Time course of vascular response after an a priori strategy of bare metal stent implantation post-dilated with a paclitaxel-coated balloon: Implementation of a three-dimensional analysis algorithm with optical coherence tomography.

BACKGROUND: An a priori combined therapy of a bare metal stent post-dilated with a paclitaxel- -coated balloon (PCB) was investigated with optical coherence tomography (OCT) at 2 and 6 months regarding vessel response. Previous studies have shown inconsistent results and the time course of vessel healing after such an interventional strategy is unknown.

METHODS: Thirty-three de novo lesions in 32 patients were electively treated. Six-month OCT analysis was available in 24 lesions. Two-month OCT follow-up was obtained in 16 lesions. Sequential OCT at 2 and 6 months was available in 7 patients. A novel 3-dimensional picture of vessel segments as spread outs was implemented.

RESULTS: Severe incomplete stent apposition (ISA) accompanied by significantly lower strut coverage were found at 2-month compared with 6-month follow-up (ISA struts: 11.4 ± 11.8% vs. 1.8 ± 4.8%, p = 0.001; uncovered struts: 14.5 ± 14.8% vs. 2.0 ± 5.3%, p = 0.001). ISA size diminished over time and the possibly observed phenomenon of positive vessel remodeling (remodeling volume: 4.9 ± 5.9 mm3 at 2-months vs. 2.0 ± 2.6 mm3 at 6-months; p = 0.042) was largely reversible in most lesions.

CONCLUSIONS: Bare metal stenting with adjunctive application of paclitaxel by a coated bal-loon shows transient severe incomplete strut apposition, most likely due to focal positive ves-sel remodeling. Thus, caution is needed in bailout situations following a PCB angioplasty. A novel illustration of OCT parameters as "carpet views" enables a comprehensive analysis of investigated stents.