PROFI Published: Better Cerebral Protection with Balloon Occlusion after CAS

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In patients undergoing carotid artery stenting (CAS), proximal balloon occlusion significantly reduces embolic load to the brain and results in about half as many new cerebral ischemic lesions compared with filter protection, according to results from a study published online January 25, 2012, ahead of print in the Journal of the American College of Cardiology.

The findings from the prospective, single-center PROFI (Prevention of Cerebral Embolization by Proximal Balloon Occlusion Compared to Filter Protection During Carotid Artery Stenting) trial were originally presented November 11, 2011, at the annual Transcatheter Cardiovascular Therapeutics scientific symposium in San Francisco, CA.

Joachim Schofer, MD, PhD, of Hamburg University Cardiovascular Center (Hamburg, Germany), and colleagues randomized patients undergoing CAS with cerebral protection for symptomatic (≥ 60%) or asymptomatic (≥ 80%) internal carotid artery stenosis to proximal balloon occlusion (n = 31) or filter protection (n = 31). Patients were on dual antiplatelet therapy (100 mg aspirin and 75 mg clopidogrel per day) before and for 4 weeks after the intervention.

Balloon Occlusion Shows Advantage

As assessed by diffusion-weighted MRI, the incidence of new cerebral ischemic lesions per patient was higher in the filter group vs. the balloon group at 30 days (87.1% vs. 45.2%; P = 0.001). These differences were maintained in the symptomatic (P = 0.04) and asymptomatic (P = 0.02) patient subgroups. In subjects older than 80 years, there was a trend toward a higher rate of new lesions in the filter group, but the difference was not significant.

Compared with the balloon group, patients receiving filter protection also had a higher mean volume (0.59 ± 0.6 cm³ vs. 0.16 ± 0.2 cm³; P = 0.0001) and number (3.6 ± 3.2 vs. 1.0 ± 1.4; P = 0.0001) of new ischemic lesions.

Lesions were located in the ipsilateral hemisphere in all patients with positive findings. New lesions also were present in the contralateral hemisphere in 29% of patients in the filter group and in 6.5% of patients in the balloon occlusion group (P = 0.047).

The incidence of MACCE at 30 days was minimal, with only 1 minor stroke in the filter arm. Balloon intolerance was observed in about 10% of patients, and no bleeding or vascular complications were observed.

Unanswered Questions

Mark H. Wholey, MD, of the University of Pittsburgh Medical Center, Shadyside (Pittsburgh, PA), told TCTMD in a telephone interview that while PROFI provides an “interesting observation,” it is a “very, very limited study because the sample size is so small.”

“We know from single-arm registries and from this study that there are fewer diffusion-weighted MRI [findings] with proximal control than there have been with filter protection. But [proximal occlusion] is not without [findings] too, they’re only half as common,” he said adding that because none of the new lesions were clinically significant, it is difficult to draw conclusions about what they may mean for patients.

Adding the percentages of contralateral lesions found in each arm, Dr. Wholey said, “What this study told me is that 35% of the [findings] of the MRI positive results were contralateral, and what that means is that the aortic arch is the culprit. Embolic events are occurring from the aortic arch and [if the operator approaches] from below, and you’re bumping around the aortic arch, that’s the voluble plaque site for contralateral strokes.”

Additionally, he questioned the origin of the events, suggesting they could have occurred when the guidewire was being passed for either the filter or the proximal occlusion.

Time for Equipoise

In an editorial accompanying the article, Robert D. Safian, MD, of the Beaumont Health System (Royal Oak, MI), related the PROFI findings to the larger issue of the current national coverage determination from the Centers for Medicare and Medicaid Services (CMS).

“In the 1990s, Food and Drug Administration (FDA) approval for new devices for coronary and peripheral revascularization was a necessary and sufficient requisite for reimbursement from the Centers for Medicare and Medicaid Services,” he writes. “However, in the new millennium,

FDA approval is necessary, but not sufficient, for CMS reimbursement, an issue that has become strikingly apparent with regard to carotid artery stenting.”

Dr. Safian notes that while PROFI is limited and not powered to evaluate the risk of stroke, “these data are sensible.” However, he questions whether these and findings from other, similar trials will be enough to influence the CMS reimbursement decision.

“Because 70% of CAS procedures are performed by interventional cardiologists, there is concern among our professional societies that some physicians advocate against expansion of CMS coverage to protect their turf,” he writes. “In the minds of advocates for expansion of coverage, this political viewpoint seems to be supported by the failure of CMS to modify its [National Coverage Determination] policy, despite mounting evidence to do so.”

Ultimately, Dr. Safian argues that with nearly a decade of research supporting the benefits and safety of CAS, “it is time for CMS to align with professional guidelines, and establish equipoise for [carotid endarterectomy] and CAS.”

Dr. Wholey said that future research on CAS is dependent on the CMS decision.

“Industry is exhausted. They’ve been at it now for thirteen to fourteen years, and as a result, there have been no new developments,” he concluded. “No one is willing to put money into research for carotid stenting based on the past history of CMS. CMS is being unreasonable. The FDA has approved it, yet they continue to deny it.”

Study Details 

The protocol specified use of the Cristallo ideale stent (Invatec; Roncadelle, Italy), the Emboshield Protection System for filter protection (Abbott Vascular; Abbott Park, Illinois), and the MO.MA ultra system (Invatec) for proximal balloon occlusion, respectively.

The mean age of all patients was 71.7 years and about three-quarters were male. Baseline characteristics were similar between the 2 groups. However the type of aortic arch did differ (P = 0.03) and the procedural duration was longer in the balloon occlusion group vs. the filter group (P = 0.003). 

 

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Sources:
1. Bijuklic K, Wandler A, Hazizi F, et al. The PROFI study (prevention of cerebral embolization by proximal balloon occlusion compared to filter protection during carotid artery stenting). J Am Coll Cardiol. 2012;Epub ahead of print.

2. Safian RD. Carotid artery stenting: Payment, politics, and equipoise. J Am Coll Cardiol. 2012; Epub ahead of print.

 

 

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• Balloon Occlusion Bests Filter in Cerebral Protection After Carotid Stenting
• Diagnostic Balloon Occlusion Can Be Safely Performed in Healthy Vessels
• Proximal Protection Device Safe, Effective in Unselected Carotid Patients