Impact of strut thickness on acute mechanical performance: A comparison study using optical coherence tomography...

To evaluate the acute performance of a novolimus-eluting bioresorbable scaffold (BRS) with different strut thickness (DESolve system 150 and 100) using optical coherence tomography (OCT) in terms of appropriate scaffold deployment.

Outcome after BRS implantation seen in registries and meta-analyses continue to show a higher rate of scaffold thrombosis than those reported with DES. Thus, second scaffold generations with lower strut thickness might have potential advantages in terms of flow disturbance. However, whether mechanical properties are comparable has to be evaluated.

Fifty-seven patients undergoing OCT-guided scaffold implantation were enrolled consecutively in this retrospective study. The final pullback after DESolve 150 (n=42) and DESolve 100 (n=15) were compared. The following indices were calculated: mean and minimum area, residual area stenosis, incomplete strut apposition, tissue prolapse, eccentricity and symmetry indexes, strut fracture, and edge dissection. Most patients suffered a multi vessel disease. Maximum pre-dilatation balloon inflation pressure was 13.5±3.2 vs 14.5±2.5atm. OCT analysis showed a minimal lumen area of 6.1±1.9 vs 5.2±1.6mm², p=0.06. Mean residual area stenosis was 15.3% vs 21.3, p=0.22. Mean eccentricity index did not differ significantly (0.8±0.1 vs 0.6±0.1, p=0.61). Prolapse area was 4.5±8.8 vs 5.6±9.8mm².

OCT showed similar post-procedural scaffold geometry and outcome indicating that both BRS may be implanted with good acute performance. However, the trend towards a smaller MLA and a higher percentage of RAS suggest a decreased radial strength for the 100μm BRS. The attempt to reduce strut thickness should not result in loss of radial strength.

Rates of scaffold thrombosis after bioresorbable scaffold (BRS) implantation are reported to be higher than after metallic stent (DES) implantation. Thus, second scaffold generations with lower strut thickness might have potential advantages in terms of flow disturbance. We aimed to evaluate the acute performance of a novolimus-eluting BRS with different strut thickness (DESolve system 150 and 100) using optical coherence tomography (OCT) in terms of appropriate scaffold deployment. OCT showed similar post-procedural scaffold geometry and outcome indicating that both BRS may be implanted with good acute performance. However, the data suggest a decreased radial strength for the 100μm BRS.