Impact of Side Branch Predilatation on Provisional Bifurcation Percutaneous Coronary Intervention Outcomes: Insights From PROGRESS‐BIFURCATION Registry

ABSTRACT Background Whether side branch (SB) predilatation should be performed in patients undergoing bifurcation percutaneous coronary interventions (PCI) remains controversial. Methods We performed an observational cohort study across six international centers from 2013 to 2024, as part of the Prospective Global Registry of PCI in Bifurcation Lesions (PROGRESS‐BIFURCATION). We analyzed procedural characteristics and in‐hospital outcomes of patients undergoing provisional bifurcation PCI with and without SB lesion predilatation. Significant SB lesions were defined as those with ≥50% diameter stenosis. Multivariable adjusted hazard ratios (aHR) with 95% confidence intervals [CI] were calculated using mixed effects Cox regression. Results Of 1042 lesions treated with provisional bifurcation PCI, 428 (41.1%) had significant SB lesions (true bifurcation lesions). Among these, 143 (33.4%) underwent predilatation. Lesions that underwent SB predilatation had longer SB lesion length (median 10.0 mm [IQR 5.0−10.0] vs. 5.0 mm [IQR 5.0−10.0], p = 0.001) and more SB diameter stenosis (median 90% [IQR 70%−95%] vs. 70% [IQR 60−90]). Technical success (95.1% vs. 87.7%; p = 0.015) and procedural success (93.7% vs. 82.8%; p = 0.003) were more common in the SB predilatation group, although the rates of crossover to a 2‐stent technique were also higher in the SB predilatation group (23.1% vs. 10.9%; p < 0.001). The incidence of procedural complications (22.3% vs. 21.3%, p = 0.897) and in‐hospital major adverse cardiovascular events (2.4% vs. 6.4%, p = 0.097) was similar between the groups. Conclusion In provisional bifurcation PCI of true bifurcation lesions, SB predilatation was performed in approximately one‐third and was associated with higher technical and procedural success, higher rates to crossover to a 2‐stent technique, and similar incidence of in‐hospital and long‐term follow‐up outcomes.