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 SB treatment is not established. The objective of the present study was to compare the stent configuration obtained by two different side-branch (SB) optimisation techniques performed after main vessel (MV) stent implantation: proximal optimisation technique (POT) + kissing balloon inflation + final POT (PKP) versus POT + isolated SB dilation + final 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 (OCT) and micro-computed tomography (micro-CT) dividing the stent in 4 segments. Primary study endpoint was minimum stent expansion (MSE) at the distal MV segment. Results: A total of 30 PCIs were successfully performed according to randomization obtaining overall good results (average MSE > 90% at OCT and micro-CT) with PSP or PKP. MSE at the distal MV segment was significantly higher with PKP as compared with PSP at OCT (97.9 ± 4.2% vs. 91.0 ± 7.7%; p = 0.002) and micro-CT (98.1 ± 4.1% vs. 91.3 ± 7.9%; p = 0.006). Other significant findings included higher stent eccentricity index at proximal MV with PSP, higher SB 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.