new cerebral ischemic lesions were significantly reduced by proximal balloon occlusion. Lesions in the contralateral hemisphere were found in 29% and 6.5% of patients (filter vs balloon occlusion, respectively; P = .047). The 30-day MACCE rate was 3.2% and 0% for filter versus balloon occlusion, respectively (P = NS), the investigators reported.

In an editorial in the Journal of the American College of Cardiology, “Carotid Artery Stenting Payment, Politics, and Equipoise,” Robert D. Safian, MD, noted that this small, randomized clinical trial demonstrated that CAS with a proximal EPD provides better cerebral protection than distal a EPD, based on quantitative brain diffusion-weighted magnetic resonance imaging. He asserted that these and similarly positive findings should influence the Centers for Medicare & Medicaid Services (CMS) to move toward reimbursement of CAS procedures.

Dr. Safian observed that although PROFI was not powered to evaluate the risk of stroke, the findings are similar to another randomized clinical trial that reported less cerebral embolization by transcranial Doppler with proximal EPD compared with distal EPD. He commented, “These data are sensible, since in contrast to distal EPDs, proximal EPDs provide embolic protection prior to crossing the target lesion with a guidewire and should be more efficient at capturing and removing debris since they are not dependent on filter pore size or particle dimensions.”

Dr. Safian posed the question: “The findings of both studies add further incremental understanding of CAS technique, but are they likely to influence CMS reimbursement?”

After a review of currently available data from the major CAS studies and the demonstration of effectiveness of proximal embolic protection, he concluded: “Taken together, it appears that current CAS outcomes in all patients satisfy the American Heart Association/American Stroke Association benchmarks. When considering central and cranial nerve injury, CAS is at least as safe as CEA, and the risk of myocardial infarction is lower after CAS. The continued decline in 30-day major adverse cardiovascular events after CAS is attributable to improvements in technology, technique, patient selection, and operator experience, including the use of proximal EPDs; imaging studies suggest less intracranial embolization with proximal EPDs than distal EPDs, although the risk of stroke is low with both techniques. Carotid revascularization for symptomatic stenosis > 50% and asymptomatic stenosis > 70% is the current standard of care according to major professional societies, and is safely performed by CEA and CAS; further CAS trials are not needed to support reimbursement. It is time for CMS to align with professional guidelines, and establish equipoise for CEA and CAS.”