Importance of Coronary Artery Disease Treatment

Coronary artery disease (CAD) is the most prevalent type of heart disease and a primary cause of mortality in the United States. Consequently, effective treatment options for CAD are crucial. A recent study has evaluated the safety and effectiveness of bioresorbable vascular scaffolds (BVS) in comparison to drug-eluting stents (DES) for managing this condition.

Comparing Treatments for Coronary Artery Disease

Bioresorbable Vascular Scaffolds (BVS)

BVS represent a novel approach to treating CAD. These devices, made from biodegradable and synthetic polymers, are designed to offer temporary mechanical support to vascular injuries, particularly in the arteries. Over time, the BVS can be fully absorbed by the body, potentially facilitating the restoration of normal vascular function and enhancing long-term patient outcomes.

Drug-Eluting Stents (DES)

In contrast, drug-eluting stents are small devices inserted into the arteries, which release medication to maintain arterial patency and ensure proper blood flow. However, DES are associated with certain limitations, including strut fractures that may lead to restenosis (narrowing of the arteries) and abnormal vasomotion (irregular oscillation of blood vessel walls).

Previous Clinical Findings

Previous clinical trials indicated no significant differences in most outcomes between BVS and DES after one year. However, BVS were linked to a higher incidence of target vessel-related heart attacks, potentially due to increased device thrombosis (blood clot formation).

Recent Systematic Review

A systematic review conducted by Ali and colleagues and published in The Lancet analyzed seven randomized trials comparing BVS and DES over a two-year follow-up period. The trials involved 5,583 patients, with 3,261 receiving BVS and 2,322 receiving DES. The primary efficacy endpoint focused on cardiac mortality or target vessel-related heart attacks, while the primary safety outcome assessed probable or definite device thrombosis.

Results of the Review

The study concluded that BVS usage was associated with a higher rate of target vessel-related heart attacks after two years, thus increasing the rate of device-oriented endpoints in comparison to DES. Additionally, the incidence of device thrombosis was also found to be elevated with BVS.

Study Limitations

Several limitations were noted in the clinical trials included in this analysis. Certain sub-groups, such as patients with diabetes, showed better outcomes with BVS, suggesting the need for further research to explore this relationship. Furthermore, many high-risk patients were excluded from these trials, which could affect the generalizability of the findings. Additionally, for many researchers, the use of BVS was a new experience, indicating that optimal techniques for utilizing BVS have yet to be fully established.

Conclusion: DES as a Superior Treatment

The review suggests that DES provide a more effective and safer treatment option for coronary artery disease compared to BVS over a two-year period. However, long-term follow-ups and larger-scale trials are essential to ascertain if the risks associated with BVS persist beyond two years or if potential benefits arise following complete bioresorption and restoration of vascular function.

Written by Lacey Hizartzidis, PhD

Reference: Ali ZA, Serruys PW, Kimura T, Gao R, Ellis SG, Kereiakes DJ, Onuma Y, Simonton C, Zhang Z, Stone GW. 2-year outcomes with the Absorb bioresorbable scaffold for treatment of coronary artery disease: a systematic review and meta-analysis of seven randomized trials with an individual patient data substudy. Lancet. 2017 Jul 18. pii: S0140-6736(17)31470-8.