Multimodal Comparisons of Results Achieved by Different Side Branch Ballooning Techniques for Bifurcation Provisional Stenting

Background: Stepwise provisional stenting is the gold standard for percutaneous coronary intervention (PCI) on bifurcation lesions, but the optimal ballooning technique for eventual side branch treatment is not established. The objective of the present study was to compare the stent configuration obtained by 2 different side branch optimization techniques performed after main vessel (MV) stent implantation: proximal optimization technique+kissing balloon inflation+final proximal optimization technique (POT/KBI/POT [PKP]) versus proximal optimization technique+isolated side branch dilation+final proximal optimization technique (POT-side-POT [PSP]). Methods: We realized a 1:1 prospective randomized trial comparing bifurcation PCI conducted (under angiographic and angioscopic visualization) with either PKP or PSP in reanimated swine hearts using commercially available drug-eluting stents. After PCI, the obtained stent configuration (expansion, eccentricity, apposition) was assessed by optical coherence tomography and micro-computed tomography dividing the stent in 4 segments. Primary study end point was minimum stent expansion at the distal MV segment. Results: A total of 30 PCIs were successfully performed according to randomization obtaining overall good results (average minimum stent expansion >90% at optical coherence tomography and micro-computed tomography) with PSP or PKP. Minimum stent expansion at the distal MV segment was significantly higher with PKP as compared with PSP at optical coherence tomography (97.9±4.2% versus 91.0±7.7%; P=0.002) and micro-computed tomography (98.1±4.1% versus 91.3±7.9%; P=0.006). Other significant findings included higher stent eccentricity index at proximal MV with PSP, higher side branch scaffolding length and lower malapposition (at bifurcation core and distal MV) with PKP. Conclusions: This first prospective randomized trial in a unique non-atherosclerotic preclinical environment showed that bifurcation PCI conducted with PSP and PKP achieves different stent configurations. These findings might be useful in bifurcation PCI practice and call for further evaluations in clinical ground.