The most common adverse effects associated with transcatheter aortic valve replacement (TAVR) are heart block, vascular complications and renal failure. However, Prateek J. Khatri, MD, lead author of the study, told Cardiovascular Business that the CoreValve had a complication rate of 25 percent, compared with 5 percent with the Sapien valve, for the most common complication of heart block, despite a newer-generation CoreValve device used the majority of the time.

“While the PARTNER trial showed us that TAVR had a remarkable impact on survival in patients with high-operative with severely symptomatic aortic stenosis compared with medical therapy, there were also some important complications with the procedure,” said Khatri. “Also, the trial did not produce any complication rate information for the CoreValve, since it only assessed the Sapien valve.”

The objective of this meta-analysis was to amalgamate the complication rates from multiple, different studies to determine if the complications rates with TAVR in the randomized controlled PARTNER trial were similar to real-world, observational studies, explained Khatri. The other objective was to compare complication rates between the Sapien valve (Edwards Lifesciences) and the CoreValve (Medtronic).

The researchers assessed a total of 49 studies enrolling 16,063 patients who met the inclusion criteria. All the included studies enrolled at least 100 patients who had TAVR, and reported at least one outcome of interest. Overall 30-day and one-year survival rates after TAVR were 91.9 percent and 79.2 percent, respectively.

Heart block requiring permanent pacemaker implantation was the most common adverse outcome (13.1 percent) and was five times more common with the CoreValve than the Sapien valve implanted using the transarterial route (25.2 percent vs. 5 percent, respectively). Among the devices used, the most common were the third-generation CoreValve, and the first-generation Sapien valve, but not the newer-generation Sapien XT, Khatri said.

The overall rate of vascular complications was 10.4 percent—the second most common complication rate—and was highest with transarterial implantation of the Sapien valve (22.3 percent). “This is where the generation of the valves is important,” said Khatri. “The first-generation Sapien valve has a larger sheath size, compared with the third-generation CoreValve.” Previous studies have shown that the largest predictor of major vascular complications is the ratio of the outer diameter of the vascular access sheath to the femoral artery diameter, he said.

“Thus, the difference in major vascular complication rates between the two valves is likely a reflection between the two sheath sizes,” Khatri said.

Acute renal failure requiring renal replacement therapy was the third most common complication, occurring in 4.9 percent of patients.

The finding of higher complication rates with the transarterial approach compared with the transapical approach was “expected,” said Khatri, due to more manipulation of the vessels.

The researchers noted that a limitation of their study was that rates of major vascular complications may be overestimated due to the “rapidly evolving TAVR technology.” Also, the researchers did not assess if body mass index or gender impacted complication rates.

The study was published Jan. 1 in the Annals of Internal Medicine. The Heart and Stroke Foundation of Canada funded the meta-analysis.