Using the recently standardized definition of vascular complications of transfemoral transcatheter aortic valve implantation (TAVI), researchers reported that a novel tool, the sheath to femoral artery ratio (SFAR), predicted major vascular complications, which they found occurred relatively frequently and were associated with increased 30-day and in-hospital mortality. In an accompanying editorial, the authors suggested that SFAR findings, if confirmed by others, be considered in future recommendations for TAVI guidance.
The Valve Academic Research Consortium (VARC), published in January, standardized consensus definitions for clinical endpoints in TAVI to allow comparisons among clinical trials.
In the August issue of the Journal of the American College of Cardiology: Cardiovascular Interventions, Kentaro Hayashida, MD, PhD, of the Institut Cardiovasculaire Paris Sud in Massy, France, and colleagues describe how they applied the VARC definitions for major and minor vascular complications in a prospective cohort study to better understand the incidence, impact and predictors of these complications.
“Vascular complications are among the most frequent and serious complications of transfemoral TAVI,” Hayashida and colleagues wrote. “Despite improved patient selection and down-sizing of the delivery system, these complications remain the Achilles’ heel of this novel procedure.”
They selected 130 consecutive high-risk patients between October 2006 and June 2010 who had symptomatic severe aortic stenosis, were identified as transfemoral TAVI candidates and underwent valve implantation at their institution. Of those patients, 102 received the Edwards valve system (Edwards Lifesciences) and 28 received the CoreValve Revalving system (Medtronic). Valve implantation was not achieved in three patients.
The mean age for patients was 83.3 years; logistic European System for Cardiac Operative Risk Evaluation score was 25.8 percent; femoral artery minimal lumen diameter was 8.17 mm and the mean sheath outer diameter was 8.10 mm for a mean SFAR of 0.99. Calcification and tortuosity scores were also calculated.
The researchers found vascular complications occurred in 27.6 percent of patients, with 17.3 percent classified as major and 10.2 percent as minor. Major vascular complications were defined as any thoracic aortic dissection; access site or access-related vascular injury leading to either death, significant blood transfusion, unplanned percutaneous or surgical intervention or irreversible end-stage organ disease; or distal embolization from a vascular source requiring surgery or resulting in amputation or irreversible end-stage organ failure. Patients with major complications had increased rates of in-hospital mortality, 30-day mortality and longer hospital stays, they found.
The authors observed that the uniform definitions may impact results in the future. “The rate of major complications in our study was 17.3 percent, and is comparable to other published series; however, the overall rate of complications was amplified by the addition of VARC minor complications (10.2 percent),” they wrote. “Although the routine application of 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 experience and device safety.”
The researchers identified femoral artery calcification and center experience as predictors of complications, in keeping with previous studies. But they also discovered that SFAR predicted major vascular complications and was strongly associated with clinical outcomes and mortality.
“This novel index reflects both femoral artery diameter and size of the introducer sheath, and was a more powerful predictor of vascular events than either of these two criteria taken in isolation,” they wrote. “We believe that the routine application of SFAR will improve patient selection for transfemoral TAVI, reduce vascular complications and ultimately, improve patient outcome.”
Nicolo Piazza, MD and Ruediger S. Lange, MD, PhD, of the German Heart Center in Munich and Patrick W. Serruys, MD, PhD, of Erasmus Medical University in Rotterdam, The Netherlands, commended Hayashida et al in an accompanying editorial for providing a detailed description of vascular complications but also suggested that alternative screening and surgical strategies should be considered. They added