ASSURE Registry: Angiographic, Clinical Outcomes of BRS Similar to DES at 1 Year
Use of a bioresorbable scaffold (BRS) for ischemic heart disease appears to provide a similar degree of safety and efficacy compared with a metallic DES, according to a registry study published online December 15, 2014, ahead of print in EuroIntervention.
Detlef G. Mathey, MD, of University Cardiovascular Center Hamburg (Hamburg, Germany), and colleagues looked at 183 patients (average age 63.5 years; 79.8% men) with ischemic heart disease and a total of 198 lesions (percent diameter stenosis ≥ 50%; median length 11.6 mm) who were treated with the everolimus-eluting Absorb bioresorbable vascular scaffold (BVS; Abbott Vascular). All patients were consecutively enrolled in the ASSURE registry between April 2012 and March 2013 at 6 German centers.
Patients treated during the first 6 months received only the 3.0-mm BVS (18 mm in length). Thereafter, the 2.5-mm (18 and 28 mm in length), 3.0-mm (28 mm in length), and 3.5-mm (12, 18, and 28 mm in length) were also available. Overlap of multiple BVS in long lesions was permitted. Predilatation was performed in 99% of all lesions with a balloon-to-vessel diameter ratio of 1.1 ± 0.2 and a balloon-to-scaffold length ratio of 0.8 ± 0.2.
High Degree of Safety, Efficacy
Acute procedural success, defined as < 50% residual stenosis and TIMI 3 flow without occurrence of MACE during the hospital stay, was 100%. At 12 months, the rate of MACE (cardiovascular death, MI, and ischemia-driven TLR) was 5.0%, and deaths were attributed to GI bleeding on DAPT (n = 1) and MIs caused by non-target vessel failure (n = 3). Rates of TLR and TVR were 2.8% and 2.2%, respectively. There were no cases of scaffold thrombosis. Acute gain, defined as the change in the minimal lumen diameter (MLD) from baseline to 12 months, was 1.54 ± 0.51 mm.
Importantly, rates of stable and unstable angina declined dramatically by 6 months and remained similarly low at 12 months (table 1).
Diameter stenosis improved from 64.6 ± 15.1% at baseline to 16.1 ± 7.7% by 1 year, with greater improvement seen in shorter vs longer lesions. Additionally, reference vessel diameter increased by 0.3 ± 0.4 mm from baseline to 1 year.
Although visual estimation overestimated the baseline reference vessel diameter by 0.5 ± 0.5 mm and percent diameter stenosis by 13.2 ± 16.5% compared with QCA, the MLD closely matched the target of baseline reference vessel diameter (2.5 vs 2.6 mm).
Comparable to DES
According to the study authors, rates of MACE, acute gain, and residual diameter stenosis seen with the Absorb BVS are in line with expected outcomes for DES. Furthermore, they say the study broadens the scope of BVS to include a “a real-world setting including patients with a worse health status [and] a higher proportion of complex lesions” and waiving of the obligatory IVUS or OCT guidance that has been used in clinical trials.
Dr. Mathey and colleagues suggest that a “high BVS expansion pressure and slight BVS oversizing seem to be the key factors” in achieving good results.
“Unlike metallic stents, BVS are limited by their expansion capacity,” they continue. “To achieve an optimal angiographic result, it is therefore important to choose the correct BVS size carefully. If this is done, BVS seem to be safe and effective and may become a useful alternative to DES in many patients undergoing coronary stent implantation.”
Wöhrle J, Naber C, Schmitz T, et al. Beyond the early stages: insights from the ASSURE registry on bioresorbable vascular scaffolds. EuroIntervention. 2014;Epub ahead of print.
- The study was supported by an unrestricted research grant from Abbott Vascular.
- Dr. Mathey reports no relevant conflicts of interest.
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