JACC: Sheath to femoral artery ratio may improve TAVI outcomes
While vascular complications occur frequently during transcatheter aortic valve implantation (TAVI) procedures, applying sheath to femoral artery ratio (SFAR) can improve patient selection for transfemoral TAVI, which could improve outcomes, found a study published in the August issue of the Journal of the College of Cardiology: Interventions.

“Transcatheter aortic valve implantation (TAVI) has emerged as a promising therapeutic option for patients with severe symptomatic aortic stenosis (AS), who are ineligible for conventional surgical aortic valve replacement,” wrote Kentaro Hayashida, MD, PhD, of the Institut Cardiovasculaire Paris Sud in Massy, France. “Vascular complications are among the most frequent and serious complications of transfemoral TAVI, and have been associated with significantly increased patient morbidity and mortality.”

To evaluate the incidence and predictors of vascular complications during TAVI, Hayashida and colleagues evaluated 130 symptomatic severe aortic stenosis patients who underwent transfemoral TAVI between October 2006 and June 2010. Another 90 patients were selected for nontransfemoral TAVI because of unfavorable aortic or iliofemoral anatomy. Of the patients, 60 were treated with transapical TAVI and five with trans-subclavian TAVI. The patients had a mean age of 83.3 years. The researchers defined vascular complications by the Valve Academic Research Consortium (VARC) criteria.

Hayashida and colleagues reported that vascular complications were observed in 35 patients and included 22 VARC major complications and 13 VARC minor complications. Major femoral complications included one ruptured vessel, six dissections and three stenosis/occlusions. Death occurred in 10.2 percent of patients and five deaths were linked to vascular complications.

SFAR, early center experience and femoral artery calcium score were independent predictors of VARC major vascular complications. Patients with VARC major complications saw heightened rates of in-hospital mortality, 30-day mortality and a longer length of stay.

“Our results demonstrate that VARC major vascular complications predict both 30-day and in-hospital mortality,” the authors wrote. “Furthermore, we have described the SFAR, a novel tool which predicts VARC major vascular complications, and is strongly associated with clinical outcomes, including mortality.”

Vascular complications occur in 8 percent to 30.7 percent of Edward valve recipients and 1.9 percent to 16 percent of CoreValve (Medtronic) patients, the researchers wrote. “The considerable variation in the reported incidence of these complications arises, in part, from the absence of a standardized definition for vascular complications of TAVI.

“Although the routine application of the VARC criteria for vascular complications will provide reliable, standardized information for TAVI-related research, it is likely to increase the reported rates of complications despite ever-improving operator expertise and device safety,” the authors wrote.

Previously, femoral artery calcification and increasing diameter of the introducer sheath have been used to identify major vascular complications; however, the authors wrote that “there is a paucity of data on the predictors of these complications in TAVI patients.” In the current study, femoral artery calcification and center experience were found to be predictors of complications during TAVI procedures.

“We believe that the routine application of SFAR will improve patient selection for transfemoral TAVI, reduce vascular complications, and ultimately, improve patient outcomes,” the authors concluded. “Routine application of the SFAR, with a cutoff value of 1.05, may improve TAVI-related outcomes.”

In an accompanying editorial, Nicolo Piazza, MD, of the German Heart Center Munich in Germany, and colleagues wrote, “The VARC definitions provide greater transparency and a better understanding of where things may go wrong. This is especially important during the adoption phase of a new catheter-based therapy.

“The learning curve associated with TAVI is multifaceted, dynamic, and difficult to describe. It may involve a change in patient-selection criteria, operator skills, or device selection,” Piazza and colleagues wrote.

Piazza et al offered that surgical cut-downs for transfemoral TAVI are underutilized and noted that 3 to 4 cm incisions that provide visualization could mitigate vascular closure device failures.

“Vascular complications remain to be a problem with TAVI—herein reported in nearly one-third of patients. Improvements in patient selection, operator experience, selected techniques, and device iterations should diminish the risk of vascular complications in the future. Getting in and out of a TAVI procedure is not always easy,” Piazza and colleagues concluded.