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For the approximately one-third of transcatheter aortic valve replacement (TAVR) candidates whose iliofemoral disease makes conventional access difficult, CoreValve implantation via a subclavian approach is both safe and feasible, according to a registry study published online June 20, 2012, ahead of print in the Journal of the American College of Cardiology. The strategy yields a 2-year survival rate similar to that of matched transfemoral patients.

The data were originally presented at the annual Transcatheter Cardiovascular Therapeutics scientific symposium in November 2011 in San Francisco, CA.

Investigators led by Anna Sonia Petronio, MD, of the University of Pisa (Pisa, Italy), identified 141 patients in the Italian CoreValve Registry who received TAVR via the subclavian route at 10 centers between June 2007 and March 2011. The patients were propensity-matched with the same number of patients from the registry who were treated transfemorally. Baseline characteristics were similar between groups except for a higher prevalence of peripheral artery disease in the subclavian group (85.1% vs. 20.6%; P < 0.0001).

No Safety Red Flags

No difference was seen between the access groups in most in-hospital events, including all-cause mortality, stroke, major vascular complications, life-threatening bleeding, and new permanent pacemaker implantation. However, the incidence of acute kidney injury/stage 3 was lower in the subclavian arm, as was the rate of major bleeding associated with 18-Fr vascular complications (table 1). In particular, major subclavian artery complications included vessel wall tears at the site of sheath insertion (3 cases), longitudinal vessel dissections (3 cases), and acute asymptomatic thrombosis (1 case).

Table 1. Clinical Outcomes: In-Hospital

 
At 30 days, all-cause mortality, cardiovascular mortality, stroke, and the Valve Academic Research Consortium (VARC) combined safety endpoint (all-cause mortality, major stroke, life-threatening bleeding, acute kidney injury/stage 3, MI, major vascular complication, and reintervention for valve-related dysfunction) did not differ between the subclavian and femoral groups (table 2).

Table 2. Clinical Outcomes: 30 Days

Median follow-up was 17 (range 8-27) months in the subclavian group and 20 (range 8-31) months in the femoral group. Two-year estimated Kaplan-Meier survival in the subclavian arm was 74.0 ± 4.0% compared with 73.7% ± 3.9% in the femoral arm (P = 0.78). Moreover, at 2 years the rates of freedom from the VARC combined efficacy endpoint (all-cause mortality after 30 days, hospitalization for valve-related or cardiac decompensation, and prosthetic valve dysfunction) were almost identical between the subclavian and femoral groups (71.7 ± 4.3% vs. 71.4 ± 4.1%; P = 0.78).

Potential for Advantage

According to the authors, “[t]hese findings demonstrate the safety of [the subclavian] approach, which can be accomplished without increased risks of vascular injury and bleeding,” even though patients with contraindications to femoral access typically have more comorbidities and a higher surgical risk (here a logistic EuroScore of 23.7%).

Dr. Petronio and colleagues suggest the subclavian approach carries an edge over the other main alternatives to femoral access, a transapical approach with the Sapien valve (Edwards Lifesciences, Irvine, CA) and direct aortic access, both of which are more invasive and require general anesthesia, which is risky for older patients with multiple comorbidities. In the Italian centers, they note, subclavian TAVR ended up being performed under local anesthesia more than half the time.

But in a telephone interview with TCTMD, James B. Hermiller Jr, MD, of the St. Vincent Heart Center of Indiana (Indianapolis, IN), played down that difference, noting that centers in the United States are much more likely to use general anesthesia for subclavian procedures.

He did, however, point to an advantage of the subclavian approach that the authors did not mention. “The precision with which the device is implanted may be better with the subclavian approach because you have such good control and it’s a shorter distance to the aortic valve,” Dr. Hermiller said.

Expanding TAVR Availability

Dr. Hermiller added that these data—representing the longest follow-up in the largest cohort of subclavian patients—help confirm that the subclavian approach is a viable alternative strategy that expands the overall availability of TAVR.

“If you look at everybody who comes in for [TAVR], 20% to 30% have enough iliofemoral disease that they are precluded from getting the standard femoral approach,” he said. “In that subset of patients, many of them may be candidates for subclavian delivery.”

However, he added, it is not unusual for patients to have both iliofemoral and subclavian disease or anatomy that also disqualifies them from a subclavian approach, and increasingly those patients are offered a direct aortic approach through a ministernotomy or minithoracotomy.

Dr. Hermiller said that at his center about 10% of TAVR patients end up receiving a subclavian approach. “The way we choose patients right now is: iliofemoral first, subclavian second, and direct aortic third. I think the default will continue to be iliofemoral, but we’ll have to see how it plays out with respect to subclavian vs. direct aortic,” he commented.

Dr. Hermiller agreed with the authors that the subclavian approach can be offered not only in cases in which femoral access is impossible but also in those for which it appears difficult. “If you have adequately sized iliofemorals but they’re very tortuous and you think with respect to controlling the device you’re going to have problems, then if there’s a good subclavian, it’s a very reasonable thing to do,” he said.

Study Details

Device success was similarly high (about 97%) and procedural mortality comparably low (about 1%) in both cohorts. Use of local anesthesia was less common in the subclavian group (46.1% vs. 83.7%; P < 0.0001) and overall procedural time was longer due to the surgical access (120 min vs. 75 min; P < 0.0001), but fluoroscopy times were similar (18 min vs. 21 min; P = 0.15).

Subclavian access was excluded when the vessel diameter was less than 6 mm, or heavy calcification, excessive tortuosity, or severe stenosis not amenable to balloon angioplasty was present. In addition, patients with a patent left internal mammary artery coronary graft needed to have a subclavian artery larger than 7 mm in diameter.

Related Stories:

• Subclavian Access Feasible, Safe with Transcatheter CoreValve Device
• Registry Studies Focus on Different TAVR Access Routes
• STACCATO: Transapical TAVR Inferior to Surgery for Operable Elderly Patients

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