first generation Bioabsorbable vascular scaffolds (BVS) may be as effective as drug-delivered metal stents, which are currently the standard treatment for heart patients undergoing percutaneous coronary intervention (PCI).
These are important findings from a global clinical trial led by a researcher from the Icahn School of Medicine at Mount Sinai. The work could lead to developments and improvements in new BVS technology and future clinical use among interventional cardiologists across the United States.
This multicenter trial is the largest trial examining the long-term safety and efficacy of PCI using Abbott’s “Absorb BVS,” a novel stent made of an absorbable polymer (plastic-like material). It shows that this treatment option, when implanted properly, may produce long-term outcomes for heart patients that are similar to conventional treatment with drug-coated metal stents.
The results of five years of the “ABSORB IV” trial were announced on Wednesday, May 17, in a late-breaking clinical trial/hotline session at the EuroPCR meeting in Paris, the official annual meeting of the European Association for Percutaneous Cardiovascular Interventions (EAPCI), and published at one time in Journal of the American College of Cardiology.
In this study, which is the largest ever of BVS in patients with coronary artery disease, the absorbable scaffold, when implanted with optimal technique, resulted in similar five-year rates of patient-directed adverse events, quality of life, and angina pectoris. repeated as standard. A metal stent filled with medication. Few adverse events with this thick first-generation scaffold were more common during the first three years, before its full biological uptake. Thereafter, event rates were nearly identical for BVS and metal stenting. It is possible that early excess risk can be eliminated with a thinner next-generation scaffold and implantation with endovascular imaging guides, enabling long-term restoration of the coronary artery to its original state without permanent implantation.
Greg W. Stone, MD, lead author, director of academic affairs for the Mount Sinai Health System and professor of medicine (cardiology) and population health science and policy, at Icahn Mount Sinai
Dr Stone adds: “There is a real desire among patients and their physicians for an absorbable stent that will be present as early as it is needed and then disappear completely. The positive long-term results from this study underscore the fact that this new technology, which has been voluntarily withdrawn from the market before Manufacturer due to market adoption less than expected, should not be abandoned.
Patients with coronary artery disease — the buildup of plaque inside arteries leading to chest pain, shortness of breath and heart attack — often undergo PCI, a noninvasive procedure in which interventional cardiologists use a catheter to place stents in blocked coronary arteries to restore blood flow. . Standard treatment uses a metal stent filled with medication, and a permanent metal implant effectively opens up the artery. However, the permanent metal cage may be responsible for an average of approximately 2 percent per year of adverse events arising from the lesion each year throughout the patient’s life. Some of these events, known as stent thrombotic events, can cause a fatal heart attack in about 20 percent of cases.
For decades, manufacturers have been working on BVS made from polymer (a type of plastic) as an alternative. These scaffolds open the blocked artery and are then safely absorbed into the bloodstream over a period of three years, where they are metabolized into carbon dioxide and water. The Food and Drug Administration approved Abbott’s “Absorb BVS” in 2016—the most widely used device of its kind—but the company has voluntarily ceased manufacturing and sales.
The ABSORB IV clinical trial compared Abbott’s volatile polymeric implants, implants with an improved technique compared to previous studies, with Abbott’s cobalt chromium (CoCr-EES) stents to compare safety and outcomes over five years after the procedure. The researchers randomized 2,604 patients at 147 sites with stable or acute coronary syndromes to receive either BVS-enhanced technique or CoCr-EES. The patients did not know which stent they had received.
At the five-year mark, 17.5 percent of patients with BV had failure of the target lesion (cardiac death, heart attack, or repeat intervention associated with the treated device or vessel), compared with 14.5 percent of patients treated with a metal-stent- ; 3 percentage difference. Twenty-one BV patients had a thrombosis (blood clot) attached to the device, compared to 13 patients with metal stents, a difference of 62 percent. The risk period for increased cardiac events was during the first three years, before the full scaffold was absorbed into the bloodstream, but the rates of these cardiac events were similar between the two groups from three to five years after transplantation. At five years, there was no significant difference between the two groups in death or total cardiac events, both groups had similar quality of life (which was measured consistently over the five-year study period using the Seattle Angina Questionnaire (SAQ)-7 and the Visual Analog Scale EuroQOL-5D (EQ-5D VAS) and there was no difference in chest pain symptoms.
A unique aspect of the study involved an in-depth look at recurrent angina; pain in chest ; This is often why patients undergo stent implantation. About 5 to 8 percent of PCI patients report these symptoms to a cardiologist at any given follow-up time. However, in this trial, the researchers had patients in both groups answer detailed questions describing their chest pain symptoms continuously for five years after PCI. Descriptions of these symptoms were reviewed by an independent panel to determine whether angina pectoris was truly the case. This analysis showed that 53 percent of patients in both groups (BVS and stent) had recurrent angina at some point in five years. This rate, which is much higher than previously estimated, may give new insights into the burden of angina on patients and raise questions about the causes of angina pectoris.
“The fact that angina was so frequent was unexpected, and much higher than we would have expected given the fact that the patients and lesions treated in this study were not overly complex. This suggests that there may be other causes of angina than obstructive coronary artery disease.” Arteries, such as microvascular disease and vasospasm, require different treatments than stenting if we are to improve a patient’s symptoms,” says Dr. Stone.
This study was funded by the Abbott Corporation.