Study results from the pivotal clinical trial ABSORB III – currently in its third year – continue to show an increase in major adverse cardiac events and bioresorbable vascular scaffold (BVS) thrombosis in patients receiving Abbott Vascular’s Absorb GT1 BVS compared to patients treated with the approved metallic XIENCE drug-eluting stent, the Food and Drug Administration (FDA) announced in an update to its March 18, 2017 letter to health care providers. The BVS is used to open heart blood vessels (coronary arteries) blocked by scar tissue (plaque) in order to increase blood flow to the heart muscle.
The FDA said it was also made aware that the manufacturer has stopped global sales of the Absorb BT1 BVS as of Sept. 14, 2017. The agency’s recommendations for health care providers outlined in its previous letter remain unchanged. “Although health care providers with available inventory may continue to implant the BVS, they should carefully consider its safety and effectiveness and only use it if they believe it is in the best interest of their patients,” the FDA’s update stated.
Abbott Vascular has discontinued sales of the BVS but will continue to monitor patients currently enrolled in the ABSORB III and ABSORB IV clinical studies through five years following implantation. Patients enrolled in these studies will be followed through standard practice and care after five years.
The three-year follow-up data from the ABSORB III study showed a 13.4 percent rate of major cardiac events including cardiac death, heart attack or the need for an additional procedure to re-open the treated heart vessel in patients who were implanted with the BVS at three years. Patients treated with Abbott Vascular’s approved metal drug-eluting stent, the XIENCE stent, had a 10.4 percent rate of cardiac events.
The risk of scaffold thrombosis in BVS-treated patients was also higher than for those treated with the XIENCE stent. Most cases of BVS scaffold thrombosis occurred within the first year following BVS implantation. After the first year, the rate remained higher compared to XIENCE patients.
Any adverse events in patients treated with BVS should be reported to the FDA MedWatch Adverse Event Reporting Program at www.FDA.gov/MedWatch/Report.htm. The FDA says it will keep the public informed if significant new information comes available.