Fewer Vascular Complications as TAVR Evolves

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With more experience, better patient selection, and smaller sheaths, clinicians performing transcatheter aortic valve replacement (TAVR) are increasingly able to avoid vascular complications, according to a single-center study published in the January 10, 2012, issue of the Journal of the American College of Cardiology.

To ascertain whether changes in TAVR were accompanied by reductions in vascular complication rates, John G. Webb, MD, of St. Paul’s Hospital (Vancouver, Canada), and colleagues prospectively studied 137 consecutive patients who underwent transfemoral TAVR at their center from April 2009 to March 2011. Clinical outcomes were evaluated using current Valve Academic Research Consortium definitions.

Change Seen from One Year to the Next

Patients were implanted with a variety of valves, including the Sapien (n = 25) and Sapien XT (n = 96; both Edwards Lifesciences, Irvine, CA) as well as CoreValve (n = 11; Medtronic, Minneapolis, MN). Five patients received miscellaneous prototype valves via 18-Fr sheaths. Preclosure using a percutaneous technique was performed in all but 1 patient.

Overall mortality was 5.1% at 30 days. Twenty-four patients (18%) experienced vascular complications, all but 2 of which were iliofemoral. Major complications included dissection or perforation of the iliac artery (3%) and guidewire perforation of the left ventricle (1%). Minor complications were femoral bleeding, stenosis, or occlusion (12%), pseudoaneurysm (1%), and retroperitoneal bleeding (1%). No aortic rupture or dissection occurred despite the presence of porcelain aorta in 5% of patients.

Such complications were more common in patients whose minimal artery diameter exceeded external sheath diameter and in those with peripheral vascular disease.

Both complication rates and procedural characteristics differed between 2009 and 2010.

Major and minor vascular complications decreased, as did instances of major bleeding and unplanned surgery. When complications did occur, operators also were more likely to attempt percutaneous treatment in 2010 than in 2009; all such attempts were successful (table 1).

Table 1. Complications

At the same time, procedural characteristics also shifted. Multidetector computed tomographic (MDTC) angiography screening of the iliofemoral arteries and ultrasound-guided puncture were used more frequently in the latter half of the study, while sheath size greater than 19 Fr was progressively less common. There also was a trend toward using expandable sheaths, which measure 14 to 18 Fr and expand after insertion to accommodate larger valves (table 2).

Table 2. Procedural Characteristics

The utility of MDCT screening was assessed in a subset of 82 patients. Among them, minimal artery diameter less than sheath external diameter and moderate or severe calcification both were significantly more common in patients who experienced complications than in those who did not.

Many Reasons for Improvement

In an e-mail communication with TCTMD, Dr. Webb admitted that it is difficult to tease out exactly why vascular complications decreased as much as they did. “The improvement was partly due to better patient selection, partly better techniques, partly smaller catheters, and maybe a little luck. All were important,” he commented.

Dr. Webb added that the researchers were pleasantly surprised by their results in comparison to major vascular complication rates from PARTNER A and B, which were 11% and 16.2%, respectively. “As vascular complications fall, so too will mortality,” he predicted.

Ted Feldman, MD, of Evanston Hospital (Evanston, IL), told TCTMD in a telephone interview that what the study observed at a single center is representative of what is happening on a larger scale, with many centers cooperating to share knowledge.

“I think that the growing experience with transcatheter aortic valve replacement is leading to better outcomes,” he said, agreeing that the causes are “multifactorial.” Experience leads to better case selection and understanding of how to interpret screening studies, Dr. Feldman noted, while the equipment itself has evolved.

Dr. Feldman said that it remains to be seen whether stroke is dropping as much as vascular complications. PARTNER II—which will compare the Sapien valve delivered via the Noraflex system vs. the newer Sapien XT delivered via RetroFlex 3—may help determine if delivery size alone can make a difference.

Imaging Plays Crucial Role

In an editorial accompanying the paper, Carlos E. Ruiz, MD, PhD, of Lenox Hill Heart and Vascular Institute of New York (New York, NY), stresses that imaging is also key.

“A procedure once reliant on the operative visual information and feedback afforded to the cardiovascular surgeon is now supplanted by a multitude of imaging technologies available to the interventional cardiologist,” he writes, adding that “[u]nfortunately, no single imaging modality provides all of the necessary anatomical and functional information needed for safe and effective transcatheter valve implantation.”

In particular, MDCT may have made a direct and substantial contribution toward reducing vascular complications in the current study, Dr. Ruiz proposes.

“Currently, most interventionalists rely on plain angiography and/or CT technologies to assess inner lumen diameters, tortuosity, and calcification of the vasculature. These methodologies trust single-diameter measurements of a 2-dimensional (2-D) planar image, unless curve multiplanar reconstruction and 3-dimensional (3-D) vessel analysis is performed. Perhaps routine 3-D imaging interpretation could enhance the accuracy of vessel assessment,” he comments, adding that “quantifiable imaging parameters that can be universally applied will be a major advance toward improving success and decreasing [TAVR] complications.”

Dr. Feldman agreed that imaging is the focal point of screening for TAVR. “Angiographic images are planar, and that’s really not enough. We really do need the 3-D,” he said. In his own experience, Dr. Feldman related, a large part of the learning curve for TAVR was gaining the expertise to read CT images.

1. Toggweiler S, Gurvitch R, Leipsic J, et al. Percutaneous aortic valve replacement: Vascular outcomes with a fully percutaneous procedure. J Am Coll Cardiol. 2012;59:113-118.

2. Ruiz CE. Optimizing transcatheter aortic valve sizing and minimizing vascular complications. J Am Coll Cardiol. 2012;59:128-129.

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