Abstract 2646: Intravascular Ultrasound Evaluation of Optimal Drug-eluting Stent Expansion after Post-stent Balloon Dilation Using Non-compliant Balloon versus Semi-compliant Balloon. Post-stent Optimal Stent Expansion Trial (POET).
Background: The impact of type of balloon catheters such as non-compliant (NC) or semi-compliant (SC) balloon catheters used for post-stent dilation on optimal stent expansion has not been established for DES.
Methods: We conducted a prospective multicenter, randomized study to compare Quantum® (NC, group I) versus Maverick® (SC, group II) balloon catheter in the efficacy of achieving optimal stent expansion (OSE) after stenting. A total of 210 patients (M:F = 127:83, 61.8±8.8 years), who underwent elective coronary stenting for a de-novo lesion were included. Infarct-related lesions within 7 days were excluded. Stent was serially expanded with gradual increase in balloon inflation pressures (1. stenting with nominal pressure; 2. adjuvant ballooning up to 14 atm; 3. up to 20 atm) until OSE criteria were met. The OSE was defined according to the criteria of MUSIC study. IVUS was performed before and after inflation of balloon. The primary end points are the incidence of OSE and IVUS parameters after each post-stent adjuvant balloon inflation step.
Result: In all lesions, either Cypher® (n=104) or TAXUS® (n=106) was deployed (diameter; 3.23±0.30 mm, length 24.79±5.53 mm). Of these, 200(95%) lesions required post-stent adjuvant dilation after stent implantation with nominal pressure ballooning. Quantum® (diameter; 3.22±0.29 mm, length 8.54±1.38 mm) was used in 100 lesions and Maverick® (diameter; 3.21±0.31 mm, length 12.20±1.04 mm) was used in 100 lesions. Baseline clinical, lesion and stent characteristics of both groups showed no significant difference. The incidence of OSE was 26 (26%) in group I and 38 (38%) in group II after final adjuvant balloon inflation (p=0.07). The ratio of minimal stent area (MSA) to reference area was significantly higher in the Group II (Quantum 79.2±13.1% vs Maverick 84.4±13.1%, p=0.007).
Conclusion: Despite post adjuvant balloon inflations at high pressures, under-expansion of DES was seen commonly. Between two types of balloon catheters for adjuvant balloon dilation after DES implantation, there were a tendency that the OSE could be obtained by using the semi-compliant balloon and the ratio of MSA to reference area could be obtained by using the SC balloon compared to the NC balloon.