Fewer than six percent of patients who underwent transcatheter aortic valve replacement (TAVR) with the CoreValve device had strokes within two years of the procedure, according to a recent study. Researchers mentioned the 5.6 percent overall stroke rate was relatively low considering all patients were high-risk and had symptomatic aortic stenosis.

Lead researcher Johan Bosmans, MD, PHD, and colleagues found that the early predictors of stroke varied depending on if patients had stroke alone or stroke with a transient ischemic attack (TIA). The only predictor of long-term stroke was if patients had undergone CABG, although the researchers said the increased risk likely did not have to do with the TAVR procedure.

Patients with a clinically relevant neurological event (stroke or TIA) within the first month of the procedure had a significant effect on long-term survival. Within the first 30 days, half of the neurological events occurred within a day of the procedure.

Results were published in the July issue of the Journal of the American College of Cardiology.

Previous studies showed the self-expanding CoreValve bioprosthesis (Medtronic) was superior to standard therapy in inoperable patients and noninferior to surgical aortic valve replacement (SAVR) in high-risk patients who had severe symptomatic aortic stenosis. In the pivotal randomized CoreValve trial, the rates of stroke were 6.2 percent in the SAVR group and 4.9 percent in the TAVR group at 30 days.

In this study, researchers analyzed the ADVANCE study, which enrolled 1,015 patients at 44 sites in 12 countries in Europe, Israel and Colombia from March 2010 through July 2011. The mean age was 81.1, and 51 percent of patients were females. Medtronic funded the ADVANCE study.

The stroke rates were 1.4 percent through the first day after the procedure, 3 percent at 30 days and 5.6 percent at two years. Most of the strokes were ischemic and not hemorrhagic. Patients who had strokes within 30 days were more likely to be female, have acute kidney injury or have major vascular complications.

“Although it fortunately appears that stroke rates in TAVR are diminishing, it is undeniable that permanent neurological injury is the single most significant and most feared morbidity of cardiac interventions,” Vinod H. Thourani, MD, of Emory University in Atlanta, and colleagues wrote in an accompanying editorial. “A debilitating stroke is viewed by many as the greater evil, even compared with operative death. As the target audience for TAVR expands, the identification of any procedural risk factors for neurological complications is imperative.”

Thourani and colleagues noted that patients in the ADVANCE study were healthier than those enrolled in previous trials, and the sites in the study were required to have performed at least 40 TAVR procedures. They wrote that “the study may be a victim of the investigators’ success in avoiding neurological complications, and thus, some important risk factors may have been masked.”

Although they said the results were “encouraging,” they said future studies should continue to identify neurological dysfunction, which contributes to morbidity and mortality after patients undergo TAVR.