Study sheds light on vascular complications in TAVR patients

Sapien transcatheter aortic valve. Source: Edwards Lifesciences

Major vascular complications were frequent after transfemoral transcatheter aortic valve replacement (TAVR) surgery, based on an analysis of first-generation devices used in the PARTNER trial. But in the lower-risk population, the incidence and impact on one-year mortality appeared to decrease, according to results published online Aug. 8 in the Journal of the American College of Cardiology.

Philippe Genereux, MD, of Columbia University Medical Center/New York Presbyterian Hospital in New York City, and colleagues set out to identify the incidence, predictors and impact of vascular complications after transfemoral TAVR using data from the PARTNER (Placement of AoRTic TraNscathetER Valve) trial.

For their analysis, they pooled data from both patient populations treated using the transfemoral approach: 177 patients from Cohort B (inoperable patients with severe symptomatic aortic stenosis) and 242 patients from Cohort A (high-risk patients). The analysis involved first-generation Edwards Lifesciences' Sapien valves and delivery systems using a 22-French or 24-French sheath.

The study had two endpoints: major and minor vascular complications (VCs). Major VCs included thoracic aortic dissection; access site or access-related vascular injury leading to either death, need for significant blood transfusions, unplanned intervention or irreversible end-organ damage; distal embolization (noncerebral) from a vascular source requiring surgery or resulting in amputation or irreversible end-organ damage; or left ventricular perforation.

Minor VCs were access site or access-related vascular injury not requiring unplanned intervention and not resulting in irreversible end-organ damage; distal embolization treated with embolectomy or thrombectomy and not resulting in amputation or irreversible end-organ damage; and failure of percutaneous access site closure resulting in interventional (endovascular stent) or surgical correction and not associated with death, need for significant blood transfusions or irreversible end-organ damage.

The researchers assessed the 30-day rates of major and minor VCs, predictors and effect on one-year mortality. They found that 15.3 percent of patients experienced major VCs within 30 days. Major VCs were associated with significantly higher 30-day rates of major bleeding, transfusions, and renal failure requiring dialysis, and with a significantly higher rate of 30-day and one-year mortality.

Female gender was an independent predictor of major VCs, and VCs and renal disease at baseline were independent predictors of one-year mortality.

Minor VCs occurred in 11.9 percent of patients and were not associated with higher mortality, major bleeding, transfusions or acute renal injury at 30 days and one year.

The authors summarized that major VCs were frequent after transfemoral TAVR and were associated with bleeding events, transfusions and increased mortality. They noted that the incidence and impact of major VCs appeared to decrease among the Cohort A group.

“The current study demonstrated the prognostic impact of major VC after TAVR on short- and long-term mortality,” Genereux and colleagues wrote. “Indeed, major VC were associated with a more than four-fold increase in 30-day mortality.”

They added that many factors have been associated with the occurrence of VCs, including operator experience, femoral artery and artery diameter characteristics and the sheath-to-femoral artery ratio. “In the current analysis, female sex was the only identifiable independent predictor of major VC after TAVR,” they wrote. “The smaller vessel diameters encountered in women paired with the relatively large first-generation introducer-sheath catheter system used in the PARTNER trial (22-French or 24-French) may partially explain this finding.”

The authors noted that the rate of major VCs dropped from 2009, when the 22-French or 24-French sheathes generally were in use, to 1 percent in 2010, with the introduction of the smaller 18-French and 19-French sheath system.

They observed that several factors may explain the decreased incidence and impact seen in Cohort A: learning curve issues involving Cohort B, Cohort B’s more fragile state and the availability of the transapical approach.

“These findings underline the magnitude of impact and the synergy between enhanced operator skills, TAVR team experience and device improvement,” they wrote. “These three factors are vital if the full clinical potential of the TAVR procedure is to be realized, especially when involving a lower-risk population.”

The authors emphasized that their study was observational and could not prove causality. Due to the possibility of unmeasured confounders, the findings should be considered as hypotheses generating only.